Breaking Boundaries in Battery Science: How pH Gradients Boost Zinc Performance
2025-11-06
Purdue chemists reveal how microscopic pH changes stabilize zinc batteries — paving the way for safer, cleaner and more affordable energy storage.
Jeffrey Dick, Richard B. Wetherill Professor of Chemistry, and graduate student Ashutosh Rana assemble an electrochemical cell designed for in-situ mass spectrometry. This custom setup enables real-time monitoring of the hydrogen evolution reaction during zinc electrodeposition; a key technique the team used to understand and quantify interfacial pH gradients. (Photo provided by Aaron Basiletti.)
As the world searches for cleaner, more sustainable energy solutions, zinc is stepping into the spotlight. By reducing reliance on scarce materials like lithium, zinc batteries provide a promising alternative by offering a safer, more affordable and environmentally friendly path forward.
A new study from Purdue University’s James Tarpo Jr. and Margo Tarpo Department of Chemistry and Davidson School of Chemical Engineering, published in Joule, has revealed an important mechanism that explains why zinc batteries often work better when charged quickly. Led by Jeffrey Dick, Richard B. Wetherill Professor of Chemistry, and Brian Tackett, Robert & Sally Weist Assistant Professor of Chemical Engineering, this research highlights how small pH changes at the metal interface can significantly affect battery stability and lifespan, which is crucial for advancing sustainable energy technologies.
Unlike lithium batteries, which rely on expensive and flammable materials, zinc batteries use a safe and abundant element. These characteristics make zinc batteries well-suited for renewable energy storage, such as solar and wind, where cost, sustainability and scalability are important.
For years, scientists have known that zinc batteries sometimes perform better at higher charging rates, a counterintuitive trend since most batteries degrade under those conditions. The Purdue team is the first to explain why this happens.
Their findings show that fast charging creates sharp pH gradients near the battery’s electrode surface. These gradients encourage the formation of a protective, uniform layer called a solid electrolyte interphase (SEI), which prevents unwanted hydrogen reactions that can cause instability or corrosion. This discovery reveals a delicate balance between chemistry and physics that determines how efficiently zinc batteries operate.
The research team included graduate students Ashutosh Rana, Saptarshi Paul, James H. Nguyen, and John F. Koons; postdoctoral researchers Arya Das and Kingshuk Roy; and undergraduate Chunge Li, all from the Department of Chemistry. They collaborated with graduate student Ashutosh Bhadouria and co-principal investigator Brian Tackett from Chemical Engineering.
Ashutosh Rana, a graduate student in the Dick Lab, played a key role in developing the project and conducting experiments. “This work shows how even invisible chemical gradients can protect and strengthen batteries in ways we didn’t expect,” he explained.
The study combined expertise from Dick’s electroanalytical chemistry group and Tackett’s chemical engineering team, which specializes in mass spectrometry-based analysis of volatile species. Using advanced imaging and spectroscopy techniques, the researchers mapped how local pH changes influence hydrogen evolution, which is a key factor in battery performance.
“The findings of this work can enable performance improvements in real products,” said Rana. “The insights presented in the work demonstrate how simple strategies can be leveraged to enhance battery performance at practical metrics, even without modifying the materials, conditions where batteries typically fail.”
The results suggest new opportunities for diagnostic tools, such as real-time pH mapping at the electrode surface, and provide guidance for optimizing charge and discharge processes in future zinc batteries. Beyond improving current designs, these insights could shape how we approach energy storage.
This research was supported by the Army Research Office and was accomplished under grant number W911NF-24-1-0199.
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Contributors:
Jeffrey Dick, Richard B. Wetherill Professor of Chemistry
Brian Tackett, Robert & Sally Weist Assistant Professor of Chemical Engineering
Ashutosh Rana, graduate student
Written by: Alison Harmeson, senior communications specialist for the Purdue University College of Science