The distribution of lithium concentrations is indicated by the changing colors during the charging of a graphite negative electrode. Image: Xuekun Lu et al/Nature Communications.A new study led by Xuekun Lu from Queen Mary University of London in the UK, in collaboration with an international team of researchers from the UK and US, has revealed a way to prevent lithium plating in electric vehicle batteries, which could lead to faster charging times. Lu and his team report this work in a paper in Nature Communications.
Lithium plating is a phenomenon that can occur in lithium-ion batteries during fast charging. It occurs when lithium ions build up on the surface of the battery's negative electrode instead of intercalating inside it, forming a layer of metallic lithium that continues growing. This can damage the battery, shorten its lifespan, and cause short-circuits that can lead to fire and explosion.
In the paper, Lu and his team explain that lithium plating can be significantly mitigated by optimizing the microstructure of the graphite negative electrode, which is made up of randomly distributed tiny particles. The researchers show that fine-tuning the particle and electrode morphology for a homogeneous reaction activity and reduced local lithium saturation is the key to suppressing lithium plating and improving the battery's performance.
"Our research has revealed that the lithiation mechanisms of graphite particles vary under distinct conditions, depending on their surface morphology, size, shape and orientation. It largely affects the lithium distribution and the propensity of lithium plating," said Lu. “Assisted by a pioneering 3D battery model, we can capture when and where lithium plating initiates and how fast it grows. This is a significant breakthrough that could have a major impact on the future of electric vehicles.”
The study provides new insights into developing advanced fast-charging protocols by improving the understanding of the physical processes of lithium redistribution within graphite particles during fast charging. This knowledge could lead to an efficient charging process while minimizing the risk of lithium plating.
In addition to faster charging times, the study also found that refining the microstructure of the graphite electrode can improve the battery's energy density. This means that electric cars could travel further on a single charge.
These findings are a major breakthrough in the development of electric vehicle batteries. They could lead to faster-charging, longer-lasting and safer electric cars, which would make them a more attractive option for consumers.
This story is adapted from material from Queen Mary University of London, with editorial changes made by Materials Today. The views expressed in this article do not necessarily represent those of Elsevier. Link to original source.