Holey graphene interpenetrating networks for boosting high-capacitive Co3O4 electrodes via an electrophoretic deposition process

A composite of Co 3 O 4 /holey graphene (Co 3 O 4 /HG) was prepared via a facile hydrothermal route, and was then processed into an electrode by an electrophoretic deposition process. Holey graphene (HG) wrapped Co 3 O 4 to form a 3D skeleton network, thereby providing high electrical conductivity , and the holes in HG could further shorten the electrolyte ion diffusion pathway. Therefore, by adjusting the mass ratio of Co 3 O 4 to HG, the Co 3 O 4 /HG composite afforded an enhanced capacitance of 2714 F g −1 (at a current density of 1 A g −1 ), which is 20 times higher than that of pure Co 3 O 4 . To further explore the practical applications of Co 3 O 4 /HG, a symmetric supercapacitor employing Co 3 O 4 /HG was fabricated. The supercapacitor functioned stably at potentials up to 1.2 V, with an enhanced energy density of 165 Wh kg −1 and a high power density of 0.6 kW kg −1 at 1 A g −1 .