Electrospun porous carbon nanofiber-based electrodes for redox flow batteries: Progress and opportunities

With massive deployments of renewable sources in energy systems, there is an urgent need for energy storage. Among various techniques, redox flow batteries (RFBs) are considered to have promising application prospects due to their advantages of long cycle life, environmental friendliness, and better safety in stationary longduration energy storage. One key material in RFBs is the electrode, where electrochemical reactions take place. Electrospun carbon nanofibers (CNFs) have been used as RFB electrodes due to their high specific surface area and excellent stability. However, active sites for electrochemical reactions on the surface of CNFs are limited, resulting in sluggish reaction kinetics. Therefore, it's important to develop high-performance electrodes in RFBs. This review focuses on porous carbon-based electrodes fabricated by electrospinning. Recent advances in porous electrospun CNFs are well reviewed including the synthesis and characterizations. Besides, the enhancement in battery performance by porous electrospun CNFs and relevant reaction mechanism are also analyzed. Furthermore, this paper demonstrates outlooks and future opportunities in the field of porous electrospun CNFs for RFBs.