A study of alkaline gel polymer electrolytes for rechargeable zinc–air batteries

• Published in: Electrochimica acta Vol. 327; p. 135021
• Main Authors: Tran, Thuy Nguyen Thanh, Chung, Hyun-Joong, Ivey, Douglas G.
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 10-12-2019; Elsevier BV
• Subjects: Alkaline electrolyte; Aqueous electrolytes; Battery performance; Charge transfer; Chemical composition; Conductivity; Electrolytes; Functional groups; Gel polymer electrolyte; Hydrogels; Ion currents; Ionic conductivity; Mechanical properties; Metal air batteries; Organic chemistry; Polyacrylic acid; Polymers; Polyvinyl alcohol; Rechargeable batteries; Zinc-air battery; Zinc-oxygen batteries; Alkaline electrolyte; Battery performance; Gel polymer electrolyte; Zinc-air battery; Ionic conductivity
• ISSN: 0013-4686; 1873-3859
• DOI: 10.1016/j.electacta.2019.135021

In this report, hydrated hydrogels are investigated for application in rechargeable zinc–air batteries (ZABs) based on their ionic conductivities, chemical stability, electrochemical windows and mechanical properties. Three different hydrogel networks, i.e., poly(vinyl alcohol) (PVA), poly(acrylic acid) (PAA) and poly(4-vinylbenzenesulfonate-co-[3-(methacryloylamino)propyl]trimethylammonium chloride) (PAM), were chosen based on their chemical composition and different charged functional groups in the polymer network. Since the hydrogel network affects electrolyte uptake, which in turn may influence conductivity, understanding the correlation between hydrogel species and ionic conductivity provides insight into designing an appropriate gel polymer electrolyte (GPE) for ZABs. The relationship between ionic conductivity, water uptake and temperature are discussed. In ZAB cycling tests, although GPEs have a higher bulk resistance than aqueous electrolytes, they have lower interfacial and charge transfer resistances. The total resistance values for PVA and PAA, with 6 M KOH, vary from 4 to 6 Ω, which are lower than the values for KOH solution (∼11 Ω) and PAM with 6 M KOH (∼14 Ω). As such, this study demonstrates that GPEs show considerable promise for use as electrolytes in ZABs.
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