Currently, researchers are working to improve battery technology in a variety of ways, not the least of which is addressing flammability issues. US scientists have recently developed a new electrolyte formula that could solve this problem in a very promising way, relying on extra salt content to avoid problematic chemical reactions.
It’s no secret that the lithium-ion batteries in our phones, laptops and electric cars present some fire risk because they generate heat as they work. We've seen a number of interesting ways to manage this risk, including integrated flame retardants, warning systems that alert users to system overheating, and kill switches that shut down devices before overheating occurs.
In fact, many promising solutions focus on flammable liquid electrolytes that pass electrical current between the two electrodes of a battery. Defects and elevated temperatures can cause these electrolytes to expand and/or ignite, causing a smartphone or electric car to catch fire. This process usually begins around 60°C, when the solvent in the electrolyte begins to evaporate, changing from a liquid to a gas.
Rachel ZHuang, a graduate student at Stanford University and the first author of the new study, said, "One of the biggest challenges facing the battery industry is safety, so we spent a lot of effort to create a safe battery electrolyte. ”
It is reported that the research team has developed a battery that can withstand high temperatures without catching fire. The new polymer electrolyte contains a large amount of lithium salt, called LiFSI, which accounts for 63% of its total weight. Counterintuitively, this substance pairs with flammable solvent molecules, and the two form a biological relationship that benefits battery safety and performance.
Solvent molecules enable the electrolyte to conduct ions and behave at the same level as traditional electrolytes, while high concentrations of salt immobilize these molecules, preventing them from evaporating and thus catching fire. The team's non-flammable electrolyte was tested in lithium-ion batteries, which operate safely from room temperature to 100°C.
The results of this research have been recently published in the magazine "Materials". Zhenan Bao, a professor at Stanford University, said, "This new discovery points to a new idea for the design of polymer-based electrolytes. This electrolyte is very important for the development of high energy density and safe future batteries."
The A key feature of the team's new electrolyte is that it has a viscous form similar to traditional electrolytes, meaning it can be integrated with existing battery components, unlike other experimental non-flammable electrolytes. The team sees particular potential in electric vehicle applications, where batteries can be packed more closely together without the risk of overheating. This would equate to increased energy density and range.
"This very exciting new battery electrolyte is compatible with existing lithium-ion battery technology and will have a major impact on consumer electronics and power transmission," the researchers added.