Lithographically defined porous Ni–carbon nanocomposite supercapacitors

Abstract

Ni was deposited onto lithographically-defined conductive three dimensional carbon networks to form asymmetric pseudo-capacitive electrodes. A real capacity of above 500 mF cm⁻², or specific capacitance of ∼2100 F g⁻¹ near the theoretical value, has been achieved. After a rapid thermal annealing process, amorphous carbon was partially converted into multilayer graphene depending on the annealing temperature and time duration. These annealed Ni–graphene composite structures exhibit enhanced charge transport kinetics relative to un-annealed Ni–carbon scaffolds indicated by a reduction in peak separation from 0.84 V to 0.29 V at a scan rate of 1000 mV s⁻¹.