For decades, lithium-ion batteries have powered our phones, laptops, and electric vehicles. But lithium's limited supply and volatile price have led the industry to seek more resilient alternatives. A sodium-ion battery works much like a lithium-ion one: It stores and releases energy by shuttling ions between two electrodes. But unlike lithium, a somewhat rare element...

This is today's edition ofThe Download,our weekday newsletter that provides a daily dose of what's going on in the world of technology. Sodium-ion batteries are making their way into cars-and the grid For decades, lithium-ion batteries have powered our phones, laptops, and electric vehicles. But lithium's limited supply and volatile price have led the industry...

This is today's edition ofThe Download,our weekday newsletter that provides a daily dose of what's going on in the world of technology. How next-generation nuclear reactors break out of the 20th-century blueprint The popularity of commercial nuclear reactors has surged in recent years as worries about climate change and energy independence drowned out concerns about...