Our studies on alternative technologies to Li-ion aim to extend our fundamental knowledge for each system (materials, interfaces and electrolytes). They permit to identify theirs limits and thus to develop strategies to cope with them. The final goal is to use our results to elaborate prototypes.
The RS2E essential mission is to anticipate the future. Therefore, “New chemistries” thematic is a strategic axe for the network. We want to explore beyond the Li-ion technology to foresee its possible alternatives. Lithium stocks are scarce and the use of some materials such as cobalt and nickel causes some ethical and geopolitical issues. We also want to develop environmental-friendly and sustainable technologies, to explore new energy-efficient and cheapest systems and to creating safe alternative.
- Redox Flow: The accumulators are comprised of two half-cells, one for oxidation, the other one for reduction. They are separate by an ion-exchange membrane. These systems are interesting because we canuncouple power and energy (cell quantity and size vs catholyte and anolyte concentration and volume). Our aim is to develop new configurations, new membranes and new couples without neglecting fluidic aspect and cost of systems. This project takes advantage of fructuous interactions with our industrial partners.
- All solid state: Those accumulators are based on the assembly of solid electrodes and solid electrolytes. The interfaces control and the design of more efficient ionic conductor are the deadlocks of this technology. We work on these aspects taking advantage of a Spark Plasma Sintering (SPS) to assemble the batteries.
- Na-ion: Na-ion mechanisms works similarly to Li-ion ones. The only difference is that these accumulators use sodium instead of lithium, a cheaper and more abundant element. We focus on identifying more adequate electrodes and more stable electrolytes. We also work on SEI analysis and on the performance and safety assessment of complete systems.
- Li-air: This technology interests many people because of its energy density, 10 times higher than the Li-ion one. However, it has to cope with the two electrochemical failures of this century: the oxygen electrode for fuel cells and the Li electrode. Our works focus on the reactional mechanisms understanding in order to propose alternative electrolytes and negative electrodes.
- Li-S: This technology is 40 years-old. The scientific community focus on it again, even if its inherent issues (such as polysulfide solubility) are still not resolved. However, just like the Li-air technology, the Li-S alternative propose high energy density. We work on improving the membranes and the electrolytes.
- Divalent systems: Magnesium and calcium are very abundant metals and the use of Mg2+ or Ca2+ ions makes it possible to double the capacity per exchanged ion. Researches in Mg-ion or Ca-ion aim to develop more performant and eco-friendly batteries. For these systems, we work on all the battery components: positive electrodes, negatives ones and electrolytes.
The network collaborates on the Li-S technology with the “EUROLIS” project, on the Li-air alternative with a special Task force and on the Na-ion researches with ALISTORE-ERI.