In the relentless pursuit of safer, more efficient energy storage, a team of researchers from the Hubei Research Center for New Energy & Intelligent Connected Vehicle at Wuhan University of Technology has developed an innovative strategy to mitigate one of the most daunting challenges in lithium-ion battery technology: thermal runaway. This phenomenon, where a battery overheats and can potentially lead to fires or explosions, has long been a thorn in the side of the energy sector, limiting the widespread adoption of battery energy storage systems.
The lead author of the study, Tianqi Yang, and his team have integrated liquid cooling with a novel composite phase change material (CPCM) based on sodium acetate trihydrate (SAT) to create a robust thermal runaway protection system for prismatic lithium-ion battery modules. The results, published in the journal ‘Batteries’ (translated from the Chinese title ‘电池’), are nothing short of groundbreaking.
At the heart of this innovation lies the use of SAT, a substance that undergoes a phase change, absorbing and releasing heat in the process. However, pure SAT has its limitations. “Pure SAT exhibits poor latent heat performance due to its low thermal conductivity,” explains Yang. To overcome this, the researchers incorporated expanded graphite (EG) into the SAT, significantly enhancing its thermal conductivity and overall latent heat performance.
The results speak for themselves. The SAT-EG composite demonstrated more than six times the effectiveness in delaying thermal runaway propagation compared to traditional paraffin-expanded graphite (PA-EG). When combined with liquid cooling, the protection effect is further amplified, preventing thermal runaway from being triggered when the initial abnormal heat generation rate is relatively low. Even if a battery experiences thermal runaway, its propagation can be prevented with a SAT-EG thickness exceeding 12 mm.
The implications for the energy sector are profound. As the demand for energy storage solutions continues to grow, driven by the increasing adoption of renewable energy sources and electric vehicles, the need for safe, reliable battery technology has never been greater. This innovative thermal runaway protection strategy could pave the way for more robust, safer battery modules, enhancing the overall safety and efficiency of energy storage systems.
Moreover, the study’s findings on the influence of ambient temperature and different liquid cooling layouts provide valuable insights for optimizing battery module design. The combined bottom and side cooling scheme, for instance, exhibited superior performance, offering a potential blueprint for future battery module designs.
As the energy sector continues to evolve, innovations like this one will be crucial in shaping the future of energy storage. By addressing the challenge of thermal runaway head-on, Yang and his team have taken a significant step towards a safer, more sustainable energy future. The research, published in ‘Batteries’, offers a glimpse into the potential of phase change materials in enhancing battery safety, opening up new avenues for exploration and development in the field.