Toward Practical High-Areal-Capacity Aqueous Zinc-Metal Batteries : Quantifying Hydrogen Evolution and a Solid-Ion Conductor for Stable Zinc Anodes

Research output: Journal Publications and ReviewsRGC 21 - Publication in refereed journalpeer-review

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Detail(s)

Original languageEnglish
Article number2007406
Journal / PublicationAdvanced Materials
Volume33
Issue number12
Online published19 Feb 2021
Publication statusPublished - 25 Mar 2021

Abstract

The hydrogen evolution in Zn metal battery is accurately quantified by in situ battery–gas chromatography–mass analysis. The hydrogen fluxes reach 3.76 mmol h−1 cm−2 in a Zn//Zn symmetric cell in each segment, and 7.70 mmol h−1 cm−2 in a Zn//MnO2 full cell. Then, a highly electronically insulating (0.11 mS cm−1) but highly Zn2+ ion conductive (80.2 mS cm−1) ZnF2 solid ion conductor with high Zn2+ transfer number (0.65) is constructed to isolate Zn metal from liquid electrolyte, which not only prohibits over 99.2% parasitic hydrogen evolution but also guides uniform Zn electrodeposition. Precisely quantitated, the Zn@ZnF2//Zn@ZnF2 cell only produces 0.02 mmol h−1 cm−2 of hydrogen (0.53% of the Zn//Zn cell). Encouragingly, a high-areal-capacity Zn@ZnF2//MnO2 (≈3.2 mAh cm−2) full cell only produces maximum hydrogen flux of 0.06 mmol h−1 cm−2 (0.78% of the Zn//Zn cell) at the fully charging state. Meanwhile, Zn@ZnF2//Zn@ZnF2 symmetric cell exhibits excellent stability under ultrahigh current density and areal capacity (10 mA cm−2, 10 mAh cm−2) over 590 h (285 cycles), which far outperforms all reported Zn metal anodes in aqueous systems. In light of the superior Zn@ZnF2 anode, the high-areal-capacity aqueous Zn@ZnF2//MnO2 batteries (≈3.2 mAh cm−2) shows remarkable cycling stability over 1000 cycles with 93.63% capacity retained at ≈100% Coulombic efficiency.

Research Area(s)

  • hydrogen evolution suppression, practical-level Zn batteries, quantifying hydrogen evolution, solid Zn 2+-ion conductors, Zn deposition regulation

Citation Format(s)

Toward Practical High-Areal-Capacity Aqueous Zinc-Metal Batteries: Quantifying Hydrogen Evolution and a Solid-Ion Conductor for Stable Zinc Anodes. / Ma, Longtao; Li, Qing; Ying, Yiran et al.
In: Advanced Materials, Vol. 33, No. 12, 2007406, 25.03.2021.

Research output: Journal Publications and ReviewsRGC 21 - Publication in refereed journalpeer-review