Liu Xiaoguang, Zhang Shuai, Wen Xin, Chen Xuecheng, Wen Yanliang, Shi Xiaoze, Mijowska Ewa
Nanomaterials Physicochemistry Department, Faculty of Chemical Technology and Engineering, West Pomeranian University of Technology Szczecin, al. Piastów 45, 70-311, Szczecin, Poland.
Sci Rep. 2020 Feb 26;10(1):3518. doi: 10.1038/s41598-020-60625-y.
Recently great efforts have been focused on converting biowastes into high-valued carbon materials. However, it is still a great challenge to achieve high carbon yield and controllable porous distribution in both industrial and academic research. Inspired by the multi-void structure of waste coffee grounds, herein we fabricated hierarchical porous carbon via the combination of catalytic carbonization and alkali activation. The catalytic carbonization process was applied to obtain well-defined mesoporous carbon with carbon yield as high as 42.5 wt%, and subsequent alkali activation process produced hierarchical porous carbon with ultrahigh specific surface area (3549 m g) and large meso-/macropores volume (1.64 cm g). In three-electrode system, the electrode exhibited a high capacitance of 440 F g at 0.5 A g in 6 M KOH aqueous electrolyte, superior to that of many reported biomass-derived porous carbons. In two-electrode system, its energy density reached to 101 Wh kg at the power density of 900 W kg in 1-Ethyl-3-Methylimidazolium Tetrafluoroborate (EMIMBF). This work provided a cost-effective strategy to recycle biowastes into hierarchical porous carbon with high yield for high-performance energy storage application.
近年来，人们致力于将生物废弃物转化为高价值的碳材料。然而，在工业和学术研究中，实现高碳产率和可控的孔结构分布仍然是一个巨大的挑战。受废弃咖啡渣多孔隙结构的启发，我们通过催化碳化和碱活化相结合的方法制备了分级多孔碳。催化碳化过程用于获得具有明确介孔结构的碳材料，碳产率高达42.5 wt%，随后的碱活化过程制备出具有超高比表面积（3549 m²/g）和大的介孔/大孔体积（1.64 cm³/g）的分级多孔碳。在三电极体系中，该电极在6 M KOH水溶液电解质中，电流密度为0.5 A/g时，电容高达440 F/g，优于许多已报道的生物质衍生多孔碳。在两电极体系中，在1-乙基-3-甲基咪唑四氟硼酸盐（EMIMBF₄）电解液中，功率密度为900 W/kg时，其能量密度达到101 Wh/kg。这项工作提供了一种经济有效的策略，将生物废弃物高收率地回收为分级多孔碳，用于高性能储能应用。
