Synthesis of 3D porous flower-like NiO/Ni6MnO8 composites for supercapacitor with enhanced performance

Supercapacitors (SCs) have shown great potential to be used as power sources to drive microelectronic devices. However, most of present SCs employing carbon-based materials show low energy density due to the low specific capacitance of carbon-based materials. As a result, their application potential in power sources is greatly limited. In this work, 3D porous flower-like NiO/Ni6MnO8 composite were synthesized as novel pseudocapacitive electrode materials for SCs. The composite shows high electrode/electrolyte contact surface, short path length for electronic transport, and convenient diffusion paths for ionic transport. Therefore, the mesoporous structures can effectively facilitate ion/electron transfer inside the block of electrodes and at the electrode/electrolyte interface. The novel NiO/Ni6MnO8 pseudocapacitive electrode materials exhibit enhanced specific capacitance as high as 433 F g(-1) at 1 A g(-1), much higher than that of pure NiO (193 F g(-1)) and pure Ni6MnO8 (201 F g(-1)), and excellent charge/discharge cycle life, achieving 91.9% capacitance retention after 1000 cycles.