▎ 摘　　要

NOVELTY - Reduced graphene oxide comprises a crystalline reduced graphene oxide in powder form having a two-dimensional structure, and satisfying expressions of 1 ≤ T(Q) ≤ 5 (I), 100 ≤ E(Q) ≤ 1000 (II), and 1 ≤ BET(Q) ≤ 100 (III), where T(Q) is the thickness (nm) of the reduced graphene oxide, E(Q) is the electrical conductivity (S/cm) of the reduced graphene oxide, and BET(Q) is the specific surface area (m2/g) of the reduced graphene oxide. USE - The reduced graphene oxide is used in an electrode for a secondary battery (claimed). ADVANTAGE - The reduced graphene oxide has a low specific surface area and high electrical conductivity while having a specific thickness. The reduced graphene oxide provides secondary battery with high capacity, long lifespan, and high stability electrochemical properties. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for the following: a method for producing the reduced graphene oxide, comprising synthesizing graphite oxide flakes from graphite flakes in powder form, preparing a graphene oxide dispersion solution by exfoliating and dispersing the graphite oxide flakes in a solvent through pH control, preparing a graphene oxide reduced dispersion solution by reducing the graphene oxide dispersion solution, and spray drying the dispersion solution of the reduced graphene oxide to prepare a reduced graphene oxide in powder form, where the reduced graphene oxide in powder form is a crystalline reduced graphene oxide having a two-dimensional structure; and an electrode, where the reduced graphene oxide is formed by coating the current collector.