▎ 摘　　要

NOVELTY - A graphene electrode active material preparation method involves dispersing graphite oxide powder in de-ionized water to obtain dispersion liquid, adding 0.01-16 mole/l hydrogen ion to the dispersion liquid at a temperature of 0-100 degrees C for 5-240 minutes, and carrying out solid-liquid separation to obtain a precipitate. The precipitate is dried and ground to obtain a powder A. The powder A is heat-treated at a temperature of 600-1200 degrees C under protection of inert gas atmosphere for 1-60 seconds. USE - Method for preparing a graphene electrode active material that is utilized for preparing an electrode material, an electrode sheet or an electrochemical capacitor (all claimed). ADVANTAGE - The method enables improving specific capacity, capacity retention rate and energy density of the electrochemical capacitor. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are also included for the following: (1) an electrode material containing a binder and the electrode active material (2) an electrode sheet comprising a current collector and an electrode material loaded on the current collector (3) an electrochemical capacitor comprising a shell, a diaphragm, an electrolyte and an electrode.