Effect of Graphite Properties on Reversible Capacitance and Coulomb Efficiency

The effect of structural characteristics of graphites (specific surface area, porosity, interplanar distance d002, crystallite size, amorphous fraction) on their electrochemical parameters (reversible capacity, Coulomb efficiency (CE) in the first cycle) was studied. It was found that changing the specific surface area of graphites in the range of 0.5–5 m2/g does not have a noticeable effect on the reversible capacity. High reversible capacity (350–370 mA h/g) is typical for graphites with d002 400 Å. It was found that high specific surface area (>5 m2/g) and the presence of micropores reduce the Coulomb efficiency of graphite electrodes in the first cycle. Increasing the amorphous fraction by more than >0.7% reduces the Coulomb efficiency.