Self‐Nitriding Nanostructured Transition Metal Nitrides in Architected‐Carbon Matrices: Unveiling Mechanisms and Advancing Performance in Lithium‐Sulfur Pouch Cells

Transition metal nitrides (TMNs) are attractive for cutting-edge energy storage technology, especially emerging lithium-sulfur (Li-S) batteries, owing to their electronic structures resembling those of noble metals. Herein, we unveil the underlying mechanism by which TMNs accelerate reaction kinetics, showcasing two nanostructured TMNs (Mo2N and VN) embedded within tailored carbon architectures. A novel, unexplored self-nitriding approach was developed to synthesize TMNs with precisely controlled solid (sC) or hollow (hC) carbon architectures, achieved through a colloidal route using imidazolium-based poly(ionic liquid) (PIL) nanoparticles as both a nitrogen-rich template and morphology-directing agent. Compact TMN architectures as sulfur hosts enhance ion diffusion and reaction kinetics, enabling efficient active site access and delivering high performance, such as VN@sC with high initial capacity of 792 mAh g-1 at 2 C and cyclability up to 650 cycles. Meanwhile, hollow architectures (VN@hC and Mo2N@hC) featuring hierarchical porous structures serve as cathode electrocatalytic additives, enabling high sulfur loading and delivering an initial capacity of 1143 mAh g-1 at 0.1 C. Remarkably, this performance is achieved with only 5 wt% additive content in scalable 7.9 × 11 cm2 and 12-layer pouch cells designed for drone power systems.