Bioderived Hierarchically Porous Electrode with High Polarity for Lithium–Sulfur Batterties

Abstract

Lithium–sulfur (Li–S) batteries hold great promise as future energy storage solutions owing to their low cost and environmental friendliness. Nature provides biomass materials that can serve as carriers for sulfur, featuring micropores, mesopores, and hierarchical pore structures. In this study, we utilized corncob-originated activated porous carbon (CPC), abundant agricultural wastes (AWs), as the sulfur host to prepare MXene (Ti₃C₂T_x) enhanced hierarchical bioderived porous electrode. The synthesis and function of CPC for Li–S batteries are presented, and the electrochemical effects of structural diversity, porosity and surface heteroatom doping of the Mxene in Li–S batteries are discussed. Brunauer–Emmett–Teller (BET) analysis revealed that CPC exhibited a specific surface area (SSA) of 1015.59 m² g^–1 and a total pore volume of 0.44 cm³ g^–1, significantly higher than those of P-CPC (35.30 m² g^–1 and 0.022 cm³ g^–1). Furthermore, the CPC/MXene@S composite electrode demonstrated an impressive initial discharge capacity of 1358 mAh g^–1 at 0.1C and retained a reversible capacity of 695 mAh g^–1 after 500 cycles at 0.2C, with a capacity decay rate of only 0.05% per cycle. Additionally, it showed excellent rate performance, delivering a capacity of 776 mAh g^–1 even at a high current density of 2C. The superior electrochemical performance of this composite electrode can be attributed to MXene’s effective adsorption of polysulfides. This study provides a new methodology for utilizing waste biomass as a carrier for sulfur electrodes. In addition, the economic benefits, new trends and challenges are also proposed for further design excellent AWs for Li–S batteries.