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

Abstract Herein, a cubic architecture of a self-assembled nanograined manganese carbonate (cub-MnCO 3 ) 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-MnCO 3 architecture provides large open channels by the interconnection of numerous nanograined MnCO 3 to enhance ion and electron diffusion pathways, facilitating the whole active electrode material by easier electrolyte penetration. The cub-MnCO 3 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-MnCO 3 has revealed capacitance retention of 83.8% after 5000 cycles at a high current density of 10 A g −1 .