Researchers at Kjeller Institute in Norway have discovered a breakthrough in silicon battery development that could increase capacity by up to five times. Pure silicon battery technology has had issues with longevity over the years, but researchers have discovered that mixing silicon with an unstated material fixes the longevity problems. The new mix called SiliconX shows the potential to increase EV range to 621 miles and cellphone battery life to several days before a charge is necessary. For several years, researchers have investigated the possibilities of using silicon in batteries, instead of graphite used today. In theory, pure silicon has ten times higher capacity than graphite, but also loses capacity faster. Now, however, scientists have come up with a silicon mixture that keeps the capacity stable over time, even though the capacity becomes somewhat lower than with pure silicon. However, batteries with the new silicon mixture will have three to five times higher capacity than today's batteries, according to researchers.