Manipulating Coulombic Efficiency of Cathodes in Aqueous Zinc Batteries by Anion Chemistry

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Detail(s)

Original languageEnglish
Article numbere202303292
Journal / PublicationAngewandte Chemie - International Edition
Volume62
Issue number23
Online published5 Apr 2023
Publication statusPublished - 5 Jun 2023

Abstract

Electrolyte environments, including cations, anions, and solvents are critical for the performance delivery of cathodes of batteries. Most works focused on interactions between cations and cathode materials, in contrast, there is a lack of in-depth research on the correlation between anions and cathodes. Here, we systematically investigated how anions manipulate the coulombic efficiency (CE) of cathodes of zinc batteries. We take intercalation-type V2O5 and conversion-type I2 cathodes as typical cases for profound studies. It was found that electronic properties of anions, including charge density and its distribution, can tune conversion or intercalation reactions, leading to significant CE differences. Using operando visual Raman microscopy and theoretical simulations, we confirm that competitive coordination between anions and I can regulate CEs by modulating polyiodide diffusion rates in Zn−I2 cells. In Zn−V2O5 cells, anion-tuned solvation structures vastly affect CEs through varying Zn2+ intercalation kinetics. Conversion I2 cathode achieves a 99 % CE with highly electron-donating anions, while anions with preferable charge structures that interact strongly with Zn2+ afford an intercalation V2O5 a nearly 100 % CE. Understanding the mechanism of anion-governed CEs will help us evaluate compatibility of electrolytes with electrodes, thus providing a guideline for anion selection and electrolyte design for high-energy, long-cycling zinc batteries. © 2023 Wiley-VCH GmbH.

Research Area(s)

  • Anions, Aqueous Zinc Batteries, Cathode, Coulombic Efficiency, Energy Storage

Citation Format(s)