Innovative Electrode Creation Method Could Vastly Improve Metal Battery Stability

Researchers at Chalmers University of Technology in Sweden have developed a breakthrough method to create metal electrodes directly within battery cells using electroplating, offering a promising solution to one of the most significant challenges in metal battery technology. This innovation has the potential to vastly improve the stability and safety of metal batteries, which are known for their ability to deliver more energy at a lower weight compared to traditional lithium-ion batteries.

The new method, highlighted in a recent study published in the Journal of The Electrochemical Society, addresses the long-standing issue of surface layers forming on the reactive metal electrodes. These layers, which develop due to the highly reactive nature of lithium metal, have historically shortened the lifespan of metal batteries by compromising their stability. By creating the metal electrode within the battery cell itself, the electroplating process prevents the metal from reacting with impurities in the external environment, leading to a more stable and predictable electrode.

“We work in a very inert environment, but even there the metal finds something to react with and a surface layer is formed, which affects how the metal behaves in the battery. However, we have seen that these reactions can actually be avoided by very simple means: instead of dealing with the reactive electrode materials outside the battery, we create our electrode inside the battery through a process called electroplating,” stated Josef Rizell, a doctoral student at Chalmers and lead author of the paper. “This allows us to avoid the reactive metal reacting with the environment, which is an advantage as we get a more predictable and stable electrode.”

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The promise and challenges of metal batteries

Metal batteries have long been heralded as the next step in energy storage technology, particularly for applications requiring high energy density and low weight, such as electric vehicles with extended ranges and electric aircraft. Unlike conventional lithium-ion batteries, which use a graphite electrode, metal batteries replace this with a lithium metal electrode, promising greater energy delivery.

However, the reactivity of metal electrodes has been a significant hurdle, leading to the formation of dendrites—irregular structures that develop during charging and discharging, eventually compromising battery stability and performance.

3D X-ray monitoring

Professor Aleksandar Matic's research group at Chalmers University has been at the forefront of efforts to address these challenges. Their pioneering use of 3D X-rays to monitor lithium behavior in real-time within a lithium metal battery has provided crucial insights into how and why dendrites form, and how they affect the overall functionality of the battery.

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The team’s research goes beyond identifying the problem; it offers a solution that could lead to more durable and reliable metal batteries. By isolating and analyzing individual processes within the battery, the researchers have gained a deeper understanding of the complex interactions that occur during charging and discharging. This approach has laid the groundwork for strategies aimed at enhancing battery performance and longevity.

Supporting sustainable innovation

This study is part of a broader research initiative at Chalmers, where battery technology is a key focus. Professor Matic, who also directs Chalmers’ involvement in Compel, a Swedish government initiative to boost research and education in electrification and battery technology, underscores the importance of fundamental research in driving innovation.

“This type of fundamental research is important to pave the way for new battery concepts and technologies. Without it, you can only try things out, like orientating without a map. This is where we lay the foundation for future innovations that contribute to sustainable societal development,” Matic stated. “Batteries are already a key part of that development, and their importance will only increase in the future.”