Improving Li reversibility in Li metal batteries through uniform dispersion of Ag nanoparticles on graphene

Li metal is the most attractive and promising anode material for next-generation high-energy batteries. However, uncontrolled Li dendrite growth during cycling remains a highly challenging drawback. To solve this problem, silver-coated graphene (Ag/GH) was prepared via a simple liquid-phase reduction method. The effect of Ag/GH on Li deposition behavior was investigated by adjusting the dispersion of Ag nanoparticles (Ag NPs). Subsequently, a composite electrode was fabricated via uniform deposition of metallic Li on Ag/GH. Ag was used as a lithiophilic nucleating agent to ensure uniform deposition of Li and inhibit the growth of Li dendrites on the anode. The prepared composite anode showed a significantly improved performance compared to the unmodified electrode. The symmetric cell comprising this composite electrode exhibited a stable cycling performance with a low hysteresis of similar to 40 mV and a lifetime of > 2000 h at a current density of 0.5 mA.cm(-2). Meanwhile, the discharge capacity reached 0.5 mAh.cm(-2). In addition, Ag/GH was found to be amenable to large-scale synthesis. Thus, the composite Ag/GH anode exhibited improved performance and the preparation method showed significant potential for application in the manufacture of Li metal batteries.

Automated summary

This study addresses the issue of uncontrolled Li dendrite growth in Li metal batteries by coating graphene with silver. A composite electrode was fabricated by uniformly depositing silver and metallic Li on graphene, resulting in improved performance and the potential for large-scale synthesis.