MnO decorated biomass derived carbon based on hyperaccumulative characteristics as advanced electrode materials for high-performance supercapacitors

Exploring renewable and green carbon materials with superior electrochemical performance is vital but challenging for promoting the practical application of supercapacitors. Herein, a novel Salvinia adnata based porous carbon decorated with MnO (SAC-MnO) composite was facilely fabricated from hyperaccumulator cultured in Mn ion-rich solution through hyperaccumulation and subsequent carbonization strategy. The prepared SAC-MnO composites displays hierarchical micro-mesoporous architecture with ultrahigh specific surface area (2396 m2 g−1), which facilitates ion transportation and energy storage. Additionally, manganese oxides anchored on the carbon matrix could induce the generation of pesudocapacitance. The synergistic effect of double-layer capacitance and pseudocapacitance by porous carbon and manganese oxides enable the resultant electrode materials realize excellent electrochemical properties. As a result, the SAC-MnO electrode achieves an excellent specific capacitance of 436.8 F g−1 at a current density of 1 A g−1 in the three-electrode system. Meanwhile, the symmetric supercapacitor assembled by SAC-MnO displays an energy density of 9.573 Wh kg−1 at a power density of 694.4 W kg−1 and keeps a capacity retention over 94.7 % after 1000 cycles. This research provides a facile, sustainable and eco-friendly method to synthesize porous carbon decorated with transition metal oxides for high-efficiency energy storage devices. [Display omitted] •Accumulation of manganese ions in solution using hyperaccumulative effect•High manganese element content and high specific surface area•Synergistic effect of EDLC and pesudocapacitance