Abstract:

Biomass-based carbon materials have received widespread attention in the field of energy storage. Nevertheless, the drawbacks of pure carbon materials such as poor hydrophilicity, low pseudocapacitance, and the need to use binders when assembling them into electrodes restrict their application in high-energy-density supercapacitors. Based on this, in this study, self-supported phosphorus-doped thick carbon electrodes (P-WC) are prepared using phytic acid as a pore-making agent and phosphorus source, and applied to supercapacitors. The pore-making and doping effects of phytic acid endow the P-WC with a three-dimensional porous structure and superhydrophilicity, which facilitate the rapid penetration and exchange of the electrolyte, thus significantly enhancing its electrochemical performance. When assembled as a symmetric supercapacitor (SSC), the area and mass specific capacitance of P-WC are as high as 6520mF/cm² and 198F/g at 1mA/cm²; the power density reaches 21.82W/kg (0.7mW/cm²) at an energy density of 39.54W·h/kg (1.31mW·h/cm²); even under a high current density of 20mA/cm², with an energy density of 24.12W·h/kg (0.80mW·h/cm²), the SSC maintains a power density of 436.36W/kg (14400mW/cm²). Hence, this work can offer theoretical support towards the construction and application of high-performance self-supported supercapacitors.

Key words: poplar wood, thick carbon electrode, phytic acid, phosphorus doping, supercapacitors

摘要：

生物质基碳材料因其在储能领域的潜力受到了广泛关注。然而，纯碳基材料通常亲水性差、赝电容低；组装成电极时需要使用黏结剂，限制了其在高能量密度超级电容器上的应用。基于此，本研究以植酸为造孔剂和磷源，制备出自支撑磷掺杂厚碳电极（P-WC），并将其应用于超级电容器中。植酸的造孔和掺杂作用赋予P-WC三维多孔结构和超亲水性，这促进了电解液快速渗透和交换，显著提升其电化学性能。组装成对称超级电容器（SSC）时，在1mA/cm²下，P-WC的面积比电容和质量比电容分别高达6520mF/cm²和198F/g；在能量密度为39.54W·h/kg（1.31mW·h/cm²）时，功率密度达到21.82W/kg（0.7mW/cm²）；即使在20mA/cm²的高电流密度下，能量密度为24.12W·h/kg（0.80mW·h/cm²）时，SSC仍能维持436.36W/kg（14400mW/cm²）的功率密度。因此，本项工作可为高性能自支撑超级电容器的构建和应用提供理论支撑。

关键词: 杨木, 厚碳电极, 植酸, 磷掺杂, 超级电容器