Boosting Li-ion storage in Li2MnO_(3) by unequal-valent Ti4+-substitution and interlayer Li vacancies building  

作　　者：Yu Tian Yuling Zhao Fanqi Meng Kaicheng Zhang Yanyuan Qi Yujie Zeng Congcong Cai Yuli Xiong Zelang Jian Yang Sun Lin Gu Wen Chena 

机构地区：[1]School of Materials Science and Engineering Key Laboratory of Advanced Technology for Materials Synthesis and Processing,Wuhan University of Technology,Wuhan 430070,China [2]School of Materials,Shenzhen Campus of Sun Yat-sen University,Shenzhen 518107,China [3]C Innovation Laboratory,Contemporary Amperex Technology Ltd.(CATL),Ningde 352100,China [4]Institute of Physics,Chinese Academy of Sciences,Beijing 100190,China [5]Sanya Science and Education Innovation Park of Wuhan University of Technology,Wuhan 430070,China

出　　处：《Chinese Chemical Letters》2023年第4期564-569,共6页中国化学快报（英文版）

基　　金：financially supported by the National Natural Science Foundation of China (Nos. 51972258 and 22109186);Open Fund by Sanya Science and Education Innovation Park of Wuhan University of Technology (No. 2021KF0021);supported by 21C Innovation Laboratory,Contemporary Amperex Technology Ltd. by Project No. 21C-OP-202002。

摘　　要：Lithium rich layered oxide(LRLO) has been considered as one of the promising cathodes for lithium-ion batteries(LIBs). The high voltage and large capacity of LRLO depend on Li2MnO_(3)phase. To ameliorate the electrochemical performance of Li2MnO_(3), also written as Li(Li1/3Mn2/3)O_(2), we propose a strategy to substitute Mn4+and Li+in Mn/Li transition metal layer with Ti4+, which can stabilize the structure of Li2MnO_(3)by inhibiting the excessive oxidation of O_(2)-above 4.5 V. More significantly, the unequal-valent substitution brings about the emergence of interlayer Li vacancies, which can promote the Li-ion diffusion based on the enlarged interlayer and increase the capacity by activating the Mn3+/4+redox. We designed Li0.7[Li1/3Mn2/3]0.7Ti0.3O_(2)with high interlayer Li vacancies, which presents a high capacity(290 m Ah/g at 10 m A/g) and stable cycling performance(84% over 60 cycles at 50 m A/g). We predict that this strategy will be helpful to further improve the electrochemical performance of LRLOs.

关 键 词：Lithium-ion batteries Li2MnO_(3) Unequal-valent Ti4+-substitution Interlayer Li vacancies Activated Mn3+/4+redox 

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]