This thesis focuses on increasing the storage capacity of organic redox flow batteries using redox polymer-based boosters. To this end, the student will work in a motivating and international environment on the synthesis of redox polymers and their electrochemical study. The student will also participate in the integration of the developed boosters into demonstrators. This work will be carried out at the interface between the fundamental and applied research laboratories of the CEA in Grenoble, and the student will have access to both laboratories and their characterization facilities. This project will be developed in partnership with laboratories at the University of Rennes and Amiens, and the student will be able to exchange ideas with other students working on the project.