▎ 摘　　要

NOVELTY - Producing graphene composite, comprises (a) preparing graphene oxide powder, (b) ultrasonically pulverizing the prepared graphene oxide powder, freeze-drying, and mixing with conductive material to form a graphene oxide mixture, (c) irradiating microwaves to the graphene oxide mixture to obtain a graphene composite, and (d) dispersing the obtained graphene complex in a solution, ultrasonic grinding and freeze drying. The ultrasonic grinding in step (b) and step (d) is performed under an ice bath conditions. USE - The graphene composite is useful to produce electrode active material of electrode for secondary battery (all claimed). ADVANTAGE - The graphene composite increases capacity per volume by including fine/mesopores by filling the graphene composite between particles of activated carbon or coating the surface of activated carbon, and improves electrochemical properties. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are also included for: (1) producing electrode active material, comprising (i) mixing the freeze-dried graphene composite and activated carbon; (2) electrode active material comprising multiple activated carbon/graphene composite, where the graphene composite is filled between particles of the activated carbon or coated on at least one area of the surface of the activated carbon; (3) electrode manufactured by applying an electrode active material slurry containing electrode active material on the first or second substrate; and (4) secondary battery comprising a first electrode, a second electrode facing the first electrode, and a separator interposed between the first electrode and the second electrode, where the first electrode or the second electrode is an electrode active material manufactured by the above method.