A method of producing a powder mass for a lithium battery, comprising: (a) mixing graphene sheets and a sulfonated elastomer or its precursor in a liquid medium or solvent to form a suspension; (b) dispersing a plurality of particles of an anode active material in the suspension to form a slurry; and (c) dispensing the slurry and removing the solvent and/or polymerizing or curing the precursor to form the powder mass comprising multiple particulates, wherein at least one of the particulates is composed of one or a plurality of the particles encapsulated by a thin layer of a sulfonated elastomer/graphene composite having a thickness from 1 nm to 10 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.