A liquid metal assisted dendrite-free anode for high-performance Zn-ion batteries

Zinc metal is a promising anode candidate due to its high theoretical capacity and high abundance, making aqueous zinc ion batteries (ZIBs) some of the most promising energy storage systems for large scale grids. However, the practical application of ZIBs is seriously inhibited by detrimental dendrite growth on the zinc metal anode surface. To tackle this problem, we propose a scalable approach for preventing dendrite formation by introducing a liquid Ga-In-Zn alloy as a self-healing protective layer on zinc anodes. The as-established liquid metal (LM) layer serves as an effective liquid-state diffusion barrier and accelerates Zn nucleation speed and electron transfer. Compared to the traditional solid-liquid interface of solid electrodes, the stable liquid-liquid interface between the LM and electrolyte enables better charge transfer kinetics and thus significantly reduces the interfacial resistance by 98.4%. The decreased Zn ion migration barrier energy after LM coating was also confirmed by density functional theory calculation. More impressively, the LM ensures an ultralong cycling life of 10 000 cycles by enabling dendrite-free Zn deposition due to its high fluidity and deformability. Consequently, our work suggests a novel strategy to modify the Zn anodes in ZIBs by inhibiting dendrite formation and promote future applications for a sufficient work span.