Single crystal Ni-rich cathode materials(SCNCM)are a good supplement in the market of nickel-based materials due to their safety and excellent electrochemical performance.However,the challenges of cation mixing,phase ...Single crystal Ni-rich cathode materials(SCNCM)are a good supplement in the market of nickel-based materials due to their safety and excellent electrochemical performance.However,the challenges of cation mixing,phase change during charge/discharge,and low thermal stability remain unresolved in single crystal particles.To address these issues,SCNCM are rationally modified by incorporating transition metal(TM)oxides,and the influence of metal ions with different valence states on the electrochemical properties of SCNCM is methodically explored through experimental results and theoretical calculations.Enhanced structural stability is demonstrated in SCNCM after the modifications,and the degree of improvement in the matrix materials varies depending on the valence state of doped TM ions.The highest structural stability is found in WO_(3)-modified SCNCM,due to the smaller effective ion radii,higher electro-negativity,stronger W-O bond,and efficient suppression of oxygen vacancy generation.As a result,WO_(3)-modified SCNCM have outstanding cycle performance,with a capacity retention rate of90.2%after 200 cycles.This study provides an insight into the design of advanced SCNCM with enhanced reversibility and cyclability.展开更多
基金financially supported by the National Natural Science Foundation of China,China(52004103,51974137,52274229,22350410378 and 52304328)the China Postdoctoral Science Foundation,China(2020M671361 and 2023M733189)+4 种基金the Natural Science Foundation of Jiangsu Province,China(BK20220534)the Jiangsu Postdoctoral Science Foundation,China(2020Z090)the Senior Talents Fund of Jiangsu University,China(5501220014)the Key Research and Development Project of Ningxia Province,China(2024BEE02001)the Open Project of Key Laboratory of Advanced Battery Materials of Yunnan Province,China(KLABM-2024092403).
文摘Single crystal Ni-rich cathode materials(SCNCM)are a good supplement in the market of nickel-based materials due to their safety and excellent electrochemical performance.However,the challenges of cation mixing,phase change during charge/discharge,and low thermal stability remain unresolved in single crystal particles.To address these issues,SCNCM are rationally modified by incorporating transition metal(TM)oxides,and the influence of metal ions with different valence states on the electrochemical properties of SCNCM is methodically explored through experimental results and theoretical calculations.Enhanced structural stability is demonstrated in SCNCM after the modifications,and the degree of improvement in the matrix materials varies depending on the valence state of doped TM ions.The highest structural stability is found in WO_(3)-modified SCNCM,due to the smaller effective ion radii,higher electro-negativity,stronger W-O bond,and efficient suppression of oxygen vacancy generation.As a result,WO_(3)-modified SCNCM have outstanding cycle performance,with a capacity retention rate of90.2%after 200 cycles.This study provides an insight into the design of advanced SCNCM with enhanced reversibility and cyclability.
