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
High-voltage Li-rich Mn-based oxide(LRMO)cathodes are promising for breaking through the energy density limits of lithium-ion batteries,yet their practical application remains limited by electrochemical performance de...High-voltage Li-rich Mn-based oxide(LRMO)cathodes are promising for breaking through the energy density limits of lithium-ion batteries,yet their practical application remains limited by electrochemical performance degradation caused by unstable cathode-electrolyte interphase(CEI)evolution during longterm cycling.To address this issue,we propose a novel surface modification strategy using La_(0.7)Sr_(0.3)MnO_(3-σ)(LSMO)nanodots,which exhibit high electronic co nductivity and excellent corrosion resistance.These nanodots act as stable anchoring sites,facilitating the formation of a robust CEI on LRMO,The LSMOmodified cathode demonstrates significantly improved anionic redox reversibility,effectively mitigating transition metal migration and lattice oxygen loss.Furthermore,the optimized interfacial electrochemical kinetics ensure sustained rapid Li+diffusion throughout cycling,while the formation of a stable trilayer CEI structure suppresses electrolyte decomposition.Benefiting from these synergistic effects,the LSMO nanodot-engineered LRMO cathode delivers outstanding cycling stability,retaining 97.4%capacity after 300 cycles at 1 C.This work not only highlights the critical role of nanodot heterostructures in stabilizing CEI but also provides a new approach to designing high-voltage cathodes with superior interfacial compatibility and long-term durability.展开更多
Vanadium-based materials have emerged as promising cathode candidates for aqueous zinc-ion batteries(AZIBs)due to their multivalent redox characteristics and diverse crystal structures,which enable high energy storage...Vanadium-based materials have emerged as promising cathode candidates for aqueous zinc-ion batteries(AZIBs)due to their multivalent redox characteristics and diverse crystal structures,which enable high energy storage capacity.Nevertheless,practical applications are hindered by several critical challenges,including vanadium species dissolution,side-product formation,sluggish Zn^(2+)diffusion kinetics,and low electrical conductivity.Organic functionalization,benefiting from its structural tunability and abundant functional groups,has been proven to be an effective strategy for enhancing the electrochemical performance of vanadium-based cathodes.This review systematically summarizes recent advances in organic-functionalized vanadium-based cathodes.First,the energy storage mechanism of vanadiumbased cathodes and the fundamental properties of organic compounds relevant to cathode optimization are outlined.Then,the functions of organic compounds are comprehensively analyzed from four key perspectives:capacity improvement,conductivity enhancement,Zn^(2+)diffusion kinetics optimization,and cycling stability promotion.Furthermore,the specific electrochemical performance modulation effects and practical application examples of this strategy are discussed in detail.Finally,current limitations and challenges in this field are highlighted,and corresponding solutions and future research directions are proposed,offering theoretical guidance and insights for the development of high-performance vanadium-based cathodes for AZIBs.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
High-capacity O3-type layered NiFeMn-based oxides are promising cathodes for sodium-ion batteries,though their practical deployment is constrained by the inherent limitations of Fe redox chemistry.Traditional designs ...High-capacity O3-type layered NiFeMn-based oxides are promising cathodes for sodium-ion batteries,though their practical deployment is constrained by the inherent limitations of Fe redox chemistry.Traditional designs generally enforcing stoichiometric symmetry(Ni=Mn)yield low Fe redox activity.Herein,we propose a valence engineering strategy that breaks conventional Ni/Mn stoichiometry to reconfigure Fe's local chemical environment and unlock unprecedented redox depth.Density functional theory(DFT)calculations reveal that the designed NaNi_(0.35)Fe_(0.225)Mn_(0.425)O_(2)cathode exhibits a reduced Bader charge on Fe(1.598 vs.1.638 in NaNi_(1/3)Fe_(1/3)Mn_(1/3)O_(2))and elevated Fe 3d orbital energy,signifying enhanced Fe redox activity.This configuration enables an exceptional Fe^(2.60+)/Fe^(3.88+)redox(1.28 e~-per Fe),delivering a reversible capacity of184.3 mAh g^(-1)within 2-4.2 V at 0.2 C,markedly exceeding the benchmark NaNi_(1/3)Fe_(1/3)Mn_(1/3)O_(2)(161.3 mAh g^(-1))with low reaction depth of Fe^(3.01+)/Fe^(3.61+).The intensified cationic redox reaction enables an ultrahigh energy density of 596 Whkg-1.The NaNi_(0.35)Fe_(0.225)Mn_(0.425)O_(2)cathode demonstrates robust performance over a broad temperature range from-15℃to 60℃.In situ and ex situ characterizations unveil a reversible O3■P3■OP2 phase transition with minimal volume change(1.88%)that circumvents detrimental deleterious O'3 intermediates and intragranular cracking.This work establishes valence engineering as a paradigm to consolidate cationic redox reaction in high-energy layered sodium oxide cathodes.展开更多
Lithium-rich layered oxides(LRLOs)are promising cathode materials due to their high specific capacity,energy density,and operating voltage.However,their performance is hindered by the limited redox activity of transit...Lithium-rich layered oxides(LRLOs)are promising cathode materials due to their high specific capacity,energy density,and operating voltage.However,their performance is hindered by the limited redox activity of transition metals,leading to oxygen redox instability,oxygen release,and capacity degradation.To address these issues,we propose an innovative lattice-oxygen modulation(LOM)strategy that incorporates Mn^(3+)and Ti^(4+)into the Li_(1.2)Cr_(0.3)Mn_(0.4)Ti_(0.1)O_(2) system,effectively mitigating Cr migration,stabilizing oxygen redox reactions,and reinforcing structural integrity.This results in improved electrochemical performance,as demonstrated by a 56.5 mAh g^(−1) increase in initial discharge capacity to 364.2 mAh g^(−1),with 71.3%capacity retention after 30 cycles,reflecting a 20.2%improvement in cycling stability.Density functional theory(DFT)calculations confirm enhanced Cr redox reversibility and reduced oxygen evolution,further strengthening structural stability.These synergistic effects highlight the pivotal role of the LOM strategy in optimizing both electrochemical performance and structural integrity,offering a scalable pathway to improve capacity and cycling stability in lithium-rich 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 P2-type Fe/Mn-based layered oxides,with cost advantages and high theoretical capacity,are considered one of the promising cathode materials for sodium-ion batteries(SIBs).However,the commercial development of thes...The P2-type Fe/Mn-based layered oxides,with cost advantages and high theoretical capacity,are considered one of the promising cathode materials for sodium-ion batteries(SIBs).However,the commercial development of these materials is impeded by two main factors:the MnO_(6) structure distortion induced by the Jahn-Teller(J-T)effect of Mn^(3+),and the unfavorable phase transitions that occur during the insertion and extraction of Na^(+).Here,we present a strategy to improve structural stability by incorporating cost-effective,robust Al-O bonds.This approach induces localized adjustments in the electronic structu re and a pinning effect,which limits the deformation of the transition metal(TM)layers,strengthens the electrostatic bonding within the TM layers,and expands the Na layer spacing.Consequently,the Na_(0.67)Fe_(0.4)Mn_(0.54)Al_(0.06)O_(2) cathode demonstrates a capacity of 168.8 mAh g^(-1) at 0.1 C,maintaining89.2%of its original capacity after 200 cycles at 1 C.Through in situ electrochemical impedance spectroscopy(EIS)with dynamic resistance transformation(DRT)analysis,ex situ X-ray absorption spectroscopy(XAS),and in situ X-ray diffraction(XRD),the study demonstrates a reduction in the J-T effect,enhanced kinetic performance,and the inhibition of detrimental phase transitions.This study offers new avenues to the development and design of future low-cost Fe/Mn-based cathodes.展开更多
The irreversible oxygen redox(OR)in Li-rich layered cathodes leads to severe structural degradation and voltage decay,particularly under harsh operating conditions.Although high-entropy oxides(HEOs)offer enhanced stab...The irreversible oxygen redox(OR)in Li-rich layered cathodes leads to severe structural degradation and voltage decay,particularly under harsh operating conditions.Although high-entropy oxides(HEOs)offer enhanced stability compared to conventional doping modifications,rational element selection for optimizing OR reversibility remains unexplored.Here,we propose an entropy engineering design paradigm for “oxygen-anchoring”,where optimal cation electronegativity(>Mn,1.55)and d(3d/4d)-p orbital hybridization synergistically enhance transition metal–oxygen(TM–O)covalency and stabilize the O2p state.Two high-entropy Li-rich layered oxides:Li_(1.2)Mn_(0.47)Ni_(0.115)Co_(0.115)Mg_(0.02)Ti_(0.02)Al_(0.02)Nb_(0.02)Mo_(0.02)O_(2)(MTANM)and Li_(1.2)Mn_(0.47)Ni_(0.115)Co_(0.115)Mg_(0.02)Ti_(0.02)Cu_(0.02)Nb_(0.02)Mo_(0.02)O_(2)(MTCNM)were synthesized using partial nano-scale precursors and comparatively evaluated.MTCNM exhibits enhanced electrochemical performance and superior oxygen stability compared to MTANM by replacing Al with higher-electronegativity Cu,which possesses improved orbital overlap with oxygen.Both experiments and density functional theory(DFT)calculations demonstrate that element selection changes the covalency of TM–O through altered electronegativity and d orbitals-p orbitals(d-p)hybridization.Further stepwise screening selected the optimal elemental combination Li_(1.2)Mn_(0.47)Ni_(0.115)Co_(0.115)Cr_(0.02)Cu_(0.02)Nb_(0.02)Mo_(0.02)Ru_(0.02)O_(2)(CCNMR),which achieved near 100%capacity retention after 150 cycles at 1 C,50℃,with its voltage decay effectively suppressed.This work establishes a rational element-screening paradigm for entropy-stabilized OR chemistry in high-energy cathodes.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
1.Introduction Driven by the growing demand for energy storage systems in portable electronic devices,electric vehicles,and unmanned aerial vehicles,lithium-ion batteries(LIBs)have received considerable and sustained ...1.Introduction Driven by the growing demand for energy storage systems in portable electronic devices,electric vehicles,and unmanned aerial vehicles,lithium-ion batteries(LIBs)have received considerable and sustained attention.The performance of routine LIBs is approaching the ceiling,particularly in terms of energy density,making it difficult to meet the ever-increasing demand for energy density[1].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
The irreversible interfacial side reactions of lithium-rich layered oxides at high voltage lead to deterioration of cycling performance.Herein,we construct a Ce^(3+)-rich surface layer on the lithium-rich layered oxid...The irreversible interfacial side reactions of lithium-rich layered oxides at high voltage lead to deterioration of cycling performance.Herein,we construct a Ce^(3+)-rich surface layer on the lithium-rich layered oxides surface.Owing to the strong chemical affinity between rare-earth elements and oxygen,the Ce-rich spinel surface layer is completely encapsulated around the lithium-rich layered oxides particles.Also,an excess of Ce^(3+)leads to the formation of Li_(x)CeO_(2-y) nanoparticles,which are adorned on the surface layer.This surface modification lowers the work function,promoting the formation of a thin,inorganic-rich,and uniform cathode-electrolyte interphase.Consequently,this layer mitigates the dissolution of transition metals and enhances the stability of the surface lattice oxygen.Consequently,the LLO@Ce cathode demonstrates a high-capacity retention of 93.12%at 1 C after 500 cycles.This work presents a promising path for stabilizing the surface of lithium-rich layered oxides,thereby enhancing its cycling performance for high-energy-density lithium-ion batteries.展开更多
Potassium-ion batteries(PIBs)were recognized for their natural abunda nce,high theoretical output voltage,and the availability of commercialized graphite anodes.However,the development of highperformance manganese-bas...Potassium-ion batteries(PIBs)were recognized for their natural abunda nce,high theoretical output voltage,and the availability of commercialized graphite anodes.However,the development of highperformance manganese-based layered oxide cathodes-a leading candidate for PIB systems-has been fundamentally constrained by irreversible phase transitions(PT)during the cycling process,manifesting as severe structural degradation and capacity fading.This review presents a transformative paradigm integrating machine learning(ML)with multiscale characterization to analyse the complex phase transition mechanisms in Mn-based cathodes.Through systematic ML-driven interrogation of structure-property relationships,we establish quantitative descriptors for phase stability and develop predictive models for transition dynamics.Furthermore,we highlight recent breakthroughs in cross-disciplinary approaches,enabling the rational design of PT-mitigated cathode architectures.By consolidating these insights into a unified knowledge framework,this work provides strategic guidelines for developing structurally robust Mn-based cathodes and outlines future research directions for next-generation PIB systems.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
LiMn_(2)O_(4)(LMO) represents one of the most prevalent cathode materials utilized in lithium-ion batteries(LIBs), yet its broader application is often hampered by its limited achievable capacity and significant capac...LiMn_(2)O_(4)(LMO) represents one of the most prevalent cathode materials utilized in lithium-ion batteries(LIBs), yet its broader application is often hampered by its limited achievable capacity and significant capacity degradation during cycling. In this work, a novel dual-doping strategy involving Al^(3+) and Zr^(4+) ions has been employed to refine the atomic structure of LMO's spinel framework. The resultant dual-doped material, Li_(1.06)Mn_(1.97)Zr_(0.01)Al_(0.02)O_(4), exhibits enhanced electrochemical properties, boasting a discharge capacity of 124.9 m Ah/g at a rate of 0.1 C. Furthermore, the formation of stronger Al–O and Zr–O bonds contributes to the stabilization of the delithiated LMO structure. Impressively, 97.7%of its initial capacity is retained after 100 cycles at a 5 C rate. Additionally, enhancements in rate performance and hightemperature cycling stability have also been observed. This study underscores the potential of Al^(3+) and Zr^(4+) dual-doping as a promising approach to enhance LMO cathodes, providing a scalable and efficient means of improving the performance of lithium manganese oxide cathode materials through the incorporation of multiple ions.展开更多
Developing advanced secondary batteries with low cost and high safety has attracted increasing research interests across the world.In particular,the aqueous zinc-ion battery(AZIB)has been regarded as a promising candi...Developing advanced secondary batteries with low cost and high safety has attracted increasing research interests across the world.In particular,the aqueous zinc-ion battery(AZIB)has been regarded as a promising candidate owing to the high abundance and capacity of Zn metal.Currently,manganese-based and vanadium-based oxides are most common choices for cathode materials used in AZIBs,but they unfortunately show a moderate cell voltage and limited rate performance induced by slow intercalation-extraction kinetics of Zn^(2+)ions.To address these issues,alternative cathode systems with tunable redox potentials and intrinsic fast kinetics have been exploited.In the past few years,conversion-type cathodes of I_(2)and S have become the most illustrative examples to match or even surpass the performance of conventional metal oxide cathodes in AZIBs.Herein,we sum up most recent progress in conversion-type cathodes and focus on novel ideas and concepts in designing/modifying cathodes for AZIBs with high voltage/capacity.Additionally,potential directions and future efforts are tentatively proposed for further development of conversion-type cathodes,aiming to speed up the practical application of AZIBs.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
Composite cathodes integrating Ni-rich layered oxides and oxide solid electrolytes are essential for highenergy all-solid-state lithium-ion batteries(ASSLBs),yet interfacial degradation during high-temperature co-sint...Composite cathodes integrating Ni-rich layered oxides and oxide solid electrolytes are essential for highenergy all-solid-state lithium-ion batteries(ASSLBs),yet interfacial degradation during high-temperature co-sintering(>600℃)remains a critical challenge.While surface passivation strategies mitigate reactions below 400℃,their effectiveness diminishes at elevated temperatures due to inability to counteract Li^(+)concentration gradients.Here,we introduce in situ lithium compensators,i.e.,LiOH/Li_(2)CO_(3),into NCM-LATP composite cathodes to dynamically replenish Li^(+)during co-sintering.These additives melt to form transient Li^(+)-rich phases that back-diffuse Li^(+)into NCM lattices,suppressing layered-to-rock salt transitions and stabilizing the interface.Quasi in situ XRD confirms retention of the layered structure at temperature up to 700℃,while electrochemical tests demonstrate a reversible capacity of 222.2 mA h g^(-1)—comparable to NCM before co-sintering—and an impressive 65.3% capacity retention improvement over100 cycles.In contrast,uncompensated cathodes exhibit severe degradation to 96.5 mA h g^(-1)due to Li depletion and resistive Li-Ti-O interphases.This strategy integrates sacrificial chemistry with scalable powder-mixing workflows,achieving a 93.4% reduction in interfacial impedance.By addressing Li^(+)flux homogenization and structural stability,this work provides a practical pathway toward industrialscale fabrication of high-performance ASSLBs.展开更多
Arising from the increasing demand for electric vehicles(EVs),Ni-rich LiNi_(x)Co_(y)Mn_(z)O_(2)(NCM,x+y+z=1,x≥0.8)cathode with greatly increased energy density are being researched and commercialized for lithium-ion ...Arising from the increasing demand for electric vehicles(EVs),Ni-rich LiNi_(x)Co_(y)Mn_(z)O_(2)(NCM,x+y+z=1,x≥0.8)cathode with greatly increased energy density are being researched and commercialized for lithium-ion batteries(LIBs).However,parasitic crack formation during the discharge–charge cycling process remains as a major degradation mechanism.Cracking leads to increase in the specific surface area,loss of electrical contact between the primary particles,and facilitates liquid electrolyte infiltration into the cathode active material,accelerating capacity fading and decrease in lifetime.In contrast,Ni-rich NCM when used as a single crystal exhibits superior cycling performances due to its rigid mechanical property that resists cracking during long charge–discharge process even under harsh conditions.In this paper,we present comparative investigation between single crystal Ni-rich LiNi_(0.92)Co_(0.04)Mn_(0.04)O_(2)(SC)and polycrystalline Ni-rich LiNi_(0.92)Co_(0.04)Mn_(0.04)O_(2)(PC).The relatively improved cycling performances of SC are attributed to smaller anisotropic volume change,higher reversibility of phase transition,and resistance to crack formation.The superior properties of SC are demonstrated by in situ characterization and battery tests.Consequently,it is inferred from the results obtained that optimization of preparation conditions can be regarded as a key approach to obtain well crystallized and superior electrochemical performances.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the financial support from the National Key Research and Development Program of China(2023YFB2504000)。
文摘High-voltage Li-rich Mn-based oxide(LRMO)cathodes are promising for breaking through the energy density limits of lithium-ion batteries,yet their practical application remains limited by electrochemical performance degradation caused by unstable cathode-electrolyte interphase(CEI)evolution during longterm cycling.To address this issue,we propose a novel surface modification strategy using La_(0.7)Sr_(0.3)MnO_(3-σ)(LSMO)nanodots,which exhibit high electronic co nductivity and excellent corrosion resistance.These nanodots act as stable anchoring sites,facilitating the formation of a robust CEI on LRMO,The LSMOmodified cathode demonstrates significantly improved anionic redox reversibility,effectively mitigating transition metal migration and lattice oxygen loss.Furthermore,the optimized interfacial electrochemical kinetics ensure sustained rapid Li+diffusion throughout cycling,while the formation of a stable trilayer CEI structure suppresses electrolyte decomposition.Benefiting from these synergistic effects,the LSMO nanodot-engineered LRMO cathode delivers outstanding cycling stability,retaining 97.4%capacity after 300 cycles at 1 C.This work not only highlights the critical role of nanodot heterostructures in stabilizing CEI but also provides a new approach to designing high-voltage cathodes with superior interfacial compatibility and long-term durability.
基金financial support from the National Natural Science Foundation of China(No.21676036)the Natural Science Foundation of Chongqing(No.CSTB2023NSCQMSX0580)the Large-scale Equipment Sharing Fund of Chongqing University(No.202403150240 and 202503150091)。
文摘Vanadium-based materials have emerged as promising cathode candidates for aqueous zinc-ion batteries(AZIBs)due to their multivalent redox characteristics and diverse crystal structures,which enable high energy storage capacity.Nevertheless,practical applications are hindered by several critical challenges,including vanadium species dissolution,side-product formation,sluggish Zn^(2+)diffusion kinetics,and low electrical conductivity.Organic functionalization,benefiting from its structural tunability and abundant functional groups,has been proven to be an effective strategy for enhancing the electrochemical performance of vanadium-based cathodes.This review systematically summarizes recent advances in organic-functionalized vanadium-based cathodes.First,the energy storage mechanism of vanadiumbased cathodes and the fundamental properties of organic compounds relevant to cathode optimization are outlined.Then,the functions of organic compounds are comprehensively analyzed from four key perspectives:capacity improvement,conductivity enhancement,Zn^(2+)diffusion kinetics optimization,and cycling stability promotion.Furthermore,the specific electrochemical performance modulation effects and practical application examples of this strategy are discussed in detail.Finally,current limitations and challenges in this field are highlighted,and corresponding solutions and future research directions are proposed,offering theoretical guidance and insights for the development of high-performance vanadium-based cathodes for AZIBs.
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 National Natural Science Foundation of China(Grant Nos.52202282,52402054,22471283,and 52202327)Natural Science Foundation of Tianjin City(Grant Nos.22JCYBJC00040,24JCQNJC00970)。
文摘High-capacity O3-type layered NiFeMn-based oxides are promising cathodes for sodium-ion batteries,though their practical deployment is constrained by the inherent limitations of Fe redox chemistry.Traditional designs generally enforcing stoichiometric symmetry(Ni=Mn)yield low Fe redox activity.Herein,we propose a valence engineering strategy that breaks conventional Ni/Mn stoichiometry to reconfigure Fe's local chemical environment and unlock unprecedented redox depth.Density functional theory(DFT)calculations reveal that the designed NaNi_(0.35)Fe_(0.225)Mn_(0.425)O_(2)cathode exhibits a reduced Bader charge on Fe(1.598 vs.1.638 in NaNi_(1/3)Fe_(1/3)Mn_(1/3)O_(2))and elevated Fe 3d orbital energy,signifying enhanced Fe redox activity.This configuration enables an exceptional Fe^(2.60+)/Fe^(3.88+)redox(1.28 e~-per Fe),delivering a reversible capacity of184.3 mAh g^(-1)within 2-4.2 V at 0.2 C,markedly exceeding the benchmark NaNi_(1/3)Fe_(1/3)Mn_(1/3)O_(2)(161.3 mAh g^(-1))with low reaction depth of Fe^(3.01+)/Fe^(3.61+).The intensified cationic redox reaction enables an ultrahigh energy density of 596 Whkg-1.The NaNi_(0.35)Fe_(0.225)Mn_(0.425)O_(2)cathode demonstrates robust performance over a broad temperature range from-15℃to 60℃.In situ and ex situ characterizations unveil a reversible O3■P3■OP2 phase transition with minimal volume change(1.88%)that circumvents detrimental deleterious O'3 intermediates and intragranular cracking.This work establishes valence engineering as a paradigm to consolidate cationic redox reaction in high-energy layered sodium oxide cathodes.
基金support from National Key R&D Program of China(2022YFB3807200)Science and Technology Commission of Shanghai Municipality(25CL2902100).
文摘Lithium-rich layered oxides(LRLOs)are promising cathode materials due to their high specific capacity,energy density,and operating voltage.However,their performance is hindered by the limited redox activity of transition metals,leading to oxygen redox instability,oxygen release,and capacity degradation.To address these issues,we propose an innovative lattice-oxygen modulation(LOM)strategy that incorporates Mn^(3+)and Ti^(4+)into the Li_(1.2)Cr_(0.3)Mn_(0.4)Ti_(0.1)O_(2) system,effectively mitigating Cr migration,stabilizing oxygen redox reactions,and reinforcing structural integrity.This results in improved electrochemical performance,as demonstrated by a 56.5 mAh g^(−1) increase in initial discharge capacity to 364.2 mAh g^(−1),with 71.3%capacity retention after 30 cycles,reflecting a 20.2%improvement in cycling stability.Density functional theory(DFT)calculations confirm enhanced Cr redox reversibility and reduced oxygen evolution,further strengthening structural stability.These synergistic effects highlight the pivotal role of the LOM strategy in optimizing both electrochemical performance and structural integrity,offering a scalable pathway to improve capacity and cycling stability in lithium-rich 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financially supported by the National Natural Science Foundation of China(52274295)the Natural Science Foundation of Hebei Province(E2025501032,E2025501028)+3 种基金the Fundamental Research Funds for the Central Universities(N2523045,N2423051,N2423005,N2423019)the Science and Technology Project of Hebei Education Department(QN2024238)the Central Guided Local Science and Technology Development Fund Project of Hebei Province(254Z1102G)the Basic Research Program Project of Shijiazhuang City for Universities Stationed in Hebei Province(241790937A)。
文摘The P2-type Fe/Mn-based layered oxides,with cost advantages and high theoretical capacity,are considered one of the promising cathode materials for sodium-ion batteries(SIBs).However,the commercial development of these materials is impeded by two main factors:the MnO_(6) structure distortion induced by the Jahn-Teller(J-T)effect of Mn^(3+),and the unfavorable phase transitions that occur during the insertion and extraction of Na^(+).Here,we present a strategy to improve structural stability by incorporating cost-effective,robust Al-O bonds.This approach induces localized adjustments in the electronic structu re and a pinning effect,which limits the deformation of the transition metal(TM)layers,strengthens the electrostatic bonding within the TM layers,and expands the Na layer spacing.Consequently,the Na_(0.67)Fe_(0.4)Mn_(0.54)Al_(0.06)O_(2) cathode demonstrates a capacity of 168.8 mAh g^(-1) at 0.1 C,maintaining89.2%of its original capacity after 200 cycles at 1 C.Through in situ electrochemical impedance spectroscopy(EIS)with dynamic resistance transformation(DRT)analysis,ex situ X-ray absorption spectroscopy(XAS),and in situ X-ray diffraction(XRD),the study demonstrates a reduction in the J-T effect,enhanced kinetic performance,and the inhibition of detrimental phase transitions.This study offers new avenues to the development and design of future low-cost Fe/Mn-based cathodes.
基金financially supported by the National Natural Science Foundation of China(no.52172209)the Shenzhen International Cooperative Research Project(GJHZ20240218113607014)。
文摘The irreversible oxygen redox(OR)in Li-rich layered cathodes leads to severe structural degradation and voltage decay,particularly under harsh operating conditions.Although high-entropy oxides(HEOs)offer enhanced stability compared to conventional doping modifications,rational element selection for optimizing OR reversibility remains unexplored.Here,we propose an entropy engineering design paradigm for “oxygen-anchoring”,where optimal cation electronegativity(>Mn,1.55)and d(3d/4d)-p orbital hybridization synergistically enhance transition metal–oxygen(TM–O)covalency and stabilize the O2p state.Two high-entropy Li-rich layered oxides:Li_(1.2)Mn_(0.47)Ni_(0.115)Co_(0.115)Mg_(0.02)Ti_(0.02)Al_(0.02)Nb_(0.02)Mo_(0.02)O_(2)(MTANM)and Li_(1.2)Mn_(0.47)Ni_(0.115)Co_(0.115)Mg_(0.02)Ti_(0.02)Cu_(0.02)Nb_(0.02)Mo_(0.02)O_(2)(MTCNM)were synthesized using partial nano-scale precursors and comparatively evaluated.MTCNM exhibits enhanced electrochemical performance and superior oxygen stability compared to MTANM by replacing Al with higher-electronegativity Cu,which possesses improved orbital overlap with oxygen.Both experiments and density functional theory(DFT)calculations demonstrate that element selection changes the covalency of TM–O through altered electronegativity and d orbitals-p orbitals(d-p)hybridization.Further stepwise screening selected the optimal elemental combination Li_(1.2)Mn_(0.47)Ni_(0.115)Co_(0.115)Cr_(0.02)Cu_(0.02)Nb_(0.02)Mo_(0.02)Ru_(0.02)O_(2)(CCNMR),which achieved near 100%capacity retention after 150 cycles at 1 C,50℃,with its voltage decay effectively suppressed.This work establishes a rational element-screening paradigm for entropy-stabilized OR chemistry in high-energy cathodes.
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supported by the Beijing Natural Science Foundation(L243019)the National Natural Science Foundation of China(22393900,22393904)+3 种基金the National Key Research and Development Program(2021YFB2500300)the JBGS project from Ordos(JBGS2024001)the Tsinghua University Initiative Scientific Research Programthe“Shuimu Tsinghua Scholar Program of Tsinghua University”。
文摘1.Introduction Driven by the growing demand for energy storage systems in portable electronic devices,electric vehicles,and unmanned aerial vehicles,lithium-ion batteries(LIBs)have received considerable and sustained attention.The performance of routine LIBs is approaching the ceiling,particularly in terms of energy density,making it difficult to meet the ever-increasing demand for energy density[1].
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 Key R&D Program of China (2024YFE0209300)the National Natural Science Foundation of China (nos. 52072282, 52150710537, and 52127816)gratefully acknowledged the Postdoctoral Fellowship Program of CPSF (no. GZC20241292).
文摘The irreversible interfacial side reactions of lithium-rich layered oxides at high voltage lead to deterioration of cycling performance.Herein,we construct a Ce^(3+)-rich surface layer on the lithium-rich layered oxides surface.Owing to the strong chemical affinity between rare-earth elements and oxygen,the Ce-rich spinel surface layer is completely encapsulated around the lithium-rich layered oxides particles.Also,an excess of Ce^(3+)leads to the formation of Li_(x)CeO_(2-y) nanoparticles,which are adorned on the surface layer.This surface modification lowers the work function,promoting the formation of a thin,inorganic-rich,and uniform cathode-electrolyte interphase.Consequently,this layer mitigates the dissolution of transition metals and enhances the stability of the surface lattice oxygen.Consequently,the LLO@Ce cathode demonstrates a high-capacity retention of 93.12%at 1 C after 500 cycles.This work presents a promising path for stabilizing the surface of lithium-rich layered oxides,thereby enhancing its cycling performance for high-energy-density lithium-ion batteries.
基金financially supported by the National Natural Science Foundation of China(U20A20247)the National Key Research and Development Program of the Ministry of Science and Technology(2022YFA1402504)+1 种基金Guangdong Provincial Key Laboratory of Materials and Technologies for Energy Conversion(MATEC2023KF002)Guangdong Science and Technology Department(STKJ2021016)。
文摘Potassium-ion batteries(PIBs)were recognized for their natural abunda nce,high theoretical output voltage,and the availability of commercialized graphite anodes.However,the development of highperformance manganese-based layered oxide cathodes-a leading candidate for PIB systems-has been fundamentally constrained by irreversible phase transitions(PT)during the cycling process,manifesting as severe structural degradation and capacity fading.This review presents a transformative paradigm integrating machine learning(ML)with multiscale characterization to analyse the complex phase transition mechanisms in Mn-based cathodes.Through systematic ML-driven interrogation of structure-property relationships,we establish quantitative descriptors for phase stability and develop predictive models for transition dynamics.Furthermore,we highlight recent breakthroughs in cross-disciplinary approaches,enabling the rational design of PT-mitigated cathode architectures.By consolidating these insights into a unified knowledge framework,this work provides strategic guidelines for developing structurally robust Mn-based cathodes and outlines future research directions for next-generation PIB systems.
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Project supported by the National Key Research and Development Program of China (Grant No. 2022YFB2404400)。
文摘LiMn_(2)O_(4)(LMO) represents one of the most prevalent cathode materials utilized in lithium-ion batteries(LIBs), yet its broader application is often hampered by its limited achievable capacity and significant capacity degradation during cycling. In this work, a novel dual-doping strategy involving Al^(3+) and Zr^(4+) ions has been employed to refine the atomic structure of LMO's spinel framework. The resultant dual-doped material, Li_(1.06)Mn_(1.97)Zr_(0.01)Al_(0.02)O_(4), exhibits enhanced electrochemical properties, boasting a discharge capacity of 124.9 m Ah/g at a rate of 0.1 C. Furthermore, the formation of stronger Al–O and Zr–O bonds contributes to the stabilization of the delithiated LMO structure. Impressively, 97.7%of its initial capacity is retained after 100 cycles at a 5 C rate. Additionally, enhancements in rate performance and hightemperature cycling stability have also been observed. This study underscores the potential of Al^(3+) and Zr^(4+) dual-doping as a promising approach to enhance LMO cathodes, providing a scalable and efficient means of improving the performance of lithium manganese oxide cathode materials through the incorporation of multiple ions.
基金the financial support from NSFC(21975027)NSFCMAECI(51861135202).
文摘Developing advanced secondary batteries with low cost and high safety has attracted increasing research interests across the world.In particular,the aqueous zinc-ion battery(AZIB)has been regarded as a promising candidate owing to the high abundance and capacity of Zn metal.Currently,manganese-based and vanadium-based oxides are most common choices for cathode materials used in AZIBs,but they unfortunately show a moderate cell voltage and limited rate performance induced by slow intercalation-extraction kinetics of Zn^(2+)ions.To address these issues,alternative cathode systems with tunable redox potentials and intrinsic fast kinetics have been exploited.In the past few years,conversion-type cathodes of I_(2)and S have become the most illustrative examples to match or even surpass the performance of conventional metal oxide cathodes in AZIBs.Herein,we sum up most recent progress in conversion-type cathodes and focus on novel ideas and concepts in designing/modifying cathodes for AZIBs with high voltage/capacity.Additionally,potential directions and future efforts are tentatively proposed for further development of conversion-type cathodes,aiming to speed up the practical application of AZIBs.
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financially supported by the National Natural Science Foundation of China(52102206)the Natural Science Foundation of Beijing Municipality-Shunyi Innovation Collaborative Joint Fund(L247018)+2 种基金the Natural Science Foundation of Beijing Municipality(2254076 and 2252024)the Central Guidance on Local Science and Technology Development Fund of Hebei Province(246Z4412G)the Fundamental Research Funds for the Central Universities(2025MS022,North China Electric Power University)。
文摘Composite cathodes integrating Ni-rich layered oxides and oxide solid electrolytes are essential for highenergy all-solid-state lithium-ion batteries(ASSLBs),yet interfacial degradation during high-temperature co-sintering(>600℃)remains a critical challenge.While surface passivation strategies mitigate reactions below 400℃,their effectiveness diminishes at elevated temperatures due to inability to counteract Li^(+)concentration gradients.Here,we introduce in situ lithium compensators,i.e.,LiOH/Li_(2)CO_(3),into NCM-LATP composite cathodes to dynamically replenish Li^(+)during co-sintering.These additives melt to form transient Li^(+)-rich phases that back-diffuse Li^(+)into NCM lattices,suppressing layered-to-rock salt transitions and stabilizing the interface.Quasi in situ XRD confirms retention of the layered structure at temperature up to 700℃,while electrochemical tests demonstrate a reversible capacity of 222.2 mA h g^(-1)—comparable to NCM before co-sintering—and an impressive 65.3% capacity retention improvement over100 cycles.In contrast,uncompensated cathodes exhibit severe degradation to 96.5 mA h g^(-1)due to Li depletion and resistive Li-Ti-O interphases.This strategy integrates sacrificial chemistry with scalable powder-mixing workflows,achieving a 93.4% reduction in interfacial impedance.By addressing Li^(+)flux homogenization and structural stability,this work provides a practical pathway toward industrialscale fabrication of high-performance ASSLBs.
基金supported by the Technology Innovation Program(RS-2023-00256202Development of MLCB design and manufacturing process technology for board mounting)funded By the Ministry of Trade,Industry&Energy(MOTIE,Korea)+2 种基金supported by the Technology Innovation Program(or Industrial Strategic Technology Development Program-Public-private joint investment semiconductor R&D program(K-CHIPS)to foster high-quality human resources)(RS-2023-00237003,High selectivity etching technology using cryoetch)funded By the Ministry of Trade,Industry&Energy(MOTIE,Korea)supported by 2022 Research Grant from Kangwon National University(No.202203080001)supported by the National Research Foundation of Korea(NRF)grant funded by the Korea government(MSIT)(RS-2023-00280367).
文摘Arising from the increasing demand for electric vehicles(EVs),Ni-rich LiNi_(x)Co_(y)Mn_(z)O_(2)(NCM,x+y+z=1,x≥0.8)cathode with greatly increased energy density are being researched and commercialized for lithium-ion batteries(LIBs).However,parasitic crack formation during the discharge–charge cycling process remains as a major degradation mechanism.Cracking leads to increase in the specific surface area,loss of electrical contact between the primary particles,and facilitates liquid electrolyte infiltration into the cathode active material,accelerating capacity fading and decrease in lifetime.In contrast,Ni-rich NCM when used as a single crystal exhibits superior cycling performances due to its rigid mechanical property that resists cracking during long charge–discharge process even under harsh conditions.In this paper,we present comparative investigation between single crystal Ni-rich LiNi_(0.92)Co_(0.04)Mn_(0.04)O_(2)(SC)and polycrystalline Ni-rich LiNi_(0.92)Co_(0.04)Mn_(0.04)O_(2)(PC).The relatively improved cycling performances of SC are attributed to smaller anisotropic volume change,higher reversibility of phase transition,and resistance to crack formation.The superior properties of SC are demonstrated by in situ characterization and battery tests.Consequently,it is inferred from the results obtained that optimization of preparation conditions can be regarded as a key approach to obtain well crystallized and superior electrochemical performances.
