A study of rechargeable zinc electrodes for alkaline cells requiring anodic limitation

Abstract

A well known technology exists for the preparation of anodes for rechargeable alkaline cells in which the zinc capacity is far in excess of the cathodic capacity, as in AgOZn or NiZn cells. However, in rechargeable alkaline zinc—air cells and zinc—manganese dioxide cells the zinc limits the discharge. Especially for the manganese dioxide cathode it is necessary to limit the discharge to a definite fraction (1/3) of its available capacity to obtain a good cycle life. This study of alkaline zinc powder electrodes evaluates parameters such as cell geometry, electrolyte additives, and current collectors (see Table 1) and shows that it is a considerable achievement to obtain 50 – 100 cycles reliably under anode limiting conditions. It is this fact which has prevented the technology of alkaline MnO 2—zinc cells from producing rechargeable batteries of consumer quality up to the present time.