The insight of self-doped phosphorus on the biocarbon substrate: Co3O4 nanocrystals anchored on porous carbon derived from Manila grass for supercapacitor electrode with long life

Abstract

A novel hive-like Co3O4 @C composite is synthesized solvothermally and calcinated using Manila grass as an interesting precursor of porous carbonous skeleton with self-doped phosphorus and oxygen, anchored by Co3O4 nanocryclusters through the sites rich in doped atoms. The capacitance of the as-fabricated materials is 767.6 F·g−1 (1 A·g−1) with long life of 96.2% retention after 12,000 cycles, according with the phosphorus content in composites. Moreover, the supercapacitor is assembled by KC-600 (+) and active-carbon () delivers an energy density of 81.42 Wh·kg1 at 875 W·kg1 and satisfactory cycling stabilities (9.17% lost after 24,000 cycles), owing to its unique microstructure and the self-doped phosphorus of Manila grass. Therefore, the porous hive-like Co3O4 @C composite can better achieve as an electrode material through an easy and eco-friendly process based on biocarbon for the energy storage devices in the future.