GANDALF aims at modifying the surface of positive electrodes (LiFexMn1-xPO4 (LFMP) and LiNi0.5Mn1.5O4 (LNMO)) of Li-ion devices by a novel atomic layer fluorination process, improving their inertness towards their electrolytic environment, augmenting their performances as high-voltage systems, and validating their use as real-life size SAFT prototypes. Through a PhD funded by the RS2E, we could study our novel atomic layer fluorination process, so-called ALF, on TiO2, Li4Ti5O12 (LTO), LiCoO2 (LCO), and Li(Ni0.80Co0.15Al0.05)O2 (NCA). For each system, we demonstrate that ALF-electrodes display improved cyclability, polarization, and cycle life. Electrochemical operando FTIR measurements show that ALF-NCA is relatively inert towards its electrolyte, as compared to pristine NCA. Encouraged by the ANR, we were advised to build this project as PRCE in order to reach the industrial validation.

Global objective of Vision project is to propose Li-ion cells for the application of energy storage associated to renewable energies, with a life duration of 15 to 20 years. These cells should also present improved safety and reduced cost. Scientific objective is to better understand ageing mechanisms on very long timeframe as a function of use conditions. This deep understanding should allow proposing solutions to improve life, that will be tested in the frame of this project. Li-ion cells using materials Li(Ni1-x-y,Mnx,Coy)O2 (NMC) for the positive electrode and graphite for the negative electrode will be studied. Thanks to the partial substitution of Ni by Mn, NMC should allow both safety betterment and cost reduction compared to LiNi1-x-yCoxAlyO2 (NCA) material used today. Task 1 of this project consists in building and age testing several generations of prototypes, the components of which will be analysed in the frame of the other tasks. Several ageing parameters will be studied: storage and cycling, temperature, rate and depth of discharge during cycling, storage voltage. The 4 issues to overcome in order to reach 20 years life are addressed in the frame of tasks 2 to 5. First issue (Task 2) comes from the ageing of active materials. Second issue (Task 3) is the degradation of electrolyte and separator. Task 4 consists in studying the evolution of active materials/electrolyte interface, which is the 3rd issue. Task 4 is therefore complementary to tasks 2 and 3. To finish, Task 5 will deal with addressing issue 4, namely the stability of electrodes structure. This last issue is particularly relevant for the NMC material, which is a poor electronic conductive material and hence is very sensitive to the electrode structure. The percolating network should be maintained for electrons access, as well as electrode porosity for lithium ions access. Aged prototypes (Task 1) will be supplied right at the beginning of the project (Gen0). Three generations of improved prototypes will follow all along the project (Gen1, Gen2 and Gen3) as a function of successive recommendations from Tasks 2 to 5. Finally, project coordination is the object of Task 0 and dissemination and exploitation of results is the object of Task6 This project implies 4 partners, one of them is industrial, the 3 others are academic. It relies on one hand on the high expertise of Pau university on surface/interface study by XPS, the solid knowledge of Orsay university in solid electrochemistry, via complex impedance and GITT for example, and the strong experience of Picardie Jules Verne university in microscopy techniques, like SEM, TEM, EELS. On the other hand, this project will benefit from advanced knowledge of Saft on materials, electrolytes and separators for batteries, its capacity and know-how to manufacture and test industrial prototype cells, its position on the batteries market and its knowledge of storage applications. Economic and social issues are very important since the penetration of renewable energy in the energetic mix relies on the development of long life energy storage systems. This project is original and new because life duration considered is twice that of the automotive application. Furthermore, very few data are available today on long term ageing of NMC material. Funding of 752 738 euros is required for this project for a total cost of 1 935 790 euros.

DAME is a 42 month collaborative public-industry project, which answers to the challenge “clean, sure and efficient energy” and more particularly concerning the electrochemical storage device. The main DAME objective is to demonstrate a 500 Wh/kg Li-ion electrochemistry based on new nanostructured cathode materials recently discovered and patented by SAFT combined with silicon based anode materials. But many issues need to be solved on this material (like high polarization leading to low energy efficiency and poor cycle life) and requires synthesis and composition optimization. Fine crystallographic and nanostructure characterization of the new cathode material are necessary to understand the mechanism for charge-discharge mechanism, high polarization and ageing mechanism. The success of DAME will make emerging new high energy density and low cost batteries which may be used for strategic applications like energy storage system for renewable energy and electric vehicle. In that respect, it must be emphasized that DAME officially recognized by the competitiveness hub MOVEO. DAME project is organized in 3 technical work packages supervised by the coordination work package. Optimization of synthesis conditions and composition with basic characterization will be implemented in WP1, (leader CRISMAT). Fine and cutting edge characterization as well as mechanism understanding will be studied in WP2 using an arsenal of complex techniques like neutron diffraction, SAXS, WAXS, XANES, HRTEM techniques (leader NEEL Institute). And finally fine electrochemical characterization, electrode formulation and prototype cell assembly and testing will be carried out in WP3 (leader SAFT).