Designing hybrid electrode materials comprising of interface‐engineered hierarchical structure and its synergetic effect on high energy density hybrid supercapacitors

Rational interface tailoring of nanomaterials is promising but still challenging for high performance electrodes for energy storage applications. Herein, we demonstrate the rational design of hierarchical porous hybrid nanostructure with robust adhesion on Ni foam as a binder-free electrode for supercapacitors (SCs). The incorporation of the carbon nanomaterial and conducting polymers into spinel metal oxide greatly boost the charge transfer. The synergistic effect among individual components maximizes accessible electroactive sites results in a supercapacitor material with superior electrochemical properties. Benefiting from the synergistic interaction, the novel RuCo2O4/RGO/PANI hybrid manifests a high specific capacity of 1028.7 C g−1 at 1 A g−1 and the best cycle stability (93.2 % after 10,000 cycles), which far outperforms the previously reported electrodes in 2 M KOH. The SC device with the newly developed RuCo2O4/RGO/PANI hybrid cathode and graphene anode achieves an exceptional energy density of 36.7 W h kg−1 at a power density of 800.4 W kg−1, as well as capacity retention of 90.1 % after 10,000 cycles. Our findings hold great promise of RuCo2O4/RGO/PANI hybrid for the use in next generation energy storage devices.