With the most advanced Synchronous Radiation Photoelectron Spectrum(SRPS),the emission mechanism of M-type cathodes has been investigated from the perspective of chemical state.Based on the experimental results of SRP...With the most advanced Synchronous Radiation Photoelectron Spectrum(SRPS),the emission mechanism of M-type cathodes has been investigated from the perspective of chemical state.Based on the experimental results of SRPS analysis,a new model of the electron emission mechanism for M-type cathode is discussed.The main topics in this paper include the research status of electron emission mechanism of M-type cathodes;the advantages of SRPS technology;the distribution of oxygen chemical state on the cathode surface and the evolvement of oxygen chemical state during activation process;the relation between barium chemical state and osmium(Os)-coating;surplus barium and its formula;the characteristics of Os,and other noble metal coatings;the relation between film characteristics and emission performance of cathodes,the inhibition effects to the emission for Platinum(Pt)-coated cathode,etc.At the end of this paper,electron emission mechanism of M-type cathode is summarized and foreseen.展开更多
Mn-based layered oxides(KMO)have emerged as one of the promising low-cost cathodes for potassiumion batteries(PIBs).However,due to the multiple-phase transitions and the distortion in the MnO6structure induced by the ...Mn-based layered oxides(KMO)have emerged as one of the promising low-cost cathodes for potassiumion batteries(PIBs).However,due to the multiple-phase transitions and the distortion in the MnO6structure induced by the Jahn-Teller(JT)effect associated with Mn-ion,the cathode exhibits poor structural stability.Herein,we propose a strategy to enhance structural stability by introducing robust metal-oxygen(M-O)bonds,which can realize the pinning effect to constrain the distortion in the transition metal(TM)layer.Concurrently,all the elements employed have exceptionally high crustal abundance.As a proof of concept,the designed K_(0.5)Mn_(0.9)Mg_(0.025)Ti_(0.025)Al_(0.05)O_(2)cathode exhibited a discharge capacity of approximately 100 mA h g^(-1)at 20 mA g^(-1)with 79%capacity retention over 50 cycles,and 73%capacity retention over 200 cycles at 200 mA g^(-1),showcased much better battery performance than the designed cathode with less robust M-O bonds.The properties of the formed M-O bonds were investigated using theoretical calculations.The enhanced dynamics,mitigated JT effect,and improved structural stability were elucidated through the in-situ X-ray diffractometer(XRD),in-situ electrochemical impedance spectroscopy(EIS)(and distribution of relaxation times(DRT)method),and ex-situ X-ray absorption fine structure(XAFS)tests.This study holds substantial reference value for the future design of costeffective Mn-based layered cathodes for PIBs.展开更多
Sodium-ion batteries(SIBs)have the advantages of environmental friendliness,cost-effectiveness,and high energy density,which are considered one of the most promising candidates for lithium-ion batteries(LIBs).The cath...Sodium-ion batteries(SIBs)have the advantages of environmental friendliness,cost-effectiveness,and high energy density,which are considered one of the most promising candidates for lithium-ion batteries(LIBs).The cathode materials influence the cost and energy output of SIBs.Therefore,the development of advanced cathode materials is crucial for the practical application of SIBs.Among various cathode materials,layered transition metal oxides(LTMOs)have received widespread attention owing to their straightforward preparation,abundant availability,and cost-competitiveness.Notably,layered Fe-based oxide cathodes are deemed to be one of the most promising candidates for the lowest price and easy-to-improve performance.Nevertheless,the challenges such as severe phase transitions,sluggish diffusion kinetics and interfacial degradation pose significant hurdles in achieving high-performance cathodes for SIBs.This review first briefly outlines the classification of layered structures and the working principle of layered oxides.Then,recent advances in modification strategies employed to address current issues with layered iron-based oxide cathodes are systematically reviewed,including ion doping,biphasic engineering and surface modification.Furthermore,the review not only outlines the prospects and development directions for layered Fe-based oxide cathodes but also provides novel insights and directions for future research endeavors for SIBs.展开更多
Sulfide-based all-solid-state lithium batteries suffer from electrochemo-mechanical damage to Ni-rich oxide-based cathode active materials(CAMs),primarily caused by severe volume changes,results in significant stress ...Sulfide-based all-solid-state lithium batteries suffer from electrochemo-mechanical damage to Ni-rich oxide-based cathode active materials(CAMs),primarily caused by severe volume changes,results in significant stress and strain,causes micro-cracks and interfacial contact loss at potentials>4.3 V(vs.Li/Li^(+)).Quantifying micro-cracks and voids in CAMs can reveal the degradation mechanisms of Ni-rich oxidebased cathodes during electrochemical cycling.Nonetheless,the origin of electrochemical-mechanical damage remains unclear.Herein,We have developed a multifunctional PEG-based soft buffer layer(SBL)on the surface of carbon black(CB).This layer functions as a percolation network in the single crystal LiNi_(0.83)Co_(0.07)Mn_(0.1)O_(2)and Li_(6)PS_(5)Cl composite cathode layer,ensuring superior ionic conductivity,reducing void formation and particle cracking,and promoting uniform utilization of the cathode active material in all-solid-state lithium batteries(ASSLBs).High-angle annular dark-field STEM combined with nanoscale X-ray holo-tomography and plasma-focused ion beam scanning electron microscopy confirmed that the PEG-based SBL mitigated strain induced by reaction heterogeneity in the cathode.This strain produces lattice stretches,distortions,and curved transition metal oxide layers near the surface,contributing to structural degradation at elevated voltages.Consequently,ASSLBs with a LiNi_(0.83)Co_(0.07)Mn_(0.1)O_(2)cathode containing LCCB-10(CB/PEG mass ratio:100/10)demonstrate a high areal capacity(2.53 mAh g^(-1)/0.32 mA g^(-1))and remarkable rate capability(0.58 mAh g^(-1)at 1.4 mA g^(-1)),with88%capacity retention over 1000 cycles.展开更多
The implementation of ultrahigh-Ni cathodes in high-energy lithium-ion batteries(LIBs)is constrained by significant structural and interfacial degradation during cycling.In this study,doping-induced surface restructur...The implementation of ultrahigh-Ni cathodes in high-energy lithium-ion batteries(LIBs)is constrained by significant structural and interfacial degradation during cycling.In this study,doping-induced surface restructuring in ultrahigh-nickel cathode materials is rapidly facilitated through an ultrafast Joule heating method.Density functional theory(DFT)calculations,synchrotron X-ray absorption spectroscopy(XAS),and single-particle force test confirmed the establishment of a stable crystal framework and lattice oxygen,which mitigated H2-H3 phase transitions and improved structural reversibility.Additionally,the Sc doping process exhibits a pinning effect on the grain boundaries,as shown by scanning transmission electron microscopy(STEM),enhancing Li~+diffusion kinetics and decreasing mechanical strain during cycling.The in situ development of a cation-mixing layer at grain boundaries also creates a robust cathode/electrolyte interphase,effectively reducing interfacial parasitic reactions and transition metal dissolution,as validated by STEM and time-of-flight secondary ion mass spectrometry(TOF-SIMS).These synergistic modifications reduce particle cracking and surface/interface degradation,leading to enhanced rate capability,structural integrity,and thermal stability.Consequently,the optimized Sc-modified ultrahigh-Ni cathode(Sc-1)exhibits 93.99%capacity retention after 100 cycles at 1 C(25℃)and87.06%capacity retention after 100 cycles at 1 C(50℃),indicating excellent cycling and thermal stability.By presenting a one-step multifunctional modification approach,this research delivers an extensive analysis of the mechanisms governing the structure,microstructure,and interface properties of nickel-rich layered cathode materials(NCMs).These results underscore the potential of ultrahigh-Ni cathodes as viable candidates for advanced lithium-ion batteries(LIBs)in next-generation electric vehicles(EVs).展开更多
Minimizing the thermal expansion coefficient(TEC)mismatch between the cathode and electrolyte in solid oxide fuel cells is crucial for achieving stable,durable operation and high performance.Recently,materials with ne...Minimizing the thermal expansion coefficient(TEC)mismatch between the cathode and electrolyte in solid oxide fuel cells is crucial for achieving stable,durable operation and high performance.Recently,materials with negative thermal expansion(NTE)have at-tracted significant attention as effective additives for tailoring the thermomechanical properties of electrodes and enhancing cell durability.In this work,for the first time,single-phase NTE perovskite Sm_(0.85)Zn_(0.15)MnO_(3−δ)(SZM15)was successfully synthesized via the sol-gel method,eliminating the unwanted ZnO phase typically observed in materials obtained through the conventional solid-state reaction route.The sol-gel approach proved highly advantageous,offering low cost,robustness,excellent chemical homogeneity,precise compositional control,and high phase purity.After optimization of synthesis parameters,a negative TEC of approximately−6.5×10^(−6)K^(−1)was achieved in the 400-850℃range.SZM15 was then incorporated as an additive(10wt%-50wt%)into a SmBa0.5Sr0.5CoCuO_(5+δ)(SBSCCO)cathode to tune the thermomechanical properties with a La_(0.8)Sr_(0.2)Ga_(0.8)Mg_(0.2)O_(3−δ)(LSGM)electrolyte,achieving a minimal TEC mismatch of only 1%.Notably,the SBSCCO+10wt%SZM15 composite cathode exhibited the lowest polarization resistance of 0.019Ω·cm^(2)at 900℃,showing approximately 70%lower than that of the pristine cathode.Excellent long-term stability after 100 h of operation was achieved.In addition,a high peak power density of 680 mW·cm^(−2)was achieved in a Ni-YSZ(yttria-stabilized zirconia)|YSZ|Ce_(0.9)Gd_(0.1)O_(2−δ)(GDC10)|SBSCCO+10wt%SZM15 anode-supported fuel cell at 850℃,highlighting the effectiveness of incorporating NTE materials as a promising strategy for regulating the thermomechanical properties and improving the long-term stability of intermediate temperature solid oxide fuel cells(IT-SOFCs).展开更多
The sodium superionic conductor(NASICON)-type cathode,Na_(3)V_(2)(PO_(4))_(3)(NVP),is considered as a promising cathode material for sodium-ion batteries(SIBs),which offers stable sodium storage capability.However,haz...The sodium superionic conductor(NASICON)-type cathode,Na_(3)V_(2)(PO_(4))_(3)(NVP),is considered as a promising cathode material for sodium-ion batteries(SIBs),which offers stable sodium storage capability.However,hazardous and expensive vanadium(V)has limited its practical application.To reduce the V dependency in NASICON-type cathodes,two new NASICON-structured materials,Na_(3)VMg_(0.5)Ti_(0.5)(PO_(4))_(3)(N_(3.0)VMTP/C)and Na_(3.5)V_(0.5)MgTi_(0.5)(PO_(4))_(3)(N_(3.5)VMTP/C),were designed for cost-effectiveness as well as improvement of battery performance.N_(3.0)VMTP/C and N_(3.5)VMTP/C provided a sodium storage capacity of 155.84 mAh g^(−1)and 105 mAh g^(−1)at 12 mA g^(−1)with 88%and 84%capacity retention after 500 cycles at 150 mA g^(−1),respectively.In-situ XRD analysis revealed that both cathodes undergo a progressive solid solution reaction in the lower voltage region and two-phase reaction at higher voltages during(de)sodiation,with only minor difference in the degree of lattice displacement,confirming their high potential for the SIBs with sustainable and cheaper Mg for grid-scale utilization.展开更多
Lithium-rich manganese-based cathodes(LRMs)have garnered significant attention as promising candidates for highenergy-density batteries due to their exceptional specific capacity exceeding 300 mAh/g,achieved through s...Lithium-rich manganese-based cathodes(LRMs)have garnered significant attention as promising candidates for highenergy-density batteries due to their exceptional specific capacity exceeding 300 mAh/g,achieved through synergistic anionic and cationic redox reactions.However,these materials face challenges including oxygen release-induced structural degradation and consequent capacity fading.To address these issues,strategies such as surface modification and bulk phase engineering have been explored.In this study,we developed a facile and cost-effective quenching approach that simultaneously modifies both surface and bulk characteristics.Multi-scale characterization and computational analysis reveal that rapid cooling partially preserves the high-temperature disordered phase in the bulk structure,thereby enhancing the structural stability.Concurrently,Li^(+)/H^(+)exchange at the surface forms a robust rock-salt/spinel passivation layer,effectively suppressing oxygen evolution and mitigating interfacial side reactions.This dual modification strategy demonstrates a synergistic stabilization effect.The enhanced oxygen redox activity coexists with the improved structural integrity,leading to superior electrochemical performance.The optimized cathode delivers an initial discharge capacity approaching 307.14 mAh/g at 0.1 C and remarkable cycling stability with 94.12%capacity retention after 200 cycles at 1 C.This study presents a straightforward and economical strategy for concurrent surface–bulk modification,offering valuable insights for designing high-capacity LRM cathodes with extended cycle life.展开更多
Ni-rich layered oxide cathode materials such as LiNi_(0.8)Mn_(0.1)Co_(0.1)O_(2)(NCM811)face poor interfacial stability and serious side reactions with sulfide solid-state electrolytes.This problem is thought to be exa...Ni-rich layered oxide cathode materials such as LiNi_(0.8)Mn_(0.1)Co_(0.1)O_(2)(NCM811)face poor interfacial stability and serious side reactions with sulfide solid-state electrolytes.This problem is thought to be exacerbated by the gradually accumulated basicity of the surface with the Ni content increasing.Herein,the acidic Li_(3)PO_(4)coating layer on NCM811 particles is introduced by ball-milling approach to neutralize the basicity and aggrandize the interfacial stability.The tailored surface structure and components of NCM811 not only suppress the direct contact of cathode particles with sulfide solid-state electrolyte,but also facilitate electrochemical dynamics by driving the Li+migration across the interface and promoting the electron exchange.Thus,cells with Li_(3)PO_(4)coating layer yield 101.3 mAh g^(-1)specific capacity at 2.0 C and highly reversed discharging capacity after suffering from harsh work conditions.Additionally,the stable coating layer broadens the electrochemical windows of cells,delivering long cycle stability(>100 cycles 0.5 C).This contribution highlights the importance of basicity regulation of Ni-rich layered oxide cathode and offers a low-cost and effective approach to design the interfacial structures for the development of all solid-state batteries.展开更多
Developing cost-effective single-crystalline Ni-rich Co-poor cathodes operating at high-voltage is one of the most important ways to achieve higher energy Li-ion batteries. However, the Li/O loss and Li/Ni mixing unde...Developing cost-effective single-crystalline Ni-rich Co-poor cathodes operating at high-voltage is one of the most important ways to achieve higher energy Li-ion batteries. However, the Li/O loss and Li/Ni mixing under high-temperature lithiation result in electrochemical kinetic hysteresis and structural instability. Herein, we report a highly-ordered single-crystalline LiNi0.85Co0.05Mn0.10O2(NCM85) cathode by doping K+and F-ions. To be specific, the K-ion as a fluxing agent can remarkably decrease the solid-state lithiation temperature by ~30°C, leading to less Li/Ni mixing and oxygen vacancy. Meanwhile, the strong transitional metal(TM)-F bonds are helpful for enhancing de-/lithiation kinetics and limiting the lattice oxygen escape even at 4.5 V high-voltage. Their advantages synergistically endow the single-crystalline NCM85 cathode with a very high reversible capacity of 222.3 mAh g-1. A superior capacity retention of 91.3% is obtained after 500 times at 1 C in pouch-type full cells, and a prediction value of 75.3% is given after cycling for 5000 h. These findings are reckoned to expedite the exploitation and application of high-voltage single-crystalline Ni-rich cathodes for next-generation Li-ion batteries.展开更多
Lithium-rich manganese-based cathode materials(LMCMs)have garnered significant attention in power lithium-ion batteries(LIBs)and energy storage systems due to their superior energy density and costeffectiveness.Howeve...Lithium-rich manganese-based cathode materials(LMCMs)have garnered significant attention in power lithium-ion batteries(LIBs)and energy storage systems due to their superior energy density and costeffectiveness.However,the commercial application of LMCMs is hindered by challenges such as low initial coulombic efficiency,severe voltage decay,and inferior cycling performance.Surface structure degradation has been confirmed as a critical factor contributing to the electrochemical performance deterioration of LMCMs.Herein,we review the recent progress in surface engineering of LMCMs towards next-generation LIBs.Besides classical surface coating,mechanism and functions of surface oxygen vacancies for greatly boosting the electrochemical performance of LMCMs are also summarized in detail.Finally,we discuss the emerging trends and propose future research directions of surface engineering of LMCMs for achieving more efficient improvements.This work underscores the indispensable potential of surface engineering in enhancing the surface structure stability and electrochemical performance of LMCMs as promising candidates for next-generation high-energy LIBs.Synergistic integration of surface engineering and single-crystal technology will be a promising modification strategy for significantly promoting the commercialization of LMCMs,and the corresponding synergistic mechanisms urgently need to be studied for rationally designing high-performance electrodes.More efforts will be devoted to understand the surface engineering of LMCMs for the large-scale application of high-energy LIBs.展开更多
Sodium-ion batteries have emerged as promising candidates for next-generation large-scale energy storage systems due to the abundance of sodium resources,low solvation energy,and cost-effectiveness.Among the available...Sodium-ion batteries have emerged as promising candidates for next-generation large-scale energy storage systems due to the abundance of sodium resources,low solvation energy,and cost-effectiveness.Among the available cathode materials,vanadium-based sodium phosphate cathodes are particularly notable for their high operating voltage,excellent thermal stability,and superior cycling performance.However,these materials face significant challenges,including sluggish reaction kinetics,the toxicity of vanadium,and poor electronic conductivity.To overcome these limitations and enhance electrochemical performance,various strategies have been explored.These include morphology regulation via diverse synthesis routes and electronic structure optimization through metal doping,which effectively improve the diffusion of Na+and electrons in vanadium-based phosphate cathodes.This review provides a comprehensive overview of the challenges associated with V-based polyanion cathodes and examines the role of morphology and electronic structure design in enhancing performance.Key vanadium-based phosphate frameworks,such as orthophosphates(Na_(3)V_(2)(PO_(4))_(3)),pyrophosphates(NaVP_(2)O_(7),Na_(2)(VO)P_(2)O_(7),Na_(7)V_(3)(P_(2)O_(7))_(4)),and mixed phosphates(Na_(7)V_(4)(P_(2)O_(7))_(4)PO_(4)),are discussed in detail,highlighting recent advances and insights into their structure-property relationships.The design of cathode material morphology offers an effective approach to optimizing material structures,compositions,porosity,and ion/electron diffusion pathways.Simultaneously,electronic structure tuning through element doping allows for the regulation of band structures,electron distribution,diffusion barriers,and the intrinsic conductivity of phosphate compounds.Addressing the challenges associated with vanadium-based sodium phosphate cathode materials,this study proposes feasible solutions and outlines future research directions toward advancement of high-performance vanadium-based polyanion cathodes.展开更多
O3-type layered oxide cathodes for sodium-ion batteries are promising owing to high theoretical capacity and broad temperature adaptability,yet hindered by structural degradation and sluggish Na^(+)diffusion kinetics....O3-type layered oxide cathodes for sodium-ion batteries are promising owing to high theoretical capacity and broad temperature adaptability,yet hindered by structural degradation and sluggish Na^(+)diffusion kinetics.Herein,we present a sodium-deficient high-entropy layered oxide cathode(Na_(0.85)Ni_(0.3)Mn_(0.3)Fe_(0.1)Co_(0.15)Ti_(0.1)Cu_(0.05)B_(0.02)O_(2),denoted as Na0.85-HEO),combining sodium content optimization and high-entropy composition design.Incorporating six transition metals and light element boron creates a unique high-entropy configuration,effectively mitigating local lattice distortion and internal strain through chemical disorder effects,thereby enabling highly reversible phase transitions(O3-P3-O3)and smaller volume change(0.6A^(3))during the initial cycle.The sodium-deficient high-entropy design effectively increases the sodium interlayer spacing to 0.322 nm,facilitating the Na^(+)diffusion kinetics.Moreover,this high-entropy strategy enables the cathode to have a completely solid solution charge curve and significantly reduces the proportion of(O_(2))^(n-),thereby suppressing gas release during the cycling process.The resultant cathode demonstrates exceptional cyclability(80% capacity retention after 400 cycles at 100 mA g^(-1)in a full cell),and remarkable low-temperature performance(108.6 mAh g^(-1)at -40℃).This work guides the design of high-entropy electrode materials with tailored ionic transport channels for extreme-temperature energy storage applications.展开更多
ⅢThe superior adaptability of Prussian blue analogues(PBAs)in interacting with potassium ions has shifted research focus toward their potential application as cathodes of potassium-ion batteries(PIBs).The large inter...ⅢThe superior adaptability of Prussian blue analogues(PBAs)in interacting with potassium ions has shifted research focus toward their potential application as cathodes of potassium-ion batteries(PIBs).The large interstitial space formed between metal ions and–C≡N–in PBAs can accommodate large-radius K^(+).However,the rapid nucleation in the co-precipitation synthesis process of PBAs induces many lattice defects of[M(CN)_(6)]^(4-)vacancies(V_([M–C≡N])),interstitial and coordinated H_(2)O molecules,which will directly lead to performance degradation.Moreover,originating from various transition metal elements in low/high-spin electron configuration states,PBAs exhibit diverse electrochemical behaviors,such as low reaction kinetics of low-spin iron(Ⅱ),Jahn-Teller distortion and dissolution of manganese(Ⅲ),and electrochemical inertness of nickel(Ⅱ)and copper(Ⅱ).Here,we summarize recently reported structures and properties of PBAs,classifying them based on the types of transition metals(iron,cobalt,manganese,copper,nickel)employed.Advanced synthesis strategies,including control engineering of crystallinity based on H_(2)O molecules and V_([M–C≡N]),were discussed.Also,the approaches for enhancing the electrochemical performance of PBAs were highlighted.Finally,the challenges and prospects towards the future development of PBAs are put forward.The review is expected to provide technical and theoretical support for the design of high-performance PBAs.展开更多
In the realm of sodium-ion batteries(SIBs),Mn-based layered oxide cathodes have garnered considerable attention owing to their anionic redox reactions(ARRs).Compared to other types of popular sodium-ion cathodes,Mn-ba...In the realm of sodium-ion batteries(SIBs),Mn-based layered oxide cathodes have garnered considerable attention owing to their anionic redox reactions(ARRs).Compared to other types of popular sodium-ion cathodes,Mn-based layered oxide cathodes with ARRs exhibit outstanding specific capacity and energy density,making them promising for SIB applications.However,these cathodes still face some scientific challenges that need to be addressed.This review systematically summarizes the composition,structure,oxygen-redox mechanism,and performance of various types of Mn-based cathodes with ARRs,as well as the main scientific challenges they face,including sluggish ion diffusion,cationic migration,O_(2) release,and element dissolution.Currently,to resolve these challenges,efforts mainly focus on six aspects:synthesis methods,structural design,doped modification,electrolyte design,and surface engineering.Finally,this review provides new insights for future direction,encompassing both fundamental research,such as novel cathode types,interface optimization,and interdisciplinary research,and considerations from an industrialization perspective,including scalability,stability,and safety.展开更多
In pursuit of low cost and long life for lithium-ion batteries in electric vehicles,the most promising strategy is to replace the commercial LiCoO_(2)with a high-energy-density Ni-rich cathode.However,the irreversible...In pursuit of low cost and long life for lithium-ion batteries in electric vehicles,the most promising strategy is to replace the commercial LiCoO_(2)with a high-energy-density Ni-rich cathode.However,the irreversible redox couples induce rapid capacity decay,poor long-term cycling life,vast gas evolution,and unstable structure transformations of the Ni-rich cathode,limiting its practical applications.Element doping has been considered as the most promising strategy for addressing these issues.However,the relationships between element doping functions and redox chemistry still remain confused.To clarify this connection,this review places the dynamic evolution of redox couples(Li^(*),Ni^(2+)/Ni^(3+)/Ni^(4+)-e^(-),O^(2-)/O^(n-)/O_(2)-e^(-))as the tree trunk.The material structure,degradation mechanisms,and addressing element doping strategies are considered as the tree branches.This comprehensive summary aims to provide an overview of the current understanding and progress of Ni-rich cathode materials.In the last section,promising strategies based on element doping functions are provided to encourage the practical application of Ni-rich cathodes.These strategies also offer a new approach for the development of other intercalated electrode materials in Na and K-based battery systems.展开更多
LiNixCoyMn_(2)O_(2)(NCM,x≥0.8,x+y+z=1)cathodes have attracted much attention due to their high specific capacity and low cost.However,severe anisotropic volume changes and oxygen evolution induced capacity decay and ...LiNixCoyMn_(2)O_(2)(NCM,x≥0.8,x+y+z=1)cathodes have attracted much attention due to their high specific capacity and low cost.However,severe anisotropic volume changes and oxygen evolution induced capacity decay and insecurity have hindered their commercial application at scale.In order to overcome these challenges,a kind of tantalum(Ta)doped nickel-rich cathode with reduced size and significantly increased number of primary particles is prepared by combining mechanical fusion with high temperature co-calcination.The elaborately designed micro-morphology of small and uniform primary particles effectively eliminates the local strain accumulation caused by the random orientation of primary particles.Moreover,the uniform distribution of small primary particles stabilizes the spherical secondary particles,thus effectively inhibiting the formation and extension of microcracks.In addition,the formed strong Ta-O bonds restrain the release of lattice oxygen,which greatly increases the structural stability and safety of NCM materials.Therefore,the cathode material with the designed primary particle morphology shows superior electrochemical performance.The 1 mol%Ta-modified cathode(defined as1%Ta-NCM)shows a capacity retention of 97.5%after 200 cycles at 1 C and a rate performance of 137.3 mAh g^(-1)at 5 C.This work presents promising approach to improve the structural stability and safety of nickel-rich NCM.展开更多
Mn-based layered oxides are widely recognized as cathode materials for potassium-ion batteries(KIBs)due to their high specific capacity derived from their low molar mass.However,the structural instability caused by th...Mn-based layered oxides are widely recognized as cathode materials for potassium-ion batteries(KIBs)due to their high specific capacity derived from their low molar mass.However,the structural instability caused by the Jahn-Teller effect of Mn^(3+)and the large ionic radius of K+results in poor electrochemical performance.Herein,we propose an effective structural stabilization strategy for P2-type Mn-based layered oxide cathodes of KIBs through Li-incorporation into the transition metal layer.Using the firstprinciples calculations and experiments,we demonstrate that the P2-K_(0.48)[Li_(0.1)Mn_(0.9)]O_(2)(P2-KLMO)delivers improved electrochemical performance,specific capacity and average discharge voltage of~124.4 m A h g^(-1)and~2.7 V(vs.K^(+)/K)at 0.05C(1C=260 mA g^(-1)),outperforming P2-K_(0.5)MnO_(2).Operando X-ray diffraction analysis confirms the P2-OP4 phase transition and Mn^(3+)-induced Jahn-Teller distortion are significantly suppressed in P2-KLMO.These improvements are attributed to the lithium introduction into transition metal layers,leading to strengthened structural stability and enhanced K+diffusion kinetics.Moreover,synthetic accessibility through the conventional solid-state method provides an additional advantage for practical application of Li-incorporated Mn-based P2-type cathodes in KIBs.We believe our study offers a simple yet effective strategy for designing highperformance and practical cathode materials for KIBs.展开更多
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
Advanced lithium-chalcogen(S,Se,Te)batteries(LCBs)are among the most promising candidates for next generation energy storage systems because of their high energy density and theoretical capacities.However,they are sti...Advanced lithium-chalcogen(S,Se,Te)batteries(LCBs)are among the most promising candidates for next generation energy storage systems because of their high energy density and theoretical capacities.However,they are still facing many challenges,such as expansion of the volume problems of chalcogen elements,the shuttle effect of intermediate products,low Coulombic efficiency and inferior cycling stability,which seriously hinder their commercial applications.The presence of a binder in the cathode causes an uneven distribution of the active substances,and also occupies a part of the electrode's volume,resulting in the unsatisfactory energy density of LCBs.In this regard,binder-free electrodes which do not need binders,conductive materials and even collectors,can be used as electrodes for flexible batteries,effectively solving the above-mentioned problems.In this review,the main methods of fabricating binder-free cathodes and their advantages and disadvantages are discussed.Furthermore,a review of representative works on binder-free cathodes for high-performance LCBs over the last decade is presented.The main binder-free electrode materials include paper cloth(PC),graphene oxide(GO),carbon nanotubes(CNTs),carbon nanofibers(CNFs),carbon cloth(CC),polymers,metallic compounds,and their composites.In addition,we discuss these works from four aspects:Advanced structures,methods of fabrication,electrochemical performance and the potential mechanism of binder-free cathode materials,providing important guidance for further researches.Finally,we propose the current challenges of binder-free LCBs and look forward to breakthroughs in this field through the use of binder-free electrodes.展开更多
基金Supported by the National Natural Science Foundation of China(No.60871053)
文摘With the most advanced Synchronous Radiation Photoelectron Spectrum(SRPS),the emission mechanism of M-type cathodes has been investigated from the perspective of chemical state.Based on the experimental results of SRPS analysis,a new model of the electron emission mechanism for M-type cathode is discussed.The main topics in this paper include the research status of electron emission mechanism of M-type cathodes;the advantages of SRPS technology;the distribution of oxygen chemical state on the cathode surface and the evolvement of oxygen chemical state during activation process;the relation between barium chemical state and osmium(Os)-coating;surplus barium and its formula;the characteristics of Os,and other noble metal coatings;the relation between film characteristics and emission performance of cathodes,the inhibition effects to the emission for Platinum(Pt)-coated cathode,etc.At the end of this paper,electron emission mechanism of M-type cathode is summarized and foreseen.
基金financially supported by the National Natural Science Foundation of China(NSFC)(52274295)the Natural Science Foundation of Hebei Province(E2021501029)+3 种基金the Fundamental Research Funds for the Central Universities(N2423051,N2423053,N2302016,N2423019,N2323013,N2423005)the Science and Technology Project of Hebei Education Department(QN2024238)the Basic Research Program Project of Shijiazhuang City for Universities Stationed in Hebei Province(241790937A)the Science and Technology Project of Qinhuangdao City in 2023.
文摘Mn-based layered oxides(KMO)have emerged as one of the promising low-cost cathodes for potassiumion batteries(PIBs).However,due to the multiple-phase transitions and the distortion in the MnO6structure induced by the Jahn-Teller(JT)effect associated with Mn-ion,the cathode exhibits poor structural stability.Herein,we propose a strategy to enhance structural stability by introducing robust metal-oxygen(M-O)bonds,which can realize the pinning effect to constrain the distortion in the transition metal(TM)layer.Concurrently,all the elements employed have exceptionally high crustal abundance.As a proof of concept,the designed K_(0.5)Mn_(0.9)Mg_(0.025)Ti_(0.025)Al_(0.05)O_(2)cathode exhibited a discharge capacity of approximately 100 mA h g^(-1)at 20 mA g^(-1)with 79%capacity retention over 50 cycles,and 73%capacity retention over 200 cycles at 200 mA g^(-1),showcased much better battery performance than the designed cathode with less robust M-O bonds.The properties of the formed M-O bonds were investigated using theoretical calculations.The enhanced dynamics,mitigated JT effect,and improved structural stability were elucidated through the in-situ X-ray diffractometer(XRD),in-situ electrochemical impedance spectroscopy(EIS)(and distribution of relaxation times(DRT)method),and ex-situ X-ray absorption fine structure(XAFS)tests.This study holds substantial reference value for the future design of costeffective Mn-based layered cathodes for PIBs.
基金supported by the National Natural Science Foundation of China(no.52374301)the Open Project of Guangxi Key Laboratory of Electrochemical Energy Materials(no.GXUEEM2024001)+2 种基金the Hebei Provincial Natural Science Foundation(no.E2024501010)the Shijiazhuang Basic Research Project(no.241790667A)the Performance subsidy fund for Key Laboratory of Dielectric and Electrolyte Functional Material Hebei Province(no.22567627H)。
文摘Sodium-ion batteries(SIBs)have the advantages of environmental friendliness,cost-effectiveness,and high energy density,which are considered one of the most promising candidates for lithium-ion batteries(LIBs).The cathode materials influence the cost and energy output of SIBs.Therefore,the development of advanced cathode materials is crucial for the practical application of SIBs.Among various cathode materials,layered transition metal oxides(LTMOs)have received widespread attention owing to their straightforward preparation,abundant availability,and cost-competitiveness.Notably,layered Fe-based oxide cathodes are deemed to be one of the most promising candidates for the lowest price and easy-to-improve performance.Nevertheless,the challenges such as severe phase transitions,sluggish diffusion kinetics and interfacial degradation pose significant hurdles in achieving high-performance cathodes for SIBs.This review first briefly outlines the classification of layered structures and the working principle of layered oxides.Then,recent advances in modification strategies employed to address current issues with layered iron-based oxide cathodes are systematically reviewed,including ion doping,biphasic engineering and surface modification.Furthermore,the review not only outlines the prospects and development directions for layered Fe-based oxide cathodes but also provides novel insights and directions for future research endeavors for SIBs.
基金supported by the Hainan Province Science and Technology Special Fund(ZDYF2021SHFZ232,ZDYF2023GXJS022)the Hainan Province Postdoctoral Science Foundation(300333)the National Natural Science Foundation of China(21203008,21975025,12274025,22372008)。
文摘Sulfide-based all-solid-state lithium batteries suffer from electrochemo-mechanical damage to Ni-rich oxide-based cathode active materials(CAMs),primarily caused by severe volume changes,results in significant stress and strain,causes micro-cracks and interfacial contact loss at potentials>4.3 V(vs.Li/Li^(+)).Quantifying micro-cracks and voids in CAMs can reveal the degradation mechanisms of Ni-rich oxidebased cathodes during electrochemical cycling.Nonetheless,the origin of electrochemical-mechanical damage remains unclear.Herein,We have developed a multifunctional PEG-based soft buffer layer(SBL)on the surface of carbon black(CB).This layer functions as a percolation network in the single crystal LiNi_(0.83)Co_(0.07)Mn_(0.1)O_(2)and Li_(6)PS_(5)Cl composite cathode layer,ensuring superior ionic conductivity,reducing void formation and particle cracking,and promoting uniform utilization of the cathode active material in all-solid-state lithium batteries(ASSLBs).High-angle annular dark-field STEM combined with nanoscale X-ray holo-tomography and plasma-focused ion beam scanning electron microscopy confirmed that the PEG-based SBL mitigated strain induced by reaction heterogeneity in the cathode.This strain produces lattice stretches,distortions,and curved transition metal oxide layers near the surface,contributing to structural degradation at elevated voltages.Consequently,ASSLBs with a LiNi_(0.83)Co_(0.07)Mn_(0.1)O_(2)cathode containing LCCB-10(CB/PEG mass ratio:100/10)demonstrate a high areal capacity(2.53 mAh g^(-1)/0.32 mA g^(-1))and remarkable rate capability(0.58 mAh g^(-1)at 1.4 mA g^(-1)),with88%capacity retention over 1000 cycles.
基金supported by the National Key R&D Program of China(2022YFB3803501)the National Natural Science Foundation of China(22179008,22209156)+5 种基金support from the Beijing Nova Program(20230484241)support from the China Postdoctoral Science Foundation(2024M754084)the Postdoctoral Fellowship Program of CPSF(GZB20230931)support from beamline BL08U1A of Shanghai Synchrotron Radiation Facility(2024-SSRF-PT-506950)beamline 1W1B of the Beijing Synchrotron Radiation Facility(2021-BEPC-PT-006276)support from Initial Energy Science&Technology Co.,Ltd(IEST)。
文摘The implementation of ultrahigh-Ni cathodes in high-energy lithium-ion batteries(LIBs)is constrained by significant structural and interfacial degradation during cycling.In this study,doping-induced surface restructuring in ultrahigh-nickel cathode materials is rapidly facilitated through an ultrafast Joule heating method.Density functional theory(DFT)calculations,synchrotron X-ray absorption spectroscopy(XAS),and single-particle force test confirmed the establishment of a stable crystal framework and lattice oxygen,which mitigated H2-H3 phase transitions and improved structural reversibility.Additionally,the Sc doping process exhibits a pinning effect on the grain boundaries,as shown by scanning transmission electron microscopy(STEM),enhancing Li~+diffusion kinetics and decreasing mechanical strain during cycling.The in situ development of a cation-mixing layer at grain boundaries also creates a robust cathode/electrolyte interphase,effectively reducing interfacial parasitic reactions and transition metal dissolution,as validated by STEM and time-of-flight secondary ion mass spectrometry(TOF-SIMS).These synergistic modifications reduce particle cracking and surface/interface degradation,leading to enhanced rate capability,structural integrity,and thermal stability.Consequently,the optimized Sc-modified ultrahigh-Ni cathode(Sc-1)exhibits 93.99%capacity retention after 100 cycles at 1 C(25℃)and87.06%capacity retention after 100 cycles at 1 C(50℃),indicating excellent cycling and thermal stability.By presenting a one-step multifunctional modification approach,this research delivers an extensive analysis of the mechanisms governing the structure,microstructure,and interface properties of nickel-rich layered cathode materials(NCMs).These results underscore the potential of ultrahigh-Ni cathodes as viable candidates for advanced lithium-ion batteries(LIBs)in next-generation electric vehicles(EVs).
基金supported by the research project within the program“Excellence Initiative-Research University”for the AGH University of Krakow(IDUB AGH,Action 21)Kun Zheng acknowledges financial support from AGH University of Krakow(No.16.16.210.476).
文摘Minimizing the thermal expansion coefficient(TEC)mismatch between the cathode and electrolyte in solid oxide fuel cells is crucial for achieving stable,durable operation and high performance.Recently,materials with negative thermal expansion(NTE)have at-tracted significant attention as effective additives for tailoring the thermomechanical properties of electrodes and enhancing cell durability.In this work,for the first time,single-phase NTE perovskite Sm_(0.85)Zn_(0.15)MnO_(3−δ)(SZM15)was successfully synthesized via the sol-gel method,eliminating the unwanted ZnO phase typically observed in materials obtained through the conventional solid-state reaction route.The sol-gel approach proved highly advantageous,offering low cost,robustness,excellent chemical homogeneity,precise compositional control,and high phase purity.After optimization of synthesis parameters,a negative TEC of approximately−6.5×10^(−6)K^(−1)was achieved in the 400-850℃range.SZM15 was then incorporated as an additive(10wt%-50wt%)into a SmBa0.5Sr0.5CoCuO_(5+δ)(SBSCCO)cathode to tune the thermomechanical properties with a La_(0.8)Sr_(0.2)Ga_(0.8)Mg_(0.2)O_(3−δ)(LSGM)electrolyte,achieving a minimal TEC mismatch of only 1%.Notably,the SBSCCO+10wt%SZM15 composite cathode exhibited the lowest polarization resistance of 0.019Ω·cm^(2)at 900℃,showing approximately 70%lower than that of the pristine cathode.Excellent long-term stability after 100 h of operation was achieved.In addition,a high peak power density of 680 mW·cm^(−2)was achieved in a Ni-YSZ(yttria-stabilized zirconia)|YSZ|Ce_(0.9)Gd_(0.1)O_(2−δ)(GDC10)|SBSCCO+10wt%SZM15 anode-supported fuel cell at 850℃,highlighting the effectiveness of incorporating NTE materials as a promising strategy for regulating the thermomechanical properties and improving the long-term stability of intermediate temperature solid oxide fuel cells(IT-SOFCs).
基金supported by the National Research Foundation of Korea(NRF)grant funded by the Korean government(MSIT)(RS-2025-00520759)supported by the National Research Foundation of Korea(NRF)grant funded by the Korean government(No.RS-2023-NR077186 and RS-2024-00405185).
文摘The sodium superionic conductor(NASICON)-type cathode,Na_(3)V_(2)(PO_(4))_(3)(NVP),is considered as a promising cathode material for sodium-ion batteries(SIBs),which offers stable sodium storage capability.However,hazardous and expensive vanadium(V)has limited its practical application.To reduce the V dependency in NASICON-type cathodes,two new NASICON-structured materials,Na_(3)VMg_(0.5)Ti_(0.5)(PO_(4))_(3)(N_(3.0)VMTP/C)and Na_(3.5)V_(0.5)MgTi_(0.5)(PO_(4))_(3)(N_(3.5)VMTP/C),were designed for cost-effectiveness as well as improvement of battery performance.N_(3.0)VMTP/C and N_(3.5)VMTP/C provided a sodium storage capacity of 155.84 mAh g^(−1)and 105 mAh g^(−1)at 12 mA g^(−1)with 88%and 84%capacity retention after 500 cycles at 150 mA g^(−1),respectively.In-situ XRD analysis revealed that both cathodes undergo a progressive solid solution reaction in the lower voltage region and two-phase reaction at higher voltages during(de)sodiation,with only minor difference in the degree of lattice displacement,confirming their high potential for the SIBs with sustainable and cheaper Mg for grid-scale utilization.
基金supported by the National Key Research and Development Program of China(Grant No.2022YFB2502200)the National Natural Science Foundation of China(Grant Nos.52325207,22239003,and 22393904).
文摘Lithium-rich manganese-based cathodes(LRMs)have garnered significant attention as promising candidates for highenergy-density batteries due to their exceptional specific capacity exceeding 300 mAh/g,achieved through synergistic anionic and cationic redox reactions.However,these materials face challenges including oxygen release-induced structural degradation and consequent capacity fading.To address these issues,strategies such as surface modification and bulk phase engineering have been explored.In this study,we developed a facile and cost-effective quenching approach that simultaneously modifies both surface and bulk characteristics.Multi-scale characterization and computational analysis reveal that rapid cooling partially preserves the high-temperature disordered phase in the bulk structure,thereby enhancing the structural stability.Concurrently,Li^(+)/H^(+)exchange at the surface forms a robust rock-salt/spinel passivation layer,effectively suppressing oxygen evolution and mitigating interfacial side reactions.This dual modification strategy demonstrates a synergistic stabilization effect.The enhanced oxygen redox activity coexists with the improved structural integrity,leading to superior electrochemical performance.The optimized cathode delivers an initial discharge capacity approaching 307.14 mAh/g at 0.1 C and remarkable cycling stability with 94.12%capacity retention after 200 cycles at 1 C.This study presents a straightforward and economical strategy for concurrent surface–bulk modification,offering valuable insights for designing high-capacity LRM cathodes with extended cycle life.
基金supported by the National Natural Science Foundation of China(22379121)the Shenzhen Foundation Research Fund(JCYJ20210324104412034)+1 种基金the Fundamental Research Funds for the Central Universities(G2024KY05103)the“Scientists+Engineers”Team in Qinchuangyuan of Shaanxi Province(2024QCY-KXJ-023)。
文摘Ni-rich layered oxide cathode materials such as LiNi_(0.8)Mn_(0.1)Co_(0.1)O_(2)(NCM811)face poor interfacial stability and serious side reactions with sulfide solid-state electrolytes.This problem is thought to be exacerbated by the gradually accumulated basicity of the surface with the Ni content increasing.Herein,the acidic Li_(3)PO_(4)coating layer on NCM811 particles is introduced by ball-milling approach to neutralize the basicity and aggrandize the interfacial stability.The tailored surface structure and components of NCM811 not only suppress the direct contact of cathode particles with sulfide solid-state electrolyte,but also facilitate electrochemical dynamics by driving the Li+migration across the interface and promoting the electron exchange.Thus,cells with Li_(3)PO_(4)coating layer yield 101.3 mAh g^(-1)specific capacity at 2.0 C and highly reversed discharging capacity after suffering from harsh work conditions.Additionally,the stable coating layer broadens the electrochemical windows of cells,delivering long cycle stability(>100 cycles 0.5 C).This contribution highlights the importance of basicity regulation of Ni-rich layered oxide cathode and offers a low-cost and effective approach to design the interfacial structures for the development of all solid-state batteries.
基金supported by the National Natural Science Foundation of China(U22A20429 and 22308103)Shanghai Pilot Program for Basic Research(22TQ1400100-13)+2 种基金Postdoctoral Fellowship Program of CPSF(GZB20230214)China Postdoctoral Science Foundation(2023M731083)the Fundamental Research Funds for the Central Universities.
文摘Developing cost-effective single-crystalline Ni-rich Co-poor cathodes operating at high-voltage is one of the most important ways to achieve higher energy Li-ion batteries. However, the Li/O loss and Li/Ni mixing under high-temperature lithiation result in electrochemical kinetic hysteresis and structural instability. Herein, we report a highly-ordered single-crystalline LiNi0.85Co0.05Mn0.10O2(NCM85) cathode by doping K+and F-ions. To be specific, the K-ion as a fluxing agent can remarkably decrease the solid-state lithiation temperature by ~30°C, leading to less Li/Ni mixing and oxygen vacancy. Meanwhile, the strong transitional metal(TM)-F bonds are helpful for enhancing de-/lithiation kinetics and limiting the lattice oxygen escape even at 4.5 V high-voltage. Their advantages synergistically endow the single-crystalline NCM85 cathode with a very high reversible capacity of 222.3 mAh g-1. A superior capacity retention of 91.3% is obtained after 500 times at 1 C in pouch-type full cells, and a prediction value of 75.3% is given after cycling for 5000 h. These findings are reckoned to expedite the exploitation and application of high-voltage single-crystalline Ni-rich cathodes for next-generation Li-ion batteries.
基金financially supported by the National Natura Science Foundation of China(51108455,52106264)Civil Aviation Safety Capacity Building Fund(ADSA2022026)+2 种基金Liaoning Revitalization Talents Program(XLYC2018013)Liaoning Province AppliedFoundation Research Program Project(2023JH2/101300215)Unveiled the List of Local Service Projects from Education Department of Liaoning Province(JYTMS20230227)。
文摘Lithium-rich manganese-based cathode materials(LMCMs)have garnered significant attention in power lithium-ion batteries(LIBs)and energy storage systems due to their superior energy density and costeffectiveness.However,the commercial application of LMCMs is hindered by challenges such as low initial coulombic efficiency,severe voltage decay,and inferior cycling performance.Surface structure degradation has been confirmed as a critical factor contributing to the electrochemical performance deterioration of LMCMs.Herein,we review the recent progress in surface engineering of LMCMs towards next-generation LIBs.Besides classical surface coating,mechanism and functions of surface oxygen vacancies for greatly boosting the electrochemical performance of LMCMs are also summarized in detail.Finally,we discuss the emerging trends and propose future research directions of surface engineering of LMCMs for achieving more efficient improvements.This work underscores the indispensable potential of surface engineering in enhancing the surface structure stability and electrochemical performance of LMCMs as promising candidates for next-generation high-energy LIBs.Synergistic integration of surface engineering and single-crystal technology will be a promising modification strategy for significantly promoting the commercialization of LMCMs,and the corresponding synergistic mechanisms urgently need to be studied for rationally designing high-performance electrodes.More efforts will be devoted to understand the surface engineering of LMCMs for the large-scale application of high-energy LIBs.
基金supported by the National Natural Science Foundation of China(NSFC)(22105059,22179078,22479115)the Beijing-Tianjin-Hebei Basic Research Cooperation Special Project(B2024204027)+5 种基金the Youth Top-notch Talent Foundation of Hebei Provincial Universities(BJK2022023)the Natural Science Foundation of Hebei Province(B2023204006)the talent training project of Hebei province(No.B20231004)the Innovative Research Team of High-level Local Universities in ShanghaiZhejiang Provincial Natural Science Foundation of China(LY24E020002)Wenzhou basic scientific research project(G20240022)。
文摘Sodium-ion batteries have emerged as promising candidates for next-generation large-scale energy storage systems due to the abundance of sodium resources,low solvation energy,and cost-effectiveness.Among the available cathode materials,vanadium-based sodium phosphate cathodes are particularly notable for their high operating voltage,excellent thermal stability,and superior cycling performance.However,these materials face significant challenges,including sluggish reaction kinetics,the toxicity of vanadium,and poor electronic conductivity.To overcome these limitations and enhance electrochemical performance,various strategies have been explored.These include morphology regulation via diverse synthesis routes and electronic structure optimization through metal doping,which effectively improve the diffusion of Na+and electrons in vanadium-based phosphate cathodes.This review provides a comprehensive overview of the challenges associated with V-based polyanion cathodes and examines the role of morphology and electronic structure design in enhancing performance.Key vanadium-based phosphate frameworks,such as orthophosphates(Na_(3)V_(2)(PO_(4))_(3)),pyrophosphates(NaVP_(2)O_(7),Na_(2)(VO)P_(2)O_(7),Na_(7)V_(3)(P_(2)O_(7))_(4)),and mixed phosphates(Na_(7)V_(4)(P_(2)O_(7))_(4)PO_(4)),are discussed in detail,highlighting recent advances and insights into their structure-property relationships.The design of cathode material morphology offers an effective approach to optimizing material structures,compositions,porosity,and ion/electron diffusion pathways.Simultaneously,electronic structure tuning through element doping allows for the regulation of band structures,electron distribution,diffusion barriers,and the intrinsic conductivity of phosphate compounds.Addressing the challenges associated with vanadium-based sodium phosphate cathode materials,this study proposes feasible solutions and outlines future research directions toward advancement of high-performance vanadium-based polyanion cathodes.
基金financially supported by the National Natural Science Foundation of China(No.52071073,52177208,and 52171202)the Hebei Province“333 talent project”(No.C20221012)+2 种基金the Science and Technology Project of Hebei Education Department(BJK2023005)the Fundamental Research Funds for the Central Universities(2024GFZD002)the Natural Science Foundation of Hebei Province(E2024501015)。
文摘O3-type layered oxide cathodes for sodium-ion batteries are promising owing to high theoretical capacity and broad temperature adaptability,yet hindered by structural degradation and sluggish Na^(+)diffusion kinetics.Herein,we present a sodium-deficient high-entropy layered oxide cathode(Na_(0.85)Ni_(0.3)Mn_(0.3)Fe_(0.1)Co_(0.15)Ti_(0.1)Cu_(0.05)B_(0.02)O_(2),denoted as Na0.85-HEO),combining sodium content optimization and high-entropy composition design.Incorporating six transition metals and light element boron creates a unique high-entropy configuration,effectively mitigating local lattice distortion and internal strain through chemical disorder effects,thereby enabling highly reversible phase transitions(O3-P3-O3)and smaller volume change(0.6A^(3))during the initial cycle.The sodium-deficient high-entropy design effectively increases the sodium interlayer spacing to 0.322 nm,facilitating the Na^(+)diffusion kinetics.Moreover,this high-entropy strategy enables the cathode to have a completely solid solution charge curve and significantly reduces the proportion of(O_(2))^(n-),thereby suppressing gas release during the cycling process.The resultant cathode demonstrates exceptional cyclability(80% capacity retention after 400 cycles at 100 mA g^(-1)in a full cell),and remarkable low-temperature performance(108.6 mAh g^(-1)at -40℃).This work guides the design of high-entropy electrode materials with tailored ionic transport channels for extreme-temperature energy storage applications.
基金financially supported by research grants from Innovative Research Group Project of National Natural Science Foundation of China(No.52021004)National Key Research and Development Program of China(2022YFB3803300)+2 种基金National Natural Science Foundation of China(62474026 and 62074022)Natural Science Foundation of Chongqing(CSTB2024NSCQ-MSX1215,cstc2021jcyj-jqX0015 and CSTB2022NSCQ-MSX1183)the Youth Talent Support Program of Chongqing(CQYC2021059206).
文摘ⅢThe superior adaptability of Prussian blue analogues(PBAs)in interacting with potassium ions has shifted research focus toward their potential application as cathodes of potassium-ion batteries(PIBs).The large interstitial space formed between metal ions and–C≡N–in PBAs can accommodate large-radius K^(+).However,the rapid nucleation in the co-precipitation synthesis process of PBAs induces many lattice defects of[M(CN)_(6)]^(4-)vacancies(V_([M–C≡N])),interstitial and coordinated H_(2)O molecules,which will directly lead to performance degradation.Moreover,originating from various transition metal elements in low/high-spin electron configuration states,PBAs exhibit diverse electrochemical behaviors,such as low reaction kinetics of low-spin iron(Ⅱ),Jahn-Teller distortion and dissolution of manganese(Ⅲ),and electrochemical inertness of nickel(Ⅱ)and copper(Ⅱ).Here,we summarize recently reported structures and properties of PBAs,classifying them based on the types of transition metals(iron,cobalt,manganese,copper,nickel)employed.Advanced synthesis strategies,including control engineering of crystallinity based on H_(2)O molecules and V_([M–C≡N]),were discussed.Also,the approaches for enhancing the electrochemical performance of PBAs were highlighted.Finally,the challenges and prospects towards the future development of PBAs are put forward.The review is expected to provide technical and theoretical support for the design of high-performance PBAs.
基金National Key Research and Development Program of China,Grant/Award Number:2022YFB2502000National Natural Science Foundation of China,Grant/Award Number:52207244。
文摘In the realm of sodium-ion batteries(SIBs),Mn-based layered oxide cathodes have garnered considerable attention owing to their anionic redox reactions(ARRs).Compared to other types of popular sodium-ion cathodes,Mn-based layered oxide cathodes with ARRs exhibit outstanding specific capacity and energy density,making them promising for SIB applications.However,these cathodes still face some scientific challenges that need to be addressed.This review systematically summarizes the composition,structure,oxygen-redox mechanism,and performance of various types of Mn-based cathodes with ARRs,as well as the main scientific challenges they face,including sluggish ion diffusion,cationic migration,O_(2) release,and element dissolution.Currently,to resolve these challenges,efforts mainly focus on six aspects:synthesis methods,structural design,doped modification,electrolyte design,and surface engineering.Finally,this review provides new insights for future direction,encompassing both fundamental research,such as novel cathode types,interface optimization,and interdisciplinary research,and considerations from an industrialization perspective,including scalability,stability,and safety.
基金supported by the National Natural Science Foundation of China(22209055)the China Postdoctoral Science Foundation(2022M721330)+2 种基金the Foshan Postdoctoral Science Foundation(X221081MS210)the Innovation Team of Universities of Guangdong Province(2022KCXTD030)the“Targeted Technology Innovation Initiative”Project at the Foshan National Institute of Innovation(JBGS2024002)。
文摘In pursuit of low cost and long life for lithium-ion batteries in electric vehicles,the most promising strategy is to replace the commercial LiCoO_(2)with a high-energy-density Ni-rich cathode.However,the irreversible redox couples induce rapid capacity decay,poor long-term cycling life,vast gas evolution,and unstable structure transformations of the Ni-rich cathode,limiting its practical applications.Element doping has been considered as the most promising strategy for addressing these issues.However,the relationships between element doping functions and redox chemistry still remain confused.To clarify this connection,this review places the dynamic evolution of redox couples(Li^(*),Ni^(2+)/Ni^(3+)/Ni^(4+)-e^(-),O^(2-)/O^(n-)/O_(2)-e^(-))as the tree trunk.The material structure,degradation mechanisms,and addressing element doping strategies are considered as the tree branches.This comprehensive summary aims to provide an overview of the current understanding and progress of Ni-rich cathode materials.In the last section,promising strategies based on element doping functions are provided to encourage the practical application of Ni-rich cathodes.These strategies also offer a new approach for the development of other intercalated electrode materials in Na and K-based battery systems.
基金financial support provided by the National Natural Science Foundation of China(52271201)the Science and Technology Department of Sichuan Province(2025NSFTD0005,2022YFG0100,2022ZYD0045)。
文摘LiNixCoyMn_(2)O_(2)(NCM,x≥0.8,x+y+z=1)cathodes have attracted much attention due to their high specific capacity and low cost.However,severe anisotropic volume changes and oxygen evolution induced capacity decay and insecurity have hindered their commercial application at scale.In order to overcome these challenges,a kind of tantalum(Ta)doped nickel-rich cathode with reduced size and significantly increased number of primary particles is prepared by combining mechanical fusion with high temperature co-calcination.The elaborately designed micro-morphology of small and uniform primary particles effectively eliminates the local strain accumulation caused by the random orientation of primary particles.Moreover,the uniform distribution of small primary particles stabilizes the spherical secondary particles,thus effectively inhibiting the formation and extension of microcracks.In addition,the formed strong Ta-O bonds restrain the release of lattice oxygen,which greatly increases the structural stability and safety of NCM materials.Therefore,the cathode material with the designed primary particle morphology shows superior electrochemical performance.The 1 mol%Ta-modified cathode(defined as1%Ta-NCM)shows a capacity retention of 97.5%after 200 cycles at 1 C and a rate performance of 137.3 mAh g^(-1)at 5 C.This work presents promising approach to improve the structural stability and safety of nickel-rich NCM.
基金supported by the National Research Foundation of Korea funded by the Ministry of Science and ICT of Korea(RS-2024-00408156)。
文摘Mn-based layered oxides are widely recognized as cathode materials for potassium-ion batteries(KIBs)due to their high specific capacity derived from their low molar mass.However,the structural instability caused by the Jahn-Teller effect of Mn^(3+)and the large ionic radius of K+results in poor electrochemical performance.Herein,we propose an effective structural stabilization strategy for P2-type Mn-based layered oxide cathodes of KIBs through Li-incorporation into the transition metal layer.Using the firstprinciples calculations and experiments,we demonstrate that the P2-K_(0.48)[Li_(0.1)Mn_(0.9)]O_(2)(P2-KLMO)delivers improved electrochemical performance,specific capacity and average discharge voltage of~124.4 m A h g^(-1)and~2.7 V(vs.K^(+)/K)at 0.05C(1C=260 mA g^(-1)),outperforming P2-K_(0.5)MnO_(2).Operando X-ray diffraction analysis confirms the P2-OP4 phase transition and Mn^(3+)-induced Jahn-Teller distortion are significantly suppressed in P2-KLMO.These improvements are attributed to the lithium introduction into transition metal layers,leading to strengthened structural stability and enhanced K+diffusion kinetics.Moreover,synthetic accessibility through the conventional solid-state method provides an additional advantage for practical application of Li-incorporated Mn-based P2-type cathodes in KIBs.We believe our study offers a simple yet effective strategy for designing highperformance and practical cathode materials for KIBs.
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supported by the Frontier Exploration Projects of Longmen Laboratory(No.LMQYTSKT008)the Natural Science Foundation of Henan Province(No.242300420021)+3 种基金the Open Fund of State Key Laboratory of Advanced Refractories(No.SKLAR202210)the Student Research Training Plan of Henan University of Science and Technology(No.2024054)the Undergraduate Innovation and Entrepreneurship Training Program of Henan Province(No.S202310464012)The Innovation Fund of Henan University of Science and Technology(No.2023-S01)。
文摘Advanced lithium-chalcogen(S,Se,Te)batteries(LCBs)are among the most promising candidates for next generation energy storage systems because of their high energy density and theoretical capacities.However,they are still facing many challenges,such as expansion of the volume problems of chalcogen elements,the shuttle effect of intermediate products,low Coulombic efficiency and inferior cycling stability,which seriously hinder their commercial applications.The presence of a binder in the cathode causes an uneven distribution of the active substances,and also occupies a part of the electrode's volume,resulting in the unsatisfactory energy density of LCBs.In this regard,binder-free electrodes which do not need binders,conductive materials and even collectors,can be used as electrodes for flexible batteries,effectively solving the above-mentioned problems.In this review,the main methods of fabricating binder-free cathodes and their advantages and disadvantages are discussed.Furthermore,a review of representative works on binder-free cathodes for high-performance LCBs over the last decade is presented.The main binder-free electrode materials include paper cloth(PC),graphene oxide(GO),carbon nanotubes(CNTs),carbon nanofibers(CNFs),carbon cloth(CC),polymers,metallic compounds,and their composites.In addition,we discuss these works from four aspects:Advanced structures,methods of fabrication,electrochemical performance and the potential mechanism of binder-free cathode materials,providing important guidance for further researches.Finally,we propose the current challenges of binder-free LCBs and look forward to breakthroughs in this field through the use of binder-free electrodes.
