Delft invention could double the lifespan of lithium-ion batteries

Researchers at the Delft University of Technology (TU Delft) believe they’ve found a way to double the lifespan of lithium-ion batteries - the most commonly used battery in mobile phones and electric cars. The Delft researchers found a more efficient formula for the electrolyte - the protective layer between the anode and cathode, the Volkskrant reports.

The protective layer is an essential part of the battery. It stops electrons, but allows lithium ions - which transport the energy in the battery - to pass through. Constant charging and recharging damage the layer, which then has to form again. That consumes lithium ions, which then can’t be used in charging and discharging, causing the battery’s capacity to decrease.

The Delft researchers added five salts to the existing cocktail in that protective layer. The salts resulted in a more controlled formation of the layer. As a result, fewer lithium ions are lost when the protective layer reforms, making the battery last up to two times longer.

“Whether a factor of two is feasible in practice, I don’t know. But even 20 percent more is already an important step forward,” said Marnix Wagemaker, a professor of electrical energy storage at TU Delft and lead author of this study, which was published in Nature Communications.

According to Wagemaker, the discovery was a bit of a coincidence. “But there were targeted choices behind it,” he said to the Volkskrant. The researchers used commercially available lithium-ion batteries in their study. “Although I am not a battery manufacturer, I think our invention can be applied directly and fairly easily in existing production techniques,” said Wagemaker.

Professor of material chemistry Moniek Tromp of the University of Groningen called the Delft discovery an exciting development. ‘It is a first step to better understanding how this layer forms and develops, and that offers opportunities to make the battery more stable in the future,” she told the newspaper.

According to Tromp, in the worldwide search for the ideal electrolyte composition, researchers often “blindly” try out combinations because little is known about the precise composition, formation, and functioning of the protective layer. “This study now offers more insights into this,” said the professor.