Advanced membranes for alkaline primary and rechargeable alkaline cells with zinc anodes

Abstract

Several advanced cellulosic and radiation grafted polypropylene membrane materials are currently under evaluation in the laboratories at Navsea Crane and Rutgers University, for application to alkaline primary and rechargeable cell chemistries which employ zinc as the anode material. A portion of these tests involve model cell evaluations of cellulosic membranes for silver migration rates through the membranes as a function of separation layers and changes in the degree of polymerisation (DP), wet tensile strength (WTS) and voltage changes at both electrodes as a function of model rechargeable cell life cycle. Other testing on the actual membranes is generating data for both cellulosic and polypropylene materials on impedance, swelling properties, and silver and zinc penetration rates. The overall goal of these investigations is to obtain candidate separation membranes which will reduce zinc anode shape change and shedding and resist alkaline oxidative degradation to extend the active wet life in primary cells and both wet and life cycle in rechargeable cells.