Hyaluronic Acid with Double Helix Ion Channels for Efficient Electrolyte Retention and Polysulfide Regulation in Lean-Electrolyte Lithium-Sulfur Batteries.

Abstract

Catalyzing sulfur conversion is an efficient solution to overcome poor ion transfer, severe shuttle effect, and unfavored electrode passivation in lean-electrolyte lithium-sulfur batteries. Herein, a natural moisturizing material, hyaluronic acid (HA), is experimentally and theoretically demonstrated to promote the adsorptions of electrolyte and polysulfides via intramolecular hydrogen bonds, providing sufficient electrolyte contacts for subsequent catalytic reactions. Rely on its radical-scavenging capability, HA facilitates the conversion of polysulfide radicals at N sites, suppressing shuttle effect. Due to the spiral acceleration effect of double helix structure, HA accelerates Li⁺ migration, enhancing the lithiation kinetics of system. Consequently, under sulfur loading of 8 mg cm^-2 and lean electrolyte of 3 µL mg^-1 conditions, the HA-modified cells deliver a high areal capacity of 11.76 mAh cm^-2 and a gravimetric energy density of 409 Wh kg^-1. This work provides a fresh insight into developing natural moisturizing materials as electrocatalysts toward practical Li-S batteries.