Modern lithium batteries for electric vehicles, as CleanTechnica explains, currently use a low-current pre-charge method, but research from the University of Washington and Stanford University, in collaboration with Toyota, has discovered a simple way to increase the effective life of a traction battery by 50. %.
Nowadays, it is customary to charge a fresh battery with a weak current for ten hours to promote the formation of a semi-solid-state layer on the negative electrode, which protects the lithium remaining in the electrode from unwanted chemical reactions. With slow primary charging and formation of this layer, up to 9% of lithium is lost, and the higher the current, the more lithium ions are lost. Meanwhile, American researchers, after experiments with almost two hundred lithium-ion cells of the stack type, came to the conclusion that short-term charging at increased current can increase the further operating life of the battery by an average of 50%, and for the most successful examples of batteries the increase reached a decent 70%.
The disadvantage of this method, which involves switching to 20-minute charging at high currents, is the high loss of lithium ions, which can reach 30%. However, battery life is becoming more important as electric vehicles become more common, so battery manufacturers must decide what is most important to them. More durable batteries, on the one hand, will make electric vehicles more attractive in the secondary market, especially considering the high share of the battery cost in the price of the car.
Additionally, if the same battery can survive multiple electric vehicles, there will be more market adoption of the swappable traction battery concept. Now such stations are distributed in China and beyond by Nio. Replacing the traction battery at an automated station takes no more than five minutes, and the driver does not even have to get out of the car. Nio’s electric car can be purchased without a battery and then leased for a set monthly fee. If you need to cover a long distance in a short period of time, you can rent a high-capacity battery. If the standardized traction battery remains the property of the car owner after changing electric vehicles, this will reduce the costs of such an exchange.