Synthesis of LiCo0.5Ni>0.5O2 powders by a sol–gel method

Abstract

Layered HT (high temperature)-LiCo _0.5 Ni _0.5 O ₂ powders, which are of potential interest as cathode materials for lithium secondary batteries, have been synthesized by a sol–gel method using poly(acrylic acid) (PAA) as a chelating agent. This method provided a variety of advantages of the processing conditions over the conventional solid-state reaction method. High-quality polycrystalline HT-LiCo _0.5 Ni _0.5 O ₂ powders of very uniformly sized particulates with an average particle size of 0.4–2 µm could be conveniently obtained at a comparatively low calcination temperature of 600 °C and short calcination time of 1 h in air. An electrochemical study showed that the LiCo _0.4 Ni _0.5 O ₂ powders had high capacity and good cycling behaviour for lithium secondary batteries.