3-D ordered bimodal porous carbon/nickel oxide hybrid electrodes for supercapacitors

•3D-ordered bimodal porous carbons were fabricated as electrode materials.•The electrodes were prepared with nickel oxide nanoparticles of 2–4 nm.•EDLC and pseudocapacitive redox reaction were applied to the electrodes.•The electrodes showed superior capacitance, rate capabilities, and cycle stability.

3D-ordered bimodal porous carbons (3D-OBPCs) were fabricated, containing well-ordered macropores and a large amount of sub-/nanometer pores (micropores) with narrow pore size distribution. Nickel oxide (NiO) nanoparticles of 2–4 nm were introduced on the 3D-OBPCs. The 3D-OBPC/NiO nanoparticle hybrid exhibited better electrochemical performance than that of 3D-ordered macroporous carbon/NiO nanoparticle hybrid, because of the synergistic effects from the electric double-layer capacitance of a large amount of micropores, enhanced wettability due to oxygen heteroatoms introduced from the activation process, and pseudocapacitive redox reactions of NiO nanoparticles.