When using electric vehicles or smartphones, users often experience inconvenience from long charging times and gradually shortening battery life. To increase charging speed and extend usage time, next-generation batteries with high energy density are essential. However, fast charging has had limitations because deposits can accumulate inside batteries, degrading performance and even increasing the risk of fire. A Korean research team has developed a new foundational technology to address this problem by creating a "highway" through which lithium ions can move rapidly inside a battery.