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.