Novel electrolyte developed can boost zinc batteries to nearly 100%

Research from Oregon State University (OSU) created a novel electrolyte that can boost the efficiency of a zinc-metal anode in zinc batteries by almost 100%. Such development is considered important in creating an alternative to lithium-ion batteries used for large-scale energy storage.

The new electrolyte was developed by Xiulei ‘David’ Ji of the OSU College of Science and his colleagues, from HP Inc. and GROTTHUSS INC., an Oregon State spinout company, in collaboration with scientists from Massachusetts Institute of Technology (MIT), Penn State, and the University of California (UC) Riverside.

Their material was able to give rise to a Coulombic Efficiency (CE) of 99.95% in zinc-metal anode for zinc batteries, as compared to Lithium-ion batteries with a CE of 99%. In battery storage and transfer, CE refers to the measure of how well electrons are transferred to batteries. Higher CE indicates a more efficient and effective electrochemical system.

In a press release, Ji said, “The breakthrough represents a significant advancement toward making zinc-metal batteries more accessible to consumers. These batteries are essential for the installation of additional solar and wind farms. In addition, they offer a secure and efficient solution for home energy storage, as well as energy-storage modules for communities that are vulnerable to natural disasters.”

Relying on metal that is safe and abundant, zinc-based batteries are considered energy dense which is seen as a possible alternative to lithium-ion batteries which are reliant on cobalt and nickel, which are toxic and can contaminate water sources if they leach out of soil.

To date, zinc batteries have been limited due to zinc anode having poor reversibility performance. Reversibility performance refers to the ability of the anode to undergo repeated cycles of oxidation and reduction without undergoing significant degradation or loss of performance over time.

Since zinc reacts with water in the electrolyte to generate hydrogen gas in what is called a hydrogen-evolution reaction, this makes zinc limited to short cycle life and is also a potential safety hazard which is why most zinc batteries are unable to have higher CE.

However, Ji and his team were able to overcome this limitation by forming a passivation layer on the surface of the zinc anode.

This approach has been credited to Ji his chemistry colleague at OSU, Chong Fang, who has uncovered electrolyte’s atomic structure using femtosecond Raman spectroscopy, and to Alex Greaney at UC Riverside for determining the passivation mechanism.

Overall, the breakthrough is seen as a step forward to the near-future commercialization of zinc-metal batteries for large-scale grid storage.