Changes in the Microstructure of a Sintered Silver Electrode after Repeated Cycling at a Low Current

Abstract

Cross sections of Ag electrodes were examined by optical microscopy. Most small particles present in an unused sintered Ag electrode were completely oxidized to during the first charge, but electrode capacity then decreased markedly during the next few cycles at the 20‐hr rate in 35% . Slow discharges resulted in the formation of large granular Ag particles which did not oxidize as readily or extensively as small Ag particles. Voids were small and well distributed in the unused electrode, but with repeated cycling the voids became large as active material clumped. Grid corrosion occurred but did not impair performance.