Construction of MnO2 Nanowire for a High-Performance Lithium Ion Supercapacitor

Abstract

Developing lithium ion capacitors possessing both brilliant energy and power density is still significant for numerous researchers. In this paper, we synthesize MnO2 nanowires via a simple hydrothermal process. The nanostructure MnO2 can expose more electrochemical sites and thus optimize the kinetics of Li+. Moreover, we use MnO2 nanowires (MnO2 NWs) as anode and a N-doped porous carbon (NPC) as cathode to assemble lithium ion capacitors (MnO2 NWs//NPC LIC). Compared to the traditional supercapacitor with aqueous electrolyte, the MnO2 NWs//NPC LIC exhibits a wider voltage of 0-4.2 V, which is helpful to enhance its energy and power density. Furthermore, MnO2 NWs//NPC LIC can deliver an excellent capacity of 150 mAh g-1 with a excellent energy density of 82.7 Wh kg-1 and power density of 1.05 kW kg-1. Meanwhile, a good cyclic stability of LICs with a 20% retention after 1000 times charge and discharge process proves its practical potential, indicating a good promising for the application in storage devices.