Mm0.3Ml0.7Ni3.55Co0.75Mn0.4-Al0.3 alloy has high chemical activity and favorable plateaus pressure. Mg2Ni is in favor of high hydrogen storage capacity and low weight, but it is difficult to be activated. In order to ...Mm0.3Ml0.7Ni3.55Co0.75Mn0.4-Al0.3 alloy has high chemical activity and favorable plateaus pressure. Mg2Ni is in favor of high hydrogen storage capacity and low weight, but it is difficult to be activated. In order to improve the capacity and cycle performances of hydrogen-storage alloy electrodes, Mm0.3Ml0.7Ni3.55Co0.75Mn0.4-Al0.3-x%Mg2Ni(x=0, 5, 10, 30) composite hydrogen storage alloys prepared by two-step re-melting were investigated in this work. The influences of Mg2Ni content on the cycle stabilities were analyzed by electrochemical methods. It was observed by XRD that the main phase of all the alloys is LaNi5 and the crystal lattice parameters of LaNi5 are changed with the increasing of x value, i.e, a-axis and unit cell volume decrease and c-axis decreases nonlinearly. The c-axis of alloy with x=5 is larger than the others. With the increasing of x value, capacity retentions of the composite hydrogen storage alloys rise from 66.21% while x=0 to 82.04% while x=10, but the capacity retention of the composite alloy with 30% Mg2Ni declines because of its decreasing axial ratio. More over, the composite alloy with 5% Mg2Ni shows the best cycle stability and higher discharge capacity, and it is an appropriate candidate for battery materials.展开更多
La-Mg-Ni system (PuNi3-type) hydrogen storage alloys La0.7Mg0.3Ni2.55-xCo0.45Mx (M=Fe, Cu, Al; x=0, 0.1) were prepared by casting and rapid quenching. Aiming to improve the cycle stabilities of the alloys, Ni in the a...La-Mg-Ni system (PuNi3-type) hydrogen storage alloys La0.7Mg0.3Ni2.55-xCo0.45Mx (M=Fe, Cu, Al; x=0, 0.1) were prepared by casting and rapid quenching. Aiming to improve the cycle stabilities of the alloys, Ni in the alloy was partly substituted by Fe, Cu and Al. The effects of the substitution of Fe, Cu and Al for Ni and the rapid quenching on the microstructures and electrochemical properties of the alloys were investigated in detail. The results obtained by XRD, SEM and TEM indicate that the element substitution has no influence on the phase compositions of the alloys, but it changes the phase abundances of the alloys. Particularly, the substitution of Al and Cu obviously increases the amount of the LaNi2 phase. The substitution of Al and Fe leads to a great refinement of the as-quenched alloy′s grains. The substitution of Al strongly restrains the formation of the amorphous in the as-quenched alloy, but the substitution of Fe and Cu is quite helpful for the formation of an amorphous phase. The effects of the substitution of Fe, Cu and Al on the cycle stabilities of the as-cast and quenched alloys are different. The positive impact of the substitution elements on the cycle stabilities of the as-cast alloys is ranked in proper order Al>Fe>Cu, and for as-quenched alloys, the order is Fe>Al>Cu. Rapid quenching engenders an unconscious influence on the phase composition, but it markedly enhances the cycle stabilities of the alloys.展开更多
Iron-chromium flow batteries(ICRFBs)have emerged as an ideal large-scale energy storage device with broad application prospects in recent years.Enhancement of the Cr^(3+)/Cr^(2+)redox reaction activity and inhibition ...Iron-chromium flow batteries(ICRFBs)have emerged as an ideal large-scale energy storage device with broad application prospects in recent years.Enhancement of the Cr^(3+)/Cr^(2+)redox reaction activity and inhibition of the hydrogen evolution side reaction(HER)are essential for the development of ICRFBs and require a novel catalyst design.However,elucidating the underlying mechanisms for modulating catalyst behaviors remains an unresolved challenge.Here,we show a novel precisely controlled preparation of a novel thermal-treated carbon cloth electrode with a uniform deposit of low-cost indium catalyst particles.The density functional theory analysis reveals the In catalyst has a significant adsorption effect on the reactants and improves the redox reaction activity of Cr^(3+)/Cr^(2+).Moreover,H+is more easily absorbed on the surface of the catalyst with a high migration energy barrier,thereby inhibiting the occurrence of HER.The assembled ICRFBs have an average energy efficiency of 83.91%at 140 mA cm^(-2),and this method minimizes the electrodeposition process and cleans the last obstacle for industry long cycle operation requirements.The ICRFBs exhibit exceptional long-term stability with an energy efficiency decay rate of 0.011%per cycle at 1000 cycles,the lowest ICRFBs reported so far.Therefore,this study provides a promising strategy for developing ICRFBs with low costs and long cycle life.展开更多
To satisfy the demands of modern society for high-energy–density sulfide-based all-solid-state lithium batteries(ASSLBs),Ni-rich cathode materials have gained much attention for their high capacity and energy density...To satisfy the demands of modern society for high-energy–density sulfide-based all-solid-state lithium batteries(ASSLBs),Ni-rich cathode materials have gained much attention for their high capacity and energy density.However,their practical deployment is hindered by accelerated interface degradation and capacity decay originating from surface oxygen release and lattice oxygen activation during prolonged cycling.In this study,Ti_(x)NbB_((1−x))C_(2)was successfully coated on the surface of LiNi_(0.94)Co_(0.05)Mn_(0.01)O_(2).Density functional theory(DFT)calculations first elucidate a“point-to-point”anchoring mechanism where each surface oxygen atom coordinates with single species(Ti/Nb/B)offered by Ti_(x)NbB_((1−x))C_(2),which forms robust O–M bonds and sustain a stable interface structure.The electron energy loss spectroscopy(EELS)reveals the segregation of Ti/Nb toward subsurface layers during cycling,creating an optimized lattice oxygen coordination environment and suppressing oxygen activation.The dual oxygen stabilization mechanism dramatically improves the reversibility of phase transition and the structural stability of the Ni-rich cathode materials.Moreover,Ti_(x)NbB_((1−x))C_(2)as the protective layer decreases mechanical strain and suppresses the parasitic reactions.Consequently,the engineered cathode delivers 91%capacity retention after 1000 cycles at 0.3 C,suggesting excellent cycling stability.The research delivers a new design philosophy for the coating layer that can stabilize surface oxygen.Furthermore,the atomistic understanding of the structure–property relationship of the Ni-rich cathode materials provides valuable guidance for the future design of new cathode materials with superior structural stability in ASSLBs.展开更多
Lithium-selenium(Li-Se)batteries have attracted considerable attentions for next-generation energy storage systems owing to high volumetric capacity of 3265 m Ah cm^(-3) and excellent electronic conductivity(~10^(-5)S...Lithium-selenium(Li-Se)batteries have attracted considerable attentions for next-generation energy storage systems owing to high volumetric capacity of 3265 m Ah cm^(-3) and excellent electronic conductivity(~10^(-5)S cm^(-1))of selenium.However,the shuttling effect and capacity fading prevent their wide applications.Herein we report a low-cost strategy for scalable fabrication of lignin derived hierarchical porous carbon(LHPC)as a new high-loading Se host for high-capacity and long-term cycling Li-Se batteries in carbonate electrolyte.The resulting LHPC exhibits three-dimensional(3D)hierarchically porous structure,high specific surface area of 1696 m^(2) g^(-1),and hetero-atom doping(O,S),which can effectively confine the Se particles into the micropores,and meanwhile,offer effective chemical binding sites for selenides from hetero-atoms(O,S).As a result,our Li-Se batteries based on Se@LHPC demonstrate high capacity of 450 m Ah g^(-1) at 0.5 C after 500 cycles,with a low capacity fading rate of only 0.027%.The theoretical simulation confirmed the strong affinity of selenides on the O and S sites of LHPC effectively mitigating the Se losing.Therefore,our strategy of using lignin as the low-cost precursor of hierarchically porous carbon for high-loading Se host offers new opportunities for high-capacity and long-life Li-Se batteries.展开更多
In order to improve the cycle stability of La-Mg-Ni-Co type alloy electrode, rapid quenching technology was employed. The effects of rapid quenching on the microstructure and cycle stability of the alloy were investig...In order to improve the cycle stability of La-Mg-Ni-Co type alloy electrode, rapid quenching technology was employed. The effects of rapid quenching on the microstructure and cycle stability of the alloy were investigated. The obtained results show that the La2Mg(Ni0.85Co0.15)9M0.1 (M=B, Cr) alloy electrodes are composed of (La, Mg)Ni3 phase, LaNi5 phase and a small amount of the LaNi2 phase. A trace of the Ni2B phase exists in the as-cast MB alloy, and the Ni2B phase in the alloy nearly disappears after rapid quenching. Rapid quenching technology can slightly improve the cycling life of the alloy. When the quenching rate increases from 0 m·s-1 (As-cast is defined as quenching rate of 0 m·s-1) to 30 m·s-1, the cycle lives of the MB, MCr alloys enhance from 86 and 87 cycles to 106 and 119 cycles, respectively. On the other hand, the average capacity decay rates of the MB, MCr alloys decrease from 1.7172 and 1.7178 mAh·g-1·cycle-1 to 1.5751 and 1.3060 mAh·g-1·cycle-1 after 86 charge-discharges cycling, respectively.展开更多
A Si/Sn/SiOC/graphite(SSSG) composite with high efficiency and long-term cycling stability was synthesized by a cost-effective and scalable method, including the processes of mechanical milling and pyrolysis. The comp...A Si/Sn/SiOC/graphite(SSSG) composite with high efficiency and long-term cycling stability was synthesized by a cost-effective and scalable method, including the processes of mechanical milling and pyrolysis. The composite was characterized by X-ray diffraction(XRD),scanning electron microscope(SEM) and energy dispersive X-ray spectrometry(EDX). The electrochemical properties were investigated until the 25th cycle. As a result, the SSSG composite anode exhibits excellent long-term cycling stability and capacity. Such SSSG composite anode shows excellent cycling stability with a specific capacity of 568.2 mAh·g^(-1) and ~80% capacity retention over 25 cycles at 0.3C rate. The reasons for good electrochemical characteristics are considered that the SiOC net with favorable chemical stability acts as a skeleton to support and segregate Si/Sn nanostructures, and the graphitic mixing in the composite is used as conductive material to enhance the electrical conductivity in this composite. The results suggest that the design of this new structure has the potential to provide a way for the other functional composite materials.展开更多
Currently,the major challenge in terms of research on K-ion batteries is to ensure that they possess satisfactory cycle stability and specific capacity,especially in terms of the intrinsically sluggish kinetics induce...Currently,the major challenge in terms of research on K-ion batteries is to ensure that they possess satisfactory cycle stability and specific capacity,especially in terms of the intrinsically sluggish kinetics induced by the large radius of K+ions.Here,we explore high-performance K-ion half/full batteries with high rate capability,high specific capacity,and extremely durable cycle stability based on carbon nanosheets with tailored N dopants,which can alleviate the change of volume,increase electronic conductivity,and enhance the K+ion adsorption.The as-assembled K-ion half-batteries show an excellent rate capability of 468 mA h g^(-1)at 100 mA g^(-1),which is superior to those of most carbon materials reported to date.Moreover,the as-assembled half-cells have an outstanding life span,running 40,000 cycles over 8 months with a specific capacity retention of 100%at a high current density of 2000 mA g^(-1),and the target full cells deliver a high reversible specific capacity of 146 mA h g^(-1)after 2000 cycles over 2 months,with a specific capacity retention of 113%at a high current density of 500 mA g^(-1),both of which are state of the art in the field of K-ion batteries.This study might provide some insights into and potential avenues for exploration of advanced K-ion batteries with durable stability for practical applications.展开更多
All-solid-state lithium-sulfur batteries(ASSLSBs) have become one of the most potential candidates for the next-generation high-energy systems due to their intrinsic safety and high theoretical energy density.However,...All-solid-state lithium-sulfur batteries(ASSLSBs) have become one of the most potential candidates for the next-generation high-energy systems due to their intrinsic safety and high theoretical energy density.However, PEO-based ASSLSBs face the dilemma of insufficient Coulombic efficiency and long-term stability caused by the coupling problems of dendrite growth of anode and polysulfide shuttle of cathode. In this work, 1,3,5-trioxane(TOX) is used as a functional additive to design a PEO-based composite solidstate electrolyte(denoted as TOX-CSE), which realizes the stable long-term cycle of an ASSLSB. The results show that TOX can in-situ decompose on the anode to form a composite solid electrolyte interphase(SEI) layer with rich-organic component. It yields a high average modulus of 5.0 GPa, greatly improving the mechanical stability of the SEI layer and thus inhibiting the growth of dendrites. Also,the robust SEI layer can act as a barrier to block the side reaction between polysulfides and lithium metal.As a result, a Li-Li symmetric cell assembled with a TOX-CSE exhibits prolonged cycling stability over 2000 h at 0.2 m A cm^(-2). The ASSLSB also shows a stable cycling performance of 500 cycles at 0.5 C.This work reveals the structure–activity relationship between the mechanical property of interface layer and the battery's cycling stability.展开更多
Hexagonal MnMX-based(M=Co or Ni,X=Si or Ge)alloys exhibit giant reversible barocaloric effects.However,giant volume expansion would result in the as-cast MnMX ingots fragmenting into powders,and inevitably bring the d...Hexagonal MnMX-based(M=Co or Ni,X=Si or Ge)alloys exhibit giant reversible barocaloric effects.However,giant volume expansion would result in the as-cast MnMX ingots fragmenting into powders,and inevitably bring the deterioration of mechanical properties and formability.Grain fragmentation can bring degradation of structural transformation entropy change during cyclic application and removal of pressure.In this paper,giant reversible barocaloric effects with high thermal cycle stability can be achieved in the epoxy bonded(MnCoGe)0.96(CuCoSn)0.04 composite.Giant reversible isothermal entropy change of 43.0 J·kg^(−1)·K^(−1) and adiabatic temperature change from barocaloric effects(ΔT_(BCE))of 15.6 K can be obtained within a wide temperature span of 30 K at 360 MPa,which is mainly attributed to the integration of the change in the transition temperature driven by pressure of−101 K·GPa^(−1) and suitable thermal hysteresis of 11.1 K.Further,the variation of reversibleΔ_(TBCE) against the applied hydrostatic pressure reaches up to 43 K·GPa^(−1),which is at the highest level among the other reported giant barocaloric compounds.More importantly,after 60 thermal cycles,the composite does not break and the calorimetric curves coincide well,demonstrating good thermal cycle stability.展开更多
Silicon(Si)is a potential high-capacity anode material for the next-generation lithium-ion battery with high energy density.However,Si anodes suff er from severe interfacial chemistry issues,such as side reactions at ...Silicon(Si)is a potential high-capacity anode material for the next-generation lithium-ion battery with high energy density.However,Si anodes suff er from severe interfacial chemistry issues,such as side reactions at the electrode/electrolyte interface,leading to poor electrochemical cycling stability.Herein,we demonstrate the fabrication of a conformal fl uorine-containing carbon(FC)layer on Si particles(Si-FC)and its in situ electrochemical conversion into a LiF-rich carbon layer above 1.5 V(vs.Li^(+)/Li).The as-formed LiF-rich carbon layer not only isolates the active Si and electrolytes,leading to the suppression of side reactions,but also induces the formation of a robust solid-electrolyte interface(SEI),leading to the stable interfacial chemistry of as-designed Si-FC particles.The Si-FC electrode has a high initial Coulombic effi ciency(CE)of 84.8%and a high reversible capacity of 1450 mAh/g at 0.4 C(1000 mA/g)for 300 cycles.In addition,a hybrid electrode consisting of 85 wt%graphite and 15 wt%Si-FC,and mass 2.3 mg/cm^(2) loading delivers a high areal capacity of 2.0 mAh/cm^(2) and a high-capacity retention of 93.2%after 100 cycles,showing the prospects for practical use.展开更多
Aqueous zinc-ion batteries(AZIBs)are gaining attention owing to their affordability,high safety,and high energy density,making them a promising solution for large-scale energy storage.However,their performance is hamp...Aqueous zinc-ion batteries(AZIBs)are gaining attention owing to their affordability,high safety,and high energy density,making them a promising solution for large-scale energy storage.However,their performance is hampered by the instability of both the anode-electrolyte interface and the cathode-electrolyte interface.The use of sodium gluconate(SG),an organic sodium salt with multiple hydroxyl groups,as an electrolyte additive is suggested.Experimental and theoretical analyses demonstrate that Na^(+)from SG can intercalate and deintercalate within the associated V_(2)O_(5) cathode during in situ electrochemical processes.This action supports the layered structure of V_(2)O_(5),prevents structural collapse and phase transitions,and enhances Zn^(2+)diffusion kinetics.Additionally,the gluconate anion disrupts the original Zn^(2+)solvation structure,mitigates water-induced side reactions,and suppresses Zn dendrite growth.The synchronous regulation of both the V_(2)O_(5) cathode and Zn anode by the SG additive leads to considerable performance improvements.Zn‖Zn symmetric batteries demonstrate a cycle life exceeding 2800 h at 0.5 mA cm^(-2)and 1 mAh cm^(-2).In Zn‖V_(2)O_(5) full batteries,a high specific capacity of 288.92 mAh g^(-1)and capacity retention of 82.29%are maintained over 1000 cycles at a current density of 2 A g^(-1).This multifunctional additive strategy offers a new pathway for the practical application of AZIBs.展开更多
TiFe alloys are AB-based hydrogen storage materials with unique characteristics and a wide range of applications.However,the presence of impurity gases(such as O_(2),CO,CO_(2),and CH4)has a considerable impact on the ...TiFe alloys are AB-based hydrogen storage materials with unique characteristics and a wide range of applications.However,the presence of impurity gases(such as O_(2),CO,CO_(2),and CH4)has a considerable impact on the hydrogen storage capacity and kinetics of TiFe alloys,drastically limiting their practical application in hydrogen storage.Consequently,in this study,we investigated the hydrogen absorption kinetics and cycling performance of the TiFe_(0.9) alloy in the presence of common impurity gases(including CH4,CO,CO_(2),and O_(2))and determined the corresponding poisoning mechanisms.Specifically,we found that CH4 did not react with the alloy but acted through physical coverage.In contrast,CO and CO_(2) occupy the active sites for H_(2),significantly impeding the dissociation and absorption of H_(2).In addition,O_(2) reacts directly with the alloy to form a passivating layer that prevents hydrogen absorption.These findings were fur-ther corroborated by in situ Fourier transform infrared spectrometry(FTIR)and density functional theory(DFT).The relationship between the adsorption energies of the impurity gases and hydrogen obtained through DFT calculations complements the experimental results.Un-derstanding these poisoning behaviors is crucial for designing Ti-based high-entropy hydrogen storage alloy alloys with enhanced resist-ance to poisoning.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
Aqueous sodium-ion batteries(ASIBs) offer significant advantages for energy storage on a large scale,attributed to their economical cost,secure operatio n,and eco-friend ly natu re.Among the leading cathode materials ...Aqueous sodium-ion batteries(ASIBs) offer significant advantages for energy storage on a large scale,attributed to their economical cost,secure operatio n,and eco-friend ly natu re.Among the leading cathode materials for ASIBs,Na_(3)V_(2)(PO_(4))_(3)(NVP) exhibits excellent structural stability and a high Na+diffusion coefficient,making it a promising option.However,the high solubility of vanadium-based materials in aqueous electrolytes engenders suboptimal cycling stability for Na_(3)V_(2)(PO_(4))_(3),constraining its application in ASIBs.Herein,the Cr-substituted Na_(3)V_(1.3)Cr_(0.7)(PO_(4))3@C(NV_(1.3)Cr_(0.7)P) cathode material was synthesized via a simple sol-gel method.It is found that Cr substitution reduces the cell parameters of NV_(1.3)Cr_(0.7)P,effectively reinforcing the crystal structure.Furthermore,NV_(1.3)Cr_(0.7)P alters the Na^(+)insertion/extraction mechanism,transforming the typical two-phase reaction between Na_(1)V_(2)(PO_(4))_(3)and Na_(3)V_(2)(PO_(4))3into continuous solid-solution reactions with stable intermediates.The Cr substitution diminishes the sodium-ion diffusion energy barrier in NV_(1.3)Cr_(0.7)P,leading to smoother Na+insertion and extraction processes.Consequently,NV_(1.3)Cr_(0.7)P exhibits impressive cycling stability,retaining 74.8% of its capacity after 5,000 cycles at a current density of 5 A g^(-1),along with an outstanding rate performance of 79,2% at 10 A g^(-1).This work elucidates the stable Na^(+)insertion/extraction processes in Cr-substituted NV_(1.3)Cr_(0.7)P,offering insights into the application of vanadium-based materials in aqueous sodium-ion batteries.展开更多
Lithium metal batteries(LMBs)are emerging as a promising energy storage solution owing to their high energy density and specific capacity.However,the non-uniform plating of lithium and the potential rupture of the sol...Lithium metal batteries(LMBs)are emerging as a promising energy storage solution owing to their high energy density and specific capacity.However,the non-uniform plating of lithium and the potential rupture of the solid-electrolyte interphase(SEI)during extended cycling use may result in dendrite growth,which can penetrate the separator and pose significant short-circuit risks.Forming a stable SEI is essential for the long-term operation of the batteries.Fluorine-rich SEI has garnered significant attention for its ability to effectively passivate electrodes,regulate lithium deposition,and inhibit electrolyte corrosion.Understanding the structural components and preparation methods of existing fluorinated SEI is crucial for optimizing lithium metal anode performance.This paper reviews the research on optimizing LiF passivation interfaces to protect lithium metal anodes.It focuses on four types of compositions in fluorinated SEI that work synergistically to enhance SEI performance.For instance,combining compounds with LiF can further enhance the mechanical strength and ionic conductivity of the SEI.Integrating metals with LiF significantly improves electrochemical performance at the SEI/anode interface,with a necessary focus on reducing electron tunneling risks.Additionally,incorporating polymers with LiF offers balanced improvements in interfacial toughness and ionic conductivity,though maintaining structural stability over long cycles remains a critical area for future research.Although alloys combined with LiF increase surface energy and lithium affinity,challenges such as dendrite growth and volume expansion persist.In summary,this paper emphasizes the crucial role of interfacial structures in LMBs and offers comprehensive guidance for future design and development efforts in battery technology.展开更多
Aqueous supercapacitors(SCs)exhibit exceptional electrochemical characteristics,including extended cycle stability and high-power density,making them highly promising.Though their practical application and commerciali...Aqueous supercapacitors(SCs)exhibit exceptional electrochemical characteristics,including extended cycle stability and high-power density,making them highly promising.Though their practical application and commercialization are hindered by low energy density,we developed a high-performance,self-supporting SC electrode to address this limitation using nickel manganese layered double hydroxide(NiMn-LDH)directly synthesized on activated carbon cloth(ACC).This electrode achieved an extraordinary specific capacitance of 2838.8 F g^(-1)at a current density of 1 A g^(-1),with 70.3%retention at 30 A g^(-1)and 86.1%retention after 6,000 cycles at 15 A g^(-1),demonstrating its remarkable performance and durability.After being assembled into an asymmetric SCs(ASCs)device with the ACC negative electrode in 2M potassium hydroxide(KOH),a broad operating voltage window of 1.6 V with an energy density of up to 89.7 Wh kg^(-1)was achieved at a power density of 800.0 W kg^(-1).Furthermore,the device retained 89.30%of its initial capacitance after 10,000 cycles at 10 A g^(-1),with a nearperfect Coulombic efficiency close to 100%.The fishscale-like nanostructure effectively increases the active sites of the electrode to make sufficient full contact with the electrolyte,accelerating the transport of electrons/ions and enhancing its electrochemical performance.These findings emphasize the potential of NiMn-LDH for application in wearable and microscale energy storage devices.展开更多
Li-air batteries have attracted widespread attention due to their high theoretical energy density.However,safety and environmental challenges are significant in Li-air batteries based on organic liquid electrolytes,as...Li-air batteries have attracted widespread attention due to their high theoretical energy density.However,safety and environmental challenges are significant in Li-air batteries based on organic liquid electrolytes,as they are exposed to air.In this study,we synthesized a composite electrolyte membrane filled with garnet material using a casting method and successfully applied it to Li-air batteries.The polymer electrolyte composed of poly(vinylidene fluoride-hexafluoropropylene)(PVDF-HFP)filled with garnet LLZTO as an active filler(15-PHL CPE),which exhibited excellent flexibility,wide electrochemical window,high ion conductivity and good thermal stability.Furthermore,symmetric Li‖15-PHL CPE‖Li cells stably operate over 3500h at 0.1 mA cm^(-2)and 25℃.The assembled 15-PHL CPE-based Li-air battery reaches a stable cycling performance of 97 cycles at 200 mA g^(-1)with a well-maintained potential gap of1.93 V,which demonstrates promising application in Li-air batteries.展开更多
Lithium-sulfur(Li-S)batteries with high energy density suffer from the soluble lithium polysulfide species,Traditional metal sulfides containing a single metal element used as electrocatalysts for Li-S batteries commo...Lithium-sulfur(Li-S)batteries with high energy density suffer from the soluble lithium polysulfide species,Traditional metal sulfides containing a single metal element used as electrocatalysts for Li-S batteries commonly have limited catalytic abilities to improve battery performance.Herein,based on the Hume-Rothery rule and solvothermal method,the high-entropy sulfide NiCoCuTiVS_(x)derived from Co_(9)S_(8)was designed and synthesized,to realize the combination of small local strain and excellent catalytic performance.With all five metal elements(Ni,Co,Cu,Ti,and V)capable of chemical interactions with soluble polysulfides,NiCoCuTiVS_(x)exhibited strong chemical confinement of polysulfides and promoted fast kinetics for polysulfides conversion.Consequently,the S/NiCoCuTiVS_(x)cathode can maintain a high discharge capacity of 968.9 mA h g^(-1)after 200 cycles at 0.5 C and its capacity retention is 1.3 times higher than that of S/Co_(9)S_(8).The improved cycle stability can be attributed to the synergistic effect originating from the multiple metal elements,coupled with the reduced nucleation and activation barriers of Li_(2)S.The present work opens a path to explore novel electrocatalyst materials based on high entropy materials for the achievement of advanced Li-S batteries.展开更多
High-capacity Ni-rich layered cathodes LiNi_(x)CoyMn_(1-x-y)O_(2)(NCM)have been widely recognized as highly promising candidates for lithium-ion batteries(LIBs).However,NCM cathodes are suffered from sluggish Li-ion k...High-capacity Ni-rich layered cathodes LiNi_(x)CoyMn_(1-x-y)O_(2)(NCM)have been widely recognized as highly promising candidates for lithium-ion batteries(LIBs).However,NCM cathodes are suffered from sluggish Li-ion kinetics and fast capacity decay.Herein,the Nb/Ti co-doping strategy has been proposed by formation energy analysis to enhance the mechanical and chemical integrities of NCM cathode.Nb/Ti co-doping facilitates Li-ion transport of NCM cathode for boosting the rate ability.Furthermore,the structure stability is prominently improved for the stronger Nb–O and Ti–O bonds,resulting from the suppressed sharp contraction of c axis,inhibited microcracks formation,and alleviated electrolyte corrosion.Inspired by the synergistic effect of Nb/Ti co-doping,the modified NCM exhibits superior comprehensive electrochemical performances.The Nb/Ti co-doping NCM exhibits an increased discharge capacity of 144.3 m Ah/g at10 C and an outstanding capacity retention remained 92.7%after 300 cycles at 1 C.This work offers a promising approach to developing high-performance cathode materials.展开更多
基金Project Supported bythe Talents Development Foundation of Inner Mongolia Autonomous Region (200608)
文摘Mm0.3Ml0.7Ni3.55Co0.75Mn0.4-Al0.3 alloy has high chemical activity and favorable plateaus pressure. Mg2Ni is in favor of high hydrogen storage capacity and low weight, but it is difficult to be activated. In order to improve the capacity and cycle performances of hydrogen-storage alloy electrodes, Mm0.3Ml0.7Ni3.55Co0.75Mn0.4-Al0.3-x%Mg2Ni(x=0, 5, 10, 30) composite hydrogen storage alloys prepared by two-step re-melting were investigated in this work. The influences of Mg2Ni content on the cycle stabilities were analyzed by electrochemical methods. It was observed by XRD that the main phase of all the alloys is LaNi5 and the crystal lattice parameters of LaNi5 are changed with the increasing of x value, i.e, a-axis and unit cell volume decrease and c-axis decreases nonlinearly. The c-axis of alloy with x=5 is larger than the others. With the increasing of x value, capacity retentions of the composite hydrogen storage alloys rise from 66.21% while x=0 to 82.04% while x=10, but the capacity retention of the composite alloy with 30% Mg2Ni declines because of its decreasing axial ratio. More over, the composite alloy with 5% Mg2Ni shows the best cycle stability and higher discharge capacity, and it is an appropriate candidate for battery materials.
基金National Natural Science Foundation of China (50642033)Key Technologies R&D Programof Inner Mongolia ,China (20050205)Higher Education Science Research Project of In-ner Mongolia ,China (NJ05064)
文摘La-Mg-Ni system (PuNi3-type) hydrogen storage alloys La0.7Mg0.3Ni2.55-xCo0.45Mx (M=Fe, Cu, Al; x=0, 0.1) were prepared by casting and rapid quenching. Aiming to improve the cycle stabilities of the alloys, Ni in the alloy was partly substituted by Fe, Cu and Al. The effects of the substitution of Fe, Cu and Al for Ni and the rapid quenching on the microstructures and electrochemical properties of the alloys were investigated in detail. The results obtained by XRD, SEM and TEM indicate that the element substitution has no influence on the phase compositions of the alloys, but it changes the phase abundances of the alloys. Particularly, the substitution of Al and Cu obviously increases the amount of the LaNi2 phase. The substitution of Al and Fe leads to a great refinement of the as-quenched alloy′s grains. The substitution of Al strongly restrains the formation of the amorphous in the as-quenched alloy, but the substitution of Fe and Cu is quite helpful for the formation of an amorphous phase. The effects of the substitution of Fe, Cu and Al on the cycle stabilities of the as-cast and quenched alloys are different. The positive impact of the substitution elements on the cycle stabilities of the as-cast alloys is ranked in proper order Al>Fe>Cu, and for as-quenched alloys, the order is Fe>Al>Cu. Rapid quenching engenders an unconscious influence on the phase composition, but it markedly enhances the cycle stabilities of the alloys.
基金support from the National Natural Science Foundation of China(No.22308378,22308380,22393963)the Science Foundation of China University of Petroleum,Beijing(No.2462023XKBH005,ZX20230078).
文摘Iron-chromium flow batteries(ICRFBs)have emerged as an ideal large-scale energy storage device with broad application prospects in recent years.Enhancement of the Cr^(3+)/Cr^(2+)redox reaction activity and inhibition of the hydrogen evolution side reaction(HER)are essential for the development of ICRFBs and require a novel catalyst design.However,elucidating the underlying mechanisms for modulating catalyst behaviors remains an unresolved challenge.Here,we show a novel precisely controlled preparation of a novel thermal-treated carbon cloth electrode with a uniform deposit of low-cost indium catalyst particles.The density functional theory analysis reveals the In catalyst has a significant adsorption effect on the reactants and improves the redox reaction activity of Cr^(3+)/Cr^(2+).Moreover,H+is more easily absorbed on the surface of the catalyst with a high migration energy barrier,thereby inhibiting the occurrence of HER.The assembled ICRFBs have an average energy efficiency of 83.91%at 140 mA cm^(-2),and this method minimizes the electrodeposition process and cleans the last obstacle for industry long cycle operation requirements.The ICRFBs exhibit exceptional long-term stability with an energy efficiency decay rate of 0.011%per cycle at 1000 cycles,the lowest ICRFBs reported so far.Therefore,this study provides a promising strategy for developing ICRFBs with low costs and long cycle life.
基金supported by the National Natural Science Foundation of China(21203008,21975025,12274025,22372008,and 22179007)Hainan Province Science and Technology Special Fund(ZDYF2021SHFZ232 and ZDYF2023GXJS022)Hainan Province Postdoctoral Science Foundation(300333)。
文摘To satisfy the demands of modern society for high-energy–density sulfide-based all-solid-state lithium batteries(ASSLBs),Ni-rich cathode materials have gained much attention for their high capacity and energy density.However,their practical deployment is hindered by accelerated interface degradation and capacity decay originating from surface oxygen release and lattice oxygen activation during prolonged cycling.In this study,Ti_(x)NbB_((1−x))C_(2)was successfully coated on the surface of LiNi_(0.94)Co_(0.05)Mn_(0.01)O_(2).Density functional theory(DFT)calculations first elucidate a“point-to-point”anchoring mechanism where each surface oxygen atom coordinates with single species(Ti/Nb/B)offered by Ti_(x)NbB_((1−x))C_(2),which forms robust O–M bonds and sustain a stable interface structure.The electron energy loss spectroscopy(EELS)reveals the segregation of Ti/Nb toward subsurface layers during cycling,creating an optimized lattice oxygen coordination environment and suppressing oxygen activation.The dual oxygen stabilization mechanism dramatically improves the reversibility of phase transition and the structural stability of the Ni-rich cathode materials.Moreover,Ti_(x)NbB_((1−x))C_(2)as the protective layer decreases mechanical strain and suppresses the parasitic reactions.Consequently,the engineered cathode delivers 91%capacity retention after 1000 cycles at 0.3 C,suggesting excellent cycling stability.The research delivers a new design philosophy for the coating layer that can stabilize surface oxygen.Furthermore,the atomistic understanding of the structure–property relationship of the Ni-rich cathode materials provides valuable guidance for the future design of new cathode materials with superior structural stability in ASSLBs.
基金financially supported by the National Key R&D Program of China(Grants 2016YBF0100100,2016YFA0200200)the National Natural Science Foundation of China(Grants 51872283,21805273)+1 种基金the Liaoning Bai Qian Wan Talents Program,Natural Science Foundation of Liaoning Province,Joint Research Fund Liaoning-Shenyang National Laboratory for Materials Science(Grant 20180510038)the Liao Ning Revitalization Talents Program(Grant XLYC1807153),DICP(DICP ZZBS201708,DICP ZZBS201802,DICP I202032),DNL Cooperation Fund,CAS(DNL180310,DNL180308,DNL201912,and DNL201915),DICP&QIBEBT(Grant DICP&QIBEBT UN201702)。
文摘Lithium-selenium(Li-Se)batteries have attracted considerable attentions for next-generation energy storage systems owing to high volumetric capacity of 3265 m Ah cm^(-3) and excellent electronic conductivity(~10^(-5)S cm^(-1))of selenium.However,the shuttling effect and capacity fading prevent their wide applications.Herein we report a low-cost strategy for scalable fabrication of lignin derived hierarchical porous carbon(LHPC)as a new high-loading Se host for high-capacity and long-term cycling Li-Se batteries in carbonate electrolyte.The resulting LHPC exhibits three-dimensional(3D)hierarchically porous structure,high specific surface area of 1696 m^(2) g^(-1),and hetero-atom doping(O,S),which can effectively confine the Se particles into the micropores,and meanwhile,offer effective chemical binding sites for selenides from hetero-atoms(O,S).As a result,our Li-Se batteries based on Se@LHPC demonstrate high capacity of 450 m Ah g^(-1) at 0.5 C after 500 cycles,with a low capacity fading rate of only 0.027%.The theoretical simulation confirmed the strong affinity of selenides on the O and S sites of LHPC effectively mitigating the Se losing.Therefore,our strategy of using lignin as the low-cost precursor of hierarchically porous carbon for high-loading Se host offers new opportunities for high-capacity and long-life Li-Se batteries.
基金This work was financially supported by National Natural Science Foundations of China (No.50131040)Key Technologies R & D Program of Inner Mongolia (No.20050205)College Scientific Research Project of Inner Mongolia (No.NJ05064).
文摘In order to improve the cycle stability of La-Mg-Ni-Co type alloy electrode, rapid quenching technology was employed. The effects of rapid quenching on the microstructure and cycle stability of the alloy were investigated. The obtained results show that the La2Mg(Ni0.85Co0.15)9M0.1 (M=B, Cr) alloy electrodes are composed of (La, Mg)Ni3 phase, LaNi5 phase and a small amount of the LaNi2 phase. A trace of the Ni2B phase exists in the as-cast MB alloy, and the Ni2B phase in the alloy nearly disappears after rapid quenching. Rapid quenching technology can slightly improve the cycling life of the alloy. When the quenching rate increases from 0 m·s-1 (As-cast is defined as quenching rate of 0 m·s-1) to 30 m·s-1, the cycle lives of the MB, MCr alloys enhance from 86 and 87 cycles to 106 and 119 cycles, respectively. On the other hand, the average capacity decay rates of the MB, MCr alloys decrease from 1.7172 and 1.7178 mAh·g-1·cycle-1 to 1.5751 and 1.3060 mAh·g-1·cycle-1 after 86 charge-discharges cycling, respectively.
基金the National High Technology Research and Development Program of China(Nos.2011AA11A256,2013AA050903,and 2013AA050906)。
文摘A Si/Sn/SiOC/graphite(SSSG) composite with high efficiency and long-term cycling stability was synthesized by a cost-effective and scalable method, including the processes of mechanical milling and pyrolysis. The composite was characterized by X-ray diffraction(XRD),scanning electron microscope(SEM) and energy dispersive X-ray spectrometry(EDX). The electrochemical properties were investigated until the 25th cycle. As a result, the SSSG composite anode exhibits excellent long-term cycling stability and capacity. Such SSSG composite anode shows excellent cycling stability with a specific capacity of 568.2 mAh·g^(-1) and ~80% capacity retention over 25 cycles at 0.3C rate. The reasons for good electrochemical characteristics are considered that the SiOC net with favorable chemical stability acts as a skeleton to support and segregate Si/Sn nanostructures, and the graphitic mixing in the composite is used as conductive material to enhance the electrical conductivity in this composite. The results suggest that the design of this new structure has the potential to provide a way for the other functional composite materials.
基金National Natural Science Foundation of China,Grant/Award Numbers:51972178,52202061Hunan Provincial Nature Science Foundation,Grant/Award Number:2022JJ40068。
文摘Currently,the major challenge in terms of research on K-ion batteries is to ensure that they possess satisfactory cycle stability and specific capacity,especially in terms of the intrinsically sluggish kinetics induced by the large radius of K+ions.Here,we explore high-performance K-ion half/full batteries with high rate capability,high specific capacity,and extremely durable cycle stability based on carbon nanosheets with tailored N dopants,which can alleviate the change of volume,increase electronic conductivity,and enhance the K+ion adsorption.The as-assembled K-ion half-batteries show an excellent rate capability of 468 mA h g^(-1)at 100 mA g^(-1),which is superior to those of most carbon materials reported to date.Moreover,the as-assembled half-cells have an outstanding life span,running 40,000 cycles over 8 months with a specific capacity retention of 100%at a high current density of 2000 mA g^(-1),and the target full cells deliver a high reversible specific capacity of 146 mA h g^(-1)after 2000 cycles over 2 months,with a specific capacity retention of 113%at a high current density of 500 mA g^(-1),both of which are state of the art in the field of K-ion batteries.This study might provide some insights into and potential avenues for exploration of advanced K-ion batteries with durable stability for practical applications.
基金National Natural Science Foundation of China (Grant Nos. 22178125 and 21875071)。
文摘All-solid-state lithium-sulfur batteries(ASSLSBs) have become one of the most potential candidates for the next-generation high-energy systems due to their intrinsic safety and high theoretical energy density.However, PEO-based ASSLSBs face the dilemma of insufficient Coulombic efficiency and long-term stability caused by the coupling problems of dendrite growth of anode and polysulfide shuttle of cathode. In this work, 1,3,5-trioxane(TOX) is used as a functional additive to design a PEO-based composite solidstate electrolyte(denoted as TOX-CSE), which realizes the stable long-term cycle of an ASSLSB. The results show that TOX can in-situ decompose on the anode to form a composite solid electrolyte interphase(SEI) layer with rich-organic component. It yields a high average modulus of 5.0 GPa, greatly improving the mechanical stability of the SEI layer and thus inhibiting the growth of dendrites. Also,the robust SEI layer can act as a barrier to block the side reaction between polysulfides and lithium metal.As a result, a Li-Li symmetric cell assembled with a TOX-CSE exhibits prolonged cycling stability over 2000 h at 0.2 m A cm^(-2). The ASSLSB also shows a stable cycling performance of 500 cycles at 0.5 C.This work reveals the structure–activity relationship between the mechanical property of interface layer and the battery's cycling stability.
基金financially supported by the National Natural Science Foundation of China(Nos.52301248,52271166,52071071,and 52275567)the Foundational Research Project of Shanxi Province,China(Nos.202203021222201 and 202203021212304)+1 种基金PhD Research Startup Foundation of Taiyuan University of Science and Technology(No.20222057)PhD Research Startup Foundation of Shanxi Province,China(No.20232051)。
文摘Hexagonal MnMX-based(M=Co or Ni,X=Si or Ge)alloys exhibit giant reversible barocaloric effects.However,giant volume expansion would result in the as-cast MnMX ingots fragmenting into powders,and inevitably bring the deterioration of mechanical properties and formability.Grain fragmentation can bring degradation of structural transformation entropy change during cyclic application and removal of pressure.In this paper,giant reversible barocaloric effects with high thermal cycle stability can be achieved in the epoxy bonded(MnCoGe)0.96(CuCoSn)0.04 composite.Giant reversible isothermal entropy change of 43.0 J·kg^(−1)·K^(−1) and adiabatic temperature change from barocaloric effects(ΔT_(BCE))of 15.6 K can be obtained within a wide temperature span of 30 K at 360 MPa,which is mainly attributed to the integration of the change in the transition temperature driven by pressure of−101 K·GPa^(−1) and suitable thermal hysteresis of 11.1 K.Further,the variation of reversibleΔ_(TBCE) against the applied hydrostatic pressure reaches up to 43 K·GPa^(−1),which is at the highest level among the other reported giant barocaloric compounds.More importantly,after 60 thermal cycles,the composite does not break and the calorimetric curves coincide well,demonstrating good thermal cycle stability.
基金supported by the Innovation Fund of Wuhan National Laboratory for Optoelectronics of Huazhong University of Science and Technology.
文摘Silicon(Si)is a potential high-capacity anode material for the next-generation lithium-ion battery with high energy density.However,Si anodes suff er from severe interfacial chemistry issues,such as side reactions at the electrode/electrolyte interface,leading to poor electrochemical cycling stability.Herein,we demonstrate the fabrication of a conformal fl uorine-containing carbon(FC)layer on Si particles(Si-FC)and its in situ electrochemical conversion into a LiF-rich carbon layer above 1.5 V(vs.Li^(+)/Li).The as-formed LiF-rich carbon layer not only isolates the active Si and electrolytes,leading to the suppression of side reactions,but also induces the formation of a robust solid-electrolyte interface(SEI),leading to the stable interfacial chemistry of as-designed Si-FC particles.The Si-FC electrode has a high initial Coulombic effi ciency(CE)of 84.8%and a high reversible capacity of 1450 mAh/g at 0.4 C(1000 mA/g)for 300 cycles.In addition,a hybrid electrode consisting of 85 wt%graphite and 15 wt%Si-FC,and mass 2.3 mg/cm^(2) loading delivers a high areal capacity of 2.0 mAh/cm^(2) and a high-capacity retention of 93.2%after 100 cycles,showing the prospects for practical use.
基金supported by the Battery Energy Storage Testing Center of Chongqing through their provision of testing support and technical assistance。
文摘Aqueous zinc-ion batteries(AZIBs)are gaining attention owing to their affordability,high safety,and high energy density,making them a promising solution for large-scale energy storage.However,their performance is hampered by the instability of both the anode-electrolyte interface and the cathode-electrolyte interface.The use of sodium gluconate(SG),an organic sodium salt with multiple hydroxyl groups,as an electrolyte additive is suggested.Experimental and theoretical analyses demonstrate that Na^(+)from SG can intercalate and deintercalate within the associated V_(2)O_(5) cathode during in situ electrochemical processes.This action supports the layered structure of V_(2)O_(5),prevents structural collapse and phase transitions,and enhances Zn^(2+)diffusion kinetics.Additionally,the gluconate anion disrupts the original Zn^(2+)solvation structure,mitigates water-induced side reactions,and suppresses Zn dendrite growth.The synchronous regulation of both the V_(2)O_(5) cathode and Zn anode by the SG additive leads to considerable performance improvements.Zn‖Zn symmetric batteries demonstrate a cycle life exceeding 2800 h at 0.5 mA cm^(-2)and 1 mAh cm^(-2).In Zn‖V_(2)O_(5) full batteries,a high specific capacity of 288.92 mAh g^(-1)and capacity retention of 82.29%are maintained over 1000 cycles at a current density of 2 A g^(-1).This multifunctional additive strategy offers a new pathway for the practical application of AZIBs.
基金supported by the National Key Research&Development Program of China(No.2022YFB4004301)the National Natural Science Foundation of China(Nos.52201274 and 52307250)the Shaanxi Province key research and development plan,China(No.2024CY2-GJHX-53).
文摘TiFe alloys are AB-based hydrogen storage materials with unique characteristics and a wide range of applications.However,the presence of impurity gases(such as O_(2),CO,CO_(2),and CH4)has a considerable impact on the hydrogen storage capacity and kinetics of TiFe alloys,drastically limiting their practical application in hydrogen storage.Consequently,in this study,we investigated the hydrogen absorption kinetics and cycling performance of the TiFe_(0.9) alloy in the presence of common impurity gases(including CH4,CO,CO_(2),and O_(2))and determined the corresponding poisoning mechanisms.Specifically,we found that CH4 did not react with the alloy but acted through physical coverage.In contrast,CO and CO_(2) occupy the active sites for H_(2),significantly impeding the dissociation and absorption of H_(2).In addition,O_(2) reacts directly with the alloy to form a passivating layer that prevents hydrogen absorption.These findings were fur-ther corroborated by in situ Fourier transform infrared spectrometry(FTIR)and density functional theory(DFT).The relationship between the adsorption energies of the impurity gases and hydrogen obtained through DFT calculations complements the experimental results.Un-derstanding these poisoning behaviors is crucial for designing Ti-based high-entropy hydrogen storage alloy alloys with enhanced resist-ance to poisoning.
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financially supported by the Scientific and Technological Plan Project of Guizhou Province ([2024]054)Additional support came from the Industry and Education Combination Innovation Platform of Intelligent Manufacturing and Graduate Joint Training Base at Guizhou University (2020-520000-83-01324061)the Guizhou Engineering Research Center for Smart Services (2203-520102-04-04-298868)。
文摘Aqueous sodium-ion batteries(ASIBs) offer significant advantages for energy storage on a large scale,attributed to their economical cost,secure operatio n,and eco-friend ly natu re.Among the leading cathode materials for ASIBs,Na_(3)V_(2)(PO_(4))_(3)(NVP) exhibits excellent structural stability and a high Na+diffusion coefficient,making it a promising option.However,the high solubility of vanadium-based materials in aqueous electrolytes engenders suboptimal cycling stability for Na_(3)V_(2)(PO_(4))_(3),constraining its application in ASIBs.Herein,the Cr-substituted Na_(3)V_(1.3)Cr_(0.7)(PO_(4))3@C(NV_(1.3)Cr_(0.7)P) cathode material was synthesized via a simple sol-gel method.It is found that Cr substitution reduces the cell parameters of NV_(1.3)Cr_(0.7)P,effectively reinforcing the crystal structure.Furthermore,NV_(1.3)Cr_(0.7)P alters the Na^(+)insertion/extraction mechanism,transforming the typical two-phase reaction between Na_(1)V_(2)(PO_(4))_(3)and Na_(3)V_(2)(PO_(4))3into continuous solid-solution reactions with stable intermediates.The Cr substitution diminishes the sodium-ion diffusion energy barrier in NV_(1.3)Cr_(0.7)P,leading to smoother Na+insertion and extraction processes.Consequently,NV_(1.3)Cr_(0.7)P exhibits impressive cycling stability,retaining 74.8% of its capacity after 5,000 cycles at a current density of 5 A g^(-1),along with an outstanding rate performance of 79,2% at 10 A g^(-1).This work elucidates the stable Na^(+)insertion/extraction processes in Cr-substituted NV_(1.3)Cr_(0.7)P,offering insights into the application of vanadium-based materials in aqueous sodium-ion batteries.
基金support from the National Natural Science Foundation of China(No.U2333210)the Sichuan Science and Technology Program,China(No.21SYSX0011)。
文摘Lithium metal batteries(LMBs)are emerging as a promising energy storage solution owing to their high energy density and specific capacity.However,the non-uniform plating of lithium and the potential rupture of the solid-electrolyte interphase(SEI)during extended cycling use may result in dendrite growth,which can penetrate the separator and pose significant short-circuit risks.Forming a stable SEI is essential for the long-term operation of the batteries.Fluorine-rich SEI has garnered significant attention for its ability to effectively passivate electrodes,regulate lithium deposition,and inhibit electrolyte corrosion.Understanding the structural components and preparation methods of existing fluorinated SEI is crucial for optimizing lithium metal anode performance.This paper reviews the research on optimizing LiF passivation interfaces to protect lithium metal anodes.It focuses on four types of compositions in fluorinated SEI that work synergistically to enhance SEI performance.For instance,combining compounds with LiF can further enhance the mechanical strength and ionic conductivity of the SEI.Integrating metals with LiF significantly improves electrochemical performance at the SEI/anode interface,with a necessary focus on reducing electron tunneling risks.Additionally,incorporating polymers with LiF offers balanced improvements in interfacial toughness and ionic conductivity,though maintaining structural stability over long cycles remains a critical area for future research.Although alloys combined with LiF increase surface energy and lithium affinity,challenges such as dendrite growth and volume expansion persist.In summary,this paper emphasizes the crucial role of interfacial structures in LMBs and offers comprehensive guidance for future design and development efforts in battery technology.
基金financially supported by the National Natural Science Foundation of China(Nos.U22A20429 and 52261033)Xinjiang Uygur Autonomous Region Postgraduate Innovation Research Program and the Tianshan Innovation Team Program(No.XJ2022G070)
文摘Aqueous supercapacitors(SCs)exhibit exceptional electrochemical characteristics,including extended cycle stability and high-power density,making them highly promising.Though their practical application and commercialization are hindered by low energy density,we developed a high-performance,self-supporting SC electrode to address this limitation using nickel manganese layered double hydroxide(NiMn-LDH)directly synthesized on activated carbon cloth(ACC).This electrode achieved an extraordinary specific capacitance of 2838.8 F g^(-1)at a current density of 1 A g^(-1),with 70.3%retention at 30 A g^(-1)and 86.1%retention after 6,000 cycles at 15 A g^(-1),demonstrating its remarkable performance and durability.After being assembled into an asymmetric SCs(ASCs)device with the ACC negative electrode in 2M potassium hydroxide(KOH),a broad operating voltage window of 1.6 V with an energy density of up to 89.7 Wh kg^(-1)was achieved at a power density of 800.0 W kg^(-1).Furthermore,the device retained 89.30%of its initial capacitance after 10,000 cycles at 10 A g^(-1),with a nearperfect Coulombic efficiency close to 100%.The fishscale-like nanostructure effectively increases the active sites of the electrode to make sufficient full contact with the electrolyte,accelerating the transport of electrons/ions and enhancing its electrochemical performance.These findings emphasize the potential of NiMn-LDH for application in wearable and microscale energy storage devices.
基金supported by the National Natural Science Foundation of China(U2330124,22411560292,U20A2072,52072352,21875226)the Foundation for the Youth S&T Innovation Team of Sichuan Province(2020JDTD0035)Sichuan Science and Technology Program(2023ZYD0026)。
文摘Li-air batteries have attracted widespread attention due to their high theoretical energy density.However,safety and environmental challenges are significant in Li-air batteries based on organic liquid electrolytes,as they are exposed to air.In this study,we synthesized a composite electrolyte membrane filled with garnet material using a casting method and successfully applied it to Li-air batteries.The polymer electrolyte composed of poly(vinylidene fluoride-hexafluoropropylene)(PVDF-HFP)filled with garnet LLZTO as an active filler(15-PHL CPE),which exhibited excellent flexibility,wide electrochemical window,high ion conductivity and good thermal stability.Furthermore,symmetric Li‖15-PHL CPE‖Li cells stably operate over 3500h at 0.1 mA cm^(-2)and 25℃.The assembled 15-PHL CPE-based Li-air battery reaches a stable cycling performance of 97 cycles at 200 mA g^(-1)with a well-maintained potential gap of1.93 V,which demonstrates promising application in Li-air batteries.
基金financially supported by the National Natural Science Foundation of China(U22A20113,52261135543)。
文摘Lithium-sulfur(Li-S)batteries with high energy density suffer from the soluble lithium polysulfide species,Traditional metal sulfides containing a single metal element used as electrocatalysts for Li-S batteries commonly have limited catalytic abilities to improve battery performance.Herein,based on the Hume-Rothery rule and solvothermal method,the high-entropy sulfide NiCoCuTiVS_(x)derived from Co_(9)S_(8)was designed and synthesized,to realize the combination of small local strain and excellent catalytic performance.With all five metal elements(Ni,Co,Cu,Ti,and V)capable of chemical interactions with soluble polysulfides,NiCoCuTiVS_(x)exhibited strong chemical confinement of polysulfides and promoted fast kinetics for polysulfides conversion.Consequently,the S/NiCoCuTiVS_(x)cathode can maintain a high discharge capacity of 968.9 mA h g^(-1)after 200 cycles at 0.5 C and its capacity retention is 1.3 times higher than that of S/Co_(9)S_(8).The improved cycle stability can be attributed to the synergistic effect originating from the multiple metal elements,coupled with the reduced nucleation and activation barriers of Li_(2)S.The present work opens a path to explore novel electrocatalyst materials based on high entropy materials for the achievement of advanced Li-S batteries.
基金supported by the National Natural Science Foundation of China(Nos.52374299,52304320 and 52204306)Outstanding Youth Foundation of Hunan Province(No.2023JJ10044)+1 种基金Key Project of Hunan Provincial Department of Education(No.22A0211)Natural Science Foundation of Hunan Province(No.2023JJ40014)。
文摘High-capacity Ni-rich layered cathodes LiNi_(x)CoyMn_(1-x-y)O_(2)(NCM)have been widely recognized as highly promising candidates for lithium-ion batteries(LIBs).However,NCM cathodes are suffered from sluggish Li-ion kinetics and fast capacity decay.Herein,the Nb/Ti co-doping strategy has been proposed by formation energy analysis to enhance the mechanical and chemical integrities of NCM cathode.Nb/Ti co-doping facilitates Li-ion transport of NCM cathode for boosting the rate ability.Furthermore,the structure stability is prominently improved for the stronger Nb–O and Ti–O bonds,resulting from the suppressed sharp contraction of c axis,inhibited microcracks formation,and alleviated electrolyte corrosion.Inspired by the synergistic effect of Nb/Ti co-doping,the modified NCM exhibits superior comprehensive electrochemical performances.The Nb/Ti co-doping NCM exhibits an increased discharge capacity of 144.3 m Ah/g at10 C and an outstanding capacity retention remained 92.7%after 300 cycles at 1 C.This work offers a promising approach to developing high-performance cathode materials.
