High-performance dual carbon Li-ion hybrid capacitor constructed from N, S - co-doped candle soot derived carbon nanoparticles anode and porous carbon cathode

Lithium-ion capacitors (LICs) are one of the emerging and fast-growing energy storage devices due to their combination of high power/energy characteristics with long cyclic life. However, the kinetic imbalance between anode and cathode is a major hurdle in achieving high-performance LICs. In this work, we propose a dual carbon LIC device using a candle soot pollutant as the single source for the first time to derive a novel N, S-co-doped fractal-like carbon nanoparticles (NS-CSC) as anode and an activated co-doped porous carbon (NS-ACSC) as a cathode. The NS-CSC anode and NS-ACSC cathode half-cell demonstrate an outstanding reversible ion storage capacity of 2258 mAh g−1 and 125 mAh g−1 at 50 mA g−1, respectively. Benefitting from the doped carbon electrodes, the mass ratio optimized dual carbon NS-CSC//NS-ACSC (1:2) LIC device achieves high specific energy of 101.7 Wh kg−1 at 113 W kg−1, retaining a capacity of 81 % after 7000 cycles at 2 A g−1. Moreover, the fabricated LIC device powers a red light-emitting diode for a continuous 15 min, indicating its potential use in practical applications. This work emphasizes that the candle soot pollutant-derived carbon nanoparticles have the potential for use as an electrode in advanced energy storage devices. [Display omitted] •Novel N, S-co-doped fractal-like carbon nanospheres from candle soot as an anode•The anode cell exhibits an excellent specific capacity of 1827 mAh g−1 at 0.1 A g−1.•The dual carbon lithium-ion capacitor delivers specific energy of 101.7 Wh Kg−1.•Demonstrated lithium-ion capacitor device to power light emitting diodes