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 Al2O3 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 Al2O3 layer with Sn at room temperature. Not any acid or tedious process is needed. Benefiting from the elimination of Al2O3 and high electrochemical-activity of Sn, the obtained [email protected] 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 [email protected]@GO pellet electrode presents astonishing Li-ion storage properties both in half and full batteries. This work demonstrates that the cooperation of the Al2O3 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.