As environmental awareness grows and fuel costs rise, electric vehicles (EVs) are becoming increasingly popular. However, the performance of lithium-ion batteries (LIBs) in EVs significantly declines in colder climates, particularly in northern China, posing a major challenge to their widespread adoption.
Recently, Zhiru Liu, a 2024 undergraduate in Mechanical Engineering at the University of Nottingham Ningbo China (UNNC), made a breakthrough in this field. As the first author, she published her research in the Journal of Energy Storage, a Q1 journal in the Chinese Academy of Sciences. Her work introduces a pre-heating strategy for LIBs using graphene-enhanced microencapsulated phase change materials (G-MEPCMs), which significantly reduces the pre-heating time of LIBs in cold conditions. This innovation offers a potential solution to improve the performance and efficiency of EVs in low temperatures, enhancing user experience and paving the way for broader adoption in colder regions.
Hailing from Harbin, Zhiru is well-acquainted with the harsh winters there. "In northeast China, winter temperatures often drop to -20 to -30°C, while LIBs perform best at around 40°C. Without an efficient pre-heating solution, batteries take a long time to reach their optimal temperature," she explained.
Under the guidance of her supervisor, Professor Yong Ren, Professor in Mechanical Engineering, Zhiru decided to focus her thesis on "heat collection". After a thorough literature review, she turned to phase change materials - eco-friendly materials that change state while releasing latent heat without altering temperature. Despite various challenges, she sought advice from doctoral students and her supervisor, continuously refined her experiments, and ultimately succeeded in using G-MEPCMs to improve pre-heating efficiency.
"UNNC's curriculum emphasises the integration of practice and industry. Students are encouraged to focus on theoretical research and solve practical engineering problems," noted Professor Ren.
Hands-on projects have been a consistent theme throughout Zhiru's undergraduate studies. In her second year, she designed a spring-powered car driven by elastic potential energy. The following year, she and her team completed a challenging steamship project.
"Textbook models are all so neat and regular, but in reality, parts and components come in all sorts of weird shapes and sizes," she said with a laugh. "The gap between theory and reality? It's like the difference between 1 and 100. Scientific research isn't just about deriving formulas. It's about trial and error, getting my hands dirty, and turning ideas into real-world solutions."
"UNNC's research resources have been invaluable to my work," Zhiru said. "The guidance from my professor, the laboratory facilities, and the insights shared by doctoral students all contributed to my breakthroughs."
With a passion for new energy technologies, Zhiru is now pursuing further studies in Energy Technologies at the University of Cambridge, where she aims to explore more possibilities for the application of new energy.
Published on 25 January 2025