氢氧化镍电极导电剂的研究

研究了镍粉，镍粉和石墨的混合物，石墨以及石墨和乙炔墨的混合物分别作为导电剂以机械混合的方式添加到电极活性物质中对氢氧化镍电极性能的影响，并用循环伏安法和交流阻抗法分析了实验结果。结果表明：在这四种导电剂中，镍粉作导电剂时氢氧化镍电极的性能最好，其次是以石墨或镍粉和石墨的混合物作导电剂的氧化镍电极，当石墨和乙炔黑的混合物作导电剂时氢氧化镍电极的性能最差。这是因为当镍作导电剂时氢氧化镍电极的电化学反应电阻最小，质子扩散最容易，电要的可逆性最好，且氧气析出最困难，而当石墨和乙黑和混合物作导电剂时氢氧化镍电极的电化学反应电阻最大，质子扩菜最困难，电极充电过程和析氧过程几乎同时进行，因而充电效率最低，活性物质的利用率最小，电极性能最差。

Study on conductive agent for nickel hydroxide electrode

Performance of nickel hydroxide electrodes with nickel, mixture of nickel and graphite, graphite, or mixture of graphite and acetylene black as conductive agent, which was added by mechanical mixing with Ni(OH) 2 was studied. The experimental results were interpreted by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). It was demonstrated that when nickel was used as conductive agent, the best performance of nickel hydroxide electrode could be obtained, which was a little better than that of the nickel hydroxide electrode with graphite or the mixture of nickel and graphite as conductive agent, and the nickel hydroxide electrode with conductive agent of the mixture of graphite and acetylene black exhibited the poorest performance. This can be mainly attributed to the fact that when nickel is added as conductive agent, the smallest charge transfer resistance, the easiest proton diffusion, the most difficult oxygen evolution, and the best reversibility of the nickel hydroxide electrode are obtained. But the nickel hydroxide electrode with the mixture of graphite and acetylene black as conductive agent has the largest charge transfer resistance, the most difficult proton diffusion process, the simultaneous and competing charging and oxygen evolving processes.