Electrocatalysis for Continuous Multi-Step Reactions in Quasi-Solid-State Electrolytes Towards High-Energy and Long-Life Aluminum-Sulfur Batteries

Angew Chem Int Ed Engl. 2022 Jun 13;61(24):e202202696. doi: 10.1002/anie.202202696. Epub 2022 Apr 20.

Abstract

Aluminum-sulfur (Al-S) batteries of ultrahigh energy-to-price ratios are a promising energy storage technology, while they suffer from a large voltage gap and short lifespan. Herein, we propose an electrocatalyst-boosting quasi-solid-state Al-S battery, which involves a sulfur-anchored cobalt/nitrogen co-doped graphene (S@CoNG) positive electrode and an ionic-liquid-impregnated metal-organic framework (IL@MOF) electrolyte. The Co-N4 sites in CoNG continuously catalyze the breaking of Al-Cl and S-S bonds and accelerate the sulfur conversion, endowing the Al-S battery with a shortened voltage gap of 0.43 V and a high discharge voltage plateau of 0.9 V. In the quasi-solid-state IL@MOF electrolytes, the shuttle effect of polysulfides has been inhibited, which stabilizes the reversible sulfur reaction, enabling the Al-S battery to deliver 820 mAh g-1 specific capacity and 78 % capacity retention after 300 cycles. This finding offers novel insights to design Al-S batteries for stable energy storage.

Keywords: Aluminum-Sulfur Batteries; Catalytic Effect; Doped Graphene; Quasi-Solid-State Electrolyte; Shuttle Effect.