Tailoring Mesopores and Nitrogen Groups of Carbon Nanofibers for Polysulfide Entrapment in Lithium–Sulfur Batteries

• Main Authors: An, M. (Author), Joo, Y.L (Author), Lee, J.H (Author), Lee, S.G (Author), Sarkar, S. (Author), Won, J.S (Author), Zhang, R. (Author)
• Format: Article
• Language: English
• Published: MDPI 2022
• Subjects: Air‐controled electrospray; air‐controlled electrospray; Carbon nanofibers; Carbon nanofibres; Cathodes; Chemical modification; Electrospinning; Electrosprays; gas assisted electrospinning; Gas assisted electrospinning; Lithium; Lithium batteries; Lithium sulfur batteries; Lithium/sulfur batteries; Lithium–Sulfur batteries; Mesopore; mesoporous carbon nanofiber; Mesoporous carbon nanofibers; Mesoporous materials; nitrogen doping; Nitrogen group; Nitrogen-doping; Polyacrylonitriles; Polymethyl methacrylates; Polysulphides; Pore size; Sulfur
• Online Access: View Fulltext in Publisher

 In the current work, we combined different physical and chemical modifications of carbon nanofibers through the creation of micro‐, meso‐, and macro‐pores as well as the incorporation of nitrogen groups in cyclic polyacrylonitrile (CPAN) using gas‐assisted electrospinning and air‐con-trolled electrospray processes. We incorporated them into electrode and interlayer in Li–Sulfur bat-teries. First, we controlled pore size and distributions in mesoporous carbon fibers (mpCNF) via adding polymethyl methacrylate as a sacrificial polymer to the polyacrylonitrile carbon precursor, followed by varying activation conditions. Secondly, nitrogen groups were introduced via cycliza-tion of PAN on mesoporous carbon nanofibers (mpCPAN). We compared the synergistic effects of all these features in cathode substrate and interlayer on the performance Li–Sulfur batteries and used various characterization tools to understand them. Our results revealed that coating CPAN on both mesoporous carbon cathode and interlayer greatly enhanced the rate capability and capacity retention, leading to the capacity of 1000 mAh/g at 2 C and 1200 mAh/g at 0.5 C with the capability retention of 88% after 100 cycles. The presence of nitrogen groups and mesopores in both cathodes and interlayers resulted in more effective polysulfide confinement and also show more promise for higher loading systems. © 2022 by the authors. Licensee MDPI, Basel, Switzerland.