Chemical lithiation reveals the structures of conjugated tetralithium dicarboxylates

Abstract

Conjugated metal dicarboxylates show promising properties as rechargeable battery anode materials; however, the structures of reduced (discharged) phases remain elusive. Here, we use chemical lithiation to solve the crystal structures of two tetralithium dicarboxylates for the first time. The structures are identical to those formed by electrochemical lithiation in coin cells. Solid-state NMR and DFT calculations show that there is complete mixing of Li cations upon intercalation into the structure.