▎ 摘　　要

NOVELTY - Reduced graphene oxide-dihydroxynaphthalene composite material comprises reduced graphene oxide and dihydroxynaphthalene. USE - The reduced graphene oxide-dihydroxynaphthalene composite material is used for lithium-ion secondary battery (claimed) for industrial applications related to transportation, storage and supply of electrical energy, and as power source for mobile devices such as mobile phone, notebook computer, tablet terminal and portable game machine, moving/transporting media such as electric vehicle, hybrid car, electric bike, electrically assisted bicycle, transport cart, robot and drone (small unmanned aerial vehicle), household power storage system, backup power source such as uninterruptible power source (UPS), and power storage facility for storing power generated by solar power generation and wind power generation. ADVANTAGE - The reduced graphene oxide-dihydroxynaphthalene composite material improves initial charge/discharge efficiency and capacity retention rate when used in the lithium ion secondary battery. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for the following: (1) a method for producing the reduced graphene oxide-dihydroxynaphthalene composite material, which involves performing reaction by mixing graphene oxide and dihydroxynaphthalene to obtain a reaction product and performing heat treatment by reducing the reaction product; and (2) a lithium-ion secondary battery comprising a positive electrode comprising a positive electrode active material capable of storing and releasing lithium ions, a negative electrode comprising a negative electrode active material capable of storing and releasing lithium ions, and a non-aqueous electrolyte solution, where the negative electrode active material comprises the reduced graphene oxide-dihydroxynaphthalene composite material.