Interfacial activation of anode in aluminum-air battery through incorporating 5-carboxyl benzotriazole@β-cyclodextrin assembly in synthetic seawater electrolyte

• Published in: International journal of electrochemical science 2024-10, Vol.19 (10), p.100779, Article 100779
• Main Authors: Li, Fengjuan, Tian, Hua, Li, Hang, Zhang, Jingyi, Qiu, Tian, Fan, Baomin
• Format: Article
• Language: English
• Subjects: 5-carboxylate benzotriazole; DFT; Host-guest assembling; Metal-air battery; β-cyclodextrin
• ISSN: 1452-3981; 1452-3981
• DOI: 10.1016/j.ijoes.2024.100779

Neutral electrolyte, such as synthetic seawater (SW), is a promising candidate for aluminum-air (Al-air) battery due to the alleviated hydrogen evolution along with anode self-corrosion. However, aluminum surface passivation in SW poses a serious challenge for battery's power generation. Following molecular self-assembly theory, 5-carboxylate benzotriazole (CB) was incorporated into β-cyclodextrin (β-CD), which (CB@β-CD) was utilized as an interfacial activator for aluminum anode in SW. CB could be released from β-CD, and activated aluminum surface, facilitating anode discharge. The specific capacity and energy density of Al-air battery were achieved as 2607.4 mAh/gAl and 2.37 kWh/kgAl, respectively, at an optimal CB@β-CD concentration of 120 mg/L. Density functional theory calculations revealed that the overwhelming adsorption energy of guest molecule (CB) on Al (111) plane over its binding energy inside host (β-CD) accounted for the release of CB on anode surface, and the ensuing interfacial activation effect.