Aluminum corrosion-passivation regulation prolongs aqueous batteries life.

Liu, Binghang; Lv, Tianshi; Zhou, Anxing; Zhu, Xiangzhen; Lin, Zejing; Lin, Ting; Suo, Liumin · Nat Commun · 2024

basic_science · Level V

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Abstract

Aluminum current collectors are widely used in nonaqueous batteries owing to their cost-effectiveness, lightweightness, and ease of fabrication. However, they are excluded from aqueous batteries due to their severe corrosion in aqueous solutions. Here, we propose hydrolyzation-type anodic additives to form a robust passivation layer to suppress corrosion. These additives dramatically lower the corrosion current density of aluminum by nearly three orders of magnitude to ~10<sup>-6</sup> A cm<sup>-2</sup>. In addition, realizing that electrochemical corrosion accompanies anode prelithiation, we propose a prototype of self-prolonging aqueous Li-ion batteries (Al ||LiMn<sub>2</sub>O<sub>4</sub> ||TiO<sub>2</sub>), whose capacity retention rises from 49.5% to 70.1% after 200 cycles. A sacrificial aluminum electrode where electrochemical corrosion is utilized is introduced as an electron supplement to prolong the cycling life of aqueous batteries. Our work addresses the short-life issue of aqueous batteries resulting from the corrosion of the current collector and lithium loss from side reactions.