Nano-Spheroidal MnOx/C Nanomaterial with Battery-Like and Capacitive Charge Storage for Lithium-Ion Capacitors

Lithium-ion capacitors (LICs) possess the potential to satisfy the demands of both high power and energy density for energy storage devices. In this report, a novel LIC has been designed featuring with the MnOx/C batterytype anode and activated carbon (AC) capacitortype cathode. The Nano-spheroidal MnOx/C is synthesized using facile one-step combustion method. Benefiting from the uniform distribution of the MnOx/C nano-spheroidal particle, a fast kinetics for both charge-transfer and ion-diffusion process is realized, promoting battery-like and capacitive energy storage. As anticipated, the MnOx/C composite material exhibits an exceptional capacity of 1167.2 and 828.5 mAh g^− 1 from the first and the 100th cycle at 0.1 A g^− 1, high rate capability of 171.1 mAh g^− 1 even at a high rate of 2 A g^− 1, much higher than pure MnOx. The MnOx/C//AC LIC displays an excellent electrochemical performance with excellent energy density of 66.9 Wh kg^− 1 (250 W kg^− 1) and remarkable power density of 2500 W kg^− 1 (11.7 Wh kg^− 1). These encouraging results make the electrode material and electrode system promising for nextgeneration highperformance energy storage devices.