▎ 摘　　要

NOVELTY - Manufacturing graphene quantum dot (GQD)/silicon/carbon nanomaterial composite, comprises (a) preparing hydroxy-functionalized-GQDs by hydroxy functionalization so that graphene quantum dots are negatively charged; (b) preparing positively charged silicon nanoparticles (SiNPs); (c) synthesizing GQD/SiNP binary composite by electrostatic attraction between positively charged silicon nanoparticles prepared in step (b) and hydroxy-functionalized-GQDs having a relatively negative charge in step (a); and (d) adding carbon nanofibers (CNFs) or carbon nanotubes (CNTs) to the GQD/SiNP binary composite synthesized in step (c) to synthesize a GQD/SiNP/CNFs complex or a GQD/SiNP/CNTs complex. USE - The GQD/silicon/carbon nanomaterial composite is useful for manufacturing secondary battery (claimed); in various fields e.g. displays, solar cells, and biosensors; as a cathode material for a lithium ion battery of electric vehicles (EVs), portable electronic devices, and large energy storage devices. ADVANTAGE - The GQD/silicon/carbon nanomaterial composite manufactured has excellent conductivity and physical properties and silicon having a high theoretical capacity as cathode material for lithium ion battery, and has a structure in which carbon nanomaterials surround silicon nanoparticles bonded to hydroxy-functionalized-GQDs by electrostatic attraction. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is also included for manufacturing secondary battery, comprising carrying out the above mentioned steps (a) to (d), and (e) using the GQD/SiNP/CNFs composite or GQD/SiNP/CNTs composite as an cathode material.