Interfacial electric field and p‐d‐p electron coupling of dual‐heterostructure catalysts for boosting Li‐S chemistry

Abstract Rational design of efficient dual‐heterostructure electrocatalysts and their mechanistic understanding of interfacial interactions for Li‐S batteries remain challenging. This work develops NbN/NbB 2 /MXene dual‐heterostructure catalysts via a novel nitrogen‐assisted boron‐thermal reduction strategy. This design creates dual heterointerface with an electron‐transport interface and an active‐catalytic interface. These heterointerfaces drive an interfacial electric field effect and regulate p‐d‐p electron coupling of the B‐Nb‐N interface, which accelerates electron/Li + transfer, lowers activation energy, and reduces the Gibbs free energy of the rate‐determining step, thereby boosting sulfur redox kinetics. The S/NbN/NbB 2 /MXene cathode achieves a high initial capacity of 1515.0 mAh g −1 at 0.1 C and excellent stability (72.5% retention after 1000 cycles at 5.0 C). Even under high sulfur loading (6.0 mg cm −2 ) and lean‐electrolyte conditions, it delivers a large areal capacity of 5.55 mAh cm −2 , and the pouch cell exhibits 931 mAh g −1 . This work deciphers the atomic‐level synergy of dual‐heterointerfaces for high‐performance Li‐S electro‐catalysts.