Homogenous coating of Li^(+)conductive Li_(5)AlO_(4)on single-crystalline nonstoichiometric Li_(1.04)Ni_(0.92)Al_(0.04)O_(2)for rechargeable lithium-ion batteries  

作　　者：Guoyu Ding Shizhou Wang Jinhan Li Ziyan Wu Jiayu Chen Jiayong Du Xinhui Huang Kuiming Liu Yudong Zhang Zhonghan Wu Yiyang Peng Qiancheng Zhao Meng Yu Fangyi Cheng 

机构地区：[1]Key Laboratory of Advanced Energy Materials Chemistry(Ministry of Education),Engineering Research Center of High-efficiency Energy Storage(Ministry of Education),College of Chemistry,Nankai University,Tianjin 300071,China [2]State Key Laboratory of Advanced Chemical Power Sources,Nankai University,Tianjin 300071,China [3]Haihe Laboratory of Sustainable Chemical Transformations,Tianjin 300192,China

出　　处：《Journal of Energy Chemistry》2024年第8期651-659,I0014,共10页能源化学（英文版）

基　　金：supported by the China National Funds for Distinguished Young Scientists(21925503);the National Natural Science Foundation of China(21835004);the Jilin Scientific and Technological Development Program(20220301018GX)。

摘　　要：Cobalt-free,nickel-rich LiNi_(1-x)Al_(x)O_(2)(x≤0.1)is an attractive cathode material because of high energy density and low cost but suffers from severe structural degradation and poor rate performance.In this study,we propose a molten salt-assisted synthesis in combination with a Li-refeeding induced aluminum segregation strategy to prepare Li_(5)AlO_(4)-coated single-crystalline slightly Li-rich Li_(1.04)Ni_(0.92)Al_(0.04)O_(2).The symbiotic formation of Li_(5)AlO_(4)from reaction between molten lithium hydroxide and doped aluminum in the bulk ensures a high lattice matching between the Ni-rich oxide and the homogenous conductive Li_(5)AlO_(4)that permits high Li^(+)conductivity.Benefiting from mitigated undesirable side reactions and phase evolution,the Li_(5)AlO_(4)-coated single-crystalline Li_(1.04)Ni_(0.92)Al_(0.04)O_(2)delivers a high specific capacity of220.2 mA h g^(-1)at 0.1 C and considerable rate capability(182.5 mA h g^(-1)at 10 C).Besides,superior capacity retention of 90.8%is obtained at 1/3 C after 100 cycles in a 498.1 mA h pouch full cell.Furthermore,the particulate morphology of Li_(1.04)Ni_(0.92)Al_(0.04)O_(2)remains intact after cycling at a cutoff voltage of 4.3 V,whereas slightly Li-deficient Li_(0.98)Ni_(0.97)Al_(0.05)O_(2)features intragranular cracks and irreversible lattice distortion.The results highlight the value of molten salt-assisted synthesis and Li-refeeding induced elemental segregation strategy to upgrade Ni-based layered oxide cathode materials for advanced Li-ion batteries.

关 键 词：Aluminum segregation Surface coating Nonstoichiometric oxides Molten synthesis Cathode materials 

分 类 号：TM912[电气工程—电力电子与电力传动]