Vanadium redox flow batteries(VRFBs)are a means of large-scale energy storage due to their excellent scalability,safety,long cycling life,and decoupled power and energy capacities.However,the slow redox kinetics of va...Vanadium redox flow batteries(VRFBs)are a means of large-scale energy storage due to their excellent scalability,safety,long cycling life,and decoupled power and energy capacities.However,the slow redox kinetics of vanadium species on conventional carbon electrodes remains a major limitation to their performance.We investigated the deposition of carbon black,carbon nanotubes,and electrochemically exfoliated graphene(Exf-Gr)onto thermally-activated carbon paper(ACP)by spray coating to increase the electrode electrocatalytic activity.The modified electrodes were characterized using scanning electron microscopy,X-ray diffraction,Raman spectroscopy,X-ray photoelectron microscopy,and surface area analysis,while their electrochemical properties were evaluated by cyclic voltammetry,electrochemical impedance spectroscopy,and singlecell VRFB testing.Among the modified electrodes,Exf-Gr/ACP had the best performance,achieving a 2.9-fold reduction in charge transfer resistance compared to pristine ACP and delivering 2.5 times the discharge capacity in single-cell tests.This improvement is attributed to Exf-Gr’s high surface area,favorable catalytic activity,and excellent dispersion on the ACP substrate.Surface modification with electrochemically exfoliated graphene is a highly effective strategy for improving the electrode performance in VRFB systems,with significant implications for large-scale energy storage.展开更多
The development of shape-customizable and bulk flexible electrochemical devices through processing technologies as versatile as those used for plastics promises to revolutionize the future of battery technology.Howeve...The development of shape-customizable and bulk flexible electrochemical devices through processing technologies as versatile as those used for plastics promises to revolutionize the future of battery technology.However,this pursuit has been fundamentally hindered by the absence of transformative battery materials capable of delivering the necessary electrochemical functions,robust interface adhesion,and,crucially,the suitable rheological properties required for on-demand shaping.In this work,we introduce a concept of a multifunctional plasticine electrode matrix(PEM)featuring nano-interpenetrating networks(nano-IPN)to address this challenge.Utilizing the nonflammable liquid-electrolyte hydration combined with conductive nanomaterials,we have realized a PEM in the form of a multifunctional nanocomposite that integrates ion and electron conduction,component binding,non-flammability,and plasticine-like moldability.With this PEM,we have successfully fabricated a variety of bulk-flexible electrodes with high mass loading of active material(AM)(>70 wt%)using industry-friendly extrusion and compression molding techniques.Moreover,these high AM-loading composite electrodes achieve an unparalleled bulk conformability and flexibility,remaining structurally intact even under severe mechanical stress.Ultimately,we have successfully produced shape-patternable and flexible batteries via extrusion molding.This study underscores the potential of the PEM to revolutionize battery microstructures,interfaces,manufacturing processes,and performance characteristics.展开更多
Production of green hydrogen through water electrolysis powered by renewable energy sources has garnered increasing attention as an attractive strategy for the storage of clean and sustainable energy.Among various ele...Production of green hydrogen through water electrolysis powered by renewable energy sources has garnered increasing attention as an attractive strategy for the storage of clean and sustainable energy.Among various electrolysis technologies,the emerging anion exchange membrane water electrolyser(AEMWE)exhibits the most potential for green hydrogen production,offering a potentially costeffective and sustainable approach that combines the advantages of high current density and fast start from proton exchange membrane water electrolyser(PEMWE)and low-cost catalyst from traditional alkaline water electrolyser(AWE)systems.Due to its relatively recent emergence over the past decade,a series of efforts are dedicated to improving the electrochemical reaction performance to accelerate the development and commercialization of AEMWE technology.A catalytic electrode comprising a gas diffusion layer(GDL)and a catalyst layer(CL)is usually called a gas diffusion electrode(GDE)that serves as a fundamental component within AEMWE,and also plays a core role in enhancing mass transfer during the electrolysis process.Inside the GDEs,bubbles nucleate and grow within the CL and then are transported through the GDL before eventually detaching to enter the electrolyte in the flow field.The transfer processes of water,gas bubbles,charges,and ions are intricately influenced by bubbles.This phenomenon is referred to as bubble-associated mass transfer.Like water management in fuel cells,effective bubble management is crucial in electrolysers,as its failure can result in various overpotential losses,such as activation losses,ohmic losses,and mass transfer losses,ultimately degrading the AEMWE performance.Despite significant advancements in the development of new materials and techniques in AEMWE,there is an urgent need for a comprehensive discussion focused on GDEs,with a particular emphasis on bubbleassociated mass transfer phenomena.This review aims to highlight recent findings regarding mass transfer in GDEs,particularly the impacts of bubble accumulation;and presents the latest advancements in designing CLs and GDLs to mitigate bubble-related issues.It is worth noting that a series of innovative bubble-free-GDE designs for water electrolysis are also emphasized in this review.This review is expected to be a valuable reference for gaining a deeper understanding of bubble-related mass transfer,especially the complex bubble behavior associated with GDEs,and for developing innovative practical strategies to advance AEMWE for green hydrogen production.展开更多
Developing catalysts with excellent stability while significantly reducing the overpotential of the oxygen evolution reaction(OER) is crucial for advancing overall water splitting(OWS) systems.In this study,we synthes...Developing catalysts with excellent stability while significantly reducing the overpotential of the oxygen evolution reaction(OER) is crucial for advancing overall water splitting(OWS) systems.In this study,we synthesized the electrode material Ce-NiCo-LDHs@SnO_(2)/NF through a two-step hydrothermal reaction,where Ce-doped NiCo-LDHs are grown on nickel foam modified by a SnO_(2) layer.Ce doping adjusts the internal electronic distribution of Ni Co-LDHs,while the introduction of the SnO_(2) layer enhances electron transfer capability.Together,these factors contribute to the reduction of the OER energy barrier and experimental evidence confirms that the reaction proceeds via the lattice oxygen evolution mechanism(LOM).Consequently,Ce-NiCo-LDHs@SnO_(2)/NF exhibits high level electrochemical performance in OER,requiring only 234 m V overpotential to achieve a current density of 10 m A/cm^(2),with a Tafel slope of just 27.39 m V/dec.When paired with Pt/C/NF,an external potential of only 1.54 V is needed to drive OWS to attain a current density amounting to 10 m A/cm^(2).Furthermore,the catalyst demonstrates stability for 100 h during the OWS stability test.This study underscores the feasibility of enhancing the OER performance through Ce doping and the introduction of a conductive SnO_(2) layer.展开更多
Objective:To investigate the spatial gradient of intraoperative impedance across the cochlear electrode array in pediatric cochlear implant recipients and assess its potential as a physiological indicator for the elec...Objective:To investigate the spatial gradient of intraoperative impedance across the cochlear electrode array in pediatric cochlear implant recipients and assess its potential as a physiological indicator for the electrode-neural interface.Methods:A prospective observational study involving 56 pediatric patients underwent cochlear implantation with Cochlear Nucleus devices.Intraoperative polarized impedance and electrically evoked compound action potential(ECAP)threshold were recorded across all 1232 electrodes using AutoNRT software.Eight electrodes with open-or short-circuit were excluded,leaving 1,224 for analysis.Impedance values were categorized by cochlear region(basal,middle,apical),and electrodes with elevated impedance(10-20 kΩ)were analyzed for regional distribution and clinical relevance.Data were analyzed for spatial patterns and correlation with the ECAP threshold profiles.Results:A consistent basal-to-apical increase in impedance was observed(7.7±1.9,9.2±1.4,10.8±1.5 kΩ;p<0.001).Impedance and ECAP threshold were weakly correlated(ρ=-0.20,p<0.001;β=-1.26,p<0.001),with a positive association in the apical region(ρ=0.12,p=0.048).Electrodes with higher impedance(1020 kΩ)were less likely to show elevated or absent TNRT(OR=0.175,p=0.02).The impedance gradient persisted across age groups and was significantly correlated with ECAP threshold patterns.Conclusion:Intraoperative impedance monitoring reveals a strong and physiologically consistent gradient,with higher values in apical electrodes.This gradient reflects anatomical and tissue interface variations,which may offer a valuable physiological indicator for intraoperative electrode positioning and neural interface integrity.展开更多
Thermocells are garnering increasing attention as a promising thermoelectric technology for harvesting low-grade heat.However,their performance is often limited by the scarcity of high-performance redox couples that p...Thermocells are garnering increasing attention as a promising thermoelectric technology for harvesting low-grade heat.However,their performance is often limited by the scarcity of high-performance redox couples that possess both high thermopower and rapid redox kinetics.This work addresses this challenge by leveraging our recently developed copper(Ⅰ/Ⅱ)(Cu^(+)/Cu^(2+))redox couple.We significantly enhance the performance of Cu-based liquid thermocells by integrating a thermosensitive crystallization process with etched carbon cloth electrodes,achieving synergistic improvements in thermodynamic and kinetic performance.The thermosensitive crystallization process establishes a persistent Cu^(2+)concentration gradient,boosting the thermopower from 1.47 to 2.93 mV K^(-1).Moreover,the etched carbon cloth electrodes provide a larger electroactive surface area and demonstrate a higher current density.Consequently,the optimized Cu^(+)/Cu^(2+)system achieved an exceptional normalized power density P_(max)(ΔT)^(-2)of 3.97 mW m^(-2)K^(-2).A thermocell module comprised of 20 cells directly power various electronic devices at a temperature difference of 40 K.This work successfully exhibits potential of Cu^(+)/Cu^(2+)redox couple in thermoelectric conversion and introduces a valuable redox couple for highperformance thermocells.展开更多
To enhance the electrochemical performance of lithium-ion battery anodes with higher silicon content,it is essential to engineer their microstructure for better lithium-ion transport and mitigated volume change as wel...To enhance the electrochemical performance of lithium-ion battery anodes with higher silicon content,it is essential to engineer their microstructure for better lithium-ion transport and mitigated volume change as well.Herein,we suggest an effective approach to control the micropore structure of silicon oxide(SiO_(x))/artificial graphite(AG)composite electrodes using a perforated current collector.The electrode features a unique pore structure,where alternating high-porosity domains and low-porosity domains markedly reduce overall electrode resistance,leading to a 20%improvement in rate capability at a 5C-rate discharge condition.Using microstructure-resolved modeling and simulations,we demonstrate that the patterned micropore structure enhances lithium-ion transport,mitigating the electrolyte concentration gradient of lithium-ion.Additionally,perforating current collector with a chemical etching process increases the number of hydrogen bonding sites and enlarges the interface with the SiO_(x)/AG composite electrode,significantly improving adhesion strength.This,in turn,suppresses mechanical degradation and leads to a 50%higher capacity retention.Thus,regularly arranged micropore structure enabled by the perforated current collector successfully improves both rate capability and cycle life in SiO_(x)/AG composite electrodes,providing valuable insights into electrode engineering.展开更多
Ceramic cells promise ideal energy conversion and storage devices,making the development of efficient and robust air electrodes crucial for their application.In this study,a Ba_(0.4)Sr_(0.5)Cs_(0.1)Co_(0.7)Fe_(0.2)Nb_...Ceramic cells promise ideal energy conversion and storage devices,making the development of efficient and robust air electrodes crucial for their application.In this study,a Ba_(0.4)Sr_(0.5)Cs_(0.1)Co_(0.7)Fe_(0.2)Nb_(0.1)O_(3−δ)(BSCCFN)air electrode,based on Ba_(0.5)Sr_(0.5)Co_(0.8)Fe_(0.2)O_(3−δ)(BSCF),is designed using a perovskite A-B-site ionic Lewis acid strength(ISA)polarization distribution strategy and is successfully applied in both oxygen-ion conducting solid oxide fuel cells(O-SOFCs)and proton-conducting reversible protonic ceramic cells(R-PCCs).When BSCCFN is used as the air electrode in O-SOFCs,a peak power density(PPD)of 1.45 W cm^(−2)is achieved at 650°C,whereas in R-PCCs,a PPD of 1.13 W cm^(−2)and a current density of−1.8 A cm^(−2)at 1.3 V are achieved at the same temperature and show stable reversibility over 100 h.Experimental measurements and theoretical calculations demonstrate that low-ISA Cs+doping accelerates the reaction kinetics of both oxygen ions and protons,while high-ISA Nb^(5+)doping enhances electrode stability.The synergistic effect of Cs^(+)and Nb^(5+)co-doping in the BSCCFN electrode lies in the ISA polarization distribution,which weakens the Co/Fe–O bond covalency,thereby promoting oxygen vacancy formation and facilitating the conduction of oxygen ions and protons.展开更多
Graphite-silicon species(Gr-Si)hybrid anodes have merged as potential candidates for high-energy lithium-ion batteries(LIBs),yet long been plagued by rapid capacity fading due to their unstable mechano-electrochemistr...Graphite-silicon species(Gr-Si)hybrid anodes have merged as potential candidates for high-energy lithium-ion batteries(LIBs),yet long been plagued by rapid capacity fading due to their unstable mechano-electrochemistry.The dominant approach to enhance electrochemical stability of the Gr-Si hybrid anodes typically involves the optimization of the electrode material structures and the employment of low active Si species content in electrode(<10 wt%in most instances).However,the electrode structure design,a factor of equal importance in determining the electrochemical performance of Gr-Si hybrid anodes,has received scant attention.In this study,three Gr-Si hybrid anodes with the identical material composition but distinct electrode structures are designed to investigate the mechanoelectrochemistry of the electrodes.It is revealed that the substantial volume change of Si species particles in Gr-Si hybrid anodes led to the local lattice stress of Gr at their contact interface during the charge/discharge processes,thereby increasing thermodynamic and kinetic barrier of Li-ion migration.Furthermore,the huge disparity in volume change of Si species and Gr particles trigger the separate agglomeration of these two materials,resulting in a considerable electrode volume change and increased electrochemical resistance.An advanced Gr/Si hybrid anode with upper Gr and lower Si species layer structure design addresses the above challenges using photovoltaic waste silicon sources under high Si species content(17 wt%)and areal capacity(2.0 mA h cm^(-2))in Ah-level full pouch cells with a low negative/positive(N/P)ratio of 1.09.The cell shows stable cycling for 100 cycles at 0.3 C with an impressively low capacity decay rate of 0.0546%per cycle,outperforming most reported Gr-Si hybrid anodes.展开更多
Economical,stable,and corrosion-resistant catalytic electrodes are still urgently needed for the oxygen evolution reaction(OER)in water and seawater.Herein,a mild electroless plating strategy is used to achieve large-...Economical,stable,and corrosion-resistant catalytic electrodes are still urgently needed for the oxygen evolution reaction(OER)in water and seawater.Herein,a mild electroless plating strategy is used to achieve large-scale preparation of the“integrated”phosphorus-based precatalyst(FeP-NiP)on nickel foam(NF),which is in situ reconstructed into a highly active and corrosion-resistant(Fe)NiOOH phase for OER.The interaction between phosphate anions(PO_(x)^(y-))and iron ions(Fe^(3+))tunes the electronic structure of the catalytic phase to further enhance OER kinetics.The integrated FeP-NiP@NF electrode exhibits low overpotentials for OER in alkaline water/seawater,requiring only 275/289,320/336,and 349/358 mV to reach 0.1,0.5,and 1.0 A cm^(−2),respectively.The in situ reconstructed PO_(x)^(y-)anion electrostatically repels Cl−in seawater electrolytes,allowing stable operation for over 7 days at 1.0 A cm^(−2) in extreme electrolytes(1.0 M KOH+seawater and 6.0 M KOH+seawater),demonstrating industrial-level stability.This study overcomes the complex synthesis limitations of P-based materials through innovative material design,opening new avenues for electrochemical energy conversion.展开更多
Vanadium redox flow batteries(VRFBs)hold significant promise for large-scale energy storage applications.However,the sluggish reaction kinetics on the electrode surface considerably limit their performance.Implementat...Vanadium redox flow batteries(VRFBs)hold significant promise for large-scale energy storage applications.However,the sluggish reaction kinetics on the electrode surface considerably limit their performance.Implementation of efficient surface modification on carbon electrodes through an economically viable production method is crucial for the practical application of VRFBs.Herein,a nano-carbon layer with morphology of fine nanoparticles(<90 nm)and rich oxygen functional groups was constructed on carbon felts by unbalanced magnetron sputtering coupled with thermal treatment.This modified carbon felt served as both anode and cathode in cell,enabling an improved wettability of electrolyte and high reversibility of the active mass,and promoted kinetics of redox reactions.The optimized carbon felt,achieved through one hour of deposition(1C-CF),demonstrated outstanding electrochemical performance in a single cell.The cell exhibited a high energy efficiency of 82.4%at a current density of 100 m A cm^(-2)and maintained 71.8%at a high current density of 250 mA cm^(-2).Furthermore,the energy efficiency remained at 77.2%during long-term cycling(450 cycles)at a current density of 150 mA cm^(-2),indicating good electrode stability.Our results shed light on the surface design of carbon felt electrodes for the broad application interest of VRFB energy storage systems.展开更多
The recently reported silicon/graphite(Si/Gr)composite electrode with a layered structure is a promising approach to achieve high capacity and stable cycling of Si-based electrodes in lithium-ion batteries.However,the...The recently reported silicon/graphite(Si/Gr)composite electrode with a layered structure is a promising approach to achieve high capacity and stable cycling of Si-based electrodes in lithium-ion batteries.However,there is still a need to clarify why particular layered structures are effective and why others are ineffective or even detrimental.In this work,an unreported mechanism dominated by the porosity evolution of electrodes is proposed for the degradation behavior of layered Si/Gr electrodes.First,the effect of layering sequence on the overall electrode performance is investigated experimentally,and the results suggest that the cycling performance of the silicon-on-graphite(SG)electrode is much superior to that of the graphite-on-silicon electrode.To explain this phenomenon,a coupled mechanical-electrochemical porous electrode model is developed,in which the porosity is affected by the silicon expansion and the local constraints.The modeling results suggest that the weaker constraint of the silicon layer in the SG electrode leads to a more insignificant decrease in porosity,and consequently,the more stable cycling performance.The findings of this work provide new insights into the structural design of Si-based electrodes.展开更多
Aqueous zinc-halogen batteries are promising candidates for large-scale energy storage due to their abundant resources,intrinsic safety,and high theoretical capacity.Nevertheless,the uncontrollable zinc dendrite growt...Aqueous zinc-halogen batteries are promising candidates for large-scale energy storage due to their abundant resources,intrinsic safety,and high theoretical capacity.Nevertheless,the uncontrollable zinc dendrite growth and spontaneous shuttle effect of active species have prohibited their practical implementation.Herein,a double-layered protective film based on zinc-ethylenediamine tetramethylene phosphonic acid(ZEA)artificial film and ZnF2-rich solid electrolyte interphase(SEI)layer has been successfully fabricated on the zinc metal anode via electrode/electrolyte synergistic optimization.The ZEA-based artificial film shows strong affinity for the ZnF2-rich SEI layer,therefore effectively suppressing the SEI breakage and facilitating the construction of double-layered protective film on the zinc metal anode.Such double-layered architecture not only modulates Zn2+flux and suppresses the zinc dendrite growth,but also blocks the direct contact between the metal anode and electrolyte,thus mitigating the corrosion from the active species.When employing optimized metal anodes and electrolytes,the as-developed zinc-(dual)halogen batteries present high areal capacity and satisfactory cycling stability.This work provides a new avenue for developing aqueous zinc-(dual)halogen batteries.展开更多
The publisher regrets to inform that in the article of Advanced Powder Materials 4(2025)100261,the published Figs.3 and 5 belong to the initially submitted version,which should be replaced by the final version.The dif...The publisher regrets to inform that in the article of Advanced Powder Materials 4(2025)100261,the published Figs.3 and 5 belong to the initially submitted version,which should be replaced by the final version.The differences between the initial and final versions of these figures are described below.展开更多
A unitized regenerative fuel cell(URFC)is a device that may function reversibly as either a fuel cell(FC)or water elec-trolysis(WE).An important component of this device is the Membrane electrode assembly(MEA).Therefo...A unitized regenerative fuel cell(URFC)is a device that may function reversibly as either a fuel cell(FC)or water elec-trolysis(WE).An important component of this device is the Membrane electrode assembly(MEA).Therefore,this study aimed to compare the performance outcomes of MEA using electrodes with single and three catalyst layers.This study measured Electrochemical Surface Area(ECSA),Electrochemical Impedance Spectroscopy(EIS),X-ray Diffraction analysis(XRD),and X-ray Fluorescence(XRF).Furthermore,the round-trip efficiency(RTE)of the MEA,as w ell as the performance in FC and WE mode,was measured.In comparison,The ECSA values of Pt-Ru/C and Pt/C with three catalyst layers were higher than the single catalyst layer.This result was supported by electrode characterization data for XRD and XRF.The respective electrical conductivity values of Pt-Ru/C and Pt/C with three catalyst layers are also higher than the single cata-lyst layer,and the performance of URFC using MEA with three catalyst layers has the highest value of RTE among the MEA performances of URFC,which is 100%at a current density of 4 mA·cm-2.展开更多
Layered materials,such as graphite and molybdenum disulfide,are promising for electrode materials and microelectronic devices due to their excellent ion-intercalating properties.However,the intercalation and de-interc...Layered materials,such as graphite and molybdenum disulfide,are promising for electrode materials and microelectronic devices due to their excellent ion-intercalating properties.However,the intercalation and de-intercalation of ions,causing structural deformation and material property variations,would affect battery performance and alter external field responses.The complex problem coupling multiphysics is significant for study and poses a crucial research challenge.This paper reviews the coupling between mechanics,electrochemistry,and electrics during the reaction process,including in situ experimental characterization,theoretical modeling,and design considerations at various scales.Current research has focused on experimental observations beyond the nanoscale and continuum phenomenological models.Further advancements in characterizing layered structural evolution,electron cloud interactions at the atomic level,and developing physics-based multi-field models are essential.展开更多
The largely bending bilayer electrode model battery has been widely used to measure the mechanical properties of composite electrode materials.The assumption used in the method that lithium is uniformly distributed in...The largely bending bilayer electrode model battery has been widely used to measure the mechanical properties of composite electrode materials.The assumption used in the method that lithium is uniformly distributed in the active layer lacks quantitative evaluation,and the uniformity of concentration distribution is crucial for accurate in-situ measurements of concentration-related material properties and stress in bilayer electrodes.Therefore,this paper proposes a mechanical-electrochemical coupled model to study the lithium concentration distribution in the active layer during lithiation.This model includes lithium concentration diffusion and active layer deformation.By comparing experimental and simulated curvature evolution of the active layer during lithiation and delithiation,the reliability of this simulation model is verified.We then derive the precise concentration distribution inside the active layer and suggest using relative error to quantitatively evaluate the uniformity of lithium concentration in the active layer.Results show that a low relative error in lithium concentration can be achieved in the middle region of the active layer.Additionally,the effects of different rates and geometric parameters on the lithium concentration distribution in the active layer are discussed.Results indicate that reduced rates,thinner active layers,shorter active layer lengths,and increased spacing between the working and counter electrodes can lead to a more uniform distribution of lithium concentration in the active layer.These insights help improve experimental methods and equipment,promoting uniform distribution of lithium in the active layer and enhancing measurement accuracy.展开更多
Lithium (Li) metal batteries (LMBs) featuring ultrahigh energy densities are expected as ones of the mostprominent devices for future energy storage applications. Nevertheless, the practical application of LMBs is sti...Lithium (Li) metal batteries (LMBs) featuring ultrahigh energy densities are expected as ones of the mostprominent devices for future energy storage applications. Nevertheless, the practical application of LMBs is stillplagued by the poor interfacial stability of Li metal anode. Inorganic-rich interlayer derived from anion decom-positionin advanced liquid electrolytes is demonstrated as an efficient approach to stabilize the Li metal anode,however, is electrolyte-dependent with limited application conditions due to inappropriate electrolyte properties.Herein, an efficient structuration strategy is proposed to fabricate an electrolyte-independent and sustainedinorganic-rich layer, by embedding a type of functional anion aggregates consisting of selected anions ionicallybonded to polymerized cation clusters. The anion aggregates can progressively release anions to react with Liþand form key components boosting the structural stability and Liþ transfer ability of the artificial layer uponcycling. This self-reinforcing working mechanism endows the artificial layer with a sustained inorganic-richnature and promising Li protective ability during long-term cycling, while the electrolyte-independent propertyenables its applications in LMBs using conventional low concentration electrolytes and all-solid-state LMBs withsignificantly enhanced performances. This strategy establishes an alternative designing route of Li protectivelayers for reliable LMBs.展开更多
Layered Li[Ni1/3Co1/3Mn1/3]O2 was synthesized with complex metal hydroxide precursors that were prepared by a co-precipitation method.The influence of coordination between ammonia and transition-metal cations on the s...Layered Li[Ni1/3Co1/3Mn1/3]O2 was synthesized with complex metal hydroxide precursors that were prepared by a co-precipitation method.The influence of coordination between ammonia and transition-metal cations on the structural and electrochemical properties of the Li[Ni1/3Co1/3Mn1/3]O2 materials was studied.It is found that when the molar ratio of ammonia to total transition-metal cations is 2.7：1,uniform particle size distribution of the complex metal hydroxide is observed via scanning electron microscopy.The average particle size of Li[Ni1/3Co1/3Mn1/3]O2 materials was measured to be about 500 nm,and the tap-density was measured to be approximately 2.37 g/cm3,which is comparable with that of commercialized LiCoO2.XRD analysis indicates that the presently synthesized Li[Ni1/3Co1/3Mn1/3]O2 has a hexagonal layered-structure.The initial discharge capacity of the Li[Ni1/3Co1/3Mn1/3]O2 positive-electrode material is determined to be 181.5 mA·h/g using a Li/Li[Ni1/3Co1/3Mn1/3]O2 cell operated at 0.1C in the voltage range of 2.8-4.5 V.The discharge capacity at the 50th cycle at 0.5C is 170.6 mA·h/g.展开更多
As an improvement on the conventional two-layer electrode （active material layerlcurrent collector）, a novel sandwich-like three-layer electrode （conductive layerlactive material layertcurrent collector） for catho...As an improvement on the conventional two-layer electrode （active material layerlcurrent collector）, a novel sandwich-like three-layer electrode （conductive layerlactive material layertcurrent collector） for cathode material LiFePO4/C was introduced in order to improve its electrochemical performance. LiFePO4/C in the three-layer electrode exhibited superior rate capability in comparison with that in the two-layer electrode in accordance with charge-discharge examination. Cyclic voltammetry and electrochemical impedance spectroscopy indicated that Fe3＋/Fe2＋ redox couple for LiFePO4 in the three-layer electrode displayed faster kinetics, better reversibility and much lower charge transfer resistance than that in the two-layer electrode in electrochemical process. For three-layer electrode, the holes in the surface of active material layer were filled by smaller acetylene black grains, which formed electrical connections and provided more pathways to electron transport to/from LiFePO4/C particles exposed to the bulk electrolyte.展开更多
基金supported by the University of Seoul’s 2025 Research Fund.
文摘Vanadium redox flow batteries(VRFBs)are a means of large-scale energy storage due to their excellent scalability,safety,long cycling life,and decoupled power and energy capacities.However,the slow redox kinetics of vanadium species on conventional carbon electrodes remains a major limitation to their performance.We investigated the deposition of carbon black,carbon nanotubes,and electrochemically exfoliated graphene(Exf-Gr)onto thermally-activated carbon paper(ACP)by spray coating to increase the electrode electrocatalytic activity.The modified electrodes were characterized using scanning electron microscopy,X-ray diffraction,Raman spectroscopy,X-ray photoelectron microscopy,and surface area analysis,while their electrochemical properties were evaluated by cyclic voltammetry,electrochemical impedance spectroscopy,and singlecell VRFB testing.Among the modified electrodes,Exf-Gr/ACP had the best performance,achieving a 2.9-fold reduction in charge transfer resistance compared to pristine ACP and delivering 2.5 times the discharge capacity in single-cell tests.This improvement is attributed to Exf-Gr’s high surface area,favorable catalytic activity,and excellent dispersion on the ACP substrate.Surface modification with electrochemically exfoliated graphene is a highly effective strategy for improving the electrode performance in VRFB systems,with significant implications for large-scale energy storage.
基金financial support from the National Natural Science Foundation of China(52473248,52203123,52125301,22279070 and U21A20170)the State Key Laboratory of Polymer Materials Engineering(Grant No:sklpme 2023-1-05 and sklpme 2024-2-04)+3 种基金the Ministry of Science and Technology of China(No.2019YFA0705703)the Sichuan Science and Technology Program(2023NSFSC0991 and 2025ZNSFSC1411)the Fundamental Research Funds for the Central Universitiespartially sponsored by the Double First-Class Construction Funds of Sichuan University.
文摘The development of shape-customizable and bulk flexible electrochemical devices through processing technologies as versatile as those used for plastics promises to revolutionize the future of battery technology.However,this pursuit has been fundamentally hindered by the absence of transformative battery materials capable of delivering the necessary electrochemical functions,robust interface adhesion,and,crucially,the suitable rheological properties required for on-demand shaping.In this work,we introduce a concept of a multifunctional plasticine electrode matrix(PEM)featuring nano-interpenetrating networks(nano-IPN)to address this challenge.Utilizing the nonflammable liquid-electrolyte hydration combined with conductive nanomaterials,we have realized a PEM in the form of a multifunctional nanocomposite that integrates ion and electron conduction,component binding,non-flammability,and plasticine-like moldability.With this PEM,we have successfully fabricated a variety of bulk-flexible electrodes with high mass loading of active material(AM)(>70 wt%)using industry-friendly extrusion and compression molding techniques.Moreover,these high AM-loading composite electrodes achieve an unparalleled bulk conformability and flexibility,remaining structurally intact even under severe mechanical stress.Ultimately,we have successfully produced shape-patternable and flexible batteries via extrusion molding.This study underscores the potential of the PEM to revolutionize battery microstructures,interfaces,manufacturing processes,and performance characteristics.
基金support from the National Natural Science Foundation of China(Grant No.52006029)the Promotion Foundation for Young Science and Technology Talents in Jilin Province(Grant No.QT202113)+2 种基金the Special Foundation of Industrial Innovation in Jilin Province(Grant No.2019C056-2)the Special Foundation for Outstanding Young Talents Training in Jilin(Grant No.20200104107)the UK EPSRC(EP/W03784X/1)。
文摘Production of green hydrogen through water electrolysis powered by renewable energy sources has garnered increasing attention as an attractive strategy for the storage of clean and sustainable energy.Among various electrolysis technologies,the emerging anion exchange membrane water electrolyser(AEMWE)exhibits the most potential for green hydrogen production,offering a potentially costeffective and sustainable approach that combines the advantages of high current density and fast start from proton exchange membrane water electrolyser(PEMWE)and low-cost catalyst from traditional alkaline water electrolyser(AWE)systems.Due to its relatively recent emergence over the past decade,a series of efforts are dedicated to improving the electrochemical reaction performance to accelerate the development and commercialization of AEMWE technology.A catalytic electrode comprising a gas diffusion layer(GDL)and a catalyst layer(CL)is usually called a gas diffusion electrode(GDE)that serves as a fundamental component within AEMWE,and also plays a core role in enhancing mass transfer during the electrolysis process.Inside the GDEs,bubbles nucleate and grow within the CL and then are transported through the GDL before eventually detaching to enter the electrolyte in the flow field.The transfer processes of water,gas bubbles,charges,and ions are intricately influenced by bubbles.This phenomenon is referred to as bubble-associated mass transfer.Like water management in fuel cells,effective bubble management is crucial in electrolysers,as its failure can result in various overpotential losses,such as activation losses,ohmic losses,and mass transfer losses,ultimately degrading the AEMWE performance.Despite significant advancements in the development of new materials and techniques in AEMWE,there is an urgent need for a comprehensive discussion focused on GDEs,with a particular emphasis on bubbleassociated mass transfer phenomena.This review aims to highlight recent findings regarding mass transfer in GDEs,particularly the impacts of bubble accumulation;and presents the latest advancements in designing CLs and GDLs to mitigate bubble-related issues.It is worth noting that a series of innovative bubble-free-GDE designs for water electrolysis are also emphasized in this review.This review is expected to be a valuable reference for gaining a deeper understanding of bubble-related mass transfer,especially the complex bubble behavior associated with GDEs,and for developing innovative practical strategies to advance AEMWE for green hydrogen production.
基金supported by the National Natural Science Foundation of China (No.52274304)。
文摘Developing catalysts with excellent stability while significantly reducing the overpotential of the oxygen evolution reaction(OER) is crucial for advancing overall water splitting(OWS) systems.In this study,we synthesized the electrode material Ce-NiCo-LDHs@SnO_(2)/NF through a two-step hydrothermal reaction,where Ce-doped NiCo-LDHs are grown on nickel foam modified by a SnO_(2) layer.Ce doping adjusts the internal electronic distribution of Ni Co-LDHs,while the introduction of the SnO_(2) layer enhances electron transfer capability.Together,these factors contribute to the reduction of the OER energy barrier and experimental evidence confirms that the reaction proceeds via the lattice oxygen evolution mechanism(LOM).Consequently,Ce-NiCo-LDHs@SnO_(2)/NF exhibits high level electrochemical performance in OER,requiring only 234 m V overpotential to achieve a current density of 10 m A/cm^(2),with a Tafel slope of just 27.39 m V/dec.When paired with Pt/C/NF,an external potential of only 1.54 V is needed to drive OWS to attain a current density amounting to 10 m A/cm^(2).Furthermore,the catalyst demonstrates stability for 100 h during the OWS stability test.This study underscores the feasibility of enhancing the OER performance through Ce doping and the introduction of a conductive SnO_(2) layer.
文摘Objective:To investigate the spatial gradient of intraoperative impedance across the cochlear electrode array in pediatric cochlear implant recipients and assess its potential as a physiological indicator for the electrode-neural interface.Methods:A prospective observational study involving 56 pediatric patients underwent cochlear implantation with Cochlear Nucleus devices.Intraoperative polarized impedance and electrically evoked compound action potential(ECAP)threshold were recorded across all 1232 electrodes using AutoNRT software.Eight electrodes with open-or short-circuit were excluded,leaving 1,224 for analysis.Impedance values were categorized by cochlear region(basal,middle,apical),and electrodes with elevated impedance(10-20 kΩ)were analyzed for regional distribution and clinical relevance.Data were analyzed for spatial patterns and correlation with the ECAP threshold profiles.Results:A consistent basal-to-apical increase in impedance was observed(7.7±1.9,9.2±1.4,10.8±1.5 kΩ;p<0.001).Impedance and ECAP threshold were weakly correlated(ρ=-0.20,p<0.001;β=-1.26,p<0.001),with a positive association in the apical region(ρ=0.12,p=0.048).Electrodes with higher impedance(1020 kΩ)were less likely to show elevated or absent TNRT(OR=0.175,p=0.02).The impedance gradient persisted across age groups and was significantly correlated with ECAP threshold patterns.Conclusion:Intraoperative impedance monitoring reveals a strong and physiologically consistent gradient,with higher values in apical electrodes.This gradient reflects anatomical and tissue interface variations,which may offer a valuable physiological indicator for intraoperative electrode positioning and neural interface integrity.
基金financially supported by research grants from Innovative Research Group Project of National Natural Science Foundation of China(52021004)the National Key Research and Development Program of China(2022YFB3803300)+1 种基金the National Natural Science Foundation of China(62474026,62205140,12204071)the China Postdoctoral Science Foundation(2022M710532)。
文摘Thermocells are garnering increasing attention as a promising thermoelectric technology for harvesting low-grade heat.However,their performance is often limited by the scarcity of high-performance redox couples that possess both high thermopower and rapid redox kinetics.This work addresses this challenge by leveraging our recently developed copper(Ⅰ/Ⅱ)(Cu^(+)/Cu^(2+))redox couple.We significantly enhance the performance of Cu-based liquid thermocells by integrating a thermosensitive crystallization process with etched carbon cloth electrodes,achieving synergistic improvements in thermodynamic and kinetic performance.The thermosensitive crystallization process establishes a persistent Cu^(2+)concentration gradient,boosting the thermopower from 1.47 to 2.93 mV K^(-1).Moreover,the etched carbon cloth electrodes provide a larger electroactive surface area and demonstrate a higher current density.Consequently,the optimized Cu^(+)/Cu^(2+)system achieved an exceptional normalized power density P_(max)(ΔT)^(-2)of 3.97 mW m^(-2)K^(-2).A thermocell module comprised of 20 cells directly power various electronic devices at a temperature difference of 40 K.This work successfully exhibits potential of Cu^(+)/Cu^(2+)redox couple in thermoelectric conversion and introduces a valuable redox couple for highperformance thermocells.
基金supported by the National Research Foundation of Korea(NRF)grant funded by the Korean government(MSIT)(No.NRF-2021M3H4A1A02048529)the Ministry of Trade,Industry and Energy(MOTIE)of the Korean government under grant No.RS-2022-00155854support from the DGIST Supercomputing and Big Data Center.
文摘To enhance the electrochemical performance of lithium-ion battery anodes with higher silicon content,it is essential to engineer their microstructure for better lithium-ion transport and mitigated volume change as well.Herein,we suggest an effective approach to control the micropore structure of silicon oxide(SiO_(x))/artificial graphite(AG)composite electrodes using a perforated current collector.The electrode features a unique pore structure,where alternating high-porosity domains and low-porosity domains markedly reduce overall electrode resistance,leading to a 20%improvement in rate capability at a 5C-rate discharge condition.Using microstructure-resolved modeling and simulations,we demonstrate that the patterned micropore structure enhances lithium-ion transport,mitigating the electrolyte concentration gradient of lithium-ion.Additionally,perforating current collector with a chemical etching process increases the number of hydrogen bonding sites and enlarges the interface with the SiO_(x)/AG composite electrode,significantly improving adhesion strength.This,in turn,suppresses mechanical degradation and leads to a 50%higher capacity retention.Thus,regularly arranged micropore structure enabled by the perforated current collector successfully improves both rate capability and cycle life in SiO_(x)/AG composite electrodes,providing valuable insights into electrode engineering.
基金funding from the National Natural Science Foundation of China (Award 91745203) supplemented by Central Universities’ Basic Research Funds.
文摘Ceramic cells promise ideal energy conversion and storage devices,making the development of efficient and robust air electrodes crucial for their application.In this study,a Ba_(0.4)Sr_(0.5)Cs_(0.1)Co_(0.7)Fe_(0.2)Nb_(0.1)O_(3−δ)(BSCCFN)air electrode,based on Ba_(0.5)Sr_(0.5)Co_(0.8)Fe_(0.2)O_(3−δ)(BSCF),is designed using a perovskite A-B-site ionic Lewis acid strength(ISA)polarization distribution strategy and is successfully applied in both oxygen-ion conducting solid oxide fuel cells(O-SOFCs)and proton-conducting reversible protonic ceramic cells(R-PCCs).When BSCCFN is used as the air electrode in O-SOFCs,a peak power density(PPD)of 1.45 W cm^(−2)is achieved at 650°C,whereas in R-PCCs,a PPD of 1.13 W cm^(−2)and a current density of−1.8 A cm^(−2)at 1.3 V are achieved at the same temperature and show stable reversibility over 100 h.Experimental measurements and theoretical calculations demonstrate that low-ISA Cs+doping accelerates the reaction kinetics of both oxygen ions and protons,while high-ISA Nb^(5+)doping enhances electrode stability.The synergistic effect of Cs^(+)and Nb^(5+)co-doping in the BSCCFN electrode lies in the ISA polarization distribution,which weakens the Co/Fe–O bond covalency,thereby promoting oxygen vacancy formation and facilitating the conduction of oxygen ions and protons.
基金the financial support by the National Natural Science Foundation of China(52072137)the National Natural Science Foundation of China(22205068)the"CUG Scholar"Scientific Research Funds at China University of Geosciences(Wuhan)(2022118)。
文摘Graphite-silicon species(Gr-Si)hybrid anodes have merged as potential candidates for high-energy lithium-ion batteries(LIBs),yet long been plagued by rapid capacity fading due to their unstable mechano-electrochemistry.The dominant approach to enhance electrochemical stability of the Gr-Si hybrid anodes typically involves the optimization of the electrode material structures and the employment of low active Si species content in electrode(<10 wt%in most instances).However,the electrode structure design,a factor of equal importance in determining the electrochemical performance of Gr-Si hybrid anodes,has received scant attention.In this study,three Gr-Si hybrid anodes with the identical material composition but distinct electrode structures are designed to investigate the mechanoelectrochemistry of the electrodes.It is revealed that the substantial volume change of Si species particles in Gr-Si hybrid anodes led to the local lattice stress of Gr at their contact interface during the charge/discharge processes,thereby increasing thermodynamic and kinetic barrier of Li-ion migration.Furthermore,the huge disparity in volume change of Si species and Gr particles trigger the separate agglomeration of these two materials,resulting in a considerable electrode volume change and increased electrochemical resistance.An advanced Gr/Si hybrid anode with upper Gr and lower Si species layer structure design addresses the above challenges using photovoltaic waste silicon sources under high Si species content(17 wt%)and areal capacity(2.0 mA h cm^(-2))in Ah-level full pouch cells with a low negative/positive(N/P)ratio of 1.09.The cell shows stable cycling for 100 cycles at 0.3 C with an impressively low capacity decay rate of 0.0546%per cycle,outperforming most reported Gr-Si hybrid anodes.
基金funding support from Natural Science Foundation of Shanghai(Grant No.23ZR1443900)the National Natural Science Foundation of China(Grant Nos.22178309,22476131 and 22176127)。
文摘Economical,stable,and corrosion-resistant catalytic electrodes are still urgently needed for the oxygen evolution reaction(OER)in water and seawater.Herein,a mild electroless plating strategy is used to achieve large-scale preparation of the“integrated”phosphorus-based precatalyst(FeP-NiP)on nickel foam(NF),which is in situ reconstructed into a highly active and corrosion-resistant(Fe)NiOOH phase for OER.The interaction between phosphate anions(PO_(x)^(y-))and iron ions(Fe^(3+))tunes the electronic structure of the catalytic phase to further enhance OER kinetics.The integrated FeP-NiP@NF electrode exhibits low overpotentials for OER in alkaline water/seawater,requiring only 275/289,320/336,and 349/358 mV to reach 0.1,0.5,and 1.0 A cm^(−2),respectively.The in situ reconstructed PO_(x)^(y-)anion electrostatically repels Cl−in seawater electrolytes,allowing stable operation for over 7 days at 1.0 A cm^(−2) in extreme electrolytes(1.0 M KOH+seawater and 6.0 M KOH+seawater),demonstrating industrial-level stability.This study overcomes the complex synthesis limitations of P-based materials through innovative material design,opening new avenues for electrochemical energy conversion.
基金supported by National Natural Science Foundation of China(U21B2057)。
文摘Vanadium redox flow batteries(VRFBs)hold significant promise for large-scale energy storage applications.However,the sluggish reaction kinetics on the electrode surface considerably limit their performance.Implementation of efficient surface modification on carbon electrodes through an economically viable production method is crucial for the practical application of VRFBs.Herein,a nano-carbon layer with morphology of fine nanoparticles(<90 nm)and rich oxygen functional groups was constructed on carbon felts by unbalanced magnetron sputtering coupled with thermal treatment.This modified carbon felt served as both anode and cathode in cell,enabling an improved wettability of electrolyte and high reversibility of the active mass,and promoted kinetics of redox reactions.The optimized carbon felt,achieved through one hour of deposition(1C-CF),demonstrated outstanding electrochemical performance in a single cell.The cell exhibited a high energy efficiency of 82.4%at a current density of 100 m A cm^(-2)and maintained 71.8%at a high current density of 250 mA cm^(-2).Furthermore,the energy efficiency remained at 77.2%during long-term cycling(450 cycles)at a current density of 150 mA cm^(-2),indicating good electrode stability.Our results shed light on the surface design of carbon felt electrodes for the broad application interest of VRFB energy storage systems.
基金supported by the National Natural Science Foundation of China(Grant Nos.12072183,12472174,and 12421002).
文摘The recently reported silicon/graphite(Si/Gr)composite electrode with a layered structure is a promising approach to achieve high capacity and stable cycling of Si-based electrodes in lithium-ion batteries.However,there is still a need to clarify why particular layered structures are effective and why others are ineffective or even detrimental.In this work,an unreported mechanism dominated by the porosity evolution of electrodes is proposed for the degradation behavior of layered Si/Gr electrodes.First,the effect of layering sequence on the overall electrode performance is investigated experimentally,and the results suggest that the cycling performance of the silicon-on-graphite(SG)electrode is much superior to that of the graphite-on-silicon electrode.To explain this phenomenon,a coupled mechanical-electrochemical porous electrode model is developed,in which the porosity is affected by the silicon expansion and the local constraints.The modeling results suggest that the weaker constraint of the silicon layer in the SG electrode leads to a more insignificant decrease in porosity,and consequently,the more stable cycling performance.The findings of this work provide new insights into the structural design of Si-based electrodes.
基金support from the National Natural Science Foundation of China(22209089,22178187)Natural Science Foundation of Shandong Province(ZR2022QB048,ZR2021MB006)+2 种基金Excellent Youth Science Foundation of Shandong Province(Overseas)(2023HWYQ-089)the Taishan Scholars Program of Shandong Province(tsqn201909091)Open Research Fund of School of Chemistry and Chemical Engineering,Henan Normal University.
文摘Aqueous zinc-halogen batteries are promising candidates for large-scale energy storage due to their abundant resources,intrinsic safety,and high theoretical capacity.Nevertheless,the uncontrollable zinc dendrite growth and spontaneous shuttle effect of active species have prohibited their practical implementation.Herein,a double-layered protective film based on zinc-ethylenediamine tetramethylene phosphonic acid(ZEA)artificial film and ZnF2-rich solid electrolyte interphase(SEI)layer has been successfully fabricated on the zinc metal anode via electrode/electrolyte synergistic optimization.The ZEA-based artificial film shows strong affinity for the ZnF2-rich SEI layer,therefore effectively suppressing the SEI breakage and facilitating the construction of double-layered protective film on the zinc metal anode.Such double-layered architecture not only modulates Zn2+flux and suppresses the zinc dendrite growth,but also blocks the direct contact between the metal anode and electrolyte,thus mitigating the corrosion from the active species.When employing optimized metal anodes and electrolytes,the as-developed zinc-(dual)halogen batteries present high areal capacity and satisfactory cycling stability.This work provides a new avenue for developing aqueous zinc-(dual)halogen batteries.
文摘The publisher regrets to inform that in the article of Advanced Powder Materials 4(2025)100261,the published Figs.3 and 5 belong to the initially submitted version,which should be replaced by the final version.The differences between the initial and final versions of these figures are described below.
基金support from the Ministry of Higher Education Malaysia under grant HICOE-2023-005.
文摘A unitized regenerative fuel cell(URFC)is a device that may function reversibly as either a fuel cell(FC)or water elec-trolysis(WE).An important component of this device is the Membrane electrode assembly(MEA).Therefore,this study aimed to compare the performance outcomes of MEA using electrodes with single and three catalyst layers.This study measured Electrochemical Surface Area(ECSA),Electrochemical Impedance Spectroscopy(EIS),X-ray Diffraction analysis(XRD),and X-ray Fluorescence(XRF).Furthermore,the round-trip efficiency(RTE)of the MEA,as w ell as the performance in FC and WE mode,was measured.In comparison,The ECSA values of Pt-Ru/C and Pt/C with three catalyst layers were higher than the single catalyst layer.This result was supported by electrode characterization data for XRD and XRF.The respective electrical conductivity values of Pt-Ru/C and Pt/C with three catalyst layers are also higher than the single cata-lyst layer,and the performance of URFC using MEA with three catalyst layers has the highest value of RTE among the MEA performances of URFC,which is 100%at a current density of 4 mA·cm-2.
基金supported by the National Key R&D Program of China(Grant No.2023YFB2408000).
文摘Layered materials,such as graphite and molybdenum disulfide,are promising for electrode materials and microelectronic devices due to their excellent ion-intercalating properties.However,the intercalation and de-intercalation of ions,causing structural deformation and material property variations,would affect battery performance and alter external field responses.The complex problem coupling multiphysics is significant for study and poses a crucial research challenge.This paper reviews the coupling between mechanics,electrochemistry,and electrics during the reaction process,including in situ experimental characterization,theoretical modeling,and design considerations at various scales.Current research has focused on experimental observations beyond the nanoscale and continuum phenomenological models.Further advancements in characterizing layered structural evolution,electron cloud interactions at the atomic level,and developing physics-based multi-field models are essential.
基金supported by the National Natural Science Foundation of China(Grant No.11872236).
文摘The largely bending bilayer electrode model battery has been widely used to measure the mechanical properties of composite electrode materials.The assumption used in the method that lithium is uniformly distributed in the active layer lacks quantitative evaluation,and the uniformity of concentration distribution is crucial for accurate in-situ measurements of concentration-related material properties and stress in bilayer electrodes.Therefore,this paper proposes a mechanical-electrochemical coupled model to study the lithium concentration distribution in the active layer during lithiation.This model includes lithium concentration diffusion and active layer deformation.By comparing experimental and simulated curvature evolution of the active layer during lithiation and delithiation,the reliability of this simulation model is verified.We then derive the precise concentration distribution inside the active layer and suggest using relative error to quantitatively evaluate the uniformity of lithium concentration in the active layer.Results show that a low relative error in lithium concentration can be achieved in the middle region of the active layer.Additionally,the effects of different rates and geometric parameters on the lithium concentration distribution in the active layer are discussed.Results indicate that reduced rates,thinner active layers,shorter active layer lengths,and increased spacing between the working and counter electrodes can lead to a more uniform distribution of lithium concentration in the active layer.These insights help improve experimental methods and equipment,promoting uniform distribution of lithium in the active layer and enhancing measurement accuracy.
基金supported by the Research Fund of Jianghan Univer-sity(2024JCYJ02)the Graduate Scientific Research Foundation of Jianghan University(KYCXJJ202428)+1 种基金the Excellent Discipline Cultiva-tion Project funded by Jianghan University(2023XKZ013)the Na-tional Natural Science Foundation of China(Grant No.22179052).
文摘Lithium (Li) metal batteries (LMBs) featuring ultrahigh energy densities are expected as ones of the mostprominent devices for future energy storage applications. Nevertheless, the practical application of LMBs is stillplagued by the poor interfacial stability of Li metal anode. Inorganic-rich interlayer derived from anion decom-positionin advanced liquid electrolytes is demonstrated as an efficient approach to stabilize the Li metal anode,however, is electrolyte-dependent with limited application conditions due to inappropriate electrolyte properties.Herein, an efficient structuration strategy is proposed to fabricate an electrolyte-independent and sustainedinorganic-rich layer, by embedding a type of functional anion aggregates consisting of selected anions ionicallybonded to polymerized cation clusters. The anion aggregates can progressively release anions to react with Liþand form key components boosting the structural stability and Liþ transfer ability of the artificial layer uponcycling. This self-reinforcing working mechanism endows the artificial layer with a sustained inorganic-richnature and promising Li protective ability during long-term cycling, while the electrolyte-independent propertyenables its applications in LMBs using conventional low concentration electrolytes and all-solid-state LMBs withsignificantly enhanced performances. This strategy establishes an alternative designing route of Li protectivelayers for reliable LMBs.
基金Project(50721003)supported by the National Natural Science Foundation of ChinaProject(07JJ6082)supported by the Natural Science Foundation of Hunan Province,ChinaProject supported by the Open Project of State Key Laboratory of Powder Metallurgy in Central South University,China
文摘Layered Li[Ni1/3Co1/3Mn1/3]O2 was synthesized with complex metal hydroxide precursors that were prepared by a co-precipitation method.The influence of coordination between ammonia and transition-metal cations on the structural and electrochemical properties of the Li[Ni1/3Co1/3Mn1/3]O2 materials was studied.It is found that when the molar ratio of ammonia to total transition-metal cations is 2.7：1,uniform particle size distribution of the complex metal hydroxide is observed via scanning electron microscopy.The average particle size of Li[Ni1/3Co1/3Mn1/3]O2 materials was measured to be about 500 nm,and the tap-density was measured to be approximately 2.37 g/cm3,which is comparable with that of commercialized LiCoO2.XRD analysis indicates that the presently synthesized Li[Ni1/3Co1/3Mn1/3]O2 has a hexagonal layered-structure.The initial discharge capacity of the Li[Ni1/3Co1/3Mn1/3]O2 positive-electrode material is determined to be 181.5 mA·h/g using a Li/Li[Ni1/3Co1/3Mn1/3]O2 cell operated at 0.1C in the voltage range of 2.8-4.5 V.The discharge capacity at the 50th cycle at 0.5C is 170.6 mA·h/g.
基金Project(2010ZCO51)supported by Natural Science Foundation of Yunnan ProvinceProject supported by Analysis and Testing Foundation(2009-041)Starting Research Fund(14118245)from Kunming University of Science and Technology
文摘As an improvement on the conventional two-layer electrode （active material layerlcurrent collector）, a novel sandwich-like three-layer electrode （conductive layerlactive material layertcurrent collector） for cathode material LiFePO4/C was introduced in order to improve its electrochemical performance. LiFePO4/C in the three-layer electrode exhibited superior rate capability in comparison with that in the two-layer electrode in accordance with charge-discharge examination. Cyclic voltammetry and electrochemical impedance spectroscopy indicated that Fe3＋/Fe2＋ redox couple for LiFePO4 in the three-layer electrode displayed faster kinetics, better reversibility and much lower charge transfer resistance than that in the two-layer electrode in electrochemical process. For three-layer electrode, the holes in the surface of active material layer were filled by smaller acetylene black grains, which formed electrical connections and provided more pathways to electron transport to/from LiFePO4/C particles exposed to the bulk electrolyte.
