Manipulating Sulfur Conversion Kinetics through Interfacial Built-In Electric Field Enhanced Bidirectional Mott–Schottky Electrocatalysts in Lithium–Sulfur Batteries

Efficient electrocatalysts and catalytic mechanisms remain a pressing need in Li–S electrochemistry to address lithium polysulfide (LiPS) shuttling and enhance conversion kinetics. This study presents the development of multifunctional VO 2 @rGO heterostructures, incorporating interfacial built-in electric field (BIEF) enhancement, as a Mott–Schottky electrocatalyst for Li–S batteries. Electrochemical experiments and theoretical analysis demonstrate that the interfacial BIEF between VO 2 and rGO induces self-driven charge redistribution, resulting in accelerated charge transport rates, enhanced LiPS chemisorption, reduced energy barriers for Li 2 S nucleation/decomposition, and improved Li-ion diffusion behavior. The Mott–Schottky electrocatalyst, combining the strengths of VO 2 ’s anchoring ability, rGO’s metallic conductivity, and BIEF’s optimized charge transport, exhibits an outstanding “trapping–conversion” effect. The modified Li–S battery with a VO 2 @rGO-modified separator achieves a highly reversible capacity of 558.0 mAh g –1 at 2 C over 600 cycles, with an average decay rate of 0.048% per cycle. This research offers valuable insights into the design of Mott–Schottky electrocatalysts and their catalytic mechanisms, advancing high-efficiency Li–S batteries and other multielectron energy storage and conversion devices.