Corn Protein Boosts Lithium-Sulfur Battery Performance

Researchers at Washington State University have demonstrated how corn protein can enhance the performance of lithium-sulfur batteries. This discovery could lead to wider use of these high-energy, lightweight batteries in electric vehicles, renewable energy storage, and other applications.

Compared to lithium-ion batteries, lithium-sulfur batteries are more environmentally friendly and lighter for the same energy capacity. However, their adoption has been limited by technological challenges that reduce their lifespan.

The WSU team's research shows that a button-sized lithium-sulfur battery’s efficiency improved significantly when a protective barrier made of corn protein and a commonly used plastic was used. The battery, with the protective corn separator, retained its charge for 500 cycles, a notable increase in performance compared to batteries without the barrier.

This work demonstrated a simple and efficient approach to preparing a functional separator for enhancing the battery’s performance. The results are excellent.

Katie Zhong, Study Corresponding Author and Professor, School of Mechanical and Materials Engineering, Washington State University

Lithium-sulfur batteries are considered a viable alternative to lithium-ion batteries for many applications. They offer significantly higher energy capacity, which could lead to smaller and lighter batteries for use in automobiles or aircraft.

Lithium-sulfur batteries are more environmentally friendly than current options because they use sulfur as the cathode material, which is inexpensive, widely available, and non-toxic. In contrast, lithium-ion batteries use metal oxides, including hazardous heavy metals like nickel or cobalt, for their cathodes.

However, two key issues limit the adoption of lithium-sulfur batteries. The sulfur component tends to migrate into the liquid part of the battery and move toward the lithium side, a phenomenon known as the shuttle effect, which causes rapid battery degradation. Additionally, dendrites—spikes of lithium metal—frequently form on the lithium side, which can lead to electric short circuits.

In their proof-of-concept study, the researchers used corn protein to coat a separator in the middle of the battery, preventing both of these issues.

Corn protein would make for a good battery material because it’s abundant, natural, and sustainable.

Jin Liu, Study Corresponding Author and Professor, School of Mechanical and Materials Engineering, Washington State University

The study was led by graduate students Ying Guo, Pedaballi Sireesha, and Chenxu Wang.

The protein's amino acids interact with battery materials to enhance lithium-ion mobility and reduce the shuttle effect. Since proteins naturally fold upon themselves, the researchers used a small piece of flexible plastic to flatten the protein and improve its performance.

“The first thing we need to think about is how to open the protein, so we can use those interactions and manipulate the protein,” stated Liu.

The researchers used both numerical analysis and experiments to demonstrate the battery’s success. They are continuing their research to understand how the process works, which amino acid interactions are involved, and how the protein structure can be improved.

“A protein is a very complicated structure. We need to do further simulation studies to identify which amino acids in the protein structure can work best for solving the critical shuttle effect and dendrite problems,” added Zhong.

The researchers aim to collaborate with industry partners to study larger experimental batteries and scale up the process. The study was funded by the US Department of Agriculture.

Journal Reference:

Guo,Y., et al. (2025) An interpenetrated protein-polar polymer interlayer for suppressing shuttle effect in Li-S batteries. Journal of Power Sources. doi.org/10.1016/j.jpowsour.2024.236145