Poly(1,4-anthraquinone) as an Organic Electrode Material: Interplay of the Electronic and Structural Properties due to the Unusual Lone-Pair-π Conjugation

Abstract

Organic semiconductors with lone-pair-π conjugation offer a promising yet enigmatic route to advanced electrode materials for rechargeable batteries. This study employs molecular dynamics and electronic structure simulations to explore the relationship between structural and electronic properties of poly(1,4-anthraquinone) (P14AQ), which exhibits this unusual conjugation mechanism. The results indicate that P14AQ is resistant to structural disorder, always maintaining an appreciable conjugation within its polymer chain. It also shows restrained volume changes when lithium, magnesium, and hydrogen cations are intercalated during battery cycling. These results rationalize the reported good performance of P14AQ as an organic cathode material. The analysis offers fundamental insights into the role of lone-pair-π conjugation in organic semiconductors and paves the way for developing new materials based on this unorthodox design paradigm.