The structure-electrochemical property relationship of quinone electrodes for lithium-ion batteries.

Quinones are promising electrode materials for lithium-ion batteries (LIBs), but their structure-electrochemical property relationship remains unclear. The aim of this study is to unravel the structural influence on the electrochemical properties of different quinones in LIBs. Through density functional theory calculations, redox potentials of 20 parent quinone isomers were examined, which revealed an increasing order of redox potentials as para-quinones < discrete-quinones < ortho-quinones. Two new methods were introduced to calculate and design organic electrode materials rationally. One is the vertical electron affinity in consideration of solvation effect, which was used to estimate the number of electron accommodation for quinones during lithiation. The other is a new index denoted as ΔA2Li used in para- and ortho-quinones, which was introduced to reveal the relationship between aromaticity and redox potential, establishing the theoretical basis for the design of analogous high-voltage organic electrode materials of LIBs.