Porous nitrogen-doped carbon/carbon nanocomposite electrodes enable sodium ion capacitors with high capacity and rate capability. (January 2020) - Yan, Runyu
Abstract: The realization of electrochemical energy storage devices combining high energy and power density places high demands on the electrode materials. It remains difficult to provide high metal storage capacity and rate capability at the same time in one and the same material. By decoupling metal storage and electron transport in different phases of a nanostructured electrode composed of nitrogen-rich carbon nanoparticles which are embedded into a conductive mesoporous carbon matrix, this dilemma can be minimized. The composite material has a remarkable performance for sodium storage with a reversible capacity of 343 mAh g −1 at 0.1 A g −1 and capacity retention of 124 mAh g −1 at 20 A g −1 . This work shows that a properly designed nanocomposite material can fulfill both requirements and sheds new light on resolving the seemingly conflicting energy/power density demands in current electrochemical energy storage devices. Graphical abstract: Image 1 Highlights: Carbon/Nitrogen-doped carbon nanocomposites are prepared by combining templating and molecular precursors. Intimate contact between the components leads to high capacity and rate capability in sodium ion capacitors. Decoupling of electron and ion storage can be realized in the different compartments of the composites. The material has a reversible capacity of 343 mAh g −1 at 0.1 A g −1 and capacity retention of 124 mAh g −1 at 20 A g −1 in sodium ion capacitors.