The objective of the DynaMoBat project is the analysis and quantification of the evolution of the 3D morphology of all-solid Li-ion batteries during their manufacture and their use in electrochemical cycling. The dynamic study in 3D morphology will be based on the use of X-ray tomography imaging techniques at different scales (? and nano). The non-destructive aspect, the possibility of coupling between imaging and spectroscopy and the recent improvements in terms of spatial resolution and rapid acquisition make X-ray tomography an ideal tool for the development of operando experiments. The project will be based on the optimization of electrochemical cells and compression and annealing cells dedicated to X-ray tomography (MATEIS and LRCS). The 3D data will be segmented using deep learning networks (ARMINES) to identify the different materials. The 4D dynamic data will be used to calculate 3D displacement maps allowing to follow the sintering phenomena and the propagation of cracks according to the experimental parameters. The quantification of these mechanical properties will be correlated with the evolution of electrochemical performance, to detect the origins of polarizations and capacity losses. Thus, the 3D analysis and quantification of the morphological evolution of the different constituents, depending on the state of charge in operation and the pressure applied for manufacturing, is the heart of this DynaMoBat project. Its ambition is to provide quantitative 4D data, making it possible to improve our understanding of limiting phenomena, and to open new avenues of optimization in the manufacture of these all-solid devices, which has an essential need to acquire quickly greater technological maturity.

Silicon-based photovoltaics represent ca. 90 % of the market. This technology is integrated where their properties are advantageous (roof-top or PV plants). Nevertheless, the success of PV penetration into the energetic mix strongly depends on how PV technologies can be diversified to integrate the smard grid, BIPV or urban equipment. The target of VISION is to develop dye-sensitized solar cells converting no more visible light but the near-infrared region to pave the way towards transparent and colorless photovoltaics. The project aims at developing (i) new robust NIR sensitizers (WP1), (ii) a new generation of mesoscopic semi-conducting film adapted to the opto-electronic properties of the NIR dyes (WP2), (iii) a colorless redox couple to regenerate the dye’s reduced state based on one electron redox mediator tailored specifically on modified Fe(+III/+II) and Ni(+IV/III) complexes. Those research activities will rely on a fourth workpackage gathering an arsenal of spectroscopic tools probing from millisecond down to femtosecond processes based on IMVS/IMPS, transient absorption spectroscopy and up-conversion photoluminescence spectroscopy. VISION-NIR targets the development of NIR-DSSC being transparent and colourless exhibiting above 7% power conversion efficiency, stable against IEC61646 protocol,and finally displaying above 75% total transmittance in the whole visible range.

This proposal aims to address a major issue for the energy storage, management and integration in the grid, addressed in the “Clean, Safe and Efficient Energy” challenge (#2), especially on the “improvement of the safety and energy density of supercapacitors” (Research theme #5). IVEDS is based on the design of safe and high volumetric energy electrochemical capacitors and the concomitant benchmarking of various asymmetric devices. Our final goal is to increase by 50% the volumetric energy density of nowadays symmetrical carbon ECs, i.e from 7 to 11 Wh/L, while keeping the power density close to that of state of the art devices (7.5 kW/L usable volumetric power). To reach this target, we propose to substitute conventional carbon based electrodes by high density multication oxides (>5 g/cm3) showing high pseudocapacitance (> 100 F/g), fair cycle life (>100000 cycles) in safe aqueous based electrolytes. These new oxides (task 2) will be based on active metal cations showing multiple oxidation states and lying in a specific crystallographic site that favors its pseudocapacitive rather than Faradaic behavior in aqueous based electrolytes. They will be synthesized with 10-100 m2/g specific surface area. Among all the synthesized compounds, two of the most performing chemistries will be selected and will be used as active materials in a high power electrode formulation including carbon-based nanocomposites (task 3). Two generations of advanced architecture/formulation will be provided for prototyping (18650 format cells), including the preparation of slurries for casting the electrodes, the winding of electrodes and separator for the cell manufacturing that will be implemented in a polymer casing prior to be tested (task 4). 500 F prototype cells are expected from this task. Three key players in the field of supercapacitors (IMN, ICG) and benchmarking of lithium-ion batteries (LRCS) are gathering together in this innovative project which will target a change of paradigm from carbons to oxides for large-scale applications of supercapacitors where volumetric energy density and safety are the most important parameters. This consortium will take benefit from its belonging to the French Network on Energy Storage (RS2E - http://www.energie-rs2e.com/fr). The project is expected to provide basic knowledge on the role of solid state chemistry on the electrochemical performance of oxides as supercapacitor electrodes, focusing on the crystallographic nature of the synthesized phases, as well as on the influence of "spectator" cations. This fundamental research will be used to implement more applied research based on the preparation of nanocomposite electrodes that adequately combines the active material to a high electronically and ionically conductive architecture based on carbons. This will demonstrate how an attractive oxide can be turned into a performing electrode. Again, some fundamental results are expected from this step and will give new insights on the synergies between carbon and oxides. Finally, the selection of chemistries and architecture/formulation will be done by the three partners in order to push the project from its fundamental side to a more applied field. Formulation of oxide based electrodes for casting onto stainless steel current collectors and integration in industrial prototypes has been poorly investigated up to now. It will provide valuable data both for researchers who hardly feature how their new materials behave at a cell scale, and for potential users who might like to know what can be expected from oxide based electrodes in a real cell. This comes together with a strategy for dissemination of the results to different potential industrial partners, from materials manufacturers to end-users.

Limiting global warming requires paradigm-shift discoveries in energy storage, leading to rechargeable batteries that give electric cars the desired 800-km range. The complementary use of synthesis and advanced characterization techniques in synergy with modelling have enabled the discovery of materials by design, which we apply here. We will discover nanomaterials and nanocomposites for long-lasting and inexpensive Sodium-ion batteries. We will combine computation with experiments to develop novel, inexpensive, NA-Super-Ionic-CONductor (NASICON) solid-electrolytes, NazZr2-yMySixP3-xO12, for safe solid-state batteries (SSB). By optimizing the composition and nanostructure of NaSICONs, we will decrease the operation temperatures of existing SSB from 200°C to ambient temperature. This synergistic approach is possible by bringing together the expertise of the PIs : NUS : high-throughput density functional theory; Softbond potentials for screening ion-transport, solid-state NMR. LRCS : synthesis, crystallography and electrochemistry; impedance spectroscopy and SSB manufacturing.

Concerns over environmental protection and energy independence in Europe are driving a transition towards low-carbon mobility. In this regard, the EU has recently proposed the end of combustion engine vehicles by 2035. This ambitious change can only be achieved if a favorable industrial environment for mass production of electric vehicles (EVs) is established in Europe. To date, the most mature technology is lithium-ion (Li-ion) batteries based on NMC, which dominate the EU market. However, these batteries require the use of cobalt, nickel, and lithium, critical metals produced outside the EU. Fortunately, the substitution of cobalt and nickel is entirely possible thanks to LFP technology, which offers excellent performance in terms of stability, safety, and longevity. This technology has been adopted by China (which produces over 70% of LiBs). However, the shift towards LFP technology seems to be happening with the surge in metal prices, driven by manufacturers such as Tesla and VW. However, this change in strategy to favor LFP batteries will not be sufficient to guarantee the EU's energy independence unless it is accompanied by two key measures: battery production and recycling within the EU. Although many European players have announced the construction of over forty gigafactories to produce batteries for EVs, few are investing in projects to recycle these batteries at the end of their life. Aware of this weakness, the EU is encouraging the development of a strong critical metals recycling industry through stricter regulations and targeted subsidies. In this context, the LEOREC project aims to demonstrate the feasibility of recycling LFP cathodes using mild, green, and low-energy chemistry for their reuse in the local production of new Li-ion batteries. It should be noted that current recycling techniques have been designed to recover high-value economic metals such as cobalt, via conventional methods such as pyro- and hydrometallurgy. However, these are considered non-profitable in the case of LFP. Thus, low-temperature and pressure regeneration methods will be developed in LEOREC to promote the repair of LFP instead of its destruction by conventional methods. This would enable the efficient, sustainable, and economical recycling of LFP cathodes within a circular economy. LEOREC aims to globally evaluate two direct regeneration processes: direct lithiation under ambient conditions (ADL) and direct lithiation under solvothermal conditions (SDL). The more effective of these two approaches, first optimized at the laboratory scale, will then be scaled up by the industrial partner. The main obstacles to overcome are energy, environmental, and societal. Indeed, it is a matter of proposing a method that is (i) energy-efficient (at low temperatures or even at room temperature), (ii) using solvents and lithium sources that are as ecological as possible, while (iii) minimizing the steps required for LFP electrode regeneration. In order to achieve a realistic evaluation of the entire process, electrochemical tests on industrial 18650-type batteries will be performed. The data obtained will objectively compare direct regeneration with conventional methods. If the balance is favorable, this method could be a future technology in the valorization of end-of-life LFP batteries. The success of the LEOREC project relies on the complementarity of industrial and university partners and their experience in the fields of Li-ion batteries and recycling.