Reversible halogen cathodes for high energy lithium batteries

Lithium halides are attractive as conversion cathodes for potentially high energy density lithium batteries but have not been explored in depth in aprotic electrolytes. In this issue of Joule, Wang and co-workers describe a set of design principles of the electrode and electrolyte to enable the reversibility of lithium halide/graphite mixture cathodes for lithium batteries. By establishing a general rule of liquefaction of the (inter)halogen and rationally designing the electrolyte, they introduced the interhalogen-graphite intercalation compounds as a new family of conversion cathodes for high-energy rechargeable batteries.