高密度球形Ni(OH)_2的表面修饰

Surface modification of high density spherical Ni(OH)_2

为提高镍电极的导电性 ,在电极制作过程中需添加一定量的导电剂 ,通过混合添加的导电剂 ,受工艺条件的限制 ,其均匀性和利用率不是十分理想。通过化学方法 ,利用动态积分进料工艺在Ni(OH ) 2 的表面包覆上了一层钴的化合物 ,经SEM分析观察 ,包覆层分布均匀 ,与基体结合牢固、稳定。采用包覆钴化合物的Ni(OH ) 2 制备的镍电极 ,经 0 .3C及 1.0C充放电测试表明 ,其充电电压低 ,放电平台高 ,比容量大 ,大电流充放电效率及活性材料的利用率得到了明显的改进。

It is needed to add a certain amount of conductive agents in the nickel cathode during the manufacturing process to enhance its conductivity. But the uniformity and the utilization factors of the conductive agent are not so ideal because of the blend technics. In the present work, the surface of the Ni(OH) 2 grains is micro-encapsulated with a layer of cobalt compounds by using the dynamic feeding technique. The results from SEM show that the coating layer is well distributed on the surface of the Ni(OH) 2 grains, and the layer is combined with the grains tightly. The results of the electrochemical tests of charge-discharge at 0.3C and 1.0C show that the utilization factor of the active materials and the charge-discharge efficiency of the nickel cathode using the cobalt coated Ni(OH) 2 powders were improved obviously.