Organic batteries based on just redox polymers

Redox-active polymers have gained interest as environmentally friendly alternative to inorganic materials in applications such as electrodes in lithium-ion batteries. All-polymer batteries were first disregarded with respect to other technologies due to their lower energy densities. However, the inherent benefits of redox polymers such as processability, flexibility, recyclability, high-rate performance and the perspective to prepare batteries from renewable resources has re-ignited interest in recent years. This review article aims to provide a comprehensive overview on the state of the art of batteries in which the active material is a redox polymer; including "static" all-polymer batteries and polymer-air batteries but also "flowing" systems such as polymer based redox-flow batteries (pRFB). First, a succinct overview of the recent developments of redox polymers will be given, summarizing the historic trends and developments. Second, an exhaustive discussion of the various battery prototypes will be provided, considering all steps in the development of organic batteries just based in redox polymers. Finally, future perspectives on all-polymer batteries will be discussed, summarizing the major challenges that are still to be overcome to unlock their commercial implementation.