The existing air electrode can be summarized as follows: â‘  air electrode polarization is serious: the high current oxygen diffusion difficulties caused by the oxygen electrode polarization. The difficulty of oxygen diffusion depends on the porosity of the gas diffusion layer, hole long and tortuous, that is, depends on the ratio of the gas diffusion layer materials and molding conditions. In order to reduce the polarization of the air Nickel Welding Electrodes, and the need to further optimize the structure of the air electrode to improve the speed of the gas phase mass transfer of oxygen. â‘¡ catalyst instability, and can not meet the requirements of large current discharge, and required preparation of an efficient and practical catalyst. In recent years, the organic acid catalysts, metal oxide catalysts (such as Titania and MnC2, PbO2 by), etc. by the people's attention, its source is abundant, inexpensive, and greatly reduces the cost, but the catalytic activity is not high, the battery current is too low, and therefore seek high catalytic activity and low-cost, pollution-free catalyst is the key to the impact of the air electrode practical. (3) air electrode "sweating", take the salt "is serious. Exudate of the air electrode air battery development, and more with the presence and production process of the waterproof electrode carbon. This problem has seriously affected the performance of air electrode, and makes the life of the air Tungsten Electrode is generally short. This article only describes several oxygen reduction catalyst profiles.