- Environnement :Le stage se déroule dans le cadre du projet IDEX « Circular » qui regroupe différents organismes de recherche autour de la thématique de l’économie circulaire. Les encadrants sont également en lien étroit avec une startup qui développe des BMS de hautes performances : Enerstone. Le stagiaire aura l’occasion de profiter de l’expertise de cette société.
CONTEXT and STATE-OF-THE-ART - Ceramic high-temperature fuel cell and electrolyser are efficient energy-conversion systems for electrical power generation and hydrogen production. This type of electrochemical device is constituted by a stack of elementary Solid Oxide Cells (SOCs), each one being composed of a dense electrolyte sandwiched between two porous electrodes. The industrial deployment of SOCs is still hindered by key issues related to durability and costs. For instance, the instability of the oxygen electrode made of Lanthanum Strontium Cobalt Ferrite (LSCF) is recognized as one of the prevalent mechanisms involved in the loss of SOCs performance, especially when operated in electrolysis mode . The processes of the material deterioration being thermally activated, many studies have been recently undertaken to reduce the operating temperature with new oxygen electrode materials in order to improve the performances as well as to mitigate the degradation. However, the performances of SOCs are not only due to intrinsic properties of materials but they are also strongly related to the association of functionally structured electrodes and the properties of the electrode/electrolyte interface. In this frame, architecturally designed La0.6Sr0.4Co0.2Fe0.8O3- (LSCF) and La2-xPrxNiO4+δ (x=1, LPNO) oxygen electrodes layered by Electrostatic Spray Deposition (ESD) and SP on Ce0.9Gd0.1O2-δ (CGO) electrolyte are selected as innovative solutions for the next generation of SOCs. To date, optimum polarization resistances have been reported [2-4] thanks to the presence of a nanostructured ESD active porous functional layer facilitating the oxygen surface exchange and ions diffusion, fundamental in the oxygen electrode design.
Renewable energy sources require large-scale, stationary energy storage systems to balance outfluctuations in energy generation (6.5 GW from solar panel in France at 2015 and 8.5 GW from windturbine in 2014, expected to exceed 20 GW at 2020) as well as to reduce the use of the fossil fuelsand consequently to reduce the pollutant production as well as the CO2 emissions. VSL ( Vanadium-Liquid-Solid) project will advance the development of one of the most promising storage systems i.e.redox-flow batteries which concerns the conversion of “renewable” electrical energies in to chemicalform and the reverse process i.e. the recovery of the stored electrical energy.More precisely, the energy must be stored via a redox reaction into ‘electroactive chemicalcompounds’ present in solutions; these solutions are stored into high volume storage tanks (ST) andflow across electrochemical reactor (ER), the resulting system was named redox flow battery.
Dans le contexte général du développement durable et des considérations écologiques, Aperam, un producteur d’acier de réputation mondiale (sites de production en France, Belgique et Brésil) s’est engagé à ne plus enfouir de déchets d’ici 2020. La production d’acier implique l’utilisation d’acides pour les différents traitements de surfaces des alliages. Ceci induit la formation de boues et la dégradation des bains de décapage, qui sont simplement neutralisés et enfouis par manque de procédés de recyclage efficaces et économiquement viables. L’obstacle le plus fréquent au retraitement de ces boues est leur contenu en F et S qui proviennent des acides employés.
In the general context of sustainable development and ecological concerns, Aperam, a stainless steel producer of world-wide reputation (plants in France, Belgium and Brazil), committed itself not to landfill waste anymore by the end of 2020. The production of stainless steels currently implies the use of acids in the several surface treatments undergone by the alloy. This induces the formation of sludges and degraded baths which are simply neutralized and landfilled because of the lack of efficient and cost effective way to revalorize them. It is often seen that the main obstacles to the treatment of these sludges are their content of F and S coming from the acids and other surface treatment baths used.
Every year, more than 200 000 orthopaedic prostheses (knee, hip) and a huge (but unknown) number of dental implants are implanted in France. For an optimal efficiency, these implants have to be well integrated in bone. To favour osseointegration, dental implants rely on modification of their surface morphology, while a Calcium-Phosphate coating is often required on the surface of orthopaedic implants.
Recycling and re-manufacturing of noble metal electrocatalysts for energy storage and conversion devices by use of efficient and environmentally friendlier approachesContext: Proton Exchange Membrane Fuel cell (PEMFC) and Proton Exchange Membrane Water Electrolyser (PEMWE) will play a major role in our energy transition towards sustainable energy. The core of PEMFC and PEMWE is the Membrane Electrode Assembly (MEA) which is composed of noble metal (Pt-based and Ir-based electrocatalysts respectively). The degradation of these materials upon operation is a major brake on economic growth for the large scale deployment of these technologies in view of electric energy production and storage via H2 vector. This bottleneck is mainly due to the fact that catalysts made of nanoparticles (NP) composed of noble metals (pure Pt, PtM -with M a 3d transition metal, Co or Ni- alloy for PEMFC application, Ir for PEMWE), which are mandatory elements of MEA to catalyze electrochemical reactions, are yet not recycled once degraded through working conditions.Recycling of NP from used MEA starts with a selective and efficient extraction of catalytic metal layers (Pt, Co, Ni, Ir…) followed by re-manufacturing of electrocatalysts displaying similar electrochemical performances to that of the starting one. This virtuous loop requires chemical processes displaying environmental impacts as low as achievable.It is our aim to gather the competences available at three laboratories (LEPMI, LMGP and G-SCOP, three partners in the LABEX structure CEMAM in Grenoble, France) in order to set a recycling-remanufacturing method for obtaining efficient new electrocatalysts from used ones able at limiting global environmental impacts of such energy devices.
We are looking for a talented postdoctoral fellow (PDF) willing to contribute with new skills and ideas in the field of the synthesis and development of a new membranes and electrodes for Proton Exchange Membrane Fuel Cells (PEMFC).
The Lepmi laboratory (Laboratoire d’Electrochimie et de Physico-chimie des Matériaux et desInterfaces UMR 5279) is recruiting a PhD fellow for 12 months within the frame of “BatRE ARES”project funded by ERA-MIN network. The recruited person will work at the University Campus ofSaint Martin d’ Hères(Grenoble).Starting date : January – March 2017