Metal fluoride materials with high theoretical capacities are considered the next generation of Li-free conversion cathodes.However,the inherently sluggish reaction kinetics of metal fluorides result in unsatisfactory...Metal fluoride materials with high theoretical capacities are considered the next generation of Li-free conversion cathodes.However,the inherently sluggish reaction kinetics of metal fluorides result in unsatisfactory electrochemical performance.In this study,CoF_(2)was combined with carbonaceous materials to obtain graphitic carbon-encapsulated CoF_(2)nanoparticles uniformly embedded in an interconnected N-doped carbon matrix(CoF_(2)@NC),significantly boosting the inert kinetics and electronic conductivity.The CoF_(2)@NC nanocomposites exhibited a notable reversible capacity of 352.0 mAh·g^(-1)at 0.2 A·g^(-1).Notably,it maintained superior long-term cycling stability even at a high current density of 2 A·g^(-1),with a capacity of 235.5 mAh·g^(-1)after 1200 cycles,evidently exceeding that of commercially available CoF_(2)electrodes.Kinetic analysis indicated that the enhanced electrochemical performance originated from the increased contribution of capacitive effects.Furthermore,in-situ electrochemical impedance spectroscopy(EIS)results verify that the improved cycling performance is associated with the enhanced interfacial stability of CoF_(2)@NC.This research not only proposes a solution for the challenges of conversion cathodes in lithium-ion batteries,but also offers novel synthesis strategies for designing high-energy metal fluoride materials.展开更多
Transition metal sulfides are emerging as promising electrode materials for energy storage and conversion.In this work,hierarchical FeS2/C nanospheres are synthesized through a controllable solvothermal method followe...Transition metal sulfides are emerging as promising electrode materials for energy storage and conversion.In this work,hierarchical FeS2/C nanospheres are synthesized through a controllable solvothermal method followed by the annealing process.Spherical FeS2 core is homogeneously coated by thin carbon shell.The hierarchical nanostructure and carbon coating can enhance electron transfer and accommodate the stress originated from the volume change as well as suppress the shuttle effect of polysulfide.Consequently,as the cathode material of lithium ion batteries(LIBs),the FeS2/C nanospheres exhibit high reversible capacity of 676 m Ahg^-1 and excellent cycling life with the capacity retention of 97.1%after100 cycles.In addition,even at the high current density of 1.8 C,a reversible capacity of 437 m Ahg^-1 is obtained for the FeS2/C nanospheres,demonstrating its great prospect for practical applications in highperformance LIBs.展开更多
Rechargeable aluminum batteries(RABs)are attractive cadidates for next-generation energy storage and conversion,due to the low cost and high safety of Al resources,and high capacity of metal Al based on the three-elec...Rechargeable aluminum batteries(RABs)are attractive cadidates for next-generation energy storage and conversion,due to the low cost and high safety of Al resources,and high capacity of metal Al based on the three-electrons reaction mechanism.However,the development of RABs is greatly limited,because of the lack of advanced cathode materials,and their complicated and unclear reaction mechanisms.Exploring the novel nanostructured transition metal and carbon composites is an effective route for obtaining ideal cathode materials.In this work,we synthesize porous CoSnO_(3)/C nanocubes with oxygen vacancies for utilizing as cathodes in RABs for the first time.The intrinsic structure stability of the mixed metal cations and carbon coating can improve the cycling performance of cathodes by regulating the internal strains of the electrodes during volume expansion.The nanocubes with porous structures contribute to fast mass transportation which improves the rate capability.In addition to this,abundant oxygen vacancies promote the adsorption affinity of cathodes,which improves storage capacity.As a result,the CoSnO_(3)/C cathodes display an excellent reversible capacity of 292.1 mAh g^(-1) at 0.1 A g^(-1),a good rate performance with 109 mAh g^(-1) that is maintained even at 1 A g^(-1) and the provided stable cycling behavior for 500 cycles.Besides,a mechanism of intercalation of Al^(3+)within CoSnO_(3)/C cathode is proposed for the electrochemical process.Overall,this work provides a step toward the development of advanced cathode materials for RABs by engineering novel nanostructured mixed transition-metal oxides with carbon composite and proposes novel insights into chemistry for RABs.展开更多
Owing to the utilization of lithium metal as anode with the ultrahigh theoretical capacity density of 3860 mA h g^(-1)and oxide-based ceramic solid-state electrolytes(SE),e.g.,garnet-type Li7La_(3)Zr_(2)O_(12)(LLZO),a...Owing to the utilization of lithium metal as anode with the ultrahigh theoretical capacity density of 3860 mA h g^(-1)and oxide-based ceramic solid-state electrolytes(SE),e.g.,garnet-type Li7La_(3)Zr_(2)O_(12)(LLZO),all-state-state lithium metal batteries(ASLMBs)have been widely accepted as the promising alternatives for providing the satisfactory energy density and safety.However,its applications are still challenged by plenty of technical and scientific issues.In this contribution,the co-sintering temperature at 500℃is proved as a compromise method to fabricate the composite cathode with structural integrity and declined capacity fading of LiNi_(0.5)Co_(0.2)Mn_(0.3)O_(2)(NCM).On the other hand,it tends to form weaker grain boundary(GB)inside polycrystalline LLZO at inadequate sintering temperature for LLZO,which can induce the intergranular failure of SE during the growth of Li filament inside the unavoidable defect on the interface of SE.Therefore,increasing the strength of GB,refining the grain to 0.4μm,and precluding the interfacial defect are suggested to postpone the electro-chemo-mechanical failure of SE with weak GB.Moreover,the advanced sintering techniques to lower the co-sintering temperature for both NCM-LLZO composite cathode and LLZO SE can be posted out to realize the viability of state-of-the-art ASLMBs with higher energy density as well as the guaranteed safety.展开更多
To advance the application of layered oxide cathodes in fast-charging sodium-ion batteries,it is crucial to not only suppress irreversible phase transitions but also improve the rate capability of cathode materials an...To advance the application of layered oxide cathodes in fast-charging sodium-ion batteries,it is crucial to not only suppress irreversible phase transitions but also improve the rate capability of cathode materials and optimize Na^(+)diffusion kinetics to ensure high capacity output at various charge-discharge rates.In this research,the targeted F-substitution with a heavy ratio in oxygen anion layer optimizes the Na^(+)diffusion path and electronic conductivity of the material,thereby decreasing the Na^(+)diffusion barrier and imparting high-rate performance.At a 20 C rate,the cathode achieves a capacity of over 80 mAh g^(-1)with stable cycling performance.Additionally,the dual rivet effect between the transition metal layer and oxygen layer prevents significant phase transitions during charge/discharge within the 2-4.2 V range for the modified cathode.As a result,the F-substituted oxygen anion layer improved Na^(+)diffusion,electronic conductivity,and crystal plane structure stability,which led to the development of a highperformance,fast-charging sodium-ion battery(SIB),opening new avenues for commercial applications.展开更多
LiNi0.8Co0.1Mn0.1O2 cathode was synthesized using transition metal acetates under different synthesis conditions. Simultaneous thermogravimetric–differential scanning calorimetry–derivative thermogravimetric analysi...LiNi0.8Co0.1Mn0.1O2 cathode was synthesized using transition metal acetates under different synthesis conditions. Simultaneous thermogravimetric–differential scanning calorimetry–derivative thermogravimetric analysis was applied to investigating the mixture of transition metal acetates. X-ray powder diffraction and charge–discharge test were adopted to characterize the as-prepared LiNi0.8Co0.1Mn0.1O2. The mixture of transition metal acetates undergoes dehydration and decomposition during heating. All the examined LiNi0.8Co0.1Mn0.1O2 samples have a layered structure with R3 m space group. LiNi0.8Co0.1Mn0.1O2 samples prepared with different lithium sources under different synthesis conditions exhibit very different charge–discharge performances. The sample synthesized via the procedure of sintering at 800 °C after heating lithium carbonate and transition metal acetates at 550 °C achieves a highest capacity of 200.8 m A·h/g and an average capacity of 188.1 mA ·h/g in the first 20 cycles at 0.2C.展开更多
A novel trace nickel(Ni)doped tungsten(W)matrix with coated Ni on W grains was prepared by powder metallurgy method.The introduction of Ni can inhibit the reaction between W and barium-calcium aluminates(Ba-Ca alumina...A novel trace nickel(Ni)doped tungsten(W)matrix with coated Ni on W grains was prepared by powder metallurgy method.The introduction of Ni can inhibit the reaction between W and barium-calcium aluminates(Ba-Ca aluminates)during the impregnation process of the matrix.After cathode activation,the surface Ba:O molar ratio is 0.88:1.00,much higher than the Ba dispenser cathode without Ni doping.The XPS results of the cathode surface showed that the metallic Ba appeared on the activated cathode surface,forming dipoles with oxygen,and effectively reducing the cathode surface work function.The pulse electron emission current density at 1100℃_(b)(brightness temperature)was 18.26 A/cm^(2),and the calculated work function was 1.97 eV.It has a low evaporation rate and the accelerated lifetime test predict a lifetime of over 160000 h.First-principles calculations showed that the charge transfer and dipole moment in the NiW-BaO system were both increased compared to the Ba dispenser cathode,thus improving the emission performance of the Ni-W mixed matrix cathode.展开更多
The implementation of multifunctional application scenarios for mobile terminal devices has increased the energy density requirements of batteries.Increasing the charging voltage can rapidly increase the specific capa...The implementation of multifunctional application scenarios for mobile terminal devices has increased the energy density requirements of batteries.Increasing the charging voltage can rapidly increase the specific capacity of layered transition metal oxides;however,it also exacerbates the release of lattice oxygen and the contraction of the unit cell.Ternary materials are designed in a secondary particle state to meet the requirements of power battery applications.Therefore,to create ternary materials that can operate under ultrahigh voltages,attention should be given to both surface modification and particle integrity maintenance.By utilizing elemental selenium(Se)with a low melting point,easy sublimation,and multiple variable valence states,deep grain boundary modification was implemented inside the particles.The performance of the cathode material was evaluated through pouch cells,and the improvement mechanism was explored through molecular dynamics simulation calculations.Under the protection of a three-dimensional Se-rich modified layer,LiNi_(1/3)Co_(1/3)Mn_(1/3)O_(2)achieved stable operation at ultrahigh voltages(4.6 V vs.Li/Li^(+));a sacrificial protection mechanism based on the chronic decomposition of the Se-rich layer was proposed to explain the efficacy of Se modification in stabilizing ternary materials.This deep grain boundary modification based on elemental Se provides a new solution for the ultrahigh-voltage operation of transition metal oxides and provides a scientific basis and technical support for solving the interface contact problem of all-solid-state batteries.展开更多
Long-life energy storage batteries are integral to energy storage systems and electric vehicles,with lithium-ion batteries(LIBs)currently being the preferred option for extended usage-life energy storage.To further ex...Long-life energy storage batteries are integral to energy storage systems and electric vehicles,with lithium-ion batteries(LIBs)currently being the preferred option for extended usage-life energy storage.To further extend the life span of LIBs,it is essential to intensify investments in battery design,manufacturing processes,and the advancement of ancillary materials.The pursuit of long durability introduces new challenges for battery energy density.The advent of electrode material offers effective support in enhancing the battery’s long-duration performance.Often underestimated as part of the cathode composition,the binder plays a pivotal role in the longevity and electrochemical performance of the electrode.Maintaining the mechanical integrity of the electrode through judicious binder design is a fundamental requirement for achieving consistent long-life cycles and high energy density.This paper primarily concentrates on the commonly employed cathode systems in lithium-ion batteries,elucidates the significance of binders for both,discusses the application status,strengths,and weaknesses of novel binders,and ultimately puts forth corresponding optimization strategies.It underscores the critical function of binders in enhancing battery performance and advancing the sustainable development of lithium-ion batteries,aiming to offer fresh insights and perspectives for the design of high-performance LIBs.展开更多
Lithium manganese silicate(Li-Mn-Si-O)cathodes are key components of lithium-ion batteries,and their physical and mechanical properties are strongly influenced by their underlying crystal structures.In this study,a ra...Lithium manganese silicate(Li-Mn-Si-O)cathodes are key components of lithium-ion batteries,and their physical and mechanical properties are strongly influenced by their underlying crystal structures.In this study,a range of machine learning(ML)algorithms were developed and compared to predict the crystal systems of Li-Mn-Si-O cathode materials using density functional theory(DFT)data obtained from the Materials Project database.The dataset comprised 211 compositions characterized by key descriptors,including formation energy,energy above the hull,bandgap,atomic site number,density,and unit cell volume.These features were utilized to classify the materials into monoclinic(0)and triclinic(1)crystal systems.A comprehensive comparison of various classification algorithms including Decision Tree,Random Forest,XGBoost,Support VectorMachine,k-Nearest Neighbor,Stochastic Gradient Descent,Gaussian Naive Bayes,Gaussian Process,and Artificial Neural Network(ANN)was conducted.Among these,the optimized ANN architecture(6–14-14-14-1)exhibited the highest predictive performance,achieving an accuracy of 95.3%,aMatthews correlation coefficient(MCC)of 0.894,and an F-score of 0.963,demonstrating excellent consistency with DFT-predicted crystal structures.Meanwhile,RandomForest and Gaussian Processmodels also exhibited reliable and consistent predictive capability,indicating their potential as complementary approaches,particularly when data are limited or computational efficiency is required.This comparative framework provides valuable insights into model selection for crystal system classification in complex cathode materials.展开更多
Layered transition metal oxide cathode materials have garnered increasing attention for sodium-ion batteries(SIBs).However,they are plagued by the Jahn-Teller distortion of MnO6,Na^(+)/vacancy ordering,and irreversibl...Layered transition metal oxide cathode materials have garnered increasing attention for sodium-ion batteries(SIBs).However,they are plagued by the Jahn-Teller distortion of MnO6,Na^(+)/vacancy ordering,and irreversible lattice oxygen loss,which collectively lead to capacity fading and voltage decay.Herein,we report a P2-type material,Na_(0.67)Ni_(0.3)Mn_(0.6)Li_(0.09)Sn_(0.01)O_(2)(NNMO-Li0.09Sn0.01),modified with two closed-shell dopants(i.e.,Li^(+)and Sn^(4+)).Benefiting from the unique electronic configurations of closed-shell ions,NNMO-Li0.09Sn0.01 exhibits enhanced structural and electrochemical stability.Specifically,the incorporation of Li^(+)increases the Mn^(4+)/Mn3+ratio,thereby mitigating Jahn-Teller distortion during(de)sodiation process.In addition,Li^(+)disrupts the Ni/Mn ordering in the transition metal layer,suppressing Na^(+)/vacancy ordering.Meanwhile,the introduction of Sn^(4+)forms stronger Sn-O bonds(548 kJ mol-1),thereby enhancing the bonding strength between neighboring transition metal ions and surrounding oxygen atoms,effectively reducing oxygen loss during cycling.NNMO-Li0.09Sn0.01 exhibits significantly improved cycling stability,delivering a specific capacity of 90.3 mAh g^(-1)with 62.9%capacity retention after 50 cycles at 0.1 C(1 C=200 mA g^(-1)),along with 90.3%voltage retention.This substitution strategy based on closed-shell ions offers a viable approach for enhancing the structural stability of wide-voltage layered oxide cathodes.展开更多
Cation disordering is a common issue in Ni-rich cathodes that significantly degrades cycle life and compromises safety.The cubic rock-salt phase formation and the slow oxidation kinetics of Ni^(2+)during solid-state s...Cation disordering is a common issue in Ni-rich cathodes that significantly degrades cycle life and compromises safety.The cubic rock-salt phase formation and the slow oxidation kinetics of Ni^(2+)during solid-state sintering are widely recognized as the principal causes of these structural defects.To solve this issue,a topotactic soft-chemical precursor engineering strategy is proposed for use in aqueous solution.By utilizing the layered structure of the precursor,this method allows for selective proton extraction and efficient Ni^(2+)oxidation,along with rapid Li+intercalation to form a layered lithiated intermediate.This intermediate crystallizes without further phase transitions during subsequent heat treatment,preventing structural defects caused by complex phase evolution and slow ion diffusion.The resulting cathode exhibits a long-range ordered layered structure and a uniform phase distribution,enabling efficient Li+insertion and extraction.Electrochemical tests reveal a high discharge capacity of 229.6 mAh g^(−1)and an initial coulombic efficiency of 95.77%at 0.1 C,greatly exceeding the performance of a conventionally synthesized cathode(210.3 mAh g^(−1),88.93%).Improved Li^(+)transport kinetics reduces phase-transition hysteresis and alleviates stress concentration,resulting in better cycling stability with a capacity retention of 85.3%after 300 cycles,compared to 61.5%for the conventional sample.This work presents a scalable and effective synthesis route for Ni-rich cathodes with reduced structural disorder and extended lifespan,providing valuable insights into how the regulation of intermediate phases influences electrochemical performance in high-performance Ni-rich cathodes.展开更多
The outstanding performance of O3-type NaNi_(1/3)Fe_(1/3)Mn_(1/3)O_(2)(NFM111)at both high and low temperatures coupled with its impressive specific capacity makes it an excellent cathode material for sodium-ion batte...The outstanding performance of O3-type NaNi_(1/3)Fe_(1/3)Mn_(1/3)O_(2)(NFM111)at both high and low temperatures coupled with its impressive specific capacity makes it an excellent cathode material for sodium-ion batteries.However,its poor cycling,owing to highpressure phase transitions,is one of its disadvantages.In this study,Cu/Ti was introduced into NFM111 cathode material using a solidphase method.Through both theoretically and experimentally,this study found that Cu doping provides a higher redox potential in NFM111,improving its reversible capacity and charge compensation process.The introduction of Ti would enhance the cycling stability of the material,smooth its charge and discharge curves,and suppress its high-voltage phase transitions.Accordingly,the NaNi_(0.27)Fe_(0.28)Mn_(0.33)Cu_(0.05)Ti_(0.06)O_(2)sample used in the study exhibited a remarkable rate performance of 142.97 mAh·g^(-1)at 0.1 C(2.0-4.2 V)and an excellent capacity retention of 72.81%after 300 cycles at 1C(1C=150 mA·g^(-1)).展开更多
Co-free Li-rich Li_(1.2)Ni_(0.2)Mn_(0.6)O_(2)(LR)cathode shows the highest working capacity that can be applied to high-energy density Li-ion batteries(LIBs).However,poor cycle stability and voltage decay caused by ph...Co-free Li-rich Li_(1.2)Ni_(0.2)Mn_(0.6)O_(2)(LR)cathode shows the highest working capacity that can be applied to high-energy density Li-ion batteries(LIBs).However,poor cycle stability and voltage decay caused by phase transition are always hindering its further development.Herein,a novel medium-entropy Li-rich Mn-based cathode material(LRMEF)was synthesized via a simple sol-gel method.The introduction of multivalent ions(Al^(3+)/Cu^(2+)doping at Mn sites and F−doping at O sites)effectively mitigates the Jahn-Teller distortion of Mn ions and suppresses oxygen release.High-angle annular dark-field scanning transmission electron microscopy(HAADF-STEM)images confirm that this synergistic doping strategy induces the in-situ formation of an approximately 3 nm-thick spinel surface layer,which significantly enhances structural stability and ion diffusion kinetics.Besides,a series of in-situ/ex-situ characterization methods and density functional theory(DFT)calculations have been carried out to fundamentally shed light on the optimized structure-activity relationship and reaction mechanism.As a result,the LR material with entropy regulation and anion doping exhibits excellent cycling stability(189.2 mAh g^(−1)at 1 C with 84%capacity retention after 300 cycles),rate performance(164.1 mAh g^(−1)at 5 C),and voltage retention(82.7%at 1 C after 300 cycles),demonstrating great application prospects in future high-energy-density LIBs.展开更多
The high voltage of Li||LiCoO_(2) battery can increase the energy density.However,the cycling performance associated with cathode structural stability remains challenging.To address this question,we proposed an electr...The high voltage of Li||LiCoO_(2) battery can increase the energy density.However,the cycling performance associated with cathode structural stability remains challenging.To address this question,we proposed an electrolyte strategy for improving the performance of 4.6 V Li||LiCoO_(2) battery by using trimethylsilyl isocyanate(TMIS)as electrolyte additive.The trimethylsilyl group of TMIS can trap HF while the isocyanate group brings polyamide components to the CEI and the SEI.By the synergistic action,the Co3+dissolution problem of the LiCoO_(2) cathode was effectively curbed.Furthermore,TMIS regulates the construction of anion-dominated LiF-rich SEI by influencing the solvation structure of Li+.As expected,the 4.6 V Li||LiCoO_(2) battery with TMIS retains 77.9% initial capacity after 200 cycles at 0.5 C.展开更多
Rechargeable magnesium batteries(RMBs)possess the merits of greater theoretical capacity,cheaper magnesium metal and not easily producing branched crystals,and greater safety.Therefore,the current researches mainly co...Rechargeable magnesium batteries(RMBs)possess the merits of greater theoretical capacity,cheaper magnesium metal and not easily producing branched crystals,and greater safety.Therefore,the current researches mainly concentrate on the exploration of high-performance RMBs in the initial stage,but still face many gigantic challenges.Herein,petal-shaped nanorods CoS/CuS materials are successfully synthesized as RMBs cathode materials through a two-step metal sulfide template-free solvent-thermal synthesis method,which can effectively improve the reaction kinetics due to the petal-like nano-structure and provide rich electrochemically active sites to decrease the transport barrier of Mg^(2+),thus contributing to the enhancement of the reaction kinetics of magnesium storage in RMBs.The electrochemical performance test illustrates that CoS/CuS composite nanomaterials can considerably improve the charging and discharging specific capacity of the batteries as well as the voltage of the batteries due to the existing synergistic effect between them.The specific capacity of CoS/CuS cathode still can still be maintained as high as 62.8 mAh g^(−1)after 300 cycles at 200 mA g^(−1).And the specific capacity of this electrode material changes from 180.6 mAh g^(−1)to 30 mAh g^(−1)at the current densities from 100 mA g^(−1)to 1000 mA g^(−1),and when the current density is restored to 100 mA g^(−1),the specific capacity gradually recovered to 178.6 mAh g^(−1),which showed better rate performance and ultra-high cycling stability.This work highlights how the introduction of CuS into CoS nanostructures can benefit the reversibility and cyclicity of the magnesium storage reaction and offers an original and practical route for the modification of RMBs electrode materials with good electrochemical properties.展开更多
Li_(3)V_(2)(PO_(4))_(3) is a promising high-voltage cathode for zincion batteries,but it suffers from a poor electronic conductivity and vanadium dissolution in aqueous electrolytes.The growth of carboncoated Li_(3)V_...Li_(3)V_(2)(PO_(4))_(3) is a promising high-voltage cathode for zincion batteries,but it suffers from a poor electronic conductivity and vanadium dissolution in aqueous electrolytes.The growth of carboncoated Li_(3)V_(2)(PO_(4))_(3)(LVP@C)nanoparticles on carbon nanofibers(CNFs)has been achieved by an electrospinning technique followed by calcination.The protective carbon coating prevents the aggregation of the LVP nanoparticles and suppresses V dissolution by preventing direct contact with aqueous electrolytes.The CNFs derived from the electrospun nanofibers provide a 3D network to increase the electronic conductivity of the LVP electrode,and the LVP@C-CNF hybrid film can be directly used as a freestanding cathode for zinc-ion batteries without adding conductive additives and binders.A mechanism for the formation of a uniform and continuous carbon coating has been proposed.This nanostructure,combined with the uniform and intact carbon coverage,significantly increases the electronic conductivity.This LVP@C-CNF freestanding electrode has an excellent rate capability(47.3%retention at 2 C)and cycling stability(61.2%retention after 100 cycles)within the voltage range 0.6 V to 1.95 V and is highly suitable for zinc-ion battery applications.展开更多
Carbon-based air cathodes offer low cost,high electrical conductivity,and structural tunability.However,they suffer from limited catalytic activity and inefficient gas transport,and they typically rely on noble metal ...Carbon-based air cathodes offer low cost,high electrical conductivity,and structural tunability.However,they suffer from limited catalytic activity and inefficient gas transport,and they typically rely on noble metal additives or complex multilayer configurations.To tackle these issues,this study devised a self-activated integrated carbon-based air cathode.By integrating in situ catalytic site construction with structural optimization,the strategy not only induces the formation of oxygen functional groups(─C─OH,─C═O,─COOH),hierarchical pores,and uniformly distributed active sites,but also establishes a favorable electronic and mass-transport environment.Furthermore,the roll-pressing-based integrated design streamlines electrode construction,reinforces interfacial bonding,and significantly enhances mechanical stability.Density functional theory(DFT)calculations show that oxygen functional groups initiate hydrogen bonding interaction and promote charge enrichment,which improves the activity of the cathode and facilitates intermediate adsorption/desorption in oxygen reduction and evolution reactions processes.As a result,the integrated air cathode-based rechargeable zinc-air batteries(RZABs)achieve a high specific capacity of 811 mAh g^(-1).It also performs well in quasi-solid-state RZABs and silicon-air batteries systems across a wide temperature range,demonstrating strong adaptability and application potential.This study provides a scalable and cost-effective design strategy for high-performance carbon-based air cathodes,offering new insights into advancing durable and practical metal-air energy systems.展开更多
O3-types layered cathode materials in sodium-ion batteries(SIBs)suffer from the obvious lattice distortion induced by the complex phase transitions during Na^(+)intercalation/deintercalation process,leading to severe ...O3-types layered cathode materials in sodium-ion batteries(SIBs)suffer from the obvious lattice distortion induced by the complex phase transitions during Na^(+)intercalation/deintercalation process,leading to severe structural collapse and performance degradation.Herein,a series of high valence tantalum(Ta^(5+))doped Na(Ni_(0.4)Fe_(0.2)Mn_(0.4))_(1−x)Ta_(x)O_(2)(x=0/0.0025/0.005/0.01)secondary spherical particles are firstly developed,where Ta^(5+)doping enables the refined primary grain with a tightly stacked rod-like morphology.Comprehensive structural analysis via Neutron powder diffraction(NPD)and Synchrotron radiation X-ray diffraction(SXRD)reveals an expanded NaO_(2)slab and a reduction in Na site vacancy.The potential charge compensation mechanism is further illustrated by X-ray absorption spectroscopy(XAS)and X-ray photoelectron spectroscopy(XPS),unveiling a partial reduction from Ni^(3+)to Ni^(2+)with Ta^(5+)doping.In situ X-ray diffraction(in situ XRD)suggests that the decorated sample undergoes a volume change as low as 0.8%,in contrast with the pristine one(1.5%).Thus,the optimized sample with x=0.005 retains an enhanced capacity retention up to 70.4%at 1 C after 300 cycles in half-cell and delivers a high energy density of 251 Wh kg^(-1)(0.1 C)and with a good capacity retention of 81.0%at 1 C after 200 cycles in full-cell.Our findings provide new insights into the mechanism of high valence Ta^(5+)doping in stabilizing layered oxides cathode materials for SIBs.展开更多
Waste graphitization cathode carbon blocks are a type of hazardous solid waste generated during the aluminum electrolysis process,and their proper disposal is a key step in the resource utilization of discarded graphi...Waste graphitization cathode carbon blocks are a type of hazardous solid waste generated during the aluminum electrolysis process,and their proper disposal is a key step in the resource utilization of discarded graphite.This study utilizes the porous“defect advantage”of a cathode carbon block matrix to prepare silicon-doped and asphalt-coated detoxified and purified waste graphitization cathode carbon blocks for use as high-performance silicon/carbon composite anode materials.The results show that the uniformly silicondoped silicon/carbon composite material features a unique amorphous carbon-encapsulated“locked silicon”structure,which effectively addresses issues such as cathode volume expansion,excessive growth of the solid electrolyte interphase(SEI)film,and poor electrical contact between active materials.Consequently,electrochemical performance is enhanced.After assembly in a half-cell,the PSCC/10%Si@C(purified waste graphitization cathode carbon/10%Si@C)material exhibits optimal electrochemical stability,with an initial charging specific capacity of 514.5 mAh/g at 0.1 C(1 C=170 mA/g)and a capacity retention rate of 95.1%after 100 cycles.At a charge rate of 2.0 C,a specific capacity of 216.9 mAh/g is achieved.This technology provides a new pathway for the economical and high-value utilization of waste cathode carbon blocks and the development of low-cost,high-performance anode materials.展开更多
基金supported by the National Natural Science Foundation of China(Nos.22279101,22172117 and 52072298)Foshan Science and Technology Innovation Team Project(No.1920001004098)+1 种基金Scientific Research Program Funded by Education Department of Shaanxi Provincial Government(No.22JP056)the Natural Science Basic Research Program of Shaanxi(No.2024JC-YBQN-0141).
文摘Metal fluoride materials with high theoretical capacities are considered the next generation of Li-free conversion cathodes.However,the inherently sluggish reaction kinetics of metal fluorides result in unsatisfactory electrochemical performance.In this study,CoF_(2)was combined with carbonaceous materials to obtain graphitic carbon-encapsulated CoF_(2)nanoparticles uniformly embedded in an interconnected N-doped carbon matrix(CoF_(2)@NC),significantly boosting the inert kinetics and electronic conductivity.The CoF_(2)@NC nanocomposites exhibited a notable reversible capacity of 352.0 mAh·g^(-1)at 0.2 A·g^(-1).Notably,it maintained superior long-term cycling stability even at a high current density of 2 A·g^(-1),with a capacity of 235.5 mAh·g^(-1)after 1200 cycles,evidently exceeding that of commercially available CoF_(2)electrodes.Kinetic analysis indicated that the enhanced electrochemical performance originated from the increased contribution of capacitive effects.Furthermore,in-situ electrochemical impedance spectroscopy(EIS)results verify that the improved cycling performance is associated with the enhanced interfacial stability of CoF_(2)@NC.This research not only proposes a solution for the challenges of conversion cathodes in lithium-ion batteries,but also offers novel synthesis strategies for designing high-energy metal fluoride materials.
基金funded by the Natural Science Foundation of Zhejiang Provincial (No. LQ17E020003)the National Natural Science Foundation of China (No. 51804092)
文摘Transition metal sulfides are emerging as promising electrode materials for energy storage and conversion.In this work,hierarchical FeS2/C nanospheres are synthesized through a controllable solvothermal method followed by the annealing process.Spherical FeS2 core is homogeneously coated by thin carbon shell.The hierarchical nanostructure and carbon coating can enhance electron transfer and accommodate the stress originated from the volume change as well as suppress the shuttle effect of polysulfide.Consequently,as the cathode material of lithium ion batteries(LIBs),the FeS2/C nanospheres exhibit high reversible capacity of 676 m Ahg^-1 and excellent cycling life with the capacity retention of 97.1%after100 cycles.In addition,even at the high current density of 1.8 C,a reversible capacity of 437 m Ahg^-1 is obtained for the FeS2/C nanospheres,demonstrating its great prospect for practical applications in highperformance LIBs.
基金supported by the National Natural Science Foundation of China (Grant No.22075028).
文摘Rechargeable aluminum batteries(RABs)are attractive cadidates for next-generation energy storage and conversion,due to the low cost and high safety of Al resources,and high capacity of metal Al based on the three-electrons reaction mechanism.However,the development of RABs is greatly limited,because of the lack of advanced cathode materials,and their complicated and unclear reaction mechanisms.Exploring the novel nanostructured transition metal and carbon composites is an effective route for obtaining ideal cathode materials.In this work,we synthesize porous CoSnO_(3)/C nanocubes with oxygen vacancies for utilizing as cathodes in RABs for the first time.The intrinsic structure stability of the mixed metal cations and carbon coating can improve the cycling performance of cathodes by regulating the internal strains of the electrodes during volume expansion.The nanocubes with porous structures contribute to fast mass transportation which improves the rate capability.In addition to this,abundant oxygen vacancies promote the adsorption affinity of cathodes,which improves storage capacity.As a result,the CoSnO_(3)/C cathodes display an excellent reversible capacity of 292.1 mAh g^(-1) at 0.1 A g^(-1),a good rate performance with 109 mAh g^(-1) that is maintained even at 1 A g^(-1) and the provided stable cycling behavior for 500 cycles.Besides,a mechanism of intercalation of Al^(3+)within CoSnO_(3)/C cathode is proposed for the electrochemical process.Overall,this work provides a step toward the development of advanced cathode materials for RABs by engineering novel nanostructured mixed transition-metal oxides with carbon composite and proposes novel insights into chemistry for RABs.
基金the National Natural Science Foundation of China(12102328)for supporting this work。
文摘Owing to the utilization of lithium metal as anode with the ultrahigh theoretical capacity density of 3860 mA h g^(-1)and oxide-based ceramic solid-state electrolytes(SE),e.g.,garnet-type Li7La_(3)Zr_(2)O_(12)(LLZO),all-state-state lithium metal batteries(ASLMBs)have been widely accepted as the promising alternatives for providing the satisfactory energy density and safety.However,its applications are still challenged by plenty of technical and scientific issues.In this contribution,the co-sintering temperature at 500℃is proved as a compromise method to fabricate the composite cathode with structural integrity and declined capacity fading of LiNi_(0.5)Co_(0.2)Mn_(0.3)O_(2)(NCM).On the other hand,it tends to form weaker grain boundary(GB)inside polycrystalline LLZO at inadequate sintering temperature for LLZO,which can induce the intergranular failure of SE during the growth of Li filament inside the unavoidable defect on the interface of SE.Therefore,increasing the strength of GB,refining the grain to 0.4μm,and precluding the interfacial defect are suggested to postpone the electro-chemo-mechanical failure of SE with weak GB.Moreover,the advanced sintering techniques to lower the co-sintering temperature for both NCM-LLZO composite cathode and LLZO SE can be posted out to realize the viability of state-of-the-art ASLMBs with higher energy density as well as the guaranteed safety.
基金supported by the National Natural Science Foundation of China(Nos.22178221,22208221)the Shenzhen Science and Technology Program(Nos.JCYJ20220818095805012,JCYJ20230808105109019)+2 种基金the Natural Science Foundation of Guangdong Province(Nos.2024A1515011078,2024A1515011507)the Scientific Foundation for Youth Scholars of Shenzhen University(868-000001032522,827-0001004)the Instrumental Analysis Center of Shenzhen University for the assistance with the Electron Microscope technical support。
文摘To advance the application of layered oxide cathodes in fast-charging sodium-ion batteries,it is crucial to not only suppress irreversible phase transitions but also improve the rate capability of cathode materials and optimize Na^(+)diffusion kinetics to ensure high capacity output at various charge-discharge rates.In this research,the targeted F-substitution with a heavy ratio in oxygen anion layer optimizes the Na^(+)diffusion path and electronic conductivity of the material,thereby decreasing the Na^(+)diffusion barrier and imparting high-rate performance.At a 20 C rate,the cathode achieves a capacity of over 80 mAh g^(-1)with stable cycling performance.Additionally,the dual rivet effect between the transition metal layer and oxygen layer prevents significant phase transitions during charge/discharge within the 2-4.2 V range for the modified cathode.As a result,the F-substituted oxygen anion layer improved Na^(+)diffusion,electronic conductivity,and crystal plane structure stability,which led to the development of a highperformance,fast-charging sodium-ion battery(SIB),opening new avenues for commercial applications.
基金Project(2010ZC051)supported by the Natural Science Foundation of Yunnan Province,ChinaProject(20140439)supported by the Analysis and Testing Foundation from Kunming University of Science and Technology,ChinaProject(14118245)supported by the Starting Research Fund from Kunming University of Science and Technology,China
文摘LiNi0.8Co0.1Mn0.1O2 cathode was synthesized using transition metal acetates under different synthesis conditions. Simultaneous thermogravimetric–differential scanning calorimetry–derivative thermogravimetric analysis was applied to investigating the mixture of transition metal acetates. X-ray powder diffraction and charge–discharge test were adopted to characterize the as-prepared LiNi0.8Co0.1Mn0.1O2. The mixture of transition metal acetates undergoes dehydration and decomposition during heating. All the examined LiNi0.8Co0.1Mn0.1O2 samples have a layered structure with R3 m space group. LiNi0.8Co0.1Mn0.1O2 samples prepared with different lithium sources under different synthesis conditions exhibit very different charge–discharge performances. The sample synthesized via the procedure of sintering at 800 °C after heating lithium carbonate and transition metal acetates at 550 °C achieves a highest capacity of 200.8 m A·h/g and an average capacity of 188.1 mA ·h/g in the first 20 cycles at 0.2C.
基金supported by the National Natural Science Foundation of China(Nos.U2341209 and 52130407).
文摘A novel trace nickel(Ni)doped tungsten(W)matrix with coated Ni on W grains was prepared by powder metallurgy method.The introduction of Ni can inhibit the reaction between W and barium-calcium aluminates(Ba-Ca aluminates)during the impregnation process of the matrix.After cathode activation,the surface Ba:O molar ratio is 0.88:1.00,much higher than the Ba dispenser cathode without Ni doping.The XPS results of the cathode surface showed that the metallic Ba appeared on the activated cathode surface,forming dipoles with oxygen,and effectively reducing the cathode surface work function.The pulse electron emission current density at 1100℃_(b)(brightness temperature)was 18.26 A/cm^(2),and the calculated work function was 1.97 eV.It has a low evaporation rate and the accelerated lifetime test predict a lifetime of over 160000 h.First-principles calculations showed that the charge transfer and dipole moment in the NiW-BaO system were both increased compared to the Ba dispenser cathode,thus improving the emission performance of the Ni-W mixed matrix cathode.
基金supported by the National Natural Science Foundation of China (52302259)the China Postdoctoral Science Foundation (CPSF) under Grant Number 2023M741479+4 种基金the Postdoctoral Fellowship Program of CPSF under Grant Number GZB20240280the Jiangxi Provincial Natural Science Foundation (20224ACB218006)the financial support from High-level Talent Research Special Funds of Jiangxi University of Science and Technology (Grant No. 205200100670)the Jiangxi Provincial Key Laboratory of Power Energy Storage Batteries and Materials (2024SSY10011)the Major Scientific and Technological Research R&D Special Project of Jiangxi Province(20244AFI92002)
文摘The implementation of multifunctional application scenarios for mobile terminal devices has increased the energy density requirements of batteries.Increasing the charging voltage can rapidly increase the specific capacity of layered transition metal oxides;however,it also exacerbates the release of lattice oxygen and the contraction of the unit cell.Ternary materials are designed in a secondary particle state to meet the requirements of power battery applications.Therefore,to create ternary materials that can operate under ultrahigh voltages,attention should be given to both surface modification and particle integrity maintenance.By utilizing elemental selenium(Se)with a low melting point,easy sublimation,and multiple variable valence states,deep grain boundary modification was implemented inside the particles.The performance of the cathode material was evaluated through pouch cells,and the improvement mechanism was explored through molecular dynamics simulation calculations.Under the protection of a three-dimensional Se-rich modified layer,LiNi_(1/3)Co_(1/3)Mn_(1/3)O_(2)achieved stable operation at ultrahigh voltages(4.6 V vs.Li/Li^(+));a sacrificial protection mechanism based on the chronic decomposition of the Se-rich layer was proposed to explain the efficacy of Se modification in stabilizing ternary materials.This deep grain boundary modification based on elemental Se provides a new solution for the ultrahigh-voltage operation of transition metal oxides and provides a scientific basis and technical support for solving the interface contact problem of all-solid-state batteries.
基金We would like to show gratitude to the Yunnan Province Basic Research Major Project(202501BC070006(Y.Wang))Key Industry Science and Technology Projects for University Services in Yunnan Province(FWCY ZNT2024002(Y.Wang))+3 种基金National Natural Science Foundation of China(22279070(L.Wang))and(U21A20170(X.He))the Ministry of Science and Technology of China(2019YFA0705703(L.Wang))Beijing Natural Science Foundation(L242005(X.He))Key Industry Science and Technology Projects for University Services in Yunnan Province(FWCY BSPY2024011(T.Lai)).
文摘Long-life energy storage batteries are integral to energy storage systems and electric vehicles,with lithium-ion batteries(LIBs)currently being the preferred option for extended usage-life energy storage.To further extend the life span of LIBs,it is essential to intensify investments in battery design,manufacturing processes,and the advancement of ancillary materials.The pursuit of long durability introduces new challenges for battery energy density.The advent of electrode material offers effective support in enhancing the battery’s long-duration performance.Often underestimated as part of the cathode composition,the binder plays a pivotal role in the longevity and electrochemical performance of the electrode.Maintaining the mechanical integrity of the electrode through judicious binder design is a fundamental requirement for achieving consistent long-life cycles and high energy density.This paper primarily concentrates on the commonly employed cathode systems in lithium-ion batteries,elucidates the significance of binders for both,discusses the application status,strengths,and weaknesses of novel binders,and ultimately puts forth corresponding optimization strategies.It underscores the critical function of binders in enhancing battery performance and advancing the sustainable development of lithium-ion batteries,aiming to offer fresh insights and perspectives for the design of high-performance LIBs.
基金supported by the Learning&Academic Research Institution for Master’s,PhD students,and Postdocs LAMP Program of the National Research Foundation of Korea(NRF)grant funded by the Ministry of Education(No.RS-2023-00301974)This work was also supported by the Glocal University 30 Project fund of Gyeongsang National University in 2025.
文摘Lithium manganese silicate(Li-Mn-Si-O)cathodes are key components of lithium-ion batteries,and their physical and mechanical properties are strongly influenced by their underlying crystal structures.In this study,a range of machine learning(ML)algorithms were developed and compared to predict the crystal systems of Li-Mn-Si-O cathode materials using density functional theory(DFT)data obtained from the Materials Project database.The dataset comprised 211 compositions characterized by key descriptors,including formation energy,energy above the hull,bandgap,atomic site number,density,and unit cell volume.These features were utilized to classify the materials into monoclinic(0)and triclinic(1)crystal systems.A comprehensive comparison of various classification algorithms including Decision Tree,Random Forest,XGBoost,Support VectorMachine,k-Nearest Neighbor,Stochastic Gradient Descent,Gaussian Naive Bayes,Gaussian Process,and Artificial Neural Network(ANN)was conducted.Among these,the optimized ANN architecture(6–14-14-14-1)exhibited the highest predictive performance,achieving an accuracy of 95.3%,aMatthews correlation coefficient(MCC)of 0.894,and an F-score of 0.963,demonstrating excellent consistency with DFT-predicted crystal structures.Meanwhile,RandomForest and Gaussian Processmodels also exhibited reliable and consistent predictive capability,indicating their potential as complementary approaches,particularly when data are limited or computational efficiency is required.This comparative framework provides valuable insights into model selection for crystal system classification in complex cathode materials.
基金supported by the Ministry of Science and Technology of China(2025YFE0100200)the Natural Science Foundation of Tianjin(24JCJQJC00220 and 24ZXZSSS00310)+3 种基金the National Natural Science Foundation of China(22479080,92372203,and 92372001)the Open Foundation of Shanghai Jiao Tong University Shaoxing Research Institute of Renewable Energy and Molecular Engineering(JDSX2023003)the Fundamental Research Funds for the Central Universities of Nankai University(020-63253167)the"111 Center"(B25010)。
文摘Layered transition metal oxide cathode materials have garnered increasing attention for sodium-ion batteries(SIBs).However,they are plagued by the Jahn-Teller distortion of MnO6,Na^(+)/vacancy ordering,and irreversible lattice oxygen loss,which collectively lead to capacity fading and voltage decay.Herein,we report a P2-type material,Na_(0.67)Ni_(0.3)Mn_(0.6)Li_(0.09)Sn_(0.01)O_(2)(NNMO-Li0.09Sn0.01),modified with two closed-shell dopants(i.e.,Li^(+)and Sn^(4+)).Benefiting from the unique electronic configurations of closed-shell ions,NNMO-Li0.09Sn0.01 exhibits enhanced structural and electrochemical stability.Specifically,the incorporation of Li^(+)increases the Mn^(4+)/Mn3+ratio,thereby mitigating Jahn-Teller distortion during(de)sodiation process.In addition,Li^(+)disrupts the Ni/Mn ordering in the transition metal layer,suppressing Na^(+)/vacancy ordering.Meanwhile,the introduction of Sn^(4+)forms stronger Sn-O bonds(548 kJ mol-1),thereby enhancing the bonding strength between neighboring transition metal ions and surrounding oxygen atoms,effectively reducing oxygen loss during cycling.NNMO-Li0.09Sn0.01 exhibits significantly improved cycling stability,delivering a specific capacity of 90.3 mAh g^(-1)with 62.9%capacity retention after 50 cycles at 0.1 C(1 C=200 mA g^(-1)),along with 90.3%voltage retention.This substitution strategy based on closed-shell ions offers a viable approach for enhancing the structural stability of wide-voltage layered oxide cathodes.
基金the financial support from the Central South University Fundamental Research Funds (Grant No.2025ZZTS0444)the Innovation-Driven Research Program(Grant No. 2023 CXQD053)+3 种基金the National Natural Science Foundation of China (Grant No. 52274310)the financial support (Project No.H202111040350002)the provision of the hydroxide precursors from Ningbo Ronbay New Energy Technology Co.,Ltdsupported in part by the High-Performance Computing Center of Central South University
文摘Cation disordering is a common issue in Ni-rich cathodes that significantly degrades cycle life and compromises safety.The cubic rock-salt phase formation and the slow oxidation kinetics of Ni^(2+)during solid-state sintering are widely recognized as the principal causes of these structural defects.To solve this issue,a topotactic soft-chemical precursor engineering strategy is proposed for use in aqueous solution.By utilizing the layered structure of the precursor,this method allows for selective proton extraction and efficient Ni^(2+)oxidation,along with rapid Li+intercalation to form a layered lithiated intermediate.This intermediate crystallizes without further phase transitions during subsequent heat treatment,preventing structural defects caused by complex phase evolution and slow ion diffusion.The resulting cathode exhibits a long-range ordered layered structure and a uniform phase distribution,enabling efficient Li+insertion and extraction.Electrochemical tests reveal a high discharge capacity of 229.6 mAh g^(−1)and an initial coulombic efficiency of 95.77%at 0.1 C,greatly exceeding the performance of a conventionally synthesized cathode(210.3 mAh g^(−1),88.93%).Improved Li^(+)transport kinetics reduces phase-transition hysteresis and alleviates stress concentration,resulting in better cycling stability with a capacity retention of 85.3%after 300 cycles,compared to 61.5%for the conventional sample.This work presents a scalable and effective synthesis route for Ni-rich cathodes with reduced structural disorder and extended lifespan,providing valuable insights into how the regulation of intermediate phases influences electrochemical performance in high-performance Ni-rich cathodes.
基金supported by the Low-Cost Long-Life Batteries program,China(No.WL-24-08-01)the National Natural Science Foundation of China(No.22279007)。
文摘The outstanding performance of O3-type NaNi_(1/3)Fe_(1/3)Mn_(1/3)O_(2)(NFM111)at both high and low temperatures coupled with its impressive specific capacity makes it an excellent cathode material for sodium-ion batteries.However,its poor cycling,owing to highpressure phase transitions,is one of its disadvantages.In this study,Cu/Ti was introduced into NFM111 cathode material using a solidphase method.Through both theoretically and experimentally,this study found that Cu doping provides a higher redox potential in NFM111,improving its reversible capacity and charge compensation process.The introduction of Ti would enhance the cycling stability of the material,smooth its charge and discharge curves,and suppress its high-voltage phase transitions.Accordingly,the NaNi_(0.27)Fe_(0.28)Mn_(0.33)Cu_(0.05)Ti_(0.06)O_(2)sample used in the study exhibited a remarkable rate performance of 142.97 mAh·g^(-1)at 0.1 C(2.0-4.2 V)and an excellent capacity retention of 72.81%after 300 cycles at 1C(1C=150 mA·g^(-1)).
基金financially supported by the Research and Development Program of China (2022YFA1505700)the National Natural Science Foundation of China (22475214, 22205232, 52102216)+6 种基金the Natural Science Foundation of Fujian Province (2023J06044,2022J01625, 2022-S-002)the Talent Plan of Shanghai BranchChinese Academy of Sciences (CASSHB-QNPD-2023-020)the Selfdeployment Project Research Program of Haixi Institutes,Chinese Academy of Sciences (CXZX-2022-JQ06 and CXZX-2022-GH03)the Anhui Key Laboratory of Nanomaterials and Nanotechnology,the Major Science and Technology Projects in Anhui Province(202305a12020006)the Open Project of State Key Laboratory of Inorganic Synthesis and Preparative Chemistry (2025-22)the Innovation Training Program for College Students(2025019300A, 20250193008)
文摘Co-free Li-rich Li_(1.2)Ni_(0.2)Mn_(0.6)O_(2)(LR)cathode shows the highest working capacity that can be applied to high-energy density Li-ion batteries(LIBs).However,poor cycle stability and voltage decay caused by phase transition are always hindering its further development.Herein,a novel medium-entropy Li-rich Mn-based cathode material(LRMEF)was synthesized via a simple sol-gel method.The introduction of multivalent ions(Al^(3+)/Cu^(2+)doping at Mn sites and F−doping at O sites)effectively mitigates the Jahn-Teller distortion of Mn ions and suppresses oxygen release.High-angle annular dark-field scanning transmission electron microscopy(HAADF-STEM)images confirm that this synergistic doping strategy induces the in-situ formation of an approximately 3 nm-thick spinel surface layer,which significantly enhances structural stability and ion diffusion kinetics.Besides,a series of in-situ/ex-situ characterization methods and density functional theory(DFT)calculations have been carried out to fundamentally shed light on the optimized structure-activity relationship and reaction mechanism.As a result,the LR material with entropy regulation and anion doping exhibits excellent cycling stability(189.2 mAh g^(−1)at 1 C with 84%capacity retention after 300 cycles),rate performance(164.1 mAh g^(−1)at 5 C),and voltage retention(82.7%at 1 C after 300 cycles),demonstrating great application prospects in future high-energy-density LIBs.
基金supported by the National Natural Science Foundation of China(Nos.U21A20311 and 52400163).
文摘The high voltage of Li||LiCoO_(2) battery can increase the energy density.However,the cycling performance associated with cathode structural stability remains challenging.To address this question,we proposed an electrolyte strategy for improving the performance of 4.6 V Li||LiCoO_(2) battery by using trimethylsilyl isocyanate(TMIS)as electrolyte additive.The trimethylsilyl group of TMIS can trap HF while the isocyanate group brings polyamide components to the CEI and the SEI.By the synergistic action,the Co3+dissolution problem of the LiCoO_(2) cathode was effectively curbed.Furthermore,TMIS regulates the construction of anion-dominated LiF-rich SEI by influencing the solvation structure of Li+.As expected,the 4.6 V Li||LiCoO_(2) battery with TMIS retains 77.9% initial capacity after 200 cycles at 0.5 C.
基金financially supported by the National Natural Science Foundation of China(Nos.21804008,52102209)the International Technological Collaboration Project of Shanghai(No.17520710300)+1 种基金Anhui Provincial Natural Science Foundation(No.2108085QE197)Guangdong Basic and Applied Basic Research Foundation(Nos.2022A1515010834,2020A1515110221).
文摘Rechargeable magnesium batteries(RMBs)possess the merits of greater theoretical capacity,cheaper magnesium metal and not easily producing branched crystals,and greater safety.Therefore,the current researches mainly concentrate on the exploration of high-performance RMBs in the initial stage,but still face many gigantic challenges.Herein,petal-shaped nanorods CoS/CuS materials are successfully synthesized as RMBs cathode materials through a two-step metal sulfide template-free solvent-thermal synthesis method,which can effectively improve the reaction kinetics due to the petal-like nano-structure and provide rich electrochemically active sites to decrease the transport barrier of Mg^(2+),thus contributing to the enhancement of the reaction kinetics of magnesium storage in RMBs.The electrochemical performance test illustrates that CoS/CuS composite nanomaterials can considerably improve the charging and discharging specific capacity of the batteries as well as the voltage of the batteries due to the existing synergistic effect between them.The specific capacity of CoS/CuS cathode still can still be maintained as high as 62.8 mAh g^(−1)after 300 cycles at 200 mA g^(−1).And the specific capacity of this electrode material changes from 180.6 mAh g^(−1)to 30 mAh g^(−1)at the current densities from 100 mA g^(−1)to 1000 mA g^(−1),and when the current density is restored to 100 mA g^(−1),the specific capacity gradually recovered to 178.6 mAh g^(−1),which showed better rate performance and ultra-high cycling stability.This work highlights how the introduction of CuS into CoS nanostructures can benefit the reversibility and cyclicity of the magnesium storage reaction and offers an original and practical route for the modification of RMBs electrode materials with good electrochemical properties.
文摘Li_(3)V_(2)(PO_(4))_(3) is a promising high-voltage cathode for zincion batteries,but it suffers from a poor electronic conductivity and vanadium dissolution in aqueous electrolytes.The growth of carboncoated Li_(3)V_(2)(PO_(4))_(3)(LVP@C)nanoparticles on carbon nanofibers(CNFs)has been achieved by an electrospinning technique followed by calcination.The protective carbon coating prevents the aggregation of the LVP nanoparticles and suppresses V dissolution by preventing direct contact with aqueous electrolytes.The CNFs derived from the electrospun nanofibers provide a 3D network to increase the electronic conductivity of the LVP electrode,and the LVP@C-CNF hybrid film can be directly used as a freestanding cathode for zinc-ion batteries without adding conductive additives and binders.A mechanism for the formation of a uniform and continuous carbon coating has been proposed.This nanostructure,combined with the uniform and intact carbon coverage,significantly increases the electronic conductivity.This LVP@C-CNF freestanding electrode has an excellent rate capability(47.3%retention at 2 C)and cycling stability(61.2%retention after 100 cycles)within the voltage range 0.6 V to 1.95 V and is highly suitable for zinc-ion battery applications.
基金funded by the National Nature Science Foundation of China(62264006,62574102)“Thousand Talents Program”of Yunnan Province for Young Talents,Innovative Research Teams(in Science and Technology)in the University of Yunnan Province(IRTSTYN),XingDian Talent Support Program for Young Talents,and Frontier Research Team of Kunming University 2023,The Basic Research Project of Yunnan Province(Nos.202201AU070022)+2 种基金Kunming University Talent Introduction Fund(Nos.YJL20024)Yunnan Province Education Department Scientific Research Fund Project(Nos.2024Y759)Undergraduate Innovation and Entrepreneurship Training Program Project of Yunnan Provincial(202411393005)。
文摘Carbon-based air cathodes offer low cost,high electrical conductivity,and structural tunability.However,they suffer from limited catalytic activity and inefficient gas transport,and they typically rely on noble metal additives or complex multilayer configurations.To tackle these issues,this study devised a self-activated integrated carbon-based air cathode.By integrating in situ catalytic site construction with structural optimization,the strategy not only induces the formation of oxygen functional groups(─C─OH,─C═O,─COOH),hierarchical pores,and uniformly distributed active sites,but also establishes a favorable electronic and mass-transport environment.Furthermore,the roll-pressing-based integrated design streamlines electrode construction,reinforces interfacial bonding,and significantly enhances mechanical stability.Density functional theory(DFT)calculations show that oxygen functional groups initiate hydrogen bonding interaction and promote charge enrichment,which improves the activity of the cathode and facilitates intermediate adsorption/desorption in oxygen reduction and evolution reactions processes.As a result,the integrated air cathode-based rechargeable zinc-air batteries(RZABs)achieve a high specific capacity of 811 mAh g^(-1).It also performs well in quasi-solid-state RZABs and silicon-air batteries systems across a wide temperature range,demonstrating strong adaptability and application potential.This study provides a scalable and cost-effective design strategy for high-performance carbon-based air cathodes,offering new insights into advancing durable and practical metal-air energy systems.
基金supported by the National Natural Science Foundation of China (52402298, 52172224, 52202228, 22479112)the Science and Technology Correspondent Project of Tianjin(24YDTPJC00240)+3 种基金Science Research Project of Hebei Education Department (BJK2022011)Central Funds Guiding the Local Science and Technology Development of Hebei Province (236Z4404G)the Beijing Tianjin Hebei Basic Research Cooperation Special Project(E2024202273)Tianjin Sci.&Tech. Program (22YFYSHZ00220)
文摘O3-types layered cathode materials in sodium-ion batteries(SIBs)suffer from the obvious lattice distortion induced by the complex phase transitions during Na^(+)intercalation/deintercalation process,leading to severe structural collapse and performance degradation.Herein,a series of high valence tantalum(Ta^(5+))doped Na(Ni_(0.4)Fe_(0.2)Mn_(0.4))_(1−x)Ta_(x)O_(2)(x=0/0.0025/0.005/0.01)secondary spherical particles are firstly developed,where Ta^(5+)doping enables the refined primary grain with a tightly stacked rod-like morphology.Comprehensive structural analysis via Neutron powder diffraction(NPD)and Synchrotron radiation X-ray diffraction(SXRD)reveals an expanded NaO_(2)slab and a reduction in Na site vacancy.The potential charge compensation mechanism is further illustrated by X-ray absorption spectroscopy(XAS)and X-ray photoelectron spectroscopy(XPS),unveiling a partial reduction from Ni^(3+)to Ni^(2+)with Ta^(5+)doping.In situ X-ray diffraction(in situ XRD)suggests that the decorated sample undergoes a volume change as low as 0.8%,in contrast with the pristine one(1.5%).Thus,the optimized sample with x=0.005 retains an enhanced capacity retention up to 70.4%at 1 C after 300 cycles in half-cell and delivers a high energy density of 251 Wh kg^(-1)(0.1 C)and with a good capacity retention of 81.0%at 1 C after 200 cycles in full-cell.Our findings provide new insights into the mechanism of high valence Ta^(5+)doping in stabilizing layered oxides cathode materials for SIBs.
基金supported by the National Natural Science Foundation of China(No.52274346).
文摘Waste graphitization cathode carbon blocks are a type of hazardous solid waste generated during the aluminum electrolysis process,and their proper disposal is a key step in the resource utilization of discarded graphite.This study utilizes the porous“defect advantage”of a cathode carbon block matrix to prepare silicon-doped and asphalt-coated detoxified and purified waste graphitization cathode carbon blocks for use as high-performance silicon/carbon composite anode materials.The results show that the uniformly silicondoped silicon/carbon composite material features a unique amorphous carbon-encapsulated“locked silicon”structure,which effectively addresses issues such as cathode volume expansion,excessive growth of the solid electrolyte interphase(SEI)film,and poor electrical contact between active materials.Consequently,electrochemical performance is enhanced.After assembly in a half-cell,the PSCC/10%Si@C(purified waste graphitization cathode carbon/10%Si@C)material exhibits optimal electrochemical stability,with an initial charging specific capacity of 514.5 mAh/g at 0.1 C(1 C=170 mA/g)and a capacity retention rate of 95.1%after 100 cycles.At a charge rate of 2.0 C,a specific capacity of 216.9 mAh/g is achieved.This technology provides a new pathway for the economical and high-value utilization of waste cathode carbon blocks and the development of low-cost,high-performance anode materials.
