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

Several advanced cellulosic and radiation grafted polypropylene membrane ma terials are currently under evaluation in the laboratories at Navsea Crane and Rutgers University, for application to alkaline primary and rechargeabl e cell chemistries which employ zinc as the anode material. A portion of th ese tests involve model cell evaluations of cellulosic membranes for silver migration rates through the membranes as a function of separation layers a nd 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 prop erties, and silver and zinc penetration rates. The overall goal of these in vestigations is to obtain candidate separation membranes which will reduce zinc anode shape change and shedding and resist alkaline oxidative degradat ion to extend the active wet life in primary cells and both wet and life cy cle in rechargeable cells. (C) 2001 Elsevier Science B.V. All rights reserv ed.