High-energy Li-ion hybrid supercapacitor enabled by a long life N-rich carbon based anode

Abstract

Hybridizing battery and capacitor materials to construct hybrid supercapacitors has been regarded as a promising avenue to achieve high energy densities while maintaining high power-output. Herein, we report a lithium ion hybrid supercapacitor with high power and energy densities as well as excellent cycling stability, which is constructed of an N-rich carbon based anode and commercial activated carbon cathode. The N-rich carbon spheres (NRCS) possess high surface area, uniform mesoporous structure, and high level of N-doping, synergically enabling excellent lithium storage properties in terms of high capacity, fast rate capability and long cycling lifespan even at high current rate (638mAhg−1 after 2000 cycles at 2Ag−1). Benefitting from above merits of NRCS, the assembled hybrid supercapacitor delivers a high energy density of 105.8Whkg−1 at 650Wkg−1. Even when power density increases to 10800Wkg−1, 40.4Whkg−1 can be maintained. Long cycling life (capacity retention of 75% after 8000 cycles) is also demonstrated. This work offers a new platform for high-energy hybrid supercapacitors by assembling high-performance porous carbon based anode.