以混合价镍氢氧化物为镍源固气合成LiNi_(0.7)Co_(0.25)Al_(0.05)O_2

Synthesized of LiNi_(0.7)Co_(0.25)Al_(0.05)O_2 by solid-gas method with preoxidized 2NiOOH·Ni(OH)_2 as nickle source

层状LiCoO2作为锂离子二次电池电极正极材料已得到广泛应用。由于钴资源匮乏及成本高，致使进一步提高比容量和比能量以及降低成本的研究引起关注。诸如LiCoO2体材中钴被M（Ni，Mn，Ti，Mg）替代或部分被替代的研究，表面修饰研究，合成方法研究如固相法，溶胶凝胶法，共沉淀法，微波加热合成法训等。

LiNi0.7Co0.25Al0.05O2 was prepared by solid- gas method in O2 at the temperature of 700℃ for 8h using preoxidized nanometer - scale Ni3O2 （ OH ） 4 powders as nickel source. The products were tested by XRD, XPS, SEM and electrochemistry methods. The results indicated that the prepared product was LiNi0.7Co0.25Al0.05O2 single-phase, having the average size of 1.5p,m with globe morphology. In the LiNi0.7Co0.25Al0.05O2. the valence of nickel was ＋ 3. In the case of voltage range 4. 3 ~ 2. 5 V and the current rate 0. 25 mA/cm^2 , the first charge and discharge specific capacities were 172mAh · g^-1 and 161 mAh · g^-l respectively. According to the cycling tests , LiNi0.7Co0.25Al0.05O2 exhibited good cycling performance.