Abstract
Redox flow batteries are electrochemical energy storage devices characterized by its ability to dissociate their energy from their power. This property gives these systems a great adaptability facilitating their scalability to develop mass storage devices. These batteries, although having interesting properties, are still limited by their cost and the low energy densities they develop.In this thesis, several axes have been considered to improve their performance. Carbonaceous materials are widely used in these systems (electrodes, semi-solid configuration). Surface modifications allow to adjust the interface properties between the carbonaceous materials and the electrolyte. In a first study, a modification method based on the Diels-Alder reaction is developed. The objective is to propose a simple and adaptable modification protocol for different chemical moieties. In a second study, carbon electrode modification by chemical reduction of diazonium cations is performed with hydrophobic molecules. The objective is to prevent the access of water molecules to the electrode surface to inhibit the electrochemical reduction of water. In a third part, a battery configuration using two different pH in the positive and negative compartment is studied. This configuration should allow a better versatility in the choice of redox couples as well as the development of systems with higher cell voltages.