Water's dual role in lithium-ion batteries: lubricant and liability

At the University of Santiago de Compostela, researchers have uncovered a paradox at the heart of lithium-ion battery chemistry: water, long treated as an unwelcome contaminant, can at precise concentrations act as a lubricant for lithium ions, improving the very transport that makes batteries useful. Yet the same molecule, in excess, becomes a destructive force — splitting under voltage into gases that erode electrodes and shorten battery life. The finding invites a more mature relationship with complexity, suggesting that the future of energy storage may hinge not on eliminating impurities,