3) demonstrated that PGC had a chaotic irregular structure. A multitude of microporous was generated in the material because the water molecules were removed during GA and PEI were combined. Meanwhile, the particles agglomerated to produce secondary particles. The primary particle size was approximately 0.5 to 1 μm. These structures were conducive to the insertion and extraction of protons, which was also consistent with the results of the electrochemical performance test in Sec (3.3).