Controlled Porosity and Pore Size Substrates for Nickel‐Cadmium Cells

Abstract

A novel process for the preparation of improved cadmium electrode plaques with precisely controlled pore size and porosity is described. The requirements for these plaques include far better uniformity, reproducibility, and life than is currently available with conventional materials. The key features of the work were preparation of plaques via a powder metallurgical technique which consisted of isostatically compacting a blend of a nickel powder with a fugitive pore-former and subsequently sintering the “green” compact. Cadmium electrodes were prepared from these materials and cycle tested in negative-limited cells using an accelerated, torturous test regime. Results were obtained which showed the new structures yielded electrodes that were superior to the conventional structures in mechanical properties and performance. BET surface areas, SEM photomicrographs, and mechanical strengths using a three-point bend test were used to help in the thorough characterization of the electrodes and the components prepared.