Interfacial Engineering of Bifunctional Niobium (V)-Based Heterostructure Nanosheet Toward High Efficiency Lean-Electrolyte Lithium–Sulfur Full Batteries

High-efficiency lithium–sulfur (Li–S) batteries depend on an advanced electrode structure that can attain high sulfur utilization at lean-electrolyte conditions and minimum amount of lithium. Herein, a twinborn holey Nb 4 N 5 –Nb 2 O 5 heterostructure is designed as a dual-functional host for both redox–kinetics–accelerated sulfur cathode and dendrite-inhibited lithium anode simultaneously for long-cycling and lean-electrolyte Li–S full batteries. Benefiting from the accelerative polysulfides anchoring–diffusion–converting efficiency of Nb 4 N 5 –Nb 2 O 5 , polysulfide-shutting is significantly alleviated. Meanwhile, the lithiophilic nature of holey Nb 4 N 5 –Nb 2 O 5 is applied as an ion-redistributor for homogeneous Li-ion deposition. Taking advantage of these merits, the Li–S full batteries present excellent electrochemical properties, including a minimum capacity decay rate 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 of 2.4:1 and electrolyte to sulfur ratio of 5.1 µL mg −1 . Therefore, this work paves a new avenue for boosting high-performances Li–S batteries toward practical applications.