Solid-state chemistry of lithium power sources†

This article describes the solid-state chemistry of intercalation compounds that underpins a revolutionary new rechargeable lithium battery which has recently achieved phenomenal commercial success. The battery can store more than twice the energy compared with conventional alternatives of the same size and mass and holds the key to the future improvement of consumer electronic products (e.g. mobile telephones), electric vehicles and implantable medical devices (e.g. the artificial heart). Attention is focused on those lithium intercalation compounds that are useful as positive electrodes in rechargeable lithium batteries. The basic operation of the cell is summarised briefly and the structure/property relationships are developed that are important for the solid-state chemist when attempting to design and synthesise new lithium intercalation compounds capable of operating as positive electrodes. Finally, the structure, electronic structure and intercalation chemistry of several important positive intercalation electrodes are discussed including some which show considerable promise for applications in future generations of rechargeable lithium batteries.