▎ 摘　　要

NOVELTY - The method involves drying graphene oxide to prepare graphene oxide in a crumble form. The graphene oxide is wet in a crumbled state to obtain a dough mass in the form of a dough. The dough mass is sintered into a sheet form, where the graphene oxide has a moisture content of 50-70 wt.% before drying. The sintering is performed under an inert gas atmosphere at a temperature of 250-400 degrees C. The silicon is added in the step of obtaining the dough mass. The content of solids other than water in the dough is 30-50wt.%. The silicon has a particle diameter of 0.1-15 mu m. USE - Method for manufacturing electrode active material for electrochemical device. ADVANTAGE - The method enables manufacture of negative electrode having excellent electrical conductivity, initial efficiency and capacity retention, by a simple process. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for the following: (1) a cathode for an electrochemical device; and (2) a lithium-ion secondary battery. DESCRIPTION OF DRAWING(S) - The drawing shows a schematic view of a SEM image showing the surface of the graphene oxide sheet.