Guest: Barun Kumar Chakrabarti, SUNUM
Title: Applications of carbonized electrospun nanomaterials as electrodes and catalysts for energy storage
Date/Time: 29 May 2024, 13.40
Location: G032
Abstract: Lithium-ion battery (LiB) electrodes are typically manufactured via slurry casting, which involves mixing active material particles, conductive carbon, and a polymeric binder in a solvent, followed by casting and drying the coating on current collectors (Al or Cu). These electrodes are functional but still limited in terms of pore network percolation, electronic connectivity, and mechanical stability, leading to poor electron/ion conductivities and mechanical integrity upon cycling, which result in battery degradation. To address this, we fabricate trichome-like carbon–iron fabrics via a combination of electrospinning and pyrolysis. Compared with slurry cast Fe2O3 and graphite-based electrodes, the carbon–iron fabric (CMF) electrode provides enhanced high-rate capacity (10C and above) and stability, for both half-cell and full cell testing (the latter with a standard lithium nickel manganese oxide (LNMO) cathode). Further, the CMFs are free-standing and lightweight.
In a similar work, several positive electrodes were employed in the hydrogen/manganese (H/Mn) hybrid redox flow battery (regenerative fuel cell). This was a follow-on work from a similar investigation on a hydrogen/vanadium RFB. Graphite felt showed a better performance and thus this was used in combination with carbon metal fabrics (prepared by means of electrospinning) to improve the performance even further. High energy efficiencies more than 84% were noted at 100 mA cm−2 along with relatively high peak power densities around 0.6 W cm−2 (for gas-liquid based hybrid RFBs only). In addition, 100 charge/discharge cycles were successfully performed at the same current density with electrolyte capacities above 20 W h L−1.
Bio: Dr Barun K. Chakrabarti joined SUNUM in March 2023. His last role was as a Postdoctoral Research Fellow in WMG at the University of Warwick, UK. He completed his MEng in Chemical Engineering at Imperial College London and a PhD on Regenerative Fuel Cells at the University of Manchester, UK. Then, he worked on biodiesel development activities for a major US oilseeds processing company (Cargill PLC) in Liverpool for 1 year. After completing his industrial experience, he became an Assistant Professor in NED University in Pakistan and performed biodiesel research and development. After 5 years in Pakistan, he moved on to the University of Malaya (Malaysia) in 2010 as a Senior Lecturer, where he executed several projects on the evaluation of ionic liquid electrolytes for redox flow battery applications. From 2012 onwards, he returned to Imperial College London as a Postdoctoral Research Fellow, worked there for 7 years, and moved on to WMG. He has studied a wide range of electrochemical technologies for energy and environmental applications. His current research focuses on hydrogen-based redox flow batteries, electrospinning, lithium-ion battery anodic materials, and electrophoretic deposition of nanomaterials including graphene. He has over 60 journal publications including a few in the American Chemical Society and one in Nature Communications.