Activating commercial Al pellets by replacing the passivation layer for high-performance half/full Li-ion batteries

Al has been considered as a promising Li-ion batteries anode. However, the volume expansion always makes the electrode in an unstable structure. Meanwhile, the natural Al 2 O 3 passivation layer may lead to a large voltage dip, which could interrupt the lithiation process and result in a limited capacity. Herein, we report a neat avenue to activate the commercial Al pellet electrode by replacing the Al 2 O 3 layer with Sn at room temperature. Not any acid or tedious process is needed. Benefiting from the elimination of Al 2 O 3 and high electrochemical-activity of Sn, the obtained Al@Sn pellet electrode delivers a reversible capacity of 959.5 mAh g −1 at 0.1 A g −1 , which is larger than that (395.7 mAh g −1 ) of the commercial Al pellet electrode and approaches the calculated theoretical capacity. Notably, the voltage dip is muchly lowered to 0.03 V from 0.1 V. When graphene oxide (GO) was further attached for relieving the volume expansion, the as-prepared Al@Sn@GO pellet electrode presents astonishing Li-ion storage properties both in half and full batteries. This work demonstrates that the cooperation of the Al 2 O 3 elimination and matrix addition is successful in promoting the Li-ion storage properties of Al anode, presenting an attractive vision for the development of practical Al-based anodes.