Formulation of organic electrode materials for Li-ion batteries with low environmental impact
This project delas with the development of Li-ion battery prototype with a capacity of 500mAh only based on the use of organic elecrode materials (PTCLi4 for the negative electrode and MgLi2pDHT for the positive electrode) combined with a polymer electrolyte developped by CNRS/LEPMI. It will focus on the issues related to material implementation in order to prepare électrodes containing low carbon ration (2mAh/cm2)
Thermal conductor and electrical insulator nanocomposite for thermal management of 3D printed battery systems
Developments in energy transport and storage technologies (fast-charge technologies, high energy density batteries) mean that these systems generate considerably more heat during operation. In addition, the ever-increasing drive to miniaturise embedded systems is constantly reducing the space allocated to cooling, leading to the obsolescence of forced convection cooling systems (active systems) and inevitably affecting their performance, lifespan and reliability. These various factors inevitably lead to the need to develop a new class of materials that dissipate heat via their own structure.
The original strategy proposed consists of manufacturing thermally conductive and electrically insulating nanocomposites loaded with 1D and 2D nanoparticles with a rheology that is suitable for the 3D additive manufacturing process (FDM, Fused Deposition Modeling).
To this end, you will develop an insulating coating on the surface of conductive nanofillers using a sol-gel process, and the influence of the various synthesis parameters (T, pH, coupling agent, precursor rate, etc.) on the homogeneity and thickness of the shell will be studied and optimised. In addition, in order to reduce phonon diffraction at the nanofiller/matrix interface, surface functionalisation will be evaluated. Finally, the development of the nanocomposite, the manufacture of printable filaments and the shaping by 3D printing (fused deposition modeling - FDM) will be studied in order to optimize the thermal management of the battery casing. The anisotropy of the nanocomposite resulting from the morphology of the nanoparticles, combined with the printing process and the innovative design of the passive system, will optimise the thermal management of the entire module
Innovative biobased vitrimer electrolytes for self-healable and recyclable Li metal batteries
This post-doctoral position is part of the « ELECTRIMER » project, which aims to reduce the environmental impact and to improve the safety of the future Li-metal batteries. In this contexte, the recruited researcher will develop a new self-healable and extrudable Gel Polymer Electrolyte (GPE). Biobased monomers of generations 2 and 3 (not in competition with the food industry) will be used to synthesize a new polymer, that will be swollen with green and safe solvents. A vitrimer chemistry will be integrated in the polymer structure, in order to improve the batterie durability, by introducing self-healing properties to the GPE. The reversible chemistru will also allow to improve the batterie recyclability.
Development of high energy density hybrid positive electrodes for hybrid potassium supercapacitors
With the aim of increasing the capacity and therefore the energy density of hybrid potassium supercapacitors, a low-cost technology without dependence on critical and strategic materials, a Carnot project aims to develop a hybrid positive electrode integrating a capacitive material and a faradaic material.
The post-doctoral fellow will contribute, in close collaboration with the other people in the laboratory and the department, to the development of the hybrid electrode, from the material to the production of complete cells.
Among the processes used, the synthesis of faradic materials, the formulation and the coating of the hybrid electrode will be studied. Subsequently, prototype cells will be manufactured and then tested to assess the capacity reached and understand the charge storage mechanism resulting from the combination of the two materials. Button cells will first be produced, then “pouch” cells, similar to commercial cells. At each stage, specific characterizations of these electrodes will be carried out. For this research and development work, most of the tests take place in the chemistry laboratories and dry rooms of the battery platform.
Postdoc in Multi-instrumented operando monitoring of Li-ion battery for ageing
Nowadays, the development of new battery technology requires increasing the knowledge of degradation mechanisms occur inside the cell and monitor the key parameter in real time during cycling to increase the performances, lifetime and safety of the cells. To achieve these goals development of new sensing technology and integration inside and outside the cell is needed. The goal of the SENSIGA project is used advanced sensing technology to improve the monitoring of the cell by acquiring useful data correlate to the degradation process and develop more efficient battery management system with accurate state estimators. SENSIGA is a part of PEPR Batteries lead by CNRS and CEA and funding by the French Research Programme FRANCE 2030 to accelerate the development of new battery technology.
You will have the opportunity to work in a stimulating scientific environment focusing on the characterisation of both state of the art and latest generations of battery materials. Based on the sensing technology developed at CEA and from the state of the art, the SENSIGA project will reach the objective of the BATTERY2030+ roadmap goals for smart cells (https://battery2030.eu/research/roadmap/). One of the objectives of the project is to use external sensors to monitor the key parameters of the cell related to performances, ageing and safety behaviours.
Experimentation and numerical simulation of lithium battery thermal runaway
In the current Energy transition context, the lithium battery is an essential technology to address the strong challenge of the electrical energy storage. However, Li battery severe solicitations/loadings can lead to a thermal runaway phenomenon, which can cause an outbreak of fire, even an explosive combustion of the cell or of the whole battery pack. If this phenomenon is well known, the research and development dedicated to the battery safety is emerging and must be consolidated. The post-doctorate global objective is to develop a numerical modelling and simulation strategy for thermal runaway occurring when a Li battery is subjected to mechanical/thermal/electrical abuse, in order to gain an understanding of the phenomenon, estimate the thermal spreading risk as a result of gas combustion, or study the runaway mechanical consequences (fluid structure interaction). This strategy relies on physical testing campaigns carried out as part of the post-doctorate, and on numerical tools developed by CEA (EUROPLEXUS, Cast3M). The work will be organised into three main content areas: Understanding and modelling of the phenomena on the basis of experimental tests (shock tube, abusive tests), Development of a numerical model representative of identified phenomena, Modelling including fluid-structure interaction (case deformation due to pressure increase).