Tremella-like nitrogen-doped microporous carbon derived from housefly larvae for efficient encapsulation of small S 2-4 molecules in Li-S batteries

The commercialization of rechargeable lithium-sulfur batteries (LSBs) has been severely restricted due to the electrically insulating nature of sulfur and the dissolution of polysulfides Li2Salt;iagt;nalt;/iagt; (4 ≤ alt;iagt;nalt;/iagt; ≤ 8). Herein, we demonstrated a sustainable and proficient strategy to synthesize a unique and cost-effective tremella-like nitrogen-doped microporous carbon (TNMC) materials derived from housefly larvae. The key feature of TNMC is that it possesses interconnected 3-D channels with voids, high surface area (˃1000 malt;supagt;2alt;/supagt; galt;supagt;-1alt;/supagt;) along with large volume (0.62 cmalt;supagt;3alt;/supagt; galt;supagt;-1alt;/supagt;). Particularly, a high portion of ultra-micropore and the predominant pore width of ~ 0.54 nm play important roles in confining the metastable small sulfur molecules (Salt;subagt;2-4alt;/subagt;) physically. More importantly, TNMCs with sufficient nitrogen doping (6-8 wt.%) not only improve the conductivity of sulfur electrode materials but also act as an active site for adsorbing Salt;subagt;2-4alt;/subagt; chemically and reducing the shuttle effect efficiently. Beneficial from the unique 3-D microstructures with ultra-micropore and inherent nitrogen doping, the resultant LSBs show high reversible capacity with a stable Coulombic efficiency.