Scientists develop new batteries that maintain efficiency even at 100°C
Researchers have developed a new generation of lithium metal batteries that can withstand high temperatures and offer an extended lifespan and increased safety. The innovation focuses on microcrack-free polymer electrolytes, a significant departure from current batteries that use liquid electrolytes and carbonaceous anodes. The development of these new batteries was led by Professor Dong-Myeong Shin of the Department of Mechanical Engineering at the University of Hong Kong (HKU).
Overcoming drawbacks of existing batteries
Existing batteries have several drawbacks, including safety concerns, comparitively shorter lifespan, and inadequate power density. There is a growing demand for batteries capable of operating at extreme temperatures to meet industrial requirements and other specific tasks. This need has led researchers like Shin to explore solid electrolytes compatible with lithium metal anodes, known for their high theoretical specific power capacity.
Microcrack-free polymer electrolytes: The game changer?
The microcrack-free polymer electrolytes made by Shin's team are synthesized through a straightforward one-step click reaction. These electrolytes exhibit notable attributes including resistance to dendrite growth and non-flammability. They demonstrate a robust electrochemical stability window up to 5V, and good ionic conductivity at high temperatures. These improvements secure borate anions within the microcrack-free membranes, facilitating accelerated selective transport of Li+ ions and suppress dendrite formation.
High-temperature performance and potential for fast charging
The anionic network polymer membranes enable lithium metal batteries to function as safe and long-cycling energy storage units at high temperatures. They maintain 92.7% capacity retention and average 99.8% coulombic efficiency over 450 cycles at 100°C. In contrast, the cycling performance of traditional liquid electrolytes Li metal batteries is less than 10 cycles at such high temperatures. Apart from high-temperature applications, the microcrack-free electrolyte membranes also have the potential to allow for faster charging due to low overpotential.
