Hong Kong researchers develop better batteries
A team from the University of Hong Kong's Department of Mechanical Engineering, led by Dr Dong-Myeong Shin, has made significant progress in the technology required to make better batteries. Their research, published in the journal Advanced Science with Dr Jingyi Gao as the first author, focuses on creating a new generation of lithium metal batteries that offer enhanced safety and longevity, particularly in high-temperature environments.
Traditional batteries, which use liquid electrolytes and carbon-based anodes, often face challenges such as safety risks, limited lifespan, and insufficient power density at elevated temperatures.
The team's innovation lies in the development of polymer electrolytes without the microcracks that can lead to reduced performance issues. These electrolytes are synthesised through a simple one-step click reaction. One key property is that they resist dendrite growth . Lithium dendrites are branching structures that can form on the surface of the lithium anode during charging, potentially causing short circuits and battery failure. The electrolytes are also non-flammable, maintain high electrochemical stability up to 5 volts, and demonstrate impressive ionic conductivity at high temperatures.
The use of the new polymer electrolytes results in batteries that can retain 92.7% of their capacity and achieve an average coulombic efficiency of 99.867% over 450 cycles at 100 °C. By comparison, conventional liquid electrolyte lithium metal batteries typically last fewer than 10 cycles under similar conditions.
This development could not only lead to safer and more durable batteries for high-temperature applications but also prepare the way for rapid charging capabilities, potentially transforming electric vehicle recharging times.