Researchers at Brown University and Idaho National Laboratory say the secret to battery longevity can be found in how things get clean — specifically soap. In hand washing, soap forms structures called micelles that trap and remove grease, dirt, and germs when used with water. Soap acts as a bridge between the water and the contaminant, binding them and wrapping them into those micelle structures. Their work is published in a new study in Nature Materials.
A similar process applies to longer-lasting lithium batteries. A new type of electrolyte called a localized high-concentration electrolyte may be the missing piece to opening the door to an emerging technology sector.
According to Yue Qi, a professor at Brown’s School of Engineering. “…materials inside of traditional batteries need to be replaced to make long-life batteries that store more energy a reality — think batteries that can power a phone for a week or more or electric vehicles
that go for 500 miles.”
Batteries made from lithium have a much higher energy storage capacity than today’s lithium-ion batteries. The challenge is traditional electrolytes allow an electrical charge to pass between a battery’s two terminals, sparking the electrochemical reaction necessary to convert stored chemical energy to electric energy. Conventional electrolytes for lithium-ion are made of low-concentration salt dissolved in a liquid solvent and don’t do this well in metal-based batteries.
Scientists at Idaho National engineered localized high-concentration electrolytes. Laboratory and Pacific Northwest National Laboratory to address this challenge. The electrolyte flows better to maintain the battery’s power by mixing high concentrations of salt in a solvent with a diluent. The key is micelle-like structures that form within this electrolyte — like they do with soap.
Soap or surfactant binds the diluent and the salt, wrapping itself around the higher concentration salt in the center of the micelle. Researchers could break down the ratios and concentrations needed to bring about the optimal reactions for the batteries.