Early View e202400365
Research Article

Aqueous Acidic Pectin-Based Solution as Electrolyte and Pretreatment Solution for Zinc Ion Battery Anodes

Jooyoung Jang

Jooyoung Jang

Graduate Institute of Ferrous & Eco Materials Technology (GIFT), Pohang University of Science and Technology (POSTECH), 77 Cheongam-Ro, Nam-Gu, 37673 Pohang, Gyeongbuk, Republic of Korea

Contribution: Conceptualization (lead), Data curation (lead), ​Investigation (lead), Methodology (lead), Writing - original draft (lead)

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Won-Gwang Lim

Won-Gwang Lim

Department of Chemical and Biomolecular Engineering, Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-Ro, Yuseong-Gu, 34141 Daejeon, Republic of Korea

Contribution: Data curation (supporting), Writing - review & editing (supporting)

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Changshin Jo

Corresponding Author

Changshin Jo

Graduate Institute of Ferrous & Eco Materials Technology (GIFT), Pohang University of Science and Technology (POSTECH), 77 Cheongam-Ro, Nam-Gu, 37673 Pohang, Gyeongbuk, Republic of Korea

Department of Chemical Engineering, Pohang University of Science and Technology (POSTECH), 77 Cheongam-Ro, Nam-Gu, Pohang, 37673, Gyeongbuk Republic of Korea

Contribution: Conceptualization (lead), Funding acquisition (lead), Supervision (lead), Writing - original draft (lead), Writing - review & editing (lead)

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First published: 09 July 2024

Graphical Abstract

We utilize an acidic pectin-based ZnSO4 (ZSP) solution in aqueous Zn-ion batteries in two ways: as an electrolyte and as a pretreatment solution for the Zn anode. The ZSP electrolyte effectively prevents inactive byproduct formation, ensuring stable cycling. Immersing Zn foil in the acidic ZSP solution removes the uneven layer from the Zn anode surface.

Abstract

While considerable progress has been achieved in aqueous mildly acidic Zn-ion batteries (AZIBs), the development of metallic Zn anodes remains challenging due to dendritic growth and side reactions on the Zn surface in mildly acidic aqueous environments. Herein, we utilize pectin in two ways: firstly, as an additive for the acidic ZnSO4 electrolyte with pectin (referred to as ZSP); and secondly, as a component in the pretreatment solution for Zn electrode. The ZSP electrolyte can prevent the formation of inactive Zn4(OH)6(SO4) ⋅ 5H2O byproduct on Zn electrode and enable stable cycling under challenging conditions at 10 mA h cm−2. Interestingly, the immersion of the Zn foil in the acidic pectin solution resulted in the uniform removal of the bumpy oxides/carbonates layer on the Zn metal surface. The cells with treated Zn electrode in pectin solution exhibited lower overpotentials and effectively inhibited cell failure. Our findings indicate that utilizing an organic-based acidic ZnSO4 electrolyte shows promise as both an effective electrolyte and a pretreatment solution for the development of stable and cheap aqueous AZIB electrolytes.

Conflict of Interests

The authors declare no conflict of interest.

Data Availability Statement

The data that support the findings of this study are available from the corresponding author upon reasonable request.