Structural, electrical and electrochemical studies of LiNi$_{0.4}M_{0.1}$Mn$_{1.5}$O$_4$ ($M$ = Co, Mg) solid solutions for lithium ion battery

Bulletin of Materials Science

关键词: Lithium ion batteries;    positive electrode;    LiNi$_{0.4}M_{0.1}$Mn$_{1.5}$O$_4$-based spinels;    sol–gel method;    charge/discharge.;   

学科分类：材料工程

来源: Indian Academy of Sciences

【 摘 要 】

The LiNi$_{0.4}M_{0.1}$Mn$_{1.5}$O$_4$ ($M$ = Co, Mg) solid solutions are synthesized by citric acid assisted sol–gel method and characterized by using TG/DTA, XRD, FTIR, EPR and SEM. The electrochemical characterization is carried out using CR-2032 coin type cell configuration. The cyclic voltammogram shows two pairs of redox current peaks, 4.35/3.80 V and 4.90/4.37 V vs. Li in a typical case of Co-doped sample, ascribed to two-step reversible intercalation of Li. A.c.-impedance (Nyquist plot) shows high frequency semicircle and a sloping line in the low frequency region. The semicircle is ascribed to Li-ion migration through interface from the surface layer of the particlesto electrolyte. The LiNi$_{0.4}Co_{0.1}$Mn$_{1.5}$O$_4$ shows reasonably good capacity retention in 20 cycles of galvanostatic charge/discharge cycling.

【 授权许可】

CC BY