Microporous active carbon with ultrahigh surface area from Metaplexis japonica for high-performance supercapacitor

Microporous active carbon with tunable pore structure and ultrahigh specific surface area of about 2210 m(2) g(-1) was synthesized from sustainable biomass precursor Metaplexis japonica via a facile carbonization-activation method, among which, micropores with pore size ranging from 1 to 2 nm occupy 87% of the pore volume. This Metaplexis japonica-derived active carbon (MJAC) exhibited high specific capacitance (287 F g(-1) at 1.0 A g(-1)) with good rate capability and excellent cycling stability (capacitance retention of 99% after 20,000 cycles at 20 A g(-1)) in a three-electrode system. Notably, the interconnected hierarchical and open structure with a high specific surface area contributed to the wide operating voltage window of 2.2 V and high energy density of 29 W h kg(-1) at a power density of 550 W kg(-1) in a two-electrode system. Therefore, all the remarkable performance of MJAC makes it attractive for application in supercapacitor.

Automated summary

The active carbon derived from Metaplexis japonica shows excellent performance in supercapacitors, with high specific capacitance, good rate capability, and excellent cycling stability. Its high specific surface area and open structure contribute to a wide operating voltage window and high energy density.