A Stretchable Ionic Conductive Elastomer for High-Areal-Capacity Lithium-Metal Batteries

Developing high-areal-capacity and dendrite-free lithium (Li) anodes is of significant importance for the practical applications of the Li-metal secondary batteries. Herein, an effective strategy to stabilize the high-areal-capacity Li electrodeposition by modifying the Li metal with a stretchable ionic conductive elastomer (ICE) is demonstrated. The ICE layer prepared via an instant photocuring process shows a promising Li+-ion conductivity at room temperature. When being used in Li-metal batteries, the thin ICE coating (similar to 0.27 mu m) acts as both a stretchable constraint to minimize the Li loss and a protective layer to facilitate the uniform flux of Li ions. With this ICE-modifying strategy, the reversibility and cyclability of the Li anodes under high-areal-capacity condition in carbonate electrolyte are significantly improved, leading to a stable Li stripping/plating for 500 h at an ultrahigh areal capacity of 20 mAh cm(-2) in commercial carbonate electrolyte. When coupled with industry-level thick LiFePO4 electrodes (20.0 mg cm(-2)), the cells with ICE-Li anodes show significantly enhanced rate and cycling capability.

Automated summary

The effective strategy of modifying Li metal with a stretchable ionic conductive elastomer (ICE) stabilizes high-areal-capacity Li electrodeposition, significantly improving reversibility and cyclability under high-areal-capacity conditions. When coupled with industry-level thick LiFePO4 electrodes, ICE-Li anodes show significantly enhanced rate and cycling capability.