锂离子电池正极材料LiNi_(0.8-x)Co_(0.2)Al_xO_2的制备及性能

Preparation and Characterization of LiNi_(0.8-x)Co_(0.2)Al_xO_2 as Cathode Materials for Lithium Batteries

采用高温固相反应合成了具有二维层状结构的化合物LiNi0．8-xCo0.2AlxO2，用X-射线衍射、热重和模拟电池的充放电对所得样品的结构、热稳定性和电化学性能进行了测试．结果表明，通过湿法球磨混合和两阶段烧结可以在空气中合成结晶良好的六方单相晶体；用β-NiOOH作为镍源时产物更易生成；当铝添加量在0～10％（摩尔分数）之间时，A1含量对材料的热稳定性和放电电压的影响比较大，而对材料的放电容量影响不明显．

Two-dimension layered LiNi0. 8-xCo0.2 AlxO2 compounds are prepared by a solid-state reaction. Its structure, thermal stability and electrochemical properties are characterized by means of X-ray diffraction（XRD）, thermogravimetric analysis（TG） and charge-discharge studies. The results show that the products synthesized by two-step calcination after ball-milling with organic solvent as dispersing agent are crystallized into a well-ordered structure in air, and the products could be prepared more easily with β-NiOOH as a nickel source compound. The content of A1 plays a more important part in thermal stability and operating potential than in discharge capacity when A1 content is between 0 and 10%.