Thin Film Rechargeable Room Temperature Batteries Using Solid Redox Polymerization Electrodes

Abstract

Thin‐film solid‐state batteries consisting of lithium foils, amorphous PEO separators, and solid redox polymerization electrodes (SRPEs) were assembled, discharged, and cycled at room temperature. No solvents were added to any of the components, nor were structural additives used. Performances were studied as a function of cathode thickness and composition of separator and SRPE. At 50 μA/cm2, cells could be discharged to a depth of 0.6 to 1.3 C/cm2, at 100 μA/cm2 to a depth of 0.5 C/cm2, and at 200 μA/cm2 to a depth of 0.25 C/cm2. It was also possible to pulse batteries at higher current densities for short periods of time (ranging from 0.1 to 3 s) with instantaneous recovery of open‐circuit potential after the pulses. One cell was cycled 100 times, with inadvertent overdischarge and overcharge, before significant deterioration of performance occurred. Batteries may be designed to be paper thin, or may consist of several cells stacked together to give a somewhat thicker device. Practical energy and power densities were calculated as a function of component dimensions (cathode and current collector thicknesses) for paper thin batteries consisting of lithium anodes, amorphous PEO separators, SRPEs, and metallized plastic current collectors. Power densities of 30 W/l (continuous discharge) and pulse (0.1 s power densities over 1000 W/l may be achieved for these ultrathin devices.