Constructing a dual-conductive catalytic interface via Co-doped LLTO perovskite to synergistically accelerate sulfur reduction kinetics

Lithium–sulfur batteries (LSBs) suffer from sluggish sulfur redox kinetics and severe polysulfide shuttle, especially under lean-electrolyte conditions. Here, we report a cobalt-doped lithium lanthanum titanate (LLTO) perovskite that constructs ion/electron co-conductive catalytic interfaces to promote rapid sulfur reduction. Co doping induces oxygen vacancies and lattice distortion, thereby enhancing electronic conductivity, local density of states, and catalytic activity. These structural regulations endow LLTO with strong polysulfide adsorption and fast conversion capability. As a result, LSBs with LLTO-Co-modified separators exhibit excellent electrochemical performance, delivering high specific capacity, superior rate capability, and long-term cycling stability. Even at a high sulfur loading of 9 mg·cm −2 and a low electrolyte/sulfur ratio (E/S = 4 μL·mg −1 ), an areal capacity of 10.1 mAh·cm −2 is achieved and maintained at 7.2 mAh·cm −2 after 30 cycles. This work demonstrates a robust strategy of tailoring ion/electron co-conductive catalytic interfaces via lattice engineering, offering new insights for the design of high-performance LSBs.