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Strategy of Electrolyte Design: Triethanolamine as a Polydentate Ligand to Improve Solvation of Zinc in Zinc-Air Batteries.

Published version
Peer-reviewed

Type

Article

Change log

Authors

Huang, Huiyu 
Sun, Xueyan 
Deng, Xiaobin 
Lei, Yuan 

Abstract

The zinc-air batteries (ZABs) are regarded as the most potential energy storage device for the next generation. However, the zinc anode passivation and hydrogen evolution reaction (HER) in alkaline electrolyte situations inhibit the zinc plate working efficiency, which needs to improve zinc solvation and better electrolyte strategy. In this work, we propose a design of new electrolyte by using a polydentate ligand to stabilize the zinc ion divorced from the zinc anode. The formation of the passivation film is suppressed greatly, compared to the traditional electrolyte. The characterization result presents that the quantity of the passivation film is reduced to nearly 33% of pure KOH result. Besides, triethanolamine (TEA) as an anionic surfactant inhibits the HER effect to improve the efficiency of the zinc anode. The discharging and recycling test indicates that the specific capacity of the battery with the effect of TEA is improved to nearly 85 mA h/cm2 compared to 0.21 mA h/cm2 in 0.5 mol/L KOH, which is 350 times the result of the blank group. The electrochemical analysis results also indicate that zinc anode self-corrosion is palliated. With density function theory, calculation results prove the new complex existence and structure in electrolytes by the data of the molecular orbital (highest occupied molecular orbital-lowest unoccupied molecular orbital). A new theory of multi-dentate ligand inhibiting passivation is elicited and provides a new direction for ZABs' electrolyte design.

Description

Keywords

40 Engineering, 4016 Materials Engineering, 34 Chemical Sciences, 3406 Physical Chemistry, 7 Affordable and Clean Energy

Journal Title

ACS Omega

Conference Name

Journal ISSN

2470-1343
2470-1343

Volume Title

8

Publisher

American Chemical Society (ACS)