Conductive and porous carbon plays critical roles as electrode material for electrochemical energy storage devices, including supercapacitors. Using commonly available biomass cellulous fibers as the raw material to produce porous carbon is a promising approach to achieve high-performance and low-cost electrodes. Herein, carbon microfiber (CMF) membranes were prepared via a direct carbonization method using cotton fiber meshes as precursors. The nitrogen doping content, carbon surface area and pore density could be well adjusted by the carbonization atmosphere and temperature. With CMF membranes as freestanding electrodes in supercapacitors, remarkable electrochemical performances were demonstrated. In particular, the CMF membrane obtained at 800 °C in ammonia (CMFs-800) can achieve a high capacitance of 172 F g^-1 at the current density of 0.1 A g⁻¹, meanwhile it shows excellent rate capability and superior cycling stability. This study indicates that the pyrolyzed cotton mesh, due to its large pore density, high specific surface area, and heteroatom doping, has potential to be used as cost-effective electrode for supercapacitors.

导电碳和多孔碳作为电化学能量存储设备（包括超级电容器）的电极材料起着至关重要的作用。使用常见的生物质纤维素纤维作为原料生产多孔碳是一种获得高性能和低成本电极的有前途的方法。本文中，使用棉纤维网作为前体通过直接碳化法制备碳微纤维（CMF）膜。可以通过碳化气氛和温度很好地调节氮掺杂含量，碳表面积和孔密度。使用CMF膜作为超级电容器中的独立电极，证明了出色的电化学性能。特别是，在氨气中于800°C下获得的CMF膜（CMFs-800）可以实现172 F g ^-1的高电容 在电流密度为0.1 A g ^{-1的情况下}，它具有出色的倍率能力和出色的循环稳定性。这项研究表明，热解棉网由于其大的孔密度，高的比表面积和杂原子掺杂，有潜力用作超级电容器的经济高效电极。