Lithium-ion Batteries: Present and Future

In the past decades, lithium-ion batteries have been successfully developed to power diverse mobile electronic devices. Currently, the uses of lithium-ion batteries have been expanding toward large-scale applications such as electric vehicles and utility grids. From a technological standpoint, these larger-scale applications impose more challenging standards on the energy and the power densities, safety, and the lifetime. A variety of efforts have been dedicated to meet these requirements: Nanostructured electrodes for stress relaxation and enhanced power performance, as well as highly functional separators for high-power capability and reliable safety, are good examples along this line. Completely new concepts, such as metal‐air batteries, have also been examined as breakthrough technology.