Liquid gallium as long cycle life and recyclable negative electrode for Al-ion batteries

Although rechargeable Al batteries attract interests due to their features of abundant Al source and high safety, the Al negative electrodes suffer from critical problems, including dendrite, corrosion, pulverization, non-recyclable Al wastes, etc. For addressing these challenges, here a novel liquid gallium is demonstrated for negative electrodes of Al batteries. The results show that the liquid gallium negative electrode enables the reversible alloying/dealloying between Al and Ga. Remarkably, the essential problems in the solid Al negative electrodes, including dendrite, corrosion and pulverization, would be well avoided attributed to the liquid state of the Ga electrode during cycling. In addition to the enhanced stable cycling performance, Ga negative electrode is also recyclable, allowing the cycled Ga for further presenting stable cycling in the re-assembled batteries, and which is helpful for its practical application. The results in the present work open a precedent way to develop the advanced negative electrode with dendrite-free, corrosion resistant and recyclable features and advantages for various types of rechargeable batteries.