Effect of Temperature on Low Energy Consumption Electrolytic Preparation of Manganese Dioxide Using Oxygen Depolarized Electrode

A new method of an oxygen depolarization gas diffusion electrode (GDE) is proposed to reduce the energy consumption of the electrolysis process for electrolytic manganese dioxide (EMD). Substitute oxygen reduction reaction for hydrogen evolution reaction can reduce energy consumption, avoid acid mist, improve working environment, as well as reduce hidden danger. The effect of temperature on electrodeposition was researched. The results show that the cell voltage and the energy consumption of new method by using GDE (Pt/C type) is 4/5-2/3 of that by using Cu or Pt cathode at 40-90°C. The current efficiency is up to 95%, when the temperature is greater than 70°C. The optimum temperature of the new electrolysis process is 80°C, while the life span reaches 400 h. The as-gained EMD belongs to γ-MnO2 when temperature reaches 60°C. The performance of EMD fulfills the industrial requirements when the temperature reaches 70°C. By greatly influence the dissolution rate of Ni net, temperature affects the life span of GDE.