Batteries recycling :Development and understanding of a new deactivation concept of lithium ion domestic batteries
Domestic lithium ion batteries gather all batteries used in electronic devices, mobile phone, and tooling applications. By 2030, the domestic lithium-ion battery market will increase up to 30%. With the new European recycling regulation and the emergency to find greener and safer recycling process, it is today necessary to develop new deactivation process of domestic lithium ion batteries.
The process has to address several lithium ion chemistries, be continuous, safe, controllable and low cost.
To develop this new concept, the first step will be to define the most appropriate chemical systems. Then these chemical systems will be tested in a dedicated experimental laboratory setup using chemistry and electrochemistry, allowing the simulation of real conditions of domestic batteries deactivation.
The third step will be to characterize, understand and validate the electrochemical and physico chemical mechanisms. The last step will be to participate to the validation of the deactivation concept on a real object (a lap top battery) in representative conditions (on the abuse tests plateform of CEA).
Modelling of interstitial cluster evolution in bcc metals after helium implantation
Under irradiation, structural materials inside nuclear reactors undergo changes in mechanical properties, which result from the formation of point defect clusters, such as cavities (clusters of vacancies) and interstitial dislocation loops (clusters of self-interstitial atoms). Understanding the formation processes of such clusters is thus of prime importance. Recently, three-dimensional interstitial clusters, known as C15 clusters, have been shown theoretically to be highly stable in iron [1]. In order to detect such clusters experimentally, an idea is to make them grow, as shown for dislocation loops after helium implantation [2].
This approach will be carried out experimentally in various bcc metals in the framework of the ANR project EPigRAPH, in collaboration with Chimie ParisTech, GEMaC and LPS.
In this project, the following modelling tasks will be performed by the postdoc:
- DFT calculations will be done to obtain the energetic properties of point defects and point defect clusters in the bcc metals envisaged in the project.
- These data will then be used to parameterize a kinetic model based on cluster dynamics [3]. This formalism is particularly well adapted to simulate the evolution of point defect clusters over long physical times.
The modelling work will be performed in close collaboration with another postdoc working on the experimental part.
[1] M. C. Marinica, F. Willaime, J.-P. Crocombette, Phys. Rev. Lett. 108 (2012) 025501
[2] S. Moll, T. Jourdan, H. Lefaix-Jeuland, Phys. Rev. Lett. 111 (2013) 015503
[3] T. Jourdan, G. Bencteux, G. Adjanor, J. Nucl. Mater. 444 (2014) 298
Predictive design of heat management structures
Heat management is a paramount challenge in many cutting edge technologies, including new GaN electronic technology, turbine thermal coatings, resistive memories, or thermoelectrics. Further progress requires the help of accurate modeling tools that can predict the performance of new complex materials integrated in these increasingly demanding novel devices. However, there is currently no general predictive approach to tackle the complex multiscale modeling of heat flow through such nano and micro-structured systems. The state of the art, our predictive approach “ShengBTE.org”, currently covers the electronic and atomistic scales, going directly from them to predict the macroscopic thermal conductivity of homogeneous bulk materials, but it does not tackle a mesoscopic structure. This project will extend this predictive approach into the mesoscale, enabling it to fully describe thermal transport from the electronic ab initio level, through the atomistic one, all the way into the mesoscopic structure level, within a single model. The project is a 6 partner effort with complementary fields of expertise, 3 academic and 3 from industry. The widened approach will be validated against an extensive range of test case scenarios, including carefully designed experimental measurements taken during the project. The project will deliver a professional multiscale software permitting, for the first time, the prediction of heat flux through complex structured materials
of industrial interest. The performance of the modeling tool will be then demonstrated in an industrial setting, to design a new generation of substrates for power electronics based on innovating layered materials. This project is expected to have large impacts in a wide range of industrial applications, particularly in the rapidly evolving field of GaN based power electronics, and in all new technologies where thermal transport is a key issue.
Simulation of silicon solar cells based on n-type material : modelling and architecture optimisation.
INES is actually developping new fabrication technologies for n-type silicon solar cells. Working on simulation of photovoltaic solar cells enables the speed-up of the developement of new technologies: physical interpretation of characterisation results, support to device design, optimisation of processing steps and evaluation of original designs.
This subject open for post-doc position is focused on the study of semi-empirical models for materials and process steps for n-type solar cells. These basic road-blocks will be assembled in a complete model by using a multi-scale simulation tool. In the end, this global model will allow optimising of the p-type emitter geometrical structure, the efficiency of carrier collection on the back side or the geometry of metallisation for electrical contacts.
Electrochemical device for purifying hydrogen in a reformed gas
This project aims to establish a new research and development on purification devices for fuel reformers for hydrogen fuel cells. This work is of prime importance for fuel cell systems fed by different sources of hydrogen. Used in "power full" or "range extender" modes, the reformer and gas purification system are elements of the chain that have to be optimized.
Objective is to develop an electrochemical device for purifying the gas from a reformer whose basic principle is similar to that of a PEM electrolyzer. The gases from the reformer undergo a selective electrocatalytic oxidation to separate hydrogen and conventional pollutants directly power a fuel cell.
The project will focus on selection and characterization of catalysts electrocatalytic performance and the achievement of functional prototypes. These developments will assess the economic relevance of the device vis-à-vis other systems and identify areas of research to develop thereafter.
Multiscale Modeling of the Degradation Mechanisms in Polymer Electrolyte Fuel Cells
In an attempt to provide a rigorous physical-based description of the physicochemical phenomena occurring in the PEFC environments, the Modeling Group at CEA-Grenoble/LCPEM has developed a novel physical multi-scale theory of the PEFC electrodes electro-catalysis,the MEMEPhys model, based on a combined non-equilibrium thermodynamics/electrodynamics approach. This postdoctoral research position will consist on actively contributing on the development of the model, including the implementation of a physical-based description of water transport phenomena and water condensation in the PEFC. Heterogeneities on the electrochemical and aging processes, induced by water transport, will be in particular addressed. The candidate will strongly combine theoretical and experimental data, obtained in our laboratory, in order to establish MEA microstructure-performance relationships and to elucidate the main MEA degradation and failure mechanisms. From a fundamental point of view, this work will provide a deeper understanding of the electrochemical mechanisms responsible of the PEFC active layers aging at different spatiotemporal scales.
Study and realization of thermal energy harvesting prototypes by thermal/fluidic coupling, and then electrical conversion. Application to electronic circuits.
The objective of this study is to explore possibilities of using systems with fluidic/thermal coupling to harvest the thermal energy released by an electronic device and then convert it into electricity that can be stored or used again. In those systems, the fluidic can be also used for a cooling purpose.
The two main steps will be the design of devices allowing controlling the operating regimes of the fluidic system submitted to a constant heat source (thermo-fluidic coupling) and the characterization of the best coupling conditions with the electrical conversion devices, in particular piezo-electrical. The studies will also explore new mechanisms taking place in the small scale fluidic systems compared to models known macroscopically. The work will be mostly experimental but will also include a simulation part.
The study should also provide an estimation of the harvesting efficiency as well as the power densities taking place in this kind of new devices.
Process evaluation of 3rd generation biofuel production from micro-algae
CEA contributes to R&D activities in 3rd generation biofuel production from micro-algae by its fundamental research in biology (understanding of biological mechanism and improvement of microorganism performances) led by DSV at CEA Cadarache. LITEN Institute, belonging to CEA/DRT, investigates 2nd biofuel generation, from studies on resources (biomass, waste) up to industrial, economical and environmental integration.
This post doc fellow will use the different approaches developed at LITEN/DTBH to :
- perform a prospective study on process integration, for biofuel production from micro-algae,
- realize a technico-economical study of the more promising process solutions in the 2rd generation domain and industrial use of micro-algae,
- estimate the environmental impact (especially CO2) of these processes.
This work will take place in in frame of a collaboration of both labs (DSV/IBEB and DRT/LITEN/DTBH), the first one bringing its very fundamental knowledge on technical ability and performance of the micro-organism, the second one giving the knowledge on process and technico-economical evaluation of industrial reactor systems.
The post doc fellow, located in Grenoble, will go as needed in Cadarache to discuss with biology experts.
Synthesis and characterization of amino-phosphorous ligands for extraction of uranium in a sulfuric medium with a “liquid / liquid” process
The development of new and more effective extractants than those currently used is therefore an important issue for the mining of uranium. In particular, access to specific chelating systems with high affinity for uranium with selective properties in regards to competitor’s ions and less susceptible to hydrolysis remains a challenge.
Recently, new bifunctional molecules amio-phosphine oxide type has shown their potential for the extraction of uranyl in sulfuric media with excellent properties in terms of affinity and selectivity for the metal.
The objective of this postdoctoral fellowship will be to optimize this family of ligands, with the development of concise and efficient routes for their chemical and suitable for the preparation of large quantities of extractant for further study the optimization of the process.