Performance metrics and mechanistic considerations for the development of 3D batteries

There is an urgent need for improved energy storage devices to enable advances in markets ranging from small-scale applications (such as portable electronic devices) to large-scale energy storage for transportation and electric-grid energy. Next-generation batteries must be characterized by high energy density, high power density, fast charging capabilities, operation over a wide temperature range and safety. To achieve such ambitious performance metrics, creative solutions that synergistically combine state-of-the-art material systems with advanced architectures must be developed. The development of 3D batteries is a promising solution for achieving these targets. However, considerable challenges remain related to integrating the various components of a battery into an architecture that is truly 3D. In this Review, we describe the status of 3D batteries, highlight key advances in terms of mechanistic insights and relevant performance descriptors, and suggest future steps for translating current concepts into commercially relevant solutions.