Regulation of dual-atom doping porous carbon towards high-performance capacitive storage devices

Abstract

Zinc ion capacitors show impressive energy storage potential for well-balanced energy and power density, but exploring its implicit energy storage mechanism is crucial and still challenging. Herein, a new viewpoint is proposed for regulating nitrogen and oxygen dual-doped carbon with short-range order by sustaining the conductivity and synchronously boosting interfacial chemisorption sites. The artful nanoarchitecture engineering of cross-linked framework carbon with a high specific surface area (2702.3 m2 g−1) is beneficial to efficient electrolyte penetration and ion transfer, thus enhancing the electrode’s capacitance and rate performance. Based on electrochemical capacitor properties and theoretical calculations, the optimized hetero-carbon used for zinc ion capacitors could deliver a high capacity of 241.1 mAh g−1 at 0.1 A g−1 and an energy density of 191.6 Wh kg−1. The dynamic potential of zincate hydrated ions precipitation/dissolution behavior was explored by ex-situ X-ray diffraction and photoelectron spectroscopy experiments. This work not only provides new perception integration with porousness and nanoarchitecture engineering in carbon materials, but also sheds light on the zinc-ion capacitor storage mechanism.