Electric vehicles (EVs) hold great promise for our energy-efficient, sustainable future but among their limitations is the lack of a long-lasting, high energy density battery that reduces the need to fuel up on long-haul trips. The same is true for houses during blackouts and power grid failures—small, efficient batteries able to power a home for more than one night without electricity don’t yet exist. Next-generation lithium batteries that offer lightweight, long-lasting, and low-cost energy storage could revolutionize the industry but there have been a host of challenges that have prevented successful commercialization.