Mitigated lattice distortion and oxygen loss of Li-rich layered cathode materials through anion/cation regulation by Ti^(4+)-substitution  

作　　者：Kaicheng Zhang Yu Tian Xuanjin Chen Shan Hu Zelang Jian 

机构地区：[1]State Key Laboratory of Advanced Technology for Materials Synthesis and Processing,School of Materials Science and Engineering,Wuhan University of Technology,Wuhan 430070,China

出　　处：《Chinese Chemical Letters》2024年第2期548-552,共5页中国化学快报（英文版）

基　　金：financially supported by the National Natural Science Foundation of China(Nos.51972258,22109186).

摘　　要：Lithium-rich layered cathode material(LLM)can meet the requirement of power lithium-ion energy storage devices due to the great energy density.However,the de/intercalation of Li+will cause the irreversible loss of lattice oxygen and trigger transition metal(TM)ions migrate to Li+vacancies,resulting in capacity decay.Here we brought Ti4+in substitution of TM ions in Li_(1.2)Mn_(0.54)Ni_(0.13)Co_(0.13)O_(2),which could stabilize structure and expand the layer spacing of LLM.Moreover,optimized Ti-substitution can regulate the anions and cations of LLM,enhance the interaction with lattice oxygen,increase Ni^(3+) and Co^(3+),and improve Mn^(4+) coordination,improving reversibility of oxygen redox activation,maintaining the stable framework and facilitating the Li^(+) diffusion.Furthermore,we found 5%Ti-substitution sample delivered a high discharge capacity of 244.2 mAh/g at 50 mA/g,an improved cycling stability to 87.3%after 100 cycles and enhanced rate performance.Thereby Ti-substitution gives a new pathway to achieve high reversible cycle retention for LLMs.

关 键 词：Lithium-rich layered cathode material Ti-substitution Anion/cation regulation Structural stability Cycling stability 

分 类 号：TM912[电气工程—电力电子与电力传动] TQ131.11[化学工程—无机化工]