The development of efficient methods to achieve a porous activated carbon nanostructures electrode for high-performance electrochemical double-layer capacitor (EDLC) is urgently needed at present. In this study, biomass-based porous hollow carbon nanofiber/nanosheet with suitable micro/mesopores was successfully prepared using a low-cost simple approach through chemical activation at direct pyrolysis. Biomass-based porous carbon was performed in two different chemical activation of KOH and ZnCl₂. The effects of the different KOH/ZnCl₂ concentrations at high-temperature pyrolysis on the morphological structure and porosity were investigated. The synthesized activated carbon possesses micro/mesopores hollow nanofiber/nanosheet, which enhanced specific surface area from 15.163 m² g⁻¹ to ultrahigh specific surface area of 1041.900 m² g⁻¹. These behaviors exhibit a high specific capacitance of 213 F g⁻¹ in a two-electrode system with excellent energy and power density of 29.6 Wh kg⁻¹ and 106.6 W kg⁻¹ at 1 M H₂SO₄ aqueous electrolyte. These results provided accurate information about a feasible approach to synthesize biomass-based porous hollow carbon nanofiber/nanosheet to boost high-performance energy storage devices.

中文翻译：

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用于高性能超级电容器的多孔中空生物质基碳纳米纤维/纳米片

目前迫切需要开发有效的方法来实现用于高性能电化学双层电容器（EDLC）的多孔活性碳纳米结构电极。在这项研究中，通过直接热解的化学活化，使用低成本的简单方法成功地制备了具有合适微孔/中孔的生物质基多孔中空碳纳米纤维/纳米片。基于生物质的多孔碳在 KOH 和 ZnCl ₂的两种不同化学活化中进行。研究了高温热解时不同KOH/ZnCl _{2浓度对形态结构和孔隙率的影响。}合成的活性炭具有微/中孔中空纳米纤维/纳米片，比表面积从 15.163 m²  g ^{-1至1041.900 m 2}  g ^-1的超高比表面积。这些行为在双电极系统中表现出 213 F g ^-1的高比电容，在 1 MH ₂ SO ₄水性电解质中具有 29.6 Wh kg ^-1和 106.6 W kg ^{-1的优异能量和功率密度。}这些结果提供了有关合成基于生物质的多孔中空碳纳米纤维/纳米片以提高高性能储能装置的可行方法的准确信息。