Domain, Specialties : CHEMISTRY
Electrochemistry, Materials (carbon, thin films), Microscopy, and Spectroscopy
Research Unit : NIMBE/LICSEN
Summary
This internship focuses on a crucial issue in the field of energy storage: increasing the energy density of supercapacitors in aqueous media. The long-term goal is to improve the performance of these devices by modifying the surface properties of the carbon material using functionalized thin films. Additionally, using the BALM microscopy technique, we will study carbon degradation, the catalytic properties of carbon materials regarding water oxidation and reduction, and the morphology of electrodeposited thin films. These studies should help highlight the influence of thin films on carbon passivation and the complete suppression of its catalytic properties.
Full description
New intermittent energy sources, where production and consumption are not always synchronized, require energy storage devices. This internship focuses on the development of supercapacitors, which are energy storage devices that use carbon electrodes and electrolytes (organic, aqueous, or ionic liquid) to store electrical energy. Unlike batteries, they do not rely on chemical reactions but on the separation of electric charges. For environmental and safety reasons, the electrolyte used will be aqueous. However, this brings challenges such as water decomposition at 1.23V and carbon corrosion during the contact between the electrode and the electrolyte. The goal is to increase the voltage range by using high surface area carbon as the electrode and by modifying the active material/electrolyte interface through the creation of a thin film, with controlled thickness, ionic conduction, and hydrophobic properties. This new approach is inspired by the Solid-Electrolyte Interphase (SEI) layer. Electrografting has proven to be a powerful method for surface modification and organic grafting. It allows the easy formation of thin organic films covalently bonded to conductive substrates (carbon or metals), semiconductors, or even dielectrics. The purpose of this internship is to understand carbon degradation, particularly carbon oxidation, using high-contrast optical microscopy (BALM). Simultaneously, the fabrication of thin films composed of diazonium salts on porous carbon materials will be studied using spectroelectrochemistry. The student will investigate the catalytic properties of functionalized carbon materials concerning water reduction and oxidation. This project contributes to the development of an environmentally friendly and potentially economically competitive energy storage source to meet our future energy needs. The student in charge of the project will have an excellent opportunity to deepen their knowledge in the field of energy storage and contribute to research on materials for supercapacitors.
Location
CEA-Saclay, 91 Essonne, France
Internship conditions
- Internship duration: 6 months
- Level of study: Bac+5
- Training: Master 2
- Continuation in PhD thesis: No
- Application deadline: March 28, 2025
Experimental skills
Langue : Anglais