Pokeweed leaves derived materials for high-energy-density asymmetric supercapacitor

Abstract

Biomass derived energy storage materials with unique structure, chemical composition, and surface property have become a research hotspot. Herein, pokeweed leaves with high manganese enrichment ability are used for the preparation of activated carbon (AC) and mixed oxides (MO), which are used as the negative and positive electrodes for hybrid supercapacitor. Benefiting from the highly porous structure, the AC and MO samples exhibit high energy storage capability. The optimized AC-700 exhibits a high specific capacitance of 317.3 F∙g−1 at 0.5 A∙g−1 and excellent cycling stability with 90.8 % capacitance retention after 10,000 cycles. Furthermore, the MO-500//AC-700 asymmetric supercapacitor (ASC) fabricated by MO-500 and AC-700 displays high energy and power density (70.3 Wh∙kg−1 at 793.9 W∙kg−1) as well as excellent cyclic stability (91 % capacitance retention after 10,000 cycles), suggesting a high energy storage performance. The present work supplies a facile and efficient strategy for the preparation of high performance supercapacitor materials by using biomass with high metal enriching ability.