In-situ grown manganese silicate from biomass-derived heteroatom-doped porous carbon for supercapacitors with high performance.

Graphical abstract Abstract Supercapacitor performance is reported for manganese silicate hybridized carbon materials (MnSi-C) that is derived from natural bamboo leaves. The in-situ generated manganese silicate is in good distribution by a simple hydrothermal treatment without the addition of another controlling agent. We also study the performance of MnSi-C as a single electrode and a cathode for fabrication of asymmetric supercapacitor device with a Ni(OH) 2 anode. Remarkably, the single electrode MnSi-C-3 delivered a capacity of 162.2 F g−1 at a current density of 0.5 A g−1. The cyclic performance of single electrode MnSi-C-3 maintains high capacitance retention of 85% after 10,000 cycles of charge-discharge. By assembled MnSi-C-3 with Ni(OH) 2 , the asymmetric supercapacitor device shows a capacity of 438.5 mF cm−2 at a scan rate of 4 mA cm−2. The device exhibits an optimal electrochemical performance with an energy density of 3 mWh cm−3 (24.6 Wh kg−1) and power density of 130.4 mW cm−3 (604.8 W kg−1). A reasonable mechanism of in-situ generated manganese silicate on the surface of carbon is proposed based on the experimental data and existed theories. This MnSi-C nanocomposite proves to be a promising electrode material for high energy supercapacitor. [ABSTRACT FROM AUTHOR]