N-doped graphene nanolayer originated from the one-step template-induction methodology as anode for high-performance Li-ion capacitor

Abstract

Li-ion capacitors (LICs) have emerged as a novel energy-storage device to bridge the performance gap between Li ion batteries and supercapacitors. Herein, by employing waste tire pyrolysis oil (WTPO) as carbon precursor, N-doped graphene nanolayer (N-GNL) is directly prepared by a one-step template-induction methodology without any subsequent purification processes, according to the self-decompositon behavior of g-C3N4. Benefiting from the unique layered structure and N doping, the N-GNL affords satisfactory anode behavior with respect to capacity and rate performance. Moreover, the positive contributions of improving electronic conductivity and Li storage ability for N doping are revealed by density functional theory calculation. Besides, a full LIC fabricated with N-GNL anode and asphalt-derived cubic porous carbon cathode not only displays significantly better electrochemical performance than LIC configured with commercial activated carbon cathode and graphite anode, but also delivers outstanding Ragone performance and exceptional durability. This work also provides a feasible route to realize high efficient conversion of petroleum asphalt and WTPO into high-performance electrode materials.