Hu Zhou-Rui, Li Dan-Dan, Kim Tae-Hee, Kim Min-Seok, Xu Ting, Ma Ming-Guo, Choi Sun-Eun, Si Chuanling
Beijing Key Laboratory of Lignocellulosic Chemistry, Engineering Research Center of Forestry Biomass Materials and Bioenergy, Research Center of Biomass Clean Utilization, College of Materials Science and Technology, Beijing Forestry University, Beijing, China.
Department of Forest Biomaterials Engineering, College of Forest and Environmental Sciences, Kangwon National University, Chuncheon, South Korea.
Front Chem. 2022 Feb 8;10:841956. doi: 10.3389/fchem.2022.841956. eCollection 2022.
Tailoring the structure and properties of lignin is an important step toward electrochemical applications. In this study, lignin/polypyrrole (PPy) composite electrode films with microporous and mesoporous structures were designed effectively by electrostatic spinning, carbonization, and polymerization methods. The lignin can not only reduce the cost of carbon fiber but also increase the specific surface area of composite films due to the removal of carbonyl and phenolic functional groups of lignin during carbonization. Besides, the compact three-dimensional (3D) conductive network structures were constructed with PPy particles densely coated on the lignin nanofibers, which was helpful to improve the conductivity and fast electron transfer during the charging and discharging processes. The synthesized lignin carbon fibers/PPy anode materials had good electrochemical performance in 1 M HSO electrolyte. The results showed that, at a current density of 1 A g, the lignin carbon nanofibers/PPy (LCNFs/PPy) had a larger specific capacitance of 213.7 F g than carbon nanofibers (CNFs), lignin carbon nanofibers (LCNFs), and lignin/PPy fiber (LPAN/PPy). In addition, the specific surface area of LCNFs/PPy reached 872.60 m g and the average pore size decreased to 2.50 nm after being coated by PPy. Therefore, the independent non-binder and self-supporting conductive film is expected to be a promising electrode material for supercapacitors with high performance.
调整木质素的结构和性能是迈向电化学应用的重要一步。在本研究中，通过静电纺丝、碳化和聚合方法有效地设计了具有微孔和介孔结构的木质素/聚吡咯（PPy）复合电极膜。木质素不仅可以降低碳纤维的成本，而且由于碳化过程中木质素的羰基和酚羟基官能团的去除，还可以增加复合膜的比表面积。此外，通过在木质素纳米纤维上密集包覆PPy颗粒构建了致密的三维（3D）导电网络结构，这有助于提高充放电过程中的电导率和快速电子转移。合成的木质素碳纤维/PPy负极材料在1 M HSO电解质中具有良好的电化学性能。结果表明，在1 A g的电流密度下，木质素碳纳米纤维/PPy（LCNFs/PPy）比碳纳米纤维（CNFs）、木质素碳纳米纤维（LCNFs）和木质素/PPy纤维（LPAN/PPy）具有更大的比电容，为213.7 F g。此外，PPy包覆后LCNFs/PPy的比表面积达到872.60 m g，平均孔径降至2.50 nm。因此，独立的无粘结剂自支撑导电膜有望成为高性能超级电容器的有前途的电极材料。
