Nickel/Metal Hydride Secondary Batteries Using an Alkaline Solid Polymer Electrolyte

Sealed alkaline solid polymer electrolyte nickel/metal hydride laboratory cells have been constructed and tested to evaluate their properties. Studies of the cycle life, self‐discharge, and behavior of cells at different temperatures were carried out. The first results on the electrochemical behavior of an alkaline solid polymer electrolyte [based on poly(ethylene oxide), potassium hydroxide, and water] medium are presented here and show good reversibility of this all‐solid‐state system for more than 500 cycles, without significant loss of capacity and with a reasonable average discharge efficiency (close to 80%). The temperature‐dependence study allowed the deremination of optimum operating conditions berween 0 and 40°C. Characteristics of the solid polymer electrolyte based Ni/MH cells are compared to those of several other rechargeable battery systems. © 1999 The Electrochemical Society. All rights reserved.