钴的表面修饰对Ni(OH)_2电极性能的影响

Effects of Surface Cobalt Modifications on the Performance of Ni(OH)_2 Electrode

以球形Ni(OH) 2 为修饰基体 ,研究比较了化学镀Co、沉积包覆Co(OH) 2 和物理混合CoO的 3种表面修饰方式对Ni(OH) 2 电极性能的影响。充放电和循环伏安实验表明 ,包覆Co(OH) 2 和化学镀Co更能有效地改善充放电效率和可逆性 ,较大程度地提高活性物质的利用率和放电容量。扫描电镜显示 ,包覆Co(OH) 2 和化学镀Co可使Co元素均匀分布在球形Ni(OH) 2 表面。X射线衍射分析表明 ,包覆Co(OH) 2 和化学镀Co可有效地抑制充放电过程中γ NiOOH的形成。讨论了 3种表面修饰方式的利弊 ,认为包覆Co(OH) 2 效果较好 ,工艺简单 ,为可行的最佳修饰方式。

The spherical Ni(OH) 2 was modified with cobalt by three methods: electroless plating with cobalt, coating with Co(OH) 2 and mixing with CoO. The difference of three modification methods on the performance of Ni(OH) 2 electrode has been investigated. The charge-discharge experiments and cyclic voltammetry results show that coating with Co(OH) 2 layer and electroless plating with cobalt greatly improved the charge-discharge efficiency and the reversibility of Ni(OH) 2 electrode, significantly improving the utilization of active material and specific capacity of the electrode. The SEM micrograph shows that the Co(OH) 2 coated layer and electroless plated Co are uniformly distributed on the surface of the Ni(OH) 2 grains. The result from X-ray diffraction patterns shows that the coated Co(OH) 2 layer and electroless plated Co can effectively prevent the formation of γ-NiOOH. It is concluded that the method of coating a layer of Co(OH) 2 on the spherical Ni(OH) 2 is the best among three methods. It is cheaper and simpler in technology.