Dynamic Locking of Interfacial Side Reaction Sites Promotes Aluminum‐Air Batteries Close to Theoretical Capacity. (29th December 2021)

• Record Type: Journal Article
• Authors: Huang, Yuanlin; Fang, Lei; Gu, Yu; Wang, Pingshi; Yan, Hao; Wang, Yanjie; Cao, Zexing; Tian, Zhaowu; Mao, Bingwei; Zhang, Li
• Is Part Of: Advanced sustainable systems. Volume 6:Number 3(2022)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2021-12-29
• Subjects: aluminum anodes -- aluminum‐air batteries -- corrosion inhibitors -- self‐corrosion; Sustainable living -- Periodicals; Sustainability -- Periodicals; Green technology -- Periodicals; Periodicals; 628
• DOI: 10.1002/adsu.202100420
• Languages: English
• ISSNs: 2366-7486

Abstract

Abstract: Aluminum metal has been regarded as a promising anode material for aqueous metal‐air batteries. However, the stable cycling of Al anodes is challenging due to the severe parasitic corrosion of Al metal in alkaline electrolytes. Here, a novel additive, n ‐octylphosphonic acid (OPA), is introduced into the typical NaOH electrolyte system to improve the interfacial stability of Al anodes and thus promote high‐performance Al‐air batteries (AABs). Combining several experimental characterizations and theoretical calculation, it is proved that OPA molecules in an NaOH aqueous environment can modify the Al anode/electrolyte interface and alter the stacking of the discharge product. The electrolyte engineering is capable of anchoring dynamically to restrain side reactions through hydrogen bonds (H···O), homogenizing the dissolution of Al metal and avoiding precipitation agglomeration. As a proof of concept, AABs full cells with an electrolyte containing OPA achieve higher potential plateau and discharge capacity than those with a pure NaOH electrolyte. It paves a way to develop highly‐efficient and eco‐friendly electrolyte additive strategies for high‐performance AABs devices and advance the current understanding of organic additive mechanisms in AABs. Abstract : n ‐octylphosphonic acid (OPA) is proposed as an ideal inhibitor to suppress the self‐corrosion of Al anodes in Al‐air batteries (AABs). AAB full cells with an OPA‐based electrolyte deliver an ultrahigh discharge capacity of 2694 mAh g −1, 91% of their theoretical value (2980 mAh g −1 ). A practically useful OPA‐based AAB pile is further constructed to power a commercial digital camera steadily.