Data-Driven Cation Engineering Guides Electrolyte Design for Sustainable Aqueous Zinc Battery Chemistries.

Area of Science:

• Materials Science
• Electrochemistry
• Computational Chemistry

Background:

• Vanadium oxides are promising cathode materials for zinc-based batteries due to high capacity and redox versatility.
• Electrolyte dissolution of vanadium oxides is a major obstacle for practical zinc-based battery applications.
• Developing stable aqueous electrolytes is crucial for advancing zinc-based battery technology.

Purpose of the Study:

• To engineer a cation-based electrolyte strategy to enhance the stability of vanadium oxide cathodes in zinc-based batteries.
• To establish a data-driven framework for efficient screening of electrolyte compositions and minimizing experimental trial-and-error.
• To investigate the ion insertion mechanisms and their impact on battery performance and stability.

Main Methods:

• Integrated a data-driven framework combining Density Functional Theory (DFT) calculations, Discrete Wavelet Transform (DWT)-based multi-scale analysis, and differential feature extraction.
• Employed objective statistical quantification for screening hetero-cations and their combinations.
• Tested a predicted Na⁺-Mg²⁺-Zn²⁺ (NMZ) tri-cation electrolyte in Zn/VOx batteries.

Main Results:

• The NMZ tri-cation electrolyte demonstrated exceptional reversibility and record cycling stability in Zn/VOx batteries.
• Batteries sustained 500 cycles at 0.2 A g^-1 (1400 h) and 10,000 cycles at 5 A g^-1.
• The tri-cation electrolyte enabled a sequential ion insertion pathway, suppressing proton and hydrated Zn²⁺ intercalation.

Conclusions:

• The cation-engineered electrolyte strategy effectively suppresses vanadium oxide dissolution and enhances battery stability.
• The data-driven framework provides a reusable and statistically robust method for electrolyte design in batteries.
• This approach offers critical insights into ion-related factors for improving insertion stability in diverse battery chemistries.