Grain boundary density matters in lithiation performances of aluminum foil anode for lithium ion batteries

Alloy foils are highly promising anode materials for high energy density lithium-ion batteries (LIBs). However, limited lithiation sites and inhomogeneous lithiation processes often lead to stress concentration and severe volume changes, resulting in rapid degradation of the electrode structure. In this work, the lithiation behavior and the corresponding structural evolution of aluminum (Al) foil anode are investigated by modulating the grain boundaries (GBs) density. The results show that abundant GBs network endows Al foil with uniform and distributed lithiation sites, and improved lithiation kinetics. The derived uniform volume change can effectively delocalize stress concentration, and hinder the formation of penetrated cracking network, giving rising to good structural stability and prolonged cycle life of Al foil anode. This work can enrich feasible strategies to alleviate the pulverization and serial issues of the metal foil anode by GBs density regulation for high specific energy LIBs.