Preparation of an improved positive electrode and its application in Ni/MH batteries

Abstract

Abstract The capacity of Ni/MH batteries depends on the specific capacity of the positive electrode and the utilization of active material because of the positive electrode capacity limitation. The present study is engaged in enhancing the specific capacity of the Ni(OH)2 electrode and the utilization of the active material. Ni(OH)2 or NiOOH in the positive electrode is a semiconductor, which is different from the conductive active material (hydrogen storage alloys) of the negative electrode. In this research a new process has been developed to prepare positive electrodes with excellent electrochemical characteristics. The process consists of the positive electrode being despumated, and then coated with conductive metallic materials on the surface. The new positive electrode exhibits a better collective current effect, higher specific capacity and higher utilization of the active material. The new process comprehensively improves the characteristics of the Ni/MH battery, especially concerning the battery capacity and discharge capacity at high rates.