Silicon suboxide(SiO_(x),0<x<2)is an appealing anode material to replace traditional graphite owing to its much higher theoretical specific capacity enabling higher-energy-density lithium batteries.Nevertheless,...Silicon suboxide(SiO_(x),0<x<2)is an appealing anode material to replace traditional graphite owing to its much higher theoretical specific capacity enabling higher-energy-density lithium batteries.Nevertheless,the huge volume change and rapid capacity decay of SiO_(x)electrodes during cycling pose huge challenges to their large-scale practical applications.To eliminate this bottleneck,a dragonfly wing microstructure-inspired polymer electrolyte(denoted as PPM-PE)is developed based on in-situ polymerization of bicyclic phosphate ester-and urethane motif-containing monomer and methyl methacrylate in traditional liquid electrolyte.PPM-PE delivers excellent mechanical properties,highly correlated with the formation of a micro-phase separation structure similar with dragonfly wings.By virtue of superior mechanical properties and the in-situ solidified preparation method,PPM-PE can form a 3D polymer network buffer against stress within the electrode particles gap,enabling much suppressed electrode volume expansion and more stabilized solid electrolyte interface along with evidently decreased electrolyte decomposition.Resultantly,PPM-PE shows significant improvements in both cycling and rate performance in button and soft package batteries with SiO_(x)-based electrodes,compared with the liquid electrolyte counterpart.Such a dragonfly wing microstructure-inspired design philosophy of in-situ solidified polymer electrolytes helps facilitate the practical implementation of high-energy lithium batteries with SiO_(x)-based anodes.展开更多
Triggered seismicity is a key hazard where fluids are injected or withdrawn from the subsurface and may impact permeability. Understanding the mechanisms that control fluid injection-triggered seismicity allows its mi...Triggered seismicity is a key hazard where fluids are injected or withdrawn from the subsurface and may impact permeability. Understanding the mechanisms that control fluid injection-triggered seismicity allows its mitigation. Key controls on seismicity are defined in terms of fault and fracture strength, second-order frictional response and stability, and competing fluid-driven mechanisms for arrest. We desire to constrain maximum event magnitudes in triggered earthquakes by relating pre-existing critical stresses to fluid injection volume to explain why some recorded events are significantly larger than anticipated seismic moment thresholds. This formalism is consistent with several uncharacteristically large fluid injection-triggered earthquakes. Such methods of reactivating fractures and faults by hydraulic stimulation in shear or tensile fracturing are routinely used to create permeability in the subsurface. Microearthquakes (MEQs) generated by such stimulations can be used to diagnose permeability evolution. Although high-fidelity data sets are scarce, the EGS-Collab and Utah FORGE hydraulic stimulation field demonstration projects provide high-fidelity data sets that concurrently track permeability evolution and triggered seismicity. Machine learning deciphers the principal features of MEQs and the resulting permeability evolution that best track permeability changes – with transfer learning methods allowing robust predictions across multiple eological settings. Changes in permeability at reactivated fractures in both shear and extensional modes suggest that permeability change (Δk) scales with the seismic moment (M) of individual MEQs as Δk∝M. This scaling relation is exact at early times but degrades with successive MEQs, but provides a method for characterizing crustal permeability evolution using MEQs, alone. Importantly, we quantify for the first time the role of prestress in defining the elevated magnitude and seismic moment of fluid injection-triggered events, and demonstrate that such MEQs can also be used as diagnostic in quantifying permeability evolution in the crust.展开更多
Understanding the relationship between normal stiffness and permeability in rock fractures under high and true-triaxial in situ stress conditions is critical to assess hydro-mechanical coupling in the Earth's crus...Understanding the relationship between normal stiffness and permeability in rock fractures under high and true-triaxial in situ stress conditions is critical to assess hydro-mechanical coupling in the Earth's crust.Previous data on stiffness–permeability relations are measured under uniaxial stress states as well as under normal stress.However,many projects involve faulted formations with complex three-dimensional(3D)stress states or significant changes to the original stress state.We rectified this by following the permeability evolution using a true-triaxial stress-permeability apparatus as well as independently applying a spectrum of triaxial stresses from low to high.The relationship between permeability and fracture normal stiffness was quantified using constraints based on the principle of virtual work.The impacts of fracture-lateral and fracture-normal stresses on permeability and normal stiffness evolution were measured.It was found that permeability decreases with increasing fracture-lateral and fracture-normal stresses as a result of Poisson confinement,independent of the orientation of the fracture relative to the stresses.The lateral stresses dominated the evolution of normal stiffness at lower normal stresses(σ_(3)=10 MPa)and played a supplementary role at higher normal stresses(σ_(3)>10 MPa).Moreover,correlations between the evolution of permeability and normal stiffness were extended beyond the low-stiffness,high-permeability region to the high-stiffness,low-permeability region under high fracture-lateral stresses(10–80 MPa)with fracture-normal stress(10–50 MPa)conditions.Again,high lateral stresses further confined the fracture and therefore reduced permeability and increased normal stiffness,which exceeded the previous reported stiffness under no lateral stress conditions.This process enabled us to identify a fundamental change in the flow regime from multi-channel to isolated channelized flow.These results provide important characterizations of fracture permeability in the deep crust,including recovery from deep shale-gas reservoirs.展开更多
Full concentration gradient lithium-rich layered oxides are catching lots of interest as the next generation cathode for lithium-ion batteries due to their high discharge voltage,reduced voltage decay and enhanced rat...Full concentration gradient lithium-rich layered oxides are catching lots of interest as the next generation cathode for lithium-ion batteries due to their high discharge voltage,reduced voltage decay and enhanced rate performance,whereas the high lithium residues on its surface impairs the structure stability and long-term cycle performance.Herein,a facile multifunctional surface modification method is implemented to eliminate surface lithium residues of full concentration gradient lithium-rich layered oxides by a wet chemistry reaction with tetrabutyl titanate and the post-annealing process.It realizes not only a stable Li_(2)TiO_(3)coating layer with 3D diffusion channels for fast Li^(+)ions transfer,but also dopes partial Ti^(4+)ions into the sub-surface region of full concentration gradient lithium-rich layered oxides to further strengthen its crystal structure.Consequently,the modified full concentration gradient lithium-rich layered oxides exhibit improved structure stability,elevated thermal stability with decomposition temperature from 289.57℃to 321.72℃,and enhanced cycle performance(205.1 mAh g^(-1)after 150 cycles)with slowed voltage drop(1.67 mV per cycle).This work proposes a facile and integrated modification method to enhance the comprehensive performance of full concentration gradient lithium-rich layered oxides,which can facilitate its practical application for developing higher energy density lithium-ion batteries.展开更多
Solid polymer electrolytes(SPEs)have become increasingly important in advanced lithium-ion batteries(LIBs)due to their improved safety and mechanical properties compared to organic liquid electrolytes.Cross-linked pol...Solid polymer electrolytes(SPEs)have become increasingly important in advanced lithium-ion batteries(LIBs)due to their improved safety and mechanical properties compared to organic liquid electrolytes.Cross-linked polymers have the potential to further improve the mechanical property without trading off Li-ion conductivity.In this study,focusing on a recently developed cross-linked SPE,i.e.,the one based on poly(vinylene carbonate)-poly(ethylene oxide)cross-linked network(PVCN),we used solid-state nuclear magnetic resonance(NMR)techniques to investigate the fundamental interaction between the chain segments and Li ions,as well as the lithium-ion motion.By utilizing homonuclear/heteronuclear correlation,CP(cross-polarization)kinetics,and spin-lattice relaxation experiments,etc.,we revealed the structural characteristics and their relations to lithium-ion mobilities.It is found that the network formation prevents poly(ethylene oxide)chains from crystallization,which could create sufficient space for segmental tumbling and Li-ion co nductio n.As such,the mechanical property is greatly improved with even higher Li-ion mobilities compared to the poly(vinylene carbonate)or poly(ethylene oxide)based SPE analogues.展开更多
Aqueous sodium-ion batteries are known for poor rechargeability because of the competitive water decomposition reactions and the high electrode solubility.Improvements have been reported by saltconcentrated and organi...Aqueous sodium-ion batteries are known for poor rechargeability because of the competitive water decomposition reactions and the high electrode solubility.Improvements have been reported by saltconcentrated and organic-hybridized electrolyte designs,however,at the expense of cost and safety.Here,we report the prolonged cycling of ASIBs in routine dilute electrolytes by employing artificial electrode coatings consisting of NaX zeolite and NaOH-neutralized perfluorinated sulfonic polymer.The as-formed composite interphase exhibits a molecularsieving effect jointly played by zeolite channels and size-shrunken ionic domains in the polymer matrix,which enables high rejection of hydrated Na^(+)ions while allowing fast dehydrated Na^(+)permeance.Applying this coating to electrode surfaces expands the electrochemical window of a practically feasible 2 mol kg^(-1) sodium trifluoromethanesulfonate aqueous electrolyte to 2.70 V and affords Na_(2)MnFe(CN)_(6)//NaTi_(2)(PO_(4))_(3) full cells with an unprecedented cycling stability of 94.9%capacity retention after 200 cycles at 1 C.Combined with emerging electrolyte modifications,this molecular-sieving interphase brings amplified benefits in long-term operation of ASIBs.展开更多
Rechargeable Mg-metal batteries hold considerable promise for renewable energy storage and utilization.However,the Mg stripping/plating processes suffer from sluggish ion pairs dissociation kinetics,resulting in poor ...Rechargeable Mg-metal batteries hold considerable promise for renewable energy storage and utilization.However,the Mg stripping/plating processes suffer from sluggish ion pairs dissociation kinetics,resulting in poor rate and cycle properties.In this work,an efficient skeleton host containing dissimilar coupling elements with varied electronegativity has been designed to promote interfacial reaction kinetics by accelerating the Mg–Cl bond dissociation process.As a proof-of-concept prototype,the N/O-doped cobalt nanoparticles embedded in carbonaceous polyhedrons has been synthesized via facile high temperature annealing of zeolitic imidazolate framework-67(ZIF-67).The exposed electron-rich N/O sites and electron-deficient Co sites can regulate the adsorbing structure configuration of[Mg-Cl]^(+)complex ions by selectively bonding with the Mg^(2+)and Cl^(–)through chemical coordination linkage,respectively.The elongated bond length from 2.596A to 2.679A and the weakened bond strength are beneficial for the complex ions dissociation,leading to better charge transfer kinetics.In addition,the better magnesiophilic property accompanied by the conductive and porous permeable three-dimensional architecture realizes the homogeneous electrodeposition of Mg and improved electrode kinetics.The decreased overpotential has been verified in both magnesium organohaloaluminates electrolyte(from 290 mV to 189 mV)and conventional Mg(TFSI)2-based electrolyte(from 600 mV to 200 mV).The designed skeleton host also exhibits excellent long cycle lifespan above 2300 h and extra-high average Coulombic efficiency of 99.65%within 700 cycles.The accelerated bond splitting strategy enables improved metal-anode reversibility,which is also insightful to high concentrated or other electrolyte systems that contain abundant ion pairs or aggregates.展开更多
Coal permeability measurements are normally conducted under the assumption that gas pressure in the matrix is equalized with that in fracture and that gas sorption-induced swelling/shrinking strain is uniformly distri...Coal permeability measurements are normally conducted under the assumption that gas pressure in the matrix is equalized with that in fracture and that gas sorption-induced swelling/shrinking strain is uniformly distributed within the coal.However,the validity of this assumption has long been questioned and differential strain between the fracture strain and the bulk strain has long been considered as the primary reason for the inconsistency between experimental data and poroelasticity solutions.Although efforts have been made to incorporate the impact into coal permeability models,the fundamental nature of those efforts to split the matrix strain between fracture and coal bulk remains questionable.In this study,a new concept of differential swelling index(DSI)was derived to theoretically define the relation among sorption-induced strains of the coal bulk,fracture,and coal matrix at the equilibrium state.DSI was a function of the equilibrium pressure and its magnitudes were regulated by the Langmuir constants of both the matrix and the coal bulk.Furthermore,a spectrum of DSI-based coal permeability models was developed to explicitly consider the effect of differential strains.These models were verified with the experimental data under the conditions of uniaxial strain,constant confining pressure,and constant effective stress.展开更多
Lithium–sulfur batteries have been regarded as the most promising high-energy electrochemical energy storage device owing to the high energy density, low cost and environmental friendliness. However, traditional lith...Lithium–sulfur batteries have been regarded as the most promising high-energy electrochemical energy storage device owing to the high energy density, low cost and environmental friendliness. However, traditional lithium–sulfur batteries using ether-based electrolytes often suffer from severe safety risks(i.e. combustion). Herein, we demonstrated a novel kind of flame-retardant concentrated electrolyte(6.5 M lithium bis(trifluoromethylsulphonyl)imide/fluoroethylene carbonate) for highly-safe and widetemperature lithium–sulfur batteries. It was found that such concentrated electrolyte showed superior flame retardancy, high lithium-ion transference number(0.69) and steady lithium plating/stripping behavior(2.5 m Ah cm^(-2) over 3000 h). Moreover, lithium–sulfur batteries using this flame-retardant concentrated electrolyte delivered outstanding cycle performance in a wide range of temperatures(-10 °C, 25 °C and 90 °C). This superior battery performance is mainly attributed to the LiF-rich solid electrolyte interphase formed on lithium metal anode, which can effectively suppress the continuous growth of lithium dendrites. Above-mentioned fascinating characteristics would endow this flame-retardant concentrated electrolyte a very promising candidate for highly-safe and wide-temperature lithium–sulfur batteries.展开更多
In this work,a sponge-like polysulfonamide(PSA)/SiO_2 composite membrane is unprecedentedly prepared by the phase inversion method,and successfully demonstrated as a novel separator of lithium-ion batteries(LIBs).Comp...In this work,a sponge-like polysulfonamide(PSA)/SiO_2 composite membrane is unprecedentedly prepared by the phase inversion method,and successfully demonstrated as a novel separator of lithium-ion batteries(LIBs).Compared to the commercial polypropylene(PP) separator,the sponge-like PSA/SiO_2 composite possesses better physical and electrochemical properties,such as higher porosity,ionic conductivity,thermal stability and flame retarding ability.The LiCoO_2/Li half-cells using the sponge-like composite separator demonstrate superior rate capability and cyclability over those using the commercial PP separator.Moreover,the sponge-like composite separator can ensure the normal operation of LiCoO_2/Li half-cell at an extremely high temperature of 90 °C,while the commercial PP separator cannot.All these encouraging results suggest that this phase inversion based sponge-like PSA/SiO_2 composite separator is really a promising separator for high performance LIBs.展开更多
Solid-state polymer electrolytes are an important factor in the deployment of highsafety and high-energy-density solid-state lithium metal batteries.Nevertheless,use of the traditional polyethylene oxide-based solid-s...Solid-state polymer electrolytes are an important factor in the deployment of highsafety and high-energy-density solid-state lithium metal batteries.Nevertheless,use of the traditional polyethylene oxide-based solid-state polymer electrolyte is limited due to its inherently low ionic conductivity and narrow electrochemical stability window.Herein,for the first time,we specifically designed a cyanoethyl cellulosein-deep eutectic solvent composite eutectogel as a promising candidate for hybrid solid-state polymer electrolytes.It is found that the proposed eutectogel electrolyte achieves high ionic conductivity(1.87×10^(−3) S cm^(−1) at 25℃),superior electrochemical stability(up to 4.8 V),and outstanding lithium plating/striping behavior(low overpotential of 0.04 V at 1mAcm^(−2) and 1mAh cm^(−2) over 300 h).With the eutectogel-based solid-state polymer electrolyte,a 4.45 V LiCoO_(2)/Li metal battery delivers prominent long-term lifespan(capacity retention of 85%after 200 cycles)and high average Coulombic efficiency(99.5%)under ambient conditions,significantly outperforming the traditional carbonate-based liquid electrolyte.Our work demonstrates a promising strategy for designing eutectogel-based solid-state polymer electrolytes to realize high-voltage and high-energy lithium metal batteries.展开更多
Heat production from geothermal reservoirs is a typical heat transfer process involving a cold working fluid contacting a hot rock formation.Compared to the thermal-physical characteristics of water,supercritical CO_(...Heat production from geothermal reservoirs is a typical heat transfer process involving a cold working fluid contacting a hot rock formation.Compared to the thermal-physical characteristics of water,supercritical CO_(2)(scCO_(2))has a higher heat storage capacity over a wide temperature-pressure range and may be favored as a heat transfer fluid.Singularly characteristic of scCO_(2)-based heat extraction is that the hydraulic-thermal properties of the scCO_(2) vary dramatically and dynamically with the spatial pressure gradient during unsteady-state flow along fracture.This highly nonlinear behavior presents a challenge in the accurate estimation of heat extraction efficiency in scCO_(2)-based EGS.In this paper,a thermal-h ydraulic-mechanical(THM)coupled model is developed by considering deformation of the fractured reservoir,non-Darcy flow and the varying thermal-physical properties of scCO_(2).The proposed model is validated by matching the modeling temperature distribution with published data.The results show that during continuous injection of scCO_(2),the fracture first widens and then narrows,ultimately reopening over the long term.The sequential fracture deformation behaviors are in response to the combined impacts of mechanical compression and thermally-induced deformation.By controlling the injection parameters of the scCO_(2),it is found that the heat extraction rate is positively correlated to its pore pressure or mass flow rate.The heat extraction rate can be significantly enhanced,when the inlet temperature of scCO_(2) is below its critical temperature.As a result,the heat increment recovered per unit mass of scCO_(2) decreases as the hot rock is gradually cooled.Meanwhile,the heat increment recovered per unit mass of scCO_(2) decreases by increasing the inlet temperature of scCO_(2) or its mass flow rate,but increases as the outlet pressure rises.Furthermore,multi-linear regression indicates that controlling the inlet temperature of the scCO_(2) can significantly improve the thermodynamic efficiency of heat extraction.展开更多
Silicon(Si)has been regarded as an alternative anode material to traditional graphite owing to its higher theoretical capacity(4200 vs.372 m Ah g;).However,Si anodes suffer from the inherent volume expansion and unsta...Silicon(Si)has been regarded as an alternative anode material to traditional graphite owing to its higher theoretical capacity(4200 vs.372 m Ah g;).However,Si anodes suffer from the inherent volume expansion and unstable solid electrolyte interphase,thus experiencing fast capacity decay,which hinders their commercial application.To address this,herein,an endotenon sheathinspired water-soluble double-network binder(DNB)is presented for resolving the bottleneck of Si anodes.The as-developed binder shows excellent adhesion,high mechanical properties,and a considerable self-healing capability mainly benefited by its supramolecular hybrid network.Apart from these advantages,this binder also induces a Li;N/Li F-rich solid electrolyte interface layer,contributing to a superior cycle stability of Si electrodes.As expected,the DNB can achieve mechanically more stable Si electrodes than traditional polyacrylic acid and pectin binders.As a result,DNB delivers superior electrochemical performance ofSi/Li half cells and Li Ni;Co;Mn;O;/Si full cells,even with a high loading of Si electrode,to traditional polyacrylic acid and pectin binders.The bioinspired binder design provides a promising route to achieve long-life Si anode-assembled lithium batteries.展开更多
NASICON (Na-super-ionic-conductors)-structured materials have attracted extensive research interest due to their great application potential in secondary batteries. However, the mechanism of capacity fading for NASICO...NASICON (Na-super-ionic-conductors)-structured materials have attracted extensive research interest due to their great application potential in secondary batteries. However, the mechanism of capacity fading for NASICON-structured electrode materials has been rarely studied. In this paper, we synthesized the NASICON-structured Na3V2(PO4)3/C composite by simple sol-gel and high-temperature solid-phase method and investigated its electrochemical performance in Na-Zn hybrid aqueous rechargeable batteries. After characterizing the structure, morphology and composition variations as well as the interfacial resistance changes of Na3V2(PO4)3/C cathode during cycling, we propose a mechanical and interfacial degradation mechanism for capacity fading of NASICON-structured Na3V2(PO4)3/C in Na-Zn hybrid aqueous rechargeable batteries. This work will shed light on enhancing the mechanical and in terfacial stability of NASICON-structured Na3V2(PO4)3/C in Na-Zn hybrid aqueous rechargeable batteries.展开更多
Lithium-sulfur(Li-S) batteries have been considered as one of the most promising candidates to traditional lithium ion batteries due to its low cost,high theoretical specific capacity(1675 mAh g^(-1)) and energy densi...Lithium-sulfur(Li-S) batteries have been considered as one of the most promising candidates to traditional lithium ion batteries due to its low cost,high theoretical specific capacity(1675 mAh g^(-1)) and energy density(2600 Wh kg^(-1)) of sulfur.Compared with traditional liquid electrolytes,polymer electrolytes(PEs) are ever-increasingly preferred due to their higher safety,superior compatibility,long cycling stability and so on.Despite some progresses on PEs,however,there remain lots of hurdles to be addressed prior to commercial applications.This review begins with native advantages for PEs to replace LEs,and then proposes the ideal requirements for PEs.Furthermore,a brief development history of typical PEs for Li-S batteries is presented to systematically summarize the recent achievements in Li-S batteries with PEs.Noted that the structure-performance relationships of polymer matrixes for PEs are highlighted.Finally,the challenges and opportunities on the future development of PEs are presented.We hold the view that composite polymer electrolytes in virtue of the high ionic conductivity and the compatible interfacial property will be promising solution for high performance Li-S batteries.展开更多
In advantages of their high capacity and high operating voltage,the nickel(Ni)-rich layered transition metal oxide cathode materials(LiNi_(x)Co_(y)Mn_(z)O_(2)(NCMxyz,x+y+z=1,x≥0.5)and LiNi_(0.8)Co_(0.15)Al_(0.05)O_(2...In advantages of their high capacity and high operating voltage,the nickel(Ni)-rich layered transition metal oxide cathode materials(LiNi_(x)Co_(y)Mn_(z)O_(2)(NCMxyz,x+y+z=1,x≥0.5)and LiNi_(0.8)Co_(0.15)Al_(0.05)O_(2)(NCA))have been arousing great interests to improve the energy density of LIBs.However,these Nirich cathodes always suffer from rapid capacity degradation induced by unstable cathode-electrolyte interphase(CEI)layer and destruction of bulk crystal structure.Therefore,varied electrode/electrolyte interface engineering strategies(such as electrolyte formulation,material coating or doping)have been developed for Ni-rich cathodes protection.Among them,developing electrolyte functional additives has been proven to be a simple,effective,and economic method to improve the cycling stability of Nirich cathodes.This is achieved by removing unfavorable species(such as HF,H_(2)O)or constructing a stable and protective CEI layer against unfavorable reactive species(such as HF,H_(2)O).Herein,this review mainly introduces the varied classes of electrolyte functional additives and their working mechanism for interfacial engineering of Ni-rich cathodes.Especially,key favorable species for stabilizing CEI layer are summarized.More importantly,we put forward perspectives for screening and customizing ideal functional additives for high performance Ni-rich cathodes based LIBs.展开更多
Polymer electrolytes(PEs)have been long recognized as the key materials to enable energy-dense batteries and render flexible energy devices practically viable,owing to their chemical and mechanical reliability.However...Polymer electrolytes(PEs)have been long recognized as the key materials to enable energy-dense batteries and render flexible energy devices practically viable,owing to their chemical and mechanical reliability.However,much of their promise is yet to be realized.The roomtemperature ion conductivity of existing PEs still falls short of the implementation criterion of 10^(-4) S cm^(-1) on the promise of acceptable mechanical properties,thereby precluding their practical application.The twin but inversely related duties of polymers,that is,functioning as both an ion-conducting medium and a structural backbone,underlie this issue but are less elucidated systematically.The polyacrylate(PA)family is among promising polymer matrices on account of ester polarity,electrode compatibility,chemical tunability,and mechanical durability.The extensive applicability of PA in plasticized gels,dry solids,and emerging composites makes PA-based PEs representative to illustrate the trade-off between ion conduction and mechanical strength.We herein seek to outline the stated long-standing conflict exemplified by PA-based PEs,focusing on crucial strategies toward balancing and reconciling the two mutually exclusive properties,with the intention of offering designing guidelines for next-generation PEs.展开更多
Solid electrolytes play a vital role in solid-state Li secondary batteries,which are promising high-energy storage devices for new-generation electric vehicles.Nevertheless,obtaining a suitable solid electrolyte by a ...Solid electrolytes play a vital role in solid-state Li secondary batteries,which are promising high-energy storage devices for new-generation electric vehicles.Nevertheless,obtaining a suitable solid electrolyte by a simple and residue-free preparation process,resulting in a stable interface between electrolyte and electrode,is still a great challenge for practical applications.Herein,we report a self-crosslinked polymer electrolyte(SCPE)for high-performance lithium batteries,prepared by a one-step method based on 3-methoxysilyl-terminated polypropylene glycol(SPPG,a liquid oligomer).It is worth noting that lithium bis(oxalate)borate(Li BOB)can react with SPPG to form a crosslinked structure via a curing reaction.This self-formed polymer electrolyte exhibits excellent properties,including high roomtemperature ionic conductivity(2.6×10^(-4) S cm^(-1)),wide electrochemical window(4.7 V),and high Li ion transference number(0.65).The excellent cycling stability(500 cycles,83%)further highlights the improved interfacial stability after the in situ formation of SCPE on the electrode surface.Moreover,this self-formation strategy enhances the safety of the battery under mechanical deformation.Therefore,the present self-crosslinked polymer electrolyte shows great potential for applications in high-performance lithium batteries.展开更多
Rechargeable magnesium(Mg)battery technologies show the promise of low cost,less safety concerns and relatively higher energy density.Interrogating the critical issues on the Mg stripping/plating performance as well a...Rechargeable magnesium(Mg)battery technologies show the promise of low cost,less safety concerns and relatively higher energy density.Interrogating the critical issues on the Mg stripping/plating performance as well as the Mg metal anode-electrolyte interfacial chemistry is one great importance under the practical areal capacity and rate conditions.In this work,we systematically investigate the electrochemistry of Mg stripping/plating processes within four distinctive Mg-ion electrolytes and the Mg anodeelectrolyte interfacial chemistry under practical conditions.Electrochemical results show that the cycle life of Mg//Cu asymmetric cells using these above electrolytes is significantly shortened(less than 10 cycles)when tested at a practical areal capacity of 10 mAh cm^-2.Further optical and electron microscopic analyses reveal that the gradual growth of the Mg deposits is susceptible to detachment from the copper substrate,where the initial nucleation process might occur.In spite of showing an interconnected particle-like morphology,the Mg deposits could easily penetrate the porous separator,leading to cell failure.The co-deposition of metallic Al is revealed from surface region to bulk,while the Cl-containing species exist in the near surface of Mg deposits.Our work not only highlights the critical impacts of areal capacity on the performances of Mg stripping/plating process,but calls for further efforts to eliminating the safety concerns of Mg anode under practical conditions.展开更多
Identifying changes in coal permeability with gas pressure and accurately codifying mean efective stresses in laboratory samples are crucial in predicting gas-fow behavior in coal reservoirs. Traditionally, coal perme...Identifying changes in coal permeability with gas pressure and accurately codifying mean efective stresses in laboratory samples are crucial in predicting gas-fow behavior in coal reservoirs. Traditionally, coal permeability to gas is assessed using the steady-state method, where the equivalent gas pressure in the coal is indexed to the average of upstream and downstream pressures of the coal, while ignoring the nonlinear gas pressure gradient along the gas fow path. For the fow of a compressible gas, the traditional method consistently underestimates the length/volume-averaged pressure and overestimates mean efective stress. The higher the pressure diferential within the sample, the greater the error between the true mean pressure for a compressible fuid and that assumed as the average between upstream and downstream pressures under typical reservoir conditions. A correction coefcient for the compressible fuid pressure asymptotes to approximately 1.3%, representing that the error in mean pressure and efective stress can be on the order of approximately 30%, particularly for highly pressure-sensitive permeabilities and compressibilities, further amplifying errors in evaluated reservoir properties. We utilized this volume-averaged pressure and efective stress to correct permeability and compressibility data reported in the literature. Both the corrected initial permeability and the corrected pore compressibility were found to be smaller than the uncorrected values, due to the underestimation of the true mean fuid pressure, resulting in an overestimation of reservoir permeability if not corrected. The correction coefcient for the initial permeability ranges from 0.6 to 0.1 (reservoir values are only approximately 40% to 90% of laboratory values), while the correction coefcient for pore compressibility remains at approximately 0.75 (reservoir values are only approximately 25% of laboratory value). Errors between the uncorrected and corrected parameters are quantifed under various factors, such as confning pressure, gas sorption, and temperature. By analyzing the evolutions of the initial permeability and pore compressibility, the coupling mechanisms of mechanical compression, adsorption swelling, and thermal expansion on the pore structure of the coal can be interpreted. These fndings can provide insights that are useful for assessing the sensitivity of coal permeability to gas pressure as truly representative of reservoir conditions.展开更多
基金financially supported by the National Key R&D Program of China(2023YFC2812700)the Key Scientific and Technological Innovation Project of Shandong(2022CXGC020301)+6 种基金the National Natural Science Foundation of China(22279153,U22A2044,22479154,52303287)the Taishan Scholars of Shandong Province(No.ts201511063)the Shandong Energy Institute(Grant No.SEI I202108)the Postdoctoral Fellowship Program of CPSF(E31Z3F04)China Postdoctoral Science Foundation(2024 M753350)the Natural Science Foundation of Shandong Province(ZR2023QB208)Qingdao Natural Science Foundation(23-2-1-77-zyyd-jch)。
文摘Silicon suboxide(SiO_(x),0<x<2)is an appealing anode material to replace traditional graphite owing to its much higher theoretical specific capacity enabling higher-energy-density lithium batteries.Nevertheless,the huge volume change and rapid capacity decay of SiO_(x)electrodes during cycling pose huge challenges to their large-scale practical applications.To eliminate this bottleneck,a dragonfly wing microstructure-inspired polymer electrolyte(denoted as PPM-PE)is developed based on in-situ polymerization of bicyclic phosphate ester-and urethane motif-containing monomer and methyl methacrylate in traditional liquid electrolyte.PPM-PE delivers excellent mechanical properties,highly correlated with the formation of a micro-phase separation structure similar with dragonfly wings.By virtue of superior mechanical properties and the in-situ solidified preparation method,PPM-PE can form a 3D polymer network buffer against stress within the electrode particles gap,enabling much suppressed electrode volume expansion and more stabilized solid electrolyte interface along with evidently decreased electrolyte decomposition.Resultantly,PPM-PE shows significant improvements in both cycling and rate performance in button and soft package batteries with SiO_(x)-based electrodes,compared with the liquid electrolyte counterpart.Such a dragonfly wing microstructure-inspired design philosophy of in-situ solidified polymer electrolytes helps facilitate the practical implementation of high-energy lithium batteries with SiO_(x)-based anodes.
基金Derek Elsworth acknowledges the support from a Gledden Visiting Fellowship from the Institute of Advanced Studies at the University of Western Australia,Australia,and the G.Albert Shoemaker Endowment at Pennsylvania State University,USA.
文摘Triggered seismicity is a key hazard where fluids are injected or withdrawn from the subsurface and may impact permeability. Understanding the mechanisms that control fluid injection-triggered seismicity allows its mitigation. Key controls on seismicity are defined in terms of fault and fracture strength, second-order frictional response and stability, and competing fluid-driven mechanisms for arrest. We desire to constrain maximum event magnitudes in triggered earthquakes by relating pre-existing critical stresses to fluid injection volume to explain why some recorded events are significantly larger than anticipated seismic moment thresholds. This formalism is consistent with several uncharacteristically large fluid injection-triggered earthquakes. Such methods of reactivating fractures and faults by hydraulic stimulation in shear or tensile fracturing are routinely used to create permeability in the subsurface. Microearthquakes (MEQs) generated by such stimulations can be used to diagnose permeability evolution. Although high-fidelity data sets are scarce, the EGS-Collab and Utah FORGE hydraulic stimulation field demonstration projects provide high-fidelity data sets that concurrently track permeability evolution and triggered seismicity. Machine learning deciphers the principal features of MEQs and the resulting permeability evolution that best track permeability changes – with transfer learning methods allowing robust predictions across multiple eological settings. Changes in permeability at reactivated fractures in both shear and extensional modes suggest that permeability change (Δk) scales with the seismic moment (M) of individual MEQs as Δk∝M. This scaling relation is exact at early times but degrades with successive MEQs, but provides a method for characterizing crustal permeability evolution using MEQs, alone. Importantly, we quantify for the first time the role of prestress in defining the elevated magnitude and seismic moment of fluid injection-triggered events, and demonstrate that such MEQs can also be used as diagnostic in quantifying permeability evolution in the crust.
基金funded by the joint fund of the National Key Research and Development Program of China(Grant No.2021YFC2902101)National Natural Science Foundation of China(Grant No.52374084)+1 种基金the 111 Project(Grant No.B17009)DE acknowledges support from the G.Albert Shoemaker endowment.
文摘Understanding the relationship between normal stiffness and permeability in rock fractures under high and true-triaxial in situ stress conditions is critical to assess hydro-mechanical coupling in the Earth's crust.Previous data on stiffness–permeability relations are measured under uniaxial stress states as well as under normal stress.However,many projects involve faulted formations with complex three-dimensional(3D)stress states or significant changes to the original stress state.We rectified this by following the permeability evolution using a true-triaxial stress-permeability apparatus as well as independently applying a spectrum of triaxial stresses from low to high.The relationship between permeability and fracture normal stiffness was quantified using constraints based on the principle of virtual work.The impacts of fracture-lateral and fracture-normal stresses on permeability and normal stiffness evolution were measured.It was found that permeability decreases with increasing fracture-lateral and fracture-normal stresses as a result of Poisson confinement,independent of the orientation of the fracture relative to the stresses.The lateral stresses dominated the evolution of normal stiffness at lower normal stresses(σ_(3)=10 MPa)and played a supplementary role at higher normal stresses(σ_(3)>10 MPa).Moreover,correlations between the evolution of permeability and normal stiffness were extended beyond the low-stiffness,high-permeability region to the high-stiffness,low-permeability region under high fracture-lateral stresses(10–80 MPa)with fracture-normal stress(10–50 MPa)conditions.Again,high lateral stresses further confined the fracture and therefore reduced permeability and increased normal stiffness,which exceeded the previous reported stiffness under no lateral stress conditions.This process enabled us to identify a fundamental change in the flow regime from multi-channel to isolated channelized flow.These results provide important characterizations of fracture permeability in the deep crust,including recovery from deep shale-gas reservoirs.
基金financially supported by the Natural Science Foundation of Shandong Province(ZR2022QB166,ZR2020KE032)the Strategic Priority Research Program of the Chinese Academy of Sciences(XDA22010600)+3 种基金the Youth Innovation Promotion Association of CAS(2021210)the Foundation of Qingdao Postdoctoral Application Program(Y63302190F)the Natural Science Foundation of Qingdao Institute ofBioenergy and Bioprocess Technology(QIBEBT SZ202101)support from the Max Planck-POSTECH-Hsinchu Center for Complex Phase Materials
文摘Full concentration gradient lithium-rich layered oxides are catching lots of interest as the next generation cathode for lithium-ion batteries due to their high discharge voltage,reduced voltage decay and enhanced rate performance,whereas the high lithium residues on its surface impairs the structure stability and long-term cycle performance.Herein,a facile multifunctional surface modification method is implemented to eliminate surface lithium residues of full concentration gradient lithium-rich layered oxides by a wet chemistry reaction with tetrabutyl titanate and the post-annealing process.It realizes not only a stable Li_(2)TiO_(3)coating layer with 3D diffusion channels for fast Li^(+)ions transfer,but also dopes partial Ti^(4+)ions into the sub-surface region of full concentration gradient lithium-rich layered oxides to further strengthen its crystal structure.Consequently,the modified full concentration gradient lithium-rich layered oxides exhibit improved structure stability,elevated thermal stability with decomposition temperature from 289.57℃to 321.72℃,and enhanced cycle performance(205.1 mAh g^(-1)after 150 cycles)with slowed voltage drop(1.67 mV per cycle).This work proposes a facile and integrated modification method to enhance the comprehensive performance of full concentration gradient lithium-rich layered oxides,which can facilitate its practical application for developing higher energy density lithium-ion batteries.
基金financially supported by the National Natural Science Foundation of China(Grant No.22325405,22321002,22279153)Liaoning Revitalization Talents Program(XLYC1807207,XLYC2203134)DICP I202104。
文摘Solid polymer electrolytes(SPEs)have become increasingly important in advanced lithium-ion batteries(LIBs)due to their improved safety and mechanical properties compared to organic liquid electrolytes.Cross-linked polymers have the potential to further improve the mechanical property without trading off Li-ion conductivity.In this study,focusing on a recently developed cross-linked SPE,i.e.,the one based on poly(vinylene carbonate)-poly(ethylene oxide)cross-linked network(PVCN),we used solid-state nuclear magnetic resonance(NMR)techniques to investigate the fundamental interaction between the chain segments and Li ions,as well as the lithium-ion motion.By utilizing homonuclear/heteronuclear correlation,CP(cross-polarization)kinetics,and spin-lattice relaxation experiments,etc.,we revealed the structural characteristics and their relations to lithium-ion mobilities.It is found that the network formation prevents poly(ethylene oxide)chains from crystallization,which could create sufficient space for segmental tumbling and Li-ion co nductio n.As such,the mechanical property is greatly improved with even higher Li-ion mobilities compared to the poly(vinylene carbonate)or poly(ethylene oxide)based SPE analogues.
基金supported by the National Key R&D Program of China(Grant No.2022YFB2402604)the National Natural Science Foundation of China(21975271,22209194)+3 种基金Shandong Natural Science Foundation(ZR2020ZD07,ZR2023YQ010 and ZR2021QB106)the Taishan Scholars of Shandong Province(No.ts201511063,tsqn202211277)the Shandong Energy Institute(SEI I202127)Qingdao New Energy Shandong Laboratory(QIBEBT/SEI/QNESLS202304).
文摘Aqueous sodium-ion batteries are known for poor rechargeability because of the competitive water decomposition reactions and the high electrode solubility.Improvements have been reported by saltconcentrated and organic-hybridized electrolyte designs,however,at the expense of cost and safety.Here,we report the prolonged cycling of ASIBs in routine dilute electrolytes by employing artificial electrode coatings consisting of NaX zeolite and NaOH-neutralized perfluorinated sulfonic polymer.The as-formed composite interphase exhibits a molecularsieving effect jointly played by zeolite channels and size-shrunken ionic domains in the polymer matrix,which enables high rejection of hydrated Na^(+)ions while allowing fast dehydrated Na^(+)permeance.Applying this coating to electrode surfaces expands the electrochemical window of a practically feasible 2 mol kg^(-1) sodium trifluoromethanesulfonate aqueous electrolyte to 2.70 V and affords Na_(2)MnFe(CN)_(6)//NaTi_(2)(PO_(4))_(3) full cells with an unprecedented cycling stability of 94.9%capacity retention after 200 cycles at 1 C.Combined with emerging electrolyte modifications,this molecular-sieving interphase brings amplified benefits in long-term operation of ASIBs.
基金supported by the Natural Science Foundation of Shandong Province(ZR2021QE166)the National Natural Science Foundation of China(51972187,22279068)+2 种基金the Major Basic Research Program of Natural Science Foundation of Shandong Province(ZR2020ZD09)the National Natural Science Foundation for Distinguished Young Scholars of China(51625204)We also thank the Introduction and Cultivation Plan of Young Innovative Talents in Colleges and Universities of Shandong Province(2019).
文摘Rechargeable Mg-metal batteries hold considerable promise for renewable energy storage and utilization.However,the Mg stripping/plating processes suffer from sluggish ion pairs dissociation kinetics,resulting in poor rate and cycle properties.In this work,an efficient skeleton host containing dissimilar coupling elements with varied electronegativity has been designed to promote interfacial reaction kinetics by accelerating the Mg–Cl bond dissociation process.As a proof-of-concept prototype,the N/O-doped cobalt nanoparticles embedded in carbonaceous polyhedrons has been synthesized via facile high temperature annealing of zeolitic imidazolate framework-67(ZIF-67).The exposed electron-rich N/O sites and electron-deficient Co sites can regulate the adsorbing structure configuration of[Mg-Cl]^(+)complex ions by selectively bonding with the Mg^(2+)and Cl^(–)through chemical coordination linkage,respectively.The elongated bond length from 2.596A to 2.679A and the weakened bond strength are beneficial for the complex ions dissociation,leading to better charge transfer kinetics.In addition,the better magnesiophilic property accompanied by the conductive and porous permeable three-dimensional architecture realizes the homogeneous electrodeposition of Mg and improved electrode kinetics.The decreased overpotential has been verified in both magnesium organohaloaluminates electrolyte(from 290 mV to 189 mV)and conventional Mg(TFSI)2-based electrolyte(from 600 mV to 200 mV).The designed skeleton host also exhibits excellent long cycle lifespan above 2300 h and extra-high average Coulombic efficiency of 99.65%within 700 cycles.The accelerated bond splitting strategy enables improved metal-anode reversibility,which is also insightful to high concentrated or other electrolyte systems that contain abundant ion pairs or aggregates.
基金supported by National Key R&D Program of China(Grant No.2018YFC0407006)the 111 Project(Grant No.B17009)the Australian Research Council(Grant No.DP200101293)。
文摘Coal permeability measurements are normally conducted under the assumption that gas pressure in the matrix is equalized with that in fracture and that gas sorption-induced swelling/shrinking strain is uniformly distributed within the coal.However,the validity of this assumption has long been questioned and differential strain between the fracture strain and the bulk strain has long been considered as the primary reason for the inconsistency between experimental data and poroelasticity solutions.Although efforts have been made to incorporate the impact into coal permeability models,the fundamental nature of those efforts to split the matrix strain between fracture and coal bulk remains questionable.In this study,a new concept of differential swelling index(DSI)was derived to theoretically define the relation among sorption-induced strains of the coal bulk,fracture,and coal matrix at the equilibrium state.DSI was a function of the equilibrium pressure and its magnitudes were regulated by the Langmuir constants of both the matrix and the coal bulk.Furthermore,a spectrum of DSI-based coal permeability models was developed to explicitly consider the effect of differential strains.These models were verified with the experimental data under the conditions of uniaxial strain,constant confining pressure,and constant effective stress.
基金financially supported by the National Key R&D Program of China (Grant No. 2017YFE0127600)the National Natural Science Foundation of China (Nos. 51703236 and U1706229)+1 种基金the National Science Fund for Distinguished Young Scholars (No. 51625204)Key Scientific and Technological Innovation Project of Shandong (No. 2017CXZC0505)。
文摘Lithium–sulfur batteries have been regarded as the most promising high-energy electrochemical energy storage device owing to the high energy density, low cost and environmental friendliness. However, traditional lithium–sulfur batteries using ether-based electrolytes often suffer from severe safety risks(i.e. combustion). Herein, we demonstrated a novel kind of flame-retardant concentrated electrolyte(6.5 M lithium bis(trifluoromethylsulphonyl)imide/fluoroethylene carbonate) for highly-safe and widetemperature lithium–sulfur batteries. It was found that such concentrated electrolyte showed superior flame retardancy, high lithium-ion transference number(0.69) and steady lithium plating/stripping behavior(2.5 m Ah cm^(-2) over 3000 h). Moreover, lithium–sulfur batteries using this flame-retardant concentrated electrolyte delivered outstanding cycle performance in a wide range of temperatures(-10 °C, 25 °C and 90 °C). This superior battery performance is mainly attributed to the LiF-rich solid electrolyte interphase formed on lithium metal anode, which can effectively suppress the continuous growth of lithium dendrites. Above-mentioned fascinating characteristics would endow this flame-retardant concentrated electrolyte a very promising candidate for highly-safe and wide-temperature lithium–sulfur batteries.
基金Supported by the funding from "135" Projects Fund of CAS-QIBEBT Director Innovation FoundationThink-Tank Mutual Fund of Qingdao Energy Storage Industry Scientific Research+3 种基金Qingdao Key Lab of Solar Energy Utilization and Energy Storage Technologythe Strategic Priority Research Program of the Chinese Academy of Sciences(XDA09010105)National Natural Science Foundation of China(51502319)Shandong Provincial Natural Science Foundation(ZR2016BQ18)
文摘In this work,a sponge-like polysulfonamide(PSA)/SiO_2 composite membrane is unprecedentedly prepared by the phase inversion method,and successfully demonstrated as a novel separator of lithium-ion batteries(LIBs).Compared to the commercial polypropylene(PP) separator,the sponge-like PSA/SiO_2 composite possesses better physical and electrochemical properties,such as higher porosity,ionic conductivity,thermal stability and flame retarding ability.The LiCoO_2/Li half-cells using the sponge-like composite separator demonstrate superior rate capability and cyclability over those using the commercial PP separator.Moreover,the sponge-like composite separator can ensure the normal operation of LiCoO_2/Li half-cell at an extremely high temperature of 90 °C,while the commercial PP separator cannot.All these encouraging results suggest that this phase inversion based sponge-like PSA/SiO_2 composite separator is really a promising separator for high performance LIBs.
基金supported by the National Natural Science Foundation of China(Grant Nos.52073298,U1706229,52072195)the Strategic Priority Research Program of the Chinese Academy of Sciences(Grant No.XDA21070304)the Youth Innovation Promotion Association of CAS(2020217).
文摘Solid-state polymer electrolytes are an important factor in the deployment of highsafety and high-energy-density solid-state lithium metal batteries.Nevertheless,use of the traditional polyethylene oxide-based solid-state polymer electrolyte is limited due to its inherently low ionic conductivity and narrow electrochemical stability window.Herein,for the first time,we specifically designed a cyanoethyl cellulosein-deep eutectic solvent composite eutectogel as a promising candidate for hybrid solid-state polymer electrolytes.It is found that the proposed eutectogel electrolyte achieves high ionic conductivity(1.87×10^(−3) S cm^(−1) at 25℃),superior electrochemical stability(up to 4.8 V),and outstanding lithium plating/striping behavior(low overpotential of 0.04 V at 1mAcm^(−2) and 1mAh cm^(−2) over 300 h).With the eutectogel-based solid-state polymer electrolyte,a 4.45 V LiCoO_(2)/Li metal battery delivers prominent long-term lifespan(capacity retention of 85%after 200 cycles)and high average Coulombic efficiency(99.5%)under ambient conditions,significantly outperforming the traditional carbonate-based liquid electrolyte.Our work demonstrates a promising strategy for designing eutectogel-based solid-state polymer electrolytes to realize high-voltage and high-energy lithium metal batteries.
基金The financial support from the National Natural Science Foundation of China(Nos.41772154 and 42102338)Natural Science Foundation of Shandong Province(Nos.ZR2019MA009 and ZR2020QE115)SDUST Research Fund of China(No.2018TDJH102)。
文摘Heat production from geothermal reservoirs is a typical heat transfer process involving a cold working fluid contacting a hot rock formation.Compared to the thermal-physical characteristics of water,supercritical CO_(2)(scCO_(2))has a higher heat storage capacity over a wide temperature-pressure range and may be favored as a heat transfer fluid.Singularly characteristic of scCO_(2)-based heat extraction is that the hydraulic-thermal properties of the scCO_(2) vary dramatically and dynamically with the spatial pressure gradient during unsteady-state flow along fracture.This highly nonlinear behavior presents a challenge in the accurate estimation of heat extraction efficiency in scCO_(2)-based EGS.In this paper,a thermal-h ydraulic-mechanical(THM)coupled model is developed by considering deformation of the fractured reservoir,non-Darcy flow and the varying thermal-physical properties of scCO_(2).The proposed model is validated by matching the modeling temperature distribution with published data.The results show that during continuous injection of scCO_(2),the fracture first widens and then narrows,ultimately reopening over the long term.The sequential fracture deformation behaviors are in response to the combined impacts of mechanical compression and thermally-induced deformation.By controlling the injection parameters of the scCO_(2),it is found that the heat extraction rate is positively correlated to its pore pressure or mass flow rate.The heat extraction rate can be significantly enhanced,when the inlet temperature of scCO_(2) is below its critical temperature.As a result,the heat increment recovered per unit mass of scCO_(2) decreases as the hot rock is gradually cooled.Meanwhile,the heat increment recovered per unit mass of scCO_(2) decreases by increasing the inlet temperature of scCO_(2) or its mass flow rate,but increases as the outlet pressure rises.Furthermore,multi-linear regression indicates that controlling the inlet temperature of the scCO_(2) can significantly improve the thermodynamic efficiency of heat extraction.
基金This work was financially supported by the Science Foundation for the Strategic Priority Research Program of the Chinese Academy of Sciences(XDA22010600)the National Natural Science Foundation of China(21933006)+4 种基金the Key Scientific and Technological Innovation Project of Shandong(2020CXGC010401)the Key research and development plan of Shandong Province(2019GHZ009)Fundamental Research Funds for the Central Universities(20CX02205A)and financial support from the Taishan Scholar Project(ts201511063)Open access funding provided by Shanghai Jiao Tong University
文摘Silicon(Si)has been regarded as an alternative anode material to traditional graphite owing to its higher theoretical capacity(4200 vs.372 m Ah g;).However,Si anodes suffer from the inherent volume expansion and unstable solid electrolyte interphase,thus experiencing fast capacity decay,which hinders their commercial application.To address this,herein,an endotenon sheathinspired water-soluble double-network binder(DNB)is presented for resolving the bottleneck of Si anodes.The as-developed binder shows excellent adhesion,high mechanical properties,and a considerable self-healing capability mainly benefited by its supramolecular hybrid network.Apart from these advantages,this binder also induces a Li;N/Li F-rich solid electrolyte interface layer,contributing to a superior cycle stability of Si electrodes.As expected,the DNB can achieve mechanically more stable Si electrodes than traditional polyacrylic acid and pectin binders.As a result,DNB delivers superior electrochemical performance ofSi/Li half cells and Li Ni;Co;Mn;O;/Si full cells,even with a high loading of Si electrode,to traditional polyacrylic acid and pectin binders.The bioinspired binder design provides a promising route to achieve long-life Si anode-assembled lithium batteries.
基金financially supported by"135"Projects Fund of CAS-QIBEBT Director Innovation Foundationthe Strategic Priority Research Program of the Chinese Academy of Sciences(Grant no.XDA09010105)+4 种基金the National Natural Science Foundation of China(Grant no.51502319)the Think-Tank Mutual Fund of Qingdao Energy Storage Industry Scientific Researchthe Qingdao Science and Technology Program(17-1-1-26-jch)the Youth Innovation Promotion Association CAS(No.2017253)Qingdao Key Lab of Solar Energy Utilization&Energy Storage Technology
文摘NASICON (Na-super-ionic-conductors)-structured materials have attracted extensive research interest due to their great application potential in secondary batteries. However, the mechanism of capacity fading for NASICON-structured electrode materials has been rarely studied. In this paper, we synthesized the NASICON-structured Na3V2(PO4)3/C composite by simple sol-gel and high-temperature solid-phase method and investigated its electrochemical performance in Na-Zn hybrid aqueous rechargeable batteries. After characterizing the structure, morphology and composition variations as well as the interfacial resistance changes of Na3V2(PO4)3/C cathode during cycling, we propose a mechanical and interfacial degradation mechanism for capacity fading of NASICON-structured Na3V2(PO4)3/C in Na-Zn hybrid aqueous rechargeable batteries. This work will shed light on enhancing the mechanical and in terfacial stability of NASICON-structured Na3V2(PO4)3/C in Na-Zn hybrid aqueous rechargeable batteries.
基金financially supported by the National Key R&D Program of China(2017YFE0127600)the Science Foundation for the Strategic Priority Research Program of the Chinese Academy of Sciences(XDA22010600)+3 种基金the Key-Area Research and Development Program of Guangdong Province(2020B090919005)the Distinguished Young Scholars of China(51625204)the National Natural Science Foundation of China(U1706229,51803230)support by the DICP&QIBEBT(DICP&QIBEBT UN201707)。
文摘Lithium-sulfur(Li-S) batteries have been considered as one of the most promising candidates to traditional lithium ion batteries due to its low cost,high theoretical specific capacity(1675 mAh g^(-1)) and energy density(2600 Wh kg^(-1)) of sulfur.Compared with traditional liquid electrolytes,polymer electrolytes(PEs) are ever-increasingly preferred due to their higher safety,superior compatibility,long cycling stability and so on.Despite some progresses on PEs,however,there remain lots of hurdles to be addressed prior to commercial applications.This review begins with native advantages for PEs to replace LEs,and then proposes the ideal requirements for PEs.Furthermore,a brief development history of typical PEs for Li-S batteries is presented to systematically summarize the recent achievements in Li-S batteries with PEs.Noted that the structure-performance relationships of polymer matrixes for PEs are highlighted.Finally,the challenges and opportunities on the future development of PEs are presented.We hold the view that composite polymer electrolytes in virtue of the high ionic conductivity and the compatible interfacial property will be promising solution for high performance Li-S batteries.
基金supported by the National Key R&D Program of China(Grant No.2017YFE0127600)the National Natural Science Foundation of China(Grant No.U1706229、21901248)+2 种基金the Strategic Priority Research Program of Chinese Academy of Sciences(Grant No.XDA22010600)the National Natural Science Foundation for Distinguished Young Scholars of China(No.51625204)the Taishan Scholars of Shandong Province(ts201511063)。
文摘In advantages of their high capacity and high operating voltage,the nickel(Ni)-rich layered transition metal oxide cathode materials(LiNi_(x)Co_(y)Mn_(z)O_(2)(NCMxyz,x+y+z=1,x≥0.5)and LiNi_(0.8)Co_(0.15)Al_(0.05)O_(2)(NCA))have been arousing great interests to improve the energy density of LIBs.However,these Nirich cathodes always suffer from rapid capacity degradation induced by unstable cathode-electrolyte interphase(CEI)layer and destruction of bulk crystal structure.Therefore,varied electrode/electrolyte interface engineering strategies(such as electrolyte formulation,material coating or doping)have been developed for Ni-rich cathodes protection.Among them,developing electrolyte functional additives has been proven to be a simple,effective,and economic method to improve the cycling stability of Nirich cathodes.This is achieved by removing unfavorable species(such as HF,H_(2)O)or constructing a stable and protective CEI layer against unfavorable reactive species(such as HF,H_(2)O).Herein,this review mainly introduces the varied classes of electrolyte functional additives and their working mechanism for interfacial engineering of Ni-rich cathodes.Especially,key favorable species for stabilizing CEI layer are summarized.More importantly,we put forward perspectives for screening and customizing ideal functional additives for high performance Ni-rich cathodes based LIBs.
基金National Natural Science Foundation of China,Grant/Award Numbers:21975271,22139001Shandong Energy Institute,Grant/Award Number:SEI I202127+3 种基金Youth Innovation Promotion Association of CAS,Grant/Award Number:2019214Key Scientific and Technological Innovation Project of Shandong,Grant/Award Number:2020CXGC010401Major basic research projects of Shandong Natural Science Foundation,Grant/Award Number:ZR2020ZD07Strategic Priority Research Program of Chinese Academy of Sciences,Grant/Award Number:XDA22010600。
文摘Polymer electrolytes(PEs)have been long recognized as the key materials to enable energy-dense batteries and render flexible energy devices practically viable,owing to their chemical and mechanical reliability.However,much of their promise is yet to be realized.The roomtemperature ion conductivity of existing PEs still falls short of the implementation criterion of 10^(-4) S cm^(-1) on the promise of acceptable mechanical properties,thereby precluding their practical application.The twin but inversely related duties of polymers,that is,functioning as both an ion-conducting medium and a structural backbone,underlie this issue but are less elucidated systematically.The polyacrylate(PA)family is among promising polymer matrices on account of ester polarity,electrode compatibility,chemical tunability,and mechanical durability.The extensive applicability of PA in plasticized gels,dry solids,and emerging composites makes PA-based PEs representative to illustrate the trade-off between ion conduction and mechanical strength.We herein seek to outline the stated long-standing conflict exemplified by PA-based PEs,focusing on crucial strategies toward balancing and reconciling the two mutually exclusive properties,with the intention of offering designing guidelines for next-generation PEs.
基金supported by funding from the Shandong Natural Science Excellent Youth Fund(ZR2019YQ22)the Research Initiation Fund of Qingdao University of Science and Technology。
文摘Solid electrolytes play a vital role in solid-state Li secondary batteries,which are promising high-energy storage devices for new-generation electric vehicles.Nevertheless,obtaining a suitable solid electrolyte by a simple and residue-free preparation process,resulting in a stable interface between electrolyte and electrode,is still a great challenge for practical applications.Herein,we report a self-crosslinked polymer electrolyte(SCPE)for high-performance lithium batteries,prepared by a one-step method based on 3-methoxysilyl-terminated polypropylene glycol(SPPG,a liquid oligomer).It is worth noting that lithium bis(oxalate)borate(Li BOB)can react with SPPG to form a crosslinked structure via a curing reaction.This self-formed polymer electrolyte exhibits excellent properties,including high roomtemperature ionic conductivity(2.6×10^(-4) S cm^(-1)),wide electrochemical window(4.7 V),and high Li ion transference number(0.65).The excellent cycling stability(500 cycles,83%)further highlights the improved interfacial stability after the in situ formation of SCPE on the electrode surface.Moreover,this self-formation strategy enhances the safety of the battery under mechanical deformation.Therefore,the present self-crosslinked polymer electrolyte shows great potential for applications in high-performance lithium batteries.
基金supported by the National Natural Science Foundation of China(Nos.51672146,21805157,51972187)the Natural Science Foundation of Shandong Province(ZR2018BEM011)+1 种基金the Key R and D project of Shandong Province(2019GGX103034)the Development Program in Science and Technology of Qingdao(19-6-2-12-cg)。
文摘Rechargeable magnesium(Mg)battery technologies show the promise of low cost,less safety concerns and relatively higher energy density.Interrogating the critical issues on the Mg stripping/plating performance as well as the Mg metal anode-electrolyte interfacial chemistry is one great importance under the practical areal capacity and rate conditions.In this work,we systematically investigate the electrochemistry of Mg stripping/plating processes within four distinctive Mg-ion electrolytes and the Mg anodeelectrolyte interfacial chemistry under practical conditions.Electrochemical results show that the cycle life of Mg//Cu asymmetric cells using these above electrolytes is significantly shortened(less than 10 cycles)when tested at a practical areal capacity of 10 mAh cm^-2.Further optical and electron microscopic analyses reveal that the gradual growth of the Mg deposits is susceptible to detachment from the copper substrate,where the initial nucleation process might occur.In spite of showing an interconnected particle-like morphology,the Mg deposits could easily penetrate the porous separator,leading to cell failure.The co-deposition of metallic Al is revealed from surface region to bulk,while the Cl-containing species exist in the near surface of Mg deposits.Our work not only highlights the critical impacts of areal capacity on the performances of Mg stripping/plating process,but calls for further efforts to eliminating the safety concerns of Mg anode under practical conditions.
基金support of the National Natural Science Foundation of China(1200208142102338,42202323)the Natural Science Foundation of Shandong Province(ZR2019MA009)The Technology Improvement Project of Small and Medium Enterprise in Shandong Province,China(2021TSGC1100),is also gratefully acknowledged.Derek Elsworth acknowledges support from the G.Albert Shoemaker endowment.
文摘Identifying changes in coal permeability with gas pressure and accurately codifying mean efective stresses in laboratory samples are crucial in predicting gas-fow behavior in coal reservoirs. Traditionally, coal permeability to gas is assessed using the steady-state method, where the equivalent gas pressure in the coal is indexed to the average of upstream and downstream pressures of the coal, while ignoring the nonlinear gas pressure gradient along the gas fow path. For the fow of a compressible gas, the traditional method consistently underestimates the length/volume-averaged pressure and overestimates mean efective stress. The higher the pressure diferential within the sample, the greater the error between the true mean pressure for a compressible fuid and that assumed as the average between upstream and downstream pressures under typical reservoir conditions. A correction coefcient for the compressible fuid pressure asymptotes to approximately 1.3%, representing that the error in mean pressure and efective stress can be on the order of approximately 30%, particularly for highly pressure-sensitive permeabilities and compressibilities, further amplifying errors in evaluated reservoir properties. We utilized this volume-averaged pressure and efective stress to correct permeability and compressibility data reported in the literature. Both the corrected initial permeability and the corrected pore compressibility were found to be smaller than the uncorrected values, due to the underestimation of the true mean fuid pressure, resulting in an overestimation of reservoir permeability if not corrected. The correction coefcient for the initial permeability ranges from 0.6 to 0.1 (reservoir values are only approximately 40% to 90% of laboratory values), while the correction coefcient for pore compressibility remains at approximately 0.75 (reservoir values are only approximately 25% of laboratory value). Errors between the uncorrected and corrected parameters are quantifed under various factors, such as confning pressure, gas sorption, and temperature. By analyzing the evolutions of the initial permeability and pore compressibility, the coupling mechanisms of mechanical compression, adsorption swelling, and thermal expansion on the pore structure of the coal can be interpreted. These fndings can provide insights that are useful for assessing the sensitivity of coal permeability to gas pressure as truly representative of reservoir conditions.
