Self-adaptive catalysis enabled by in-situ lithiation for durable lithium–sulfur batteries

Catalytic regulation is essential for achieving high-performance lithium-sulfur (Li-S) batteries, yet the conventional catalysis strategies typically suffer from strong stage-specific selectivity and limited adaptability due to the inherently complex sulfur redox reactions. Herein, we propose a self-adaptive catalysis strategy that enables real-time modulation to match the evolution of sulfur species upon cycling. As a proof of concept, TiS₂ is employed as a topologically transformable electrocatalyst that undergoes in-situ lithiation (TiS₂ → Li_0.5TiS₂ → LiTiS₂) to dynamically regulate the energy band structure and Ti 3d electron density. Notably, a gradually decreased orbital hybridization between Ti 3d and S 3p states enables selective adsorption of long-chain lithium polysulfides (Li₂S_x, 4 < x≤8) to suppress the shuttle effect, while the progressively enriched Ti 3d electron density accelerates the electron transfer kinetics, particularly facilitating the sluggish liquid-to-solid (Li₂S₄ → Li₂S) conversion. Therefore, the self-adaptive dynamic catalysis delivers a high sulfur utilization and long-term cycling performance with an initial areal capacity of 9.9 mAh cm^-2 and 93.1% capacity retention after 80 cycles with a high sulfur loading of 8.02 mg cm^-2. This work provides a promising catalysis strategy for sulfur-based energy storage systems and offers insights into self-adaptive catalysis for other multi-step electrochemical reactions.