Morphologically engineered cactus-like MnO2 nanostructure as a high-performance electrode material for energy-storage applications

A morphologically engineered cactus-like MnO2 nanostructure was synthesized by a simple two-step hydrothermal process for energy-storage applications. The prepared cactus-like MnO2 nanostructure exhibits superior electrochemical performance than the prepared MnO2 nanorods. FE-SEM analysis confirmed the formation of nanorods and cactus-like structures and HRTEM revealed the formation of inner parts of the cactus-like structure, such as the core (nanorods), rip (nanosheets), and areoles (nanoneedles). This combination of nanorods, nanosheets, and nanoneedles increased the electrode kinetics and enhance the electrochemical performance. The energy-storage performance of the prepared MnO2 nanostructures was analyzed by various electrochemical techniques. The cactus-like MnO2 nanostructure exhibits a relatively high specific capacity of 725 F g (- 1) at the current density of 1 A g (- 1) in 1 M Na2SO4 aqueous electrolyte. These obtained results encouraged us to fabricated a CR2032 coin-cell type lithium-ion battery using the prepared MnO2 nanostructures and studied its lithium-ion storage capacity.