Conductive Nanocrystalline Niobium Carbide as High-Efficiency Polysulfides Tamer for Lithium-Sulfur Batteries

Rational design of functional interlayer is highly significant in pursuit of highperformance Li-S batteries. Herein, a nanocrystalline niobium carbide (NbC) is developed via a facile and scalable autoclave technology, which is, for the first time, employed as the advanced interlayer material for Li-S batteries. Combining the merits of strong polysulfides (PS) anchoring with high electric conductivity, the NbC-coated membrane enables efficiently tamed PS shuttling and fast sulfur electrochemistry, achieving outstanding cyclability with negligible capacity fading rate of 0.037% cycle-1 over 1500 cycles, superb rate capability up to 5 C, high areal capacity of 3.6 mA h cm(-2) under raised sulfur loading, and reliable operation even in soft-package cells. This work offers a facile and effective method of promoting Li-S batteries for practical application.