Sawdust-Derived Activated Carbon with Hierarchical Pores for High-Performance Symmetric Supercapacitors
Yan Zhou, Jun Li, Hu Shilin, Gujie Qian, Juanjuan Shi, Shengyun Zhao, Yulin Wang, Chuan Wang, Jiabiao Lian
Abstract
The recyclable utilization of waste biomass is increasingly important for the development of a sustainable society. Here, the sawdust-derived activated carbon (SD-AC) has been prepared via a convenient H3PO4-based activation method and further trialed as an electrode for use as a high-performance symmetric supercapacitor. The as-prepared SD-AC possesses a hierarchically porous structure with micropores (0.55 nm) and mesopores (2.58 nm), accounting for its high specific surface area of 621 m2 g−1, with a pore volume of 0.35 cm3 g−1. Such a hierarchically porous structure can offer a favorable pathway for fast ion penetration and transportation, enhancing its electrochemical performance. As a result, the SD-AC electrode exhibits a maximum specific capacitance of up to 244.1 F g−1 at 1.0 A g−1, a high rate capability (129.06 F g−1 at 20 A g−1), and an excellent cycling performance, with 87% retention over 10,000 cycles at 10 A g−1. Of particular note is that the SD-AC-based symmetric supercapacitor achieves a maximum energy density of 19.9 Wh kg−1 at the power density of 650 W kg−1, with a long-term cycle lifespan. This work showcases the recyclable utilization of waste biomass for the preparation of high-value activated carbon for efficient energy storage.