Tungsten and phosphate polyanion co-doping of Ni-ultrahigh cathodes greatly enhancing crystal structure and interface stability  

作　　者：Huawei Zhu Haifeng Yu Zhaofeng Yang Hao Jiang Chunzhong Li 

机构地区：[1]Shanghai Engineering Research Center of Hierarchical Nanomaterials,Frontiers Science Center for Materiobiology and Dynamic Chemistry,School of Materials Science and Engineering,East China University of Science&Technology,Shanghai 200237,China

出　　处：《Chinese Journal of Chemical Engineering》2021年第9期144-151,共8页中国化学工程学报（英文版）

基　　金：supported by the National Natural Science Foundation of China(91834301);the Innovation Program of Shanghai Municipal Education Commission;the Shanghai Scientific and Technological Innovation Project(18JC1410500);the Fundamental Research Funds for the Central Universities(222201718002)。

摘　　要：The Ni-ultrahigh cathode material is one of the best choices for further increasing energy-density of lithium-ion batteries(LIBs),but they generally suffer from the poor structure stability and rapid capacity fade.Herein,the tungsten and phosphate polyanion co-doped LiNi_(0.9)Co_(0.1)O_(2)cathode materials are successfully fabricated in terms of Li(Ni_(0.9)Co_(0.7))_(1-x)W_(x)O_(2-4y)(PO_(4))_(y) by the precursor modification and subsequent annealing.The higher bonding energy of W—O(672 kJ·mol^(-1))can extremely stabilize the lattice oxygen of Ni-rich oxides compared with Ni—O(391.6 kJ·mol^(-1))and Co—O(368 kJ·mol^(-1)).Meanwhile,the stronger bonding of Ni—(PO_(4)^(3-))vs.Ni—O could fix Ni cations in the transition metal layer,and hence suppressing the Li/Ni disorder during the charge/discharge process.Therefore,the optimized Li(Ni_(0.9)Co_(0.1))_(0.99)W_(0.01)O_(1.96)(PO_4)_(0.01)delivers a remarkably extended cycling life with 95.1%retention of its initial capacity of 207.4 mA·h·g^(-1)at 0.2 C after 200 cycles.Meantime,the heteroatoms doping does not sacrifice the specific capacity even at different rates.

关 键 词：LiNi_(0.9)Co_(0.1)O_(2) CO-DOPING Crystal stability Cycling life Li-ion batteries 

分 类 号：TM912[电气工程—电力电子与电力传动]