The distribution of lithium concentration is indicated by colors during the charging process of a graphite negative electrode. Credit: Xuekun Lu et al/Nature Communications
Key points:
- Researchers discovered a way to prevent lithium plating in electric vehicle batteries.
- Lithium plating occurs when ions build up on the surface of the battery's negative electrode, ultimately damaging the battery and becoming a safety risk.
- Optimizing the microstructure of the graphite negative electrode is key to suppressing lithium plating.
Researchers have found a way to prevent lithium plating in electric vehicle batteries, which could lead to faster charging times.
Lithium plating is a phenomenon that can occur in lithium-ion batteries during fast charging when lithium ions build up on the surface of the battery's negative electrode instead of intercalating into 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.
According to the study, published in Nature Communications, lithium plating can be significantly mitigated by optimizing the microstructure of the graphite negative electrode. The graphite negative electrode is made up of randomly distributed tiny particles, and fine-tuning the particle and electrode morphology for a homogeneous reaction activity and reduced local lithium saturation is the key to suppress lithium plating and improve 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 study author Xuekun Lu, professor at Queen Mary University of London. “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.”
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, allowing cars to travel further on single charge.