Method for preparing electrodes for Ni/Metal hydride secondary cells using Cu

Abstract

Disclosed is a method for preparing a high performance, negative electrode for Ni/metal hydride cells. A Zr-based hydrogen storage alloy, a binder comprising a mixture of polytetrafluoroethylene and 50th and a thickening agent (hydroxypropylmethyl cellulose), and a current collector comprising carbon black and copper are slurried and molded into a paste-type electrode. In a closed type cell, the copper repetitively undergoes melting and deposition on the electrode during charging and discharging cycles, allowing the electrode to show a similar change in surface morphology and electrochemical properties to that of a conventionally electroless plated electrode. Giving a contribution to the improvement in cell properties, including inner cell pressure, high rate dischargeability and energy density per volume, the method can substitute conventional alloy surface modifying methods, such as electroless plating methods and other pre-treatment processes necessary for the preparation of electrodes, which are difficult to practice owing to the production of pollution of the environment and to requirement of additional procedures.