Researchers at the University of Hong Kong, led by Professor Dong-Myeong Shin, have developed a new generation of lithium metal batteries that are not only longer-lasting but also safer, even under extreme temperatures.
The core of this lithium metal battery is the development of microcrack-free polymer electrolytes. Current batteries, which use liquid electrolytes and carbon-based anodes, face safety problems, short lifespans, and insufficient power density. The demand for reliable and sturdy batteries has led researchers to explore solid electrolytes compatible with lithium metal anodes, renowned for their high theoretical specific power capacity.
Professor Shin’s team achieved this breakthrough by synthesizing microcrack-free polymer electrolytes via a straightforward one-step click reaction. These electrolytes exhibit remarkable properties, including resistance to dendrite growth, non-flammability, a high electrochemical stability window up to 5 V, and an ionic conductivity of 3.1 × 10?5 S cm?1 at high temperatures.
According to a release by the University of Hong Kong, these improvements are due to the tethered borate anions within the microcrack-free membranes, which accelerate selective transport of Li+ ions and suppress dendrite formation. These anionic network polymer membranes enable lithium metal batteries to function as safe, long-cycling energy storage devices at high temperatures, maintaining 92.7% capacity retention and averaging 99.867% coulombic efficiency over 450 cycles at 100°C.
In contrast, conventional liquid electrolyte lithium metal batteries typically last fewer than 10 cycles at such high temperatures.
“We believe this innovation opens doors for new battery chemistries that can revolutionize rechargeable batteries for high-temperature applications, emphasizing safety and longevity,” said Dr. Jingyi Gao, the first author of the paper.
Additionally, Professor Shin highlighted the potential for these microcrack-free electrolyte membranes to enable fast charging due to low overpotential. “This capability could allow electric vehicles to recharge in the time it takes to drink a cup of coffee, marking a significant advancement towards a clean energy future,” he added.
The findings of the study were published in the journal Advanced Science.
