Method of improving cycle-life of alkali metal-sulfur secondary battery

Abstract

The invention provides a method of improving the cycle-life of a rechargeable alkali metal-sulfur cell. The method comprises implementing an anode-protecting layer between an anode active material layer and a porous separator/electrolyte, and/or implementing a cathode-protecting layer between a cathode active material and the porous separator/electrolyte, wherein the anode-protecting layer or cathode-protecting layer comprises a conductive sulfonated elastomer composite having from 0.01% to 50% by weight of a conductive reinforcement material dispersed in a sulfonated elastomeric matrix material and the protecting layer has a thickness from 1 nm to 100 μm, a fully recoverable tensile strain from 2% to 500%, a lithium ion conductivity from 10−7 S/cm to 5×10−2 S/cm, and an electrical conductivity from 10−7 S/cm to 100 S/cm when measured at room temperature. This battery exhibits an excellent combination of high sulfur content, high sulfur utilization efficiency, high energy density, and long cycle life.

Dependencies are inferred from the claim text.