PROTECTED PARTICLES OF CATHODE ACTIVE MATERIALS FOR LITHIUM BATTERIES

Provided is a lithium battery cathode electrode comprising multiple particulates of a cathode active material, wherein at least a particulate comprises one or a plurality of particles of a cathode active material being encapsulated by a thin layer of a sulfonated elastomer, wherein the encapsulating thin layer of sulfonated elastomer has a thickness from 1 nm to 10 μm, a fully recoverable tensile strain from 2% to 800%, and a lithium ion conductivity from 10S/cm to 5×10S/cm. The encapsulating layer may further contain an electron-conducting additive and/or a lithium ion-conducting additive dispersed in the sulfonated elastomer.