Nature-inspired three-dimensional foam-like porous carbon surface modified separator for high-performance Li-S batteries
K. Vignesh, T Mathivanan, M. Ganeshbabu, N. Prasanna Naga Puneeth, Ramkumar Balasubramaniam, Yun‐Sung Lee, R. Kalai Selvan
Abstract
The increasing growth of electric vehicles and portable electronics has led to a surplus energy demand in recent decades. Lithium-sulfur (Li-S) batteries have garnered significant attention and are believed to be the most promising future for sustainable high energy supply. Despite their high theoretical capacity, polysulfide shuttling has been a thorny drawback for their experimental performance degradation. In this work, lichen ( Parmotrema stuppeum ), a unique species with a mutualistic symbiotic relationship with fungi and algae, was used as a biomass for carbon precursor to modify the glass fiber (GF) separator. The necessary 3-dimensional porous carbon structure and active surface functional groups are obtained without extra additives. The porous network associated with L-600 accompanies foam-like structures that are anticipated to filter up polysulfides and facilitate lithium ions transport in the electrode-electrolyte interface. Thereby, the porous architecture ensures physical sites and traps dissolved polysulfide intermediate compounds, holding them as potential active materials that can undergo catalytic reactions within the cathode side. The Li-S cell, accompanied by the modified separator (L-600), offered a high initial specific capacity of 1330 mAh g -1 at 0.2 C. Further, the Li-S cell offered a prolonged reversible capacity of 725 mAh g -1 after 200 cycles, with a capacity degradation rate of 0.22 % per cycle. Post-stability analysis of the Li-S separator confirms the effectiveness of the modified separator in mitigating polysulfide shuttling.