LiMg0.1Co0.9BO3 as a positive electrode material for Li-ion batteries

Abstract

LiCoBO₃ could be a promising cathode material given the electronic and ionic conductivity problems are addressed. Here, Mg substitution in LiCoBO₃ is employed to stabilise the structure and improve the electrochemical performance. LiMg_0.1Co_0.9BO₃ is synthesised for the first time via sol–gel method and Mg substitution in the structure is verified by X-ray powder diffraction and energy dispersive X-ray analyses. The electrochemical properties are investigated by galvanostatic cycling and cyclic voltammetry tests. The composite electrode with conductive carbon (reduced graphite oxide and carbon black) delivers a first discharge capacity of 32 mA h g⁻¹ within a 4.7–1.7 voltage window at a rate of 10 mA g⁻¹. The cycling is relatively stable compared to the unsubstituted LiCoBO₃. Mg substitution may enhance the electrochemical performance of borate-based electrode materials when combined with suitable electrode design techniques.