Liquid metal-based cathode for flexible ambient Li-air batteries and its regeneration by water

Abstract

Flexible lithium-air batteries (LABs) are drawing increasing attentions nowadays due to the highest theoretical capacity as power sources for flexible electronic devices. However, the insufficient mechanical strength and catalytic efficiency of air cathode would induce issues like electrode fracture, limited lifespan and reduced battery efficiency. Herein, we report a facile method to fabricate Ru-decorated liquid metals (Ru/LM) composite material as a free-standing cathode for flexible LABs. The introduction of Ru in the composite not only decreases the surface tension and promotes the spreading of LM, but also enhances the catalytic performance of cathode. As results, it demonstrates superior catalytic properties toward O2 reduction and LiOH/Li2CO3 decomposition during cycles in ambient air. Besides, the LM substrate endows robust flexible performance and stable cycle performance is achieved both at flat and bending states. Moreover, the residual discharged products on passivated cathode can be easily washed off and the cathode can be recovered in LABs. Even after regenerated for 4 times, the cathode shows no obvious performance fading. This strategy is promising in the development of flexible LABs with robust flexibility, high efficiency and low-cost during their all life-cycle.