Scientists are developing advances in battery technologies to meet increasing energy storage needs for the electric power grid and electric vehicle use. Efforts are underway to replace components of widely used lithium-ion batteries with more cost-effective, sustainable, and safe materials. Advances in longer duration storage technologies, such as flow batteries, also have the potential to help integrate renewable energy sources for electricity generation and reduce reliance on fossil fuels. This Science & Tech Spotlight discusses current research on advanced batteries and the challenges delaying their large-scale commercialization.