A carbonyl-based conjugated polymer as an organic cathode for sustainable lithium-ion batteries

Abstract

Lithium-ion batteries (LIBs) have been considered the most promising energy storage devices for various applications in portable electronics, electric transportations, and grid-scale storage systems. However, the inorganic cathode materials used in commercial LIBs cannot meet the urge to design high-performance sustainable electrode materials for next-generation rechargeable batteries. Organic electrode materials (OEMs) featuring low-cost, lightweight, and diverse chemical structures not only offer high theoretical capacity and stable cycling performance but also are safe for the environment. In this work, we designed and tested a carbonyl-based polyimide as an organic cathode in LIBs. The electrochemical performance of the polymer cathode has been investigated by several techniques such as cyclic voltammetry and galvanostatic charge-discharge tests. The carbonyl groups on the naphthalene backbone undergo a multi-electron reversible redox reaction delivering high redox potential, long cycling capability, and robust reaction kinetics. Post-cycling characterizations demonstrated high stability in the morphology and chemical structure of the electrodes upon cycling. Our results suggest that developing redox-active polymers with extended conjugation structures can be a practical approach to achieving sustainability for rechargeable batteries.