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 Nb4N5-Nb2O5 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 Nb4N5-Nb2O5, polysulfide-shutting is significantly alleviated. Meanwhile, the lithiophilic nature of holey Nb4N5-Nb2O5 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 mu L mg(-1). Therefore, this work paves a new avenue for boosting high-performances Li-S batteries toward practical applications.

Automated summary

A novel twinborn holey Nb4N5-Nb2O5 heterostructure is designed as a dual-functional host for high-efficiency Li-S batteries, accelerating the redox reactions at the sulfur cathode and inhibiting dendrite growth at the lithium anode.