Optimization of Ni2+/Ni3+ ratio in layered Li(Ni,Mn,Co)O2 cathodes for better electrochemistry

被引:204
作者
Kosova, N. V. [1 ]
Devyatkina, E. T. [1 ]
Kaichev, V. V. [2 ]
机构
[1] RAS, Inst Solid State Chem & Mechanochem, SB, Novosibirsk 630128, Russia
[2] Russian Acad Sci, Boreskov Inst Catalysis, SB, Novosibirsk 630090, Russia
基金
俄罗斯基础研究基金会;
关键词
lithium-ion batteries; layered Ni-based cathodes; mechanical activation; Ni2+/Ni3+ ratio; XPS study; electrochemical study;
D O I
10.1016/j.jpowsour.2007.06.051
中图分类号
O64 [物理化学(理论化学)、化学物理学];
学科分类号
070304 ; 081704 ;
摘要
A study of the LiNi1-x-yCoxMnyO2 (x=y=0-1; 0.2; 0.33) cathode materials prepared from mixed hydroxides and LiOH using the method of mechanical activation has been performed. All as prepared materials were indexed in the R-3m space group. The cell volume and the degree of structural disordering decrease with reducing of Ni content. According to XPS study, the main electronic state of d-ions in the surface layer of particles corresponds to Ni2+, Co3+ and Mn4+. However, the Ni2P(3/2) and Co2P(3/2) binding energy increases versus Ni content, indicating the increased Me-O bond covalency. The highest specific discharge capacity was observed for LiNi0.6Co0.2Mn0.2O2-170 mAh g(-1). The position of redox peaks on the differential capacity curves depends on the composition of the sample: it shifts towards lower voltage with increased Ni content. (c) 2007 Elsevier B.V All rights reserved.
引用
收藏
页码:965 / 969
页数:5
相关论文
共 22 条