Redox polymers for capacitive energy storage applications

Abstract Polymer-based batteries have gained popularity in recent years. The wide structural diversity of organic materials allows for a variety of redox-active polymers with different possible structures that can be used as active materials. Redox polymers are the group of those polymers that can be reversibly reduced or oxidized. Overall, polymer-based batteries have several distinct advantages, such as the ability to achieve high power densities and to fabricate devices with flexible or even bendable electrodes. The materials used do not include (heavy) metals, allowing for the fabrication of a sustainable battery. Here, we review the π‐conjugated polymers with definite isolated redox centers and non‐conjugated polymers with defined redox moieties. To summarize, polymer-based batteries are a highly innovative battery type that will enable new and interesting applications for energy storage devices.