Self-Supporting Multicomponent Hierarchical Network Aerogel as Sulfur Anchoring-Catalytic Medium for Highly Stable Lithium-Sulfur Battery.

Abstract

The low utilization rate of active materials, shuttle effect of lithium polysulfides (LiPSs), and slow reaction kinetics lead to the extremely low efficiency and poor high current cycle stability of lithium sulfur batteries (Li-S batteries). In this paper, a self-supporting multicomponent hierarchical network aerogel is proposed as the modified cathode (S/GO@MX@VS4 ). It consists of graphene (GO) and MXene nanosheets (MX) loaded with VS4 nanoparticles. The experimental results and first-principles calculations show that the GO@MX@VS4 aerogel has strong adsorption and reversible conversion effects on LiPSs. It can not only inhibit the shuttle effect and improve the utilization rate of active substances by keeping the chain crystal structure of VS4 , but also promote the reversibility and kinetics of the reaction by accelerating the liquid-solid transformation in the reduction process and the decomposition of insoluble Li2 S in the oxidation process. The GO@MX@VS4 aerogel modified cathode with a multicomponent synergy exhibits the capacity ratios (Q1 /Q2 ) at different discharge stages is close to the theoretical value (1:2.8), and the capacity decay per cycle is 0.019% in 1200 cycles at 5C. Also, a high areal capacity of 6.90 mAh cm-2 is provided even at high sulfur loading (7.39mg cm-2 ) and low electrolyte/sulfur ratio (E/S, 8.0µL mg-1 ).