Redox-Active Polymers for Batteries

Abstract

Electrochemical energy storage is critical in accelerating the transition to a low-carbon future for grid storage and transportation. While most research on electrochemical energy storage devices has focused on improving performance (energy density and power density), little attention has been paid to designing devices that can be recycled at a low cost with minimal environmental impact. Renewable organic batteries are an excellent option for storing sustainably generated energy and can help to phase out current carbon-based energy production. Over the past 80 years, several strategies have been developed that use organic redox materials as active elements in batteries. Polymers have piqued the interest of numerous research groups due to their (1) fast redox chemistry in comparison to conventional active materials, (2) simple syntheses, and (3) tuneable solubility, all of which are desirable properties for a variety of electronic devices. Notably, the beginning of redox-active polymers is linked to the discovery of conductive polymers by Heeger, Mac Diarmid, and Shirakawa in 1977. RAPs have progressed from an intriguing phenomenon to a family of promising, tailor-made battery materials that have also reached commercialization. Redox-active Polymers (RAPs) are macromolecules with chemical groups that can reversibly modify their electrochemical state by losing (oxidation) or gaining (reduction). The conventional polymerization stages of initiation, propagation, and termination are used in the creation of redox polymers. This chapter focuses on redox-active polymers, their classification, the concept of electron transfer in RAPs, and redox-active polymer-based electrochemical energy storage devices and their application in energy storage devices i.e., batteries.