Ion–polyether coordination complexes: crystalline ionic conductors for clean energy storage

Abstract

Ion–polyether complexes are the solid state analogues of crown ether and cryptand complexes. They represent a fascinating class of coordination compounds in their own right, with the ability to support ionic conductivity and the potential to be used as electrolytes in all-solid-state rechargeable lithium batteries. Here the recent discovery of ionic conductivity in crystalline ion–polyether complexes, when for 30 years such materials were considered to be insulators, is described, along with their closely related structural chemistry.