Structural Isomers: Small Change with Big Difference in Anion Storage

The effect of small changes in isomers on electrochemical performance have not been focused in batteries and two isomers are reported for Zn-ion batteries here. The isomer tetrathiafulvalene (TTF) could store two monovalent anions reversibly, showing remarkable performance that outperformed most of the reported organic electrode materials for zinc-ion batteries. The isomer tetrathianaphthalene (TTN) could only reversibly store one monovalent anion and upon further oxidation, it would undergo an irreversible solid-state molecular rearrangement to TTF.