Nitrogen-Doped nano-carbon onion rings for energy storage in Lithium-ion capacitors

Abstract Lithium-ion Capacitor is emerging as a promising strategy that integrated high energy of Lithium-ion batteries with high power of supercapacitors. However, conventional activated carbon presents great challenges as supercapacitive electrodes. In this work, porous nano-carbon onion rings (NCOR) with N-doping were synthesized via the pyrolysis of nanoarchitecture precursor, which yielded a surface area of 1769.76 m2 g − 1. The NCOR electrode showed a capacity of 68.78 mAh g − 1 with a stable capacity retention of 83.12% after 1000 cycles in a voltage window of 2.5–4.2 V vs. Li/Li+. The impedance tests measured at different potentials shed some light on the mechanism of charge storage. We demonstrated the promise of NCOR for energy storage in Lithium-ion capacitors.