Atomic Engineering Bifunctional Niobium (V)-based Heterostructure Nanosheet for High Efficiency Lean-Electrolyte Lithium-Sulfur Full Batteries

Abstract High-efficiency lithium-sulfur (Li-S) batteries depend on advanced electrode structure that can attain high sulfur utilization at lean-electrolyte and limited lithium. Herein, a twinborn holey Nb4N5-Nb2O5 heterostructure is designed as a dual-functional host for both redox-kinetics-accelerated sulfur cathode and dendrite-inhibited Li anode simultaneously for long-cycling and lean-electrolyte Li-S full batteries. Benefiting from the accelerative polysulfides anchoring-diffusion converting efficiency and electronic-conducting properties of Nb4N5-Nb2O5, polysulfide-shutting is significantly alleviated. Meanwhile, the lithiophilic nature of holey Nb4N5-Nb2O5 is applied as ion-redistributor for homogeneous Li-ion deposition. Taking advantage of these merits, the Li-S full batteries present the excellent electrochemical properties, including a minimum capacity decay of 0.025% per cycle, and a high areal-capacity of 5.0 mAh cm− 2 at sulfur loading of 6.9 mg cm− 2, corresponding to negative to positive capacity ratio (2.4:1) and electrolyte to sulfur ratio (5.1 µl mg− 1). Therefore, this work opens a new avenue for boosting high-performances Li-S batteries towards practical applications.