Electrochemical energy storage and conversion systems have many applications ranging from micro-electronics (e.g. smart cards) to independent power sources, through portable electronics (e.g. cellular phones, computers, power tools), electric traction (e.g. electric or hybrid vehicles), and storage of intermittent renewable energies, and load leveling for electric grid applications.
Our team entitled "Electrochemical Energy Conversion and Storage (EEST)" brings together IMN expertise in the areas of energy storage (supercapacitors and lithium batteries), energy transformation (SOFC, PCFC, and high temperature electrolysers), and modeling coupled to spectroscopies (XAS , EELS , NMR). We gather about 20 permanent researchers, and 30 PhD students and post-doctoral fellows on the following thematics:
- Lithium batteries
- Development of new materials for fuel cell applications
- Spectroscopy and modeling applied to the understanding of material properties
Our team develops fundamental and applied research in academic and/or industrial collaboration at regional, national, european and international levels (see "collaborations" below). In the area of energy conversion and storage, the common challenge is to improve energy performance, reliability, durability and safety of systems being developed or commercialized. It is also needed to expand the range of operating temperature, by modifying existing materials, designing new materials and controlling all interfaces.
Our goal is to maintain a balance between the very fundamental and applied/industrial aspects to meet socio-economic needs in the short to medium term. We aim to better understand the relationships between the preparation conditions, the characteristics of electrode materials and electrolyte (composition, crystal structure, micro-structure, physicochemical and surface properties) and their electrochemical properties measured in conditions that can be extrapolated to larger scale. The coupling between modeling and spectroscopy allows characterizing more thoroughly studied materials, and thus gaining a better understanding of reaction mechanisms.
Our research is renowned for the following key fields:
- formulation and shaping of composite electrodes for batteries, including the formulation in aqueous medium, negative silicon electrodes with high loading and long cycle life, and characterization at all scales of an electrode,
- characterization of interfaces at the nano level, including the quantitative monitoring of aging by NMR,
- modification and control of interfaces by molecular covalent and non-covalent grafting,
- development of more efficient supercapacitors through engineered materials, electrodes and devices, coupled to a fundamental approach combining operando characterization and modeling,
- development of innovative and efficient electrochemical generators based on the use of electro-active organic materials with low environmental impact,
- exploratory research on ionic and/or electronic conducting ceramic materials (O2- or H+), home fabrication of SOFC and PCFC fuel cell lab prototypes, and electrochemical characterization of electrolytes and electrodes of fuel cells or electrolysers operating at high temperature,
- modeling of spectroscopies, including the interpretation of the Li K-edge taking into account local fields, the determination of chemical shifts in diamagnetic crystallized compounds using the GIPAW method, and focus on operando investigations using X-Ray Absorption at the synchrotron SOLEIL.