AUTHOR=Hu Zhou-Rui , Li Dan-Dan , Kim Tae-Hee , Kim Min-Seok , Xu Ting , Ma Ming-Guo , Choi Sun-Eun , Si Chuanling TITLE=Lignin-Based/Polypyrrole Carbon Nanofiber Electrode With Enhanced Electrochemical Properties by Electrospun Method JOURNAL=Frontiers in Chemistry VOLUME=Volume 10 - 2022 YEAR=2022 URL=https://www.frontiersin.org/journals/chemistry/articles/10.3389/fchem.2022.841956 DOI=10.3389/fchem.2022.841956 ISSN=2296-2646 ABSTRACT=Tailoring the structure and properties of lignin is an important step towards electrochemical applications. In this study, lignin/polypyrrole (PPy) composite electrode films with microporous and mesoporous structures were designed effectively by electrostatic spinning, carbonization, and in-situ 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 process. The synthesized lignin carbon fibers/PPy anode materials had good electrochemical performance in 1 M H2SO4 electrolyte. The results showed that at a current density of 1 A g-1, the specific capacitance of lignin carbon fibers/PPy (LCNFs/PPy) had a larger specific capacitance of 213.7 F g-1 than those of carbon fibers (CNFs), lignin carbon fiber (LCNFs), and lignin/PPy fiber (LPAN/PPy). Therefore, the independent non-binder and self-supporting conductive film is expected to be a promising electrode material for supercapacitors with high performance.