Fused Heteroaromatic Organic Compounds for High‐Power Electrodes of Rechargeable Lithium Batteries

TLDR

Organic redox compounds are emerging electrode materials for rechargeable lithium batteries, but their electrically insulating nature hampers efficient charge transport within the electroactive bulk. The study reports a molecular‑level engineering strategy to create high‑power organic electrode materials with multi‑electron reactions, avoiding the common nanocomposite approach. The authors combine morphological observation, electrochemical impedance characterization, and theoretical modeling to elucidate how heteroaromatic building blocks enhance performance. Systematic comparison of anthraquinone analogues with fused heteroaromatic structures shows that incorporating heteroaromatics improves specific gravimetric capacity, working potential, rate capability, and cyclability; notably, benzofuro[5,6‑b]furan‑4,8‑dione delivers a reversible capacity of 181 mAh g⁻¹ at 100 C (29.8 kW kg⁻¹), demonstrating a general design route for high‑rate organic electrodes via rational heteroaromatic functionalization.

Abstract

Abstract Organic redox compounds are emerging electrode materials for rechargeable lithium batteries. However, their electrically insulating nature plagues efficient charge transport within the electroactive bulk. Alternative to the popular solution of elaborating nanocomposite materials, herein we report on a molecular‐level engineering strategy towards high‐power organic electrode materials with multi‐electron reactions. Systematic comparisons of anthraquinone analogues incorporating fused heteroaromatic structures as cathode materials in rechargeable lithium batteries reveal that the judicious incorporation of heteroaromatics improves the cell performance in terms of specific gravimetric capacity, working potential, rate capability, and cyclability. Combination studies with morphological observation, electrochemical impedance characterization, and theoretical modeling provide insight into the advantage of heteroaromatic building blocks. In particular, benzofuro[5,6‐ b ]furan‐4,8‐dione ( BFFD ) bearing furan moeities shows a reversible capacity of 181 mAh g −1 when charged/discharged at 100C, corresponding to a power density of 29.8 kW kg −1 . These results have pointed to a general design route of high‐rate organic electrode materials by rational functionalization of redox compounds with appropriate heteroaromatic units as versatile structural tools.