Researchers from University of Tokyo have discovered the structure and transport properties of the "intermediate state" in lithium-ion batteries, which is the key to understanding the mechanisms of charge and discharge in rechargeable batteries. This finding may help accelerate battery reaction speed and significantly shorten battery charging time.

The group found a striped pattern of layers of densely and loosely packed electrons. Lithium ions distribute themselves so as not to disturb this striped pattern. Moreover, both lithium ions and electrons move faster in the intermediate state, contributing significantly to accelerating lithium-ion battery charge and discharge reactions. Researchers hope to develop rechargeable batteries with quick charging time by applying this finding to the design of materials and conditions that are optimum for creating a stable intermediate state.