Dissolving Vanadium into Titanium Nitride Lattice Framework for Rational Polysulfide Regulation in Li–S Batteries

Abstract Rational regulation of host–guest interactive chemistry is of great significance but has not yet effectively been applied in lithium–sulfur (Li–S) batteries. Herein, a unique titanium vanadium nitride (TVN) solid solution fabric is developed as an ideal platform for fine structure modulation towards efficient and durable sulfur electrochemistry. The dissolution of V into the TiN lattice framework is shown to subtly tailor the coordinative and electronic structures of Ti and V, tuning their respective chemical affinity to sulfur species. Consequently, the optimized Ti–V interplay renders the highest overall polysulfide adsorpabiltiy, and contributes to strong sulfur immobilization and fast reaction kinetics. The resultant Li–S cells realize an outstanding cyclability with high capacity retention of 97.7% after 400 cycles. Moreover, reversible areal capacity over 6.11 mAh cm⁻² can be sustained under a high sulfur loading of 6.0 mg cm⁻² and a limited electrolyte concentration of 6.5 mL g⁻¹. This work provides a novel strategic perspective for the rational regulation of fine structure towards superior Li–S batteries and beyond.