An Exciting Alternative to Lithium for Batteries

Mobile phone batteries with up to three times the lifespan of current technology could become a reality, thanks to an RMIT University-led breakthrough.

Only 10% of used handheld batteries, including for mobile phones, are collected for recycling in Australia, which is low by international standards. Image Credit: Adobe Stock:

Instead of disposing of batteries after two or three years, the team believes that by using high-frequency sound waves to eliminate rust that impairs battery performance, it might be possible to have recyclable batteries that last up to nine years.

In Australia, just 10% of used handheld batteries, including those used in mobile phones, are collected for recycling, which is low by international standards. The remaining 90% of batteries are disposed of incorrectly or end up in landfills, causing significant environmental damage.

The high cost of recovering lithium and other materials from batteries is a significant obstacle to reuse, but the team’s discovery may assist to address this issue.

The team is working with MXenes, which they believe will be an intriguing alternative to lithium for batteries in the future.

MXene, according to Leslie Yeo, Distinguished Professor of Chemical Engineering and lead senior researcher, is equivalent to graphene in terms of electrical conductivity.

Unlike graphene, MXenes are highly tailorable and open up a whole range of possible technological applications in the future.

Leslie Yeo, Distinguished Professor, Chemical Engineering, School of Engineering, RMIT University

The major problem with using MXene was that it rusted easily, thus inhibiting electrical conductivity and making it unusable.

Yeo adds, “To overcome this challenge, we discovered that sound waves at a certain frequency remove rust from MXene, restoring it to close to its original state.”

According to him, the group’s breakthrough could one day help to revitalize MXene batteries every few years, prolonging their lifetime by up to three times.

The ability to prolong the shelf life of MXene is critical to ensuring its potential to be used for commercially viable electronic parts.,” Yeo adds.

The study was published in the journal Nature Communications.

How the Innovation Works:

Mr. Hossein Alijani, a Ph.D. candidate and co-lead author, stated that the most difficult aspect of employing MXene was the rust that accumulated on its surface in a humid environment or when suspended in watery solutions.

Surface oxide, which is rust, is difficult to remove especially on this material, which is much, much thinner than a human hair. Current methods used to reduce oxidation rely on the chemical coating of the material, which limits the use of the MXene in its native form. In this work, we show that exposing an oxidized MXene film to high-frequency vibrations for just a minute removes the rust on the film. This simple procedure allows its electrical and electrochemical performance to be recovered.

Mr. Hossein Alijani, Study Co-Lead Author and PhD Candidate, School of Engineering, RMIT University

The Potential Applications of the Team’s Work

According to the researchers, their work to eliminate rust from MXene paves the way for the nanomaterial to be employed in a variety of applications such as sensors, energy storage, wireless transmission, and environmental remediation.

One of the lead senior researchers, Associate Professor Amgad Rezk, said the ability to quickly recover oxidized materials to an almost pristine state indicated a game-changer in terms of the circular economy.

Materials used in electronics, including batteries, generally suffer deterioration after two or three years of use due to rust formation. With our method, we can potentially extend the lifetime of battery components by up to three times.

Amgad Rezk, Associate Professor, School of Engineering, RMIT University

Next Steps:

While the technology appears to be promising, the researchers must collaborate with the industry to incorporate its acoustic device into current manufacturing systems and processes.

The team is also investigating the potential of their innovation to remove oxide layers from other materials for sensing and renewable energy applications.

We are keen to collaborate with industry partners so that our method of rust removal can be scaled up,” concludes Yeo.

Journal Reference:

Ahmed, H., et al. (2023) Recovery of oxidized two-dimensional MXenes through high frequency nanoscale electromechanical vibration. Nature Communications.