Energy storage is a critical hurdle to the success of many clean energy technologies. Batteries with high energy density, good safety, and low cost can enable more effi cient vehicles with electrifi ed drive trains, such as hybrid electric vehicles, electric vehicles, and plug-in hybrid electric vehicles. They can also provide energy storage for intermittent energy sources, such as wind and solar. Today, and for the foreseeable future, rechargeable lithium batteries deliver the highest energy per unit weight or volume at reasonable cost. Many of the important properties of battery materials can be calculated with fi rst-principles methods, making lithium batteries fertile ground for computational materials design. In this article, we review the successes and opportunities in using fi rst-principles computations in the battery fi eld. We also highlight some technical challenges facing the accurate modeling of battery materials.