大功率碱性MnO₂-Zn二次电池研究（Ⅳ）——MnO₂电极结构的影响

大功率碱性MnO 2 -Zn二次电池研究（Ⅳ）——MnO 2 电极结构的影响 A STUDY OF HIGH POWER SECONDARY ALKALINE MnO 2 -Zn CELL（Ⅳ） 白力军 1 first-author 李国栋 1 查全性 1 廖丹雄 1 武汉大学电化学研究室 研究生 武汉大学电化学研究室 研究生 < 正 > 一前言 1965年A·Kozawa和J.F.Yeager首先提出,在碱性溶液巾MnO 2 电极的阴极还原分两步进行[1],随后大量实验工作更深刻揭示了其反应机理。A.Kozawa在[2] 中详细综述了影响两步反应的各种因素,指出第一步为均相反应,第二步为非均相反应,并涉及到可溶性反应粒子。 1975年P.Ruetsohi联合使用电位扫描与光学显微镜方法,观测了MnO 2 在碱性、中巾性、酸性溶液中的电化学行为[3],指出在碱性溶液中可溶性反应粒子起着重要作用,并拍摄了反应粒子溶解前后的照片,进一步证实了下列反应机理: The influnce of the structure of electrodes on the kinetics of the second step for MnO 2 reduction reaction in alkaline solution were investigated by means of potentiodynamic sweep and a sensor electrode. During discharge of the thin PTFE bonded MnO 2 electrodes at high current density, the second step of reduction reaction couldn’t be detected at room temperature even if electrodes were discharged at rather negative potential, since the compact structure of electrodes could restrain the solution and diffusion of Mn（Ⅲ） species. It was found that the acceleration of production and diffusion of Mn（Ⅲ）species were important factors leading to the lose of reversibility of MnO 2 eleetrodes. Restrain of these reactions by modifications of electrode structure helped to maintain the reversibility of electrode reaction. 1981-03-01 2021-04-01 3