Ni-, co-, and mn- multi-element doped positive electrode material for lithium battery and its preparation method

Abstract

A Ni—, Co—, and Mn— multi-element doped positive electrode material for lithium ion batteries and its preparation method are provided. The method for preparing said material consists of: first forming a Ni—, Co—, and Mn— multi-element doped intermediate compound by coprecipitation or chemical synthesis; mixing said multi-element intermediate compound with lithium salt and pre-processing the resulting mixture; adding polyvinyl alcohol into the mixture and mixing uniformly, then pressing the resulting mixture into blocks, and calcining these at 800˜930° C.; cooling outside the furnace, crushing and passing through a 400-mesh sieve; calcining the resulting powder at 700˜800° C., cooling outside the furnace and crushing to obtain the product. The positive electrode material obtained by the method described is in the form of non-agglomerated monocrystal particles, with a particle diameter of 0 5˜30 μm, the chemical formula LiNiCoMnMO, a compacted density of up to 3.4 g/cm, and an initial discharge capacity of 145˜152 mAh/g. This positive electrode material shows excellent cycle performance and a high degree of safety.