High Performance Solid-State Lithium-Sulfur Battery Enabled by Multi-Functional Cathode and Flexible Hybrid Solid Electrolyte

With its superior theoretical energy density as well as abundance and environment-friendliness, the lithium–sulfur battery (LiSB) is a potential candidate to replace the traditional energy storage and generation systems. An innovative design is proposed for the high-performance solid-state LiSB system by combining the multi-functional cathode comprising the sulfur-loaded Al₂O₃-modified carbon nanotubes (S@ACNTs) and the flexible hybrid solid electrolyte (HSE). Assembled with S@ACNTs active material, the polycation poly(diallyldimethylammonium bis(trifluoromethylsulfonyl)imide) (PDATFSI) binder exhibits high Li⁺ conductivity of 0.45 mS cm⁻¹ at room temperature, good thermal stability up to 450 °C, high adhesive strength with aluminum current collector up to 24 MPa, sustainable non-flammability, and desirable flexibility. When assembled with HSE membrane, the S@ACNTs/PDATFSI–60IL cathode layer demonstrates effective polysulfide trapping behavior and superior compatibility (65 Ω), resulting in high discharge capacity of 1203 mAh g⁻¹ at 0.2 C in the 1st cycle, and long-term stability up to 91.69% of the discharge capacity after 200 cycles of charge/discharge process.