Manganese carbonate nanograined assembling macrocube via a facile hydrothermal process for high performance supercapacitors

Herein, a cubic architecture of a self-assembled nanograined manganese carbonate (cub-MnCO3) on a three-dimensional (3D) macro-porous nickel-foam (NF) via a low-temperature (160 °C) hydrothermal process has been reported, which later is used as a binder-free supercapacitor electrode. The cub-MnCO3 architecture provides large open channels by the interconnection of numerous nanograined MnCO3 to enhance ion and electron diffusion pathways, facilitating the whole active electrode material by easier electrolyte penetration. The cub-MnCO3 electrode exhibits a specific capacitance of 476 F g−1 at 1 A g−1 in 1 M KOH aqueous electrolyte solution, and excellent rate ability. The cycling performance of cub-MnCO3 has revealed capacitance retention of 83.8% after 5000 cycles at a high current density of 10 A g−1.