Scientific direction Development of key enabling technologies
Transfer of knowledge to industry

PhD : selection by topics

Technological challenges >> Electrochemical energy storage incl. batteries for energy transition
5 proposition(s).

See all positions [+]

K-ion batteries, towards a full system without any critical raw materials

Département de l'Electricité et de l'Hydrogène pour les Transports (LITEN)

Laboratoire Matériaux

01-09-2021

SL-DRT-21-0524

david.peralta@cea.fr

Electrochemical energy storage incl. batteries for energy transition (.pdf)

Classic Li-ion batteries are composed of a graphite anode and a cathode containing a lithiated layered oxide (formula LiNixMnyCozO2). The development and the generalization of the electric automobile market will generate stress on certain chemical elements source, especially for lithium, nickel and cobalt. In addition, the production method consumes a lot of energy (multiple calcinations) and several solvents/products used are not respectful of the environment (NMP, ammonia). The thesis aims to develop a battery technology based on potassium. We will pay attention not to use any critical element in order to significantly reduce the ecological footprint. In terms of performance, potassium has a potential close to lithium, which suggests that high-energy batteries can be manufactured. Some potassium cathode materials have theoretical capacities of 155 mAh/g at a potential close to 4 V, which makes the technology competitive with conventional Li-ion batteries. The final target of the PhD thesis is to optimize and validate the technology in a complete system. The student will optimize the synthesis of the cathode material, the anode, the electrolyte in order to obtain an efficient system.

Download the offer (.zip)

High Energy Density Positive Electrode based on Glass Materials for Li-Ion and Na-Ion Cells

Département de l'Electricité et de l'Hydrogène pour les Transports (LITEN)

Laboratoire Matériaux

01-10-2021

SL-DRT-21-0577

sebastien.martinet@cea.fr

Electrochemical energy storage incl. batteries for energy transition (.pdf)

This PhD subject will aim at developing new positive electrode materials based on glasses for high Energy Density Li-Ion and Na-Ion cells. These developments will be held jointly between the laboratory of materials for batteries from CEA-Grenoble and LDMC lab from CEA-Marcoule that is specialized in the formulation and characterization of glass materials. The work will be focused on the optimization of the complex formulation of the glass cathodes to solve the issues related to first cycle irreversible loss and low cycling performances. The main objective will be to obtain one composition without critical raw materials exhibiting more than 1000Wh/kg at active material level vs 700 for state-of-the-art materials. This target will be reached with the support of advanced characterization techniques such as X-Ray Diffraction and RAMAN and FTIR spectroscopies. A dedicated effort will concern the development of operando or in-situ measures to be able to explain the link between electrochemical performances and glass characteristics, what has never been reported in the litterature.

Download the offer (.zip)

Charge-transfer complexes used as electrolyte for solid state lithium batteries

Département de l'Electricité et de l'Hydrogène pour les Transports (LITEN)

Laboratoire Matériaux

01-10-2021

SL-DRT-21-0804

laurent.bernard3@cea.fr

Electrochemical energy storage incl. batteries for energy transition (.pdf)

While lithium-based batteries are already the energy storage technology of choice for small- and medium-scale devices, their widespread implementation in large-scale applications like, for instance, electric vehicles remains hampered in particular by safety concerns. These concerns are, in fact, basically related to the commonly employed liquid organic electrolyte, comprising toxic, corrosive, and unstable LiPF6 as conducting salt. Thus, one of the major targets of actual research activities is the replacement of such electrolytes by intrinsically safer alternatives, including solid inorganic and polymer-based systems, both providing intrinsic advantages and challenges. Solid-state electrolytes could resolve all of these problems. However, most candidate materials have much lower ionic conductivity compared to that of liquid electrolytes, which reduces the power density of the cell and limits their practical applications. PEO-based electrolyte have been widely studied and their implementation is still hindered by their low ionic conductivity at 20°C. A new class of polymer-based materials is studied and developed at CEA, they are showing higher ionic conductivities than standard liquid electrolyte at 20°C while having a high Tg ( >80°C), wide electrochemical stability window and they have be proven to be stable on Li metal. Moreover, due to their properties, these materials can easily be processed by hot melt extrusion allowing reducing the final cost of the electrolyte. The PhD aims at synthesizing these new materials and mainly characterizing the Li-ion mobility and mechanism in these new materials. After a step of synthesizing these new materials ( molecular or polymer based materials), the PhD candidate will have access to large panel of technique to fully characterize their properties : DSC, TGA, HPLC-MS, NMR, IR, UV-Vis spectroscopy, EIS, cycling, li transference number ? . More advances characterizations techniques such as PFG-NMR, Quasi-elastic neutron scattering and SAXS could be used to better characterize the Li-ion diffusion mechanism within these materials. The performance of the materials with the most promising ionic conductivity will then be tested in all-solid-state batteries.

Download the offer (.zip)

Development of an operando gas analysis setup for all-solid-state batteries and study of the impact of doping on electrolyte stability

Département de l'Electricité et de l'Hydrogène pour les Transports (LITEN)

Laboratoire Analyse électrochimique et Post mortem

01-09-2021

SL-DRT-21-0815

irina.profatilova@cea.fr

Electrochemical energy storage incl. batteries for energy transition (.pdf)

Doctoral project will focus on the development of the characterization setup for all-solid-state batteries and conducting operando gas analysis for development of safer solid electrolytes. All-solid-state batteries represent a cutting-edge field of the development of modern batteries for electric transportation of the future. First precommercial batches of solid cells with sulfide electrolyte have been demonstrated by Samsung (cycle life: >1000 cycles). However, there is still a lot of issues to understand and solve for further wide commercialization of this type of batteries. The main obstacle for sulfide-based electrolytes is their instability vs humidity. Another problem is related to the possible gas evolution during cycling. Characterization methods for all-solid-state batteries are in the early stage of their development. There is a high demand for scientific tools and methods for investigation of various effects leading to gas generation inside the batteries and their degradation, which is directly related to their safety. The objectives of the present project are 1) development of the experimental setups for a precise study of reactions of solid electrolytes leading to gas generation in various conditions and 2) obtaining of improved electrolyte for solid batteries based on the deep understanding of its reactivity. There are three principal interconnected parts: construction and improvement of setups, conducting of fine analysis of electrolytes and synthesis of an improved solid electrolyte sample. The project will be done in French Commissary of Atomic and Alternative Energies (CEA) located in Grenoble. It is known for its excellent set of equipment and expertise in the research and development of greener energy, notably in batteries. This center offers an opportunity to join a dynamic team and to conduct a high-level research in a multidisciplinary environment. Grenoble area is a famous hiking and skiing resort. We are looking for a motivated and pro-active candidate for a Ph.D study starting in autumn 2021 for 3 years. There is a health insurance for the foreigners. Good oral and written English as well as capability to make literature reviews and write papers are essential. The experience acquired by the student during the Ph.D study will be undoubtedly of high interest for further employment.

Download the offer (.zip)

Influence of the battery electrode manufacturing process on electrode characteristics and electrochemical performance

Département de l'Electricité et de l'Hydrogène pour les Transports (LITEN)

Laboratoire Prototypage et Procédés Composants

01-10-2021

SL-DRT-21-0856

benoit.chavillon@cea.fr

Electrochemical energy storage incl. batteries for energy transition (.pdf)

For several years now, the processes for manufacturing battery electrodes have been unchanging. Indeed the electrodes are manufactured by coating on collector. The coated electrodes are then calendered to obtain the desired electrode porosity. Thus, well mastered formulations exist and can be adapted to many active materials. Once calendered and assembled into batteries, the electrodes allow to obtain cells that can be tested in laboratory. Despite this, the emergence of new materials sometimes induces difficulties in obtaining homogeneous electrodes. Thus, the aim of the thesis is to make a complete study of the influence of each component and of the manufacturing / post-manufacturing parameters on the electrode properties. This study is carried out with the aim of being able to find laws of behaviour and influence of materials. This will lead to the possibility to adapt preliminary of the manipulation to each of the components introduced in the electrode without going through a parametric study. Then, during the PhD, we will then be able to use this new knowledge to develop specific formulations for the new desired cell properties such as fast charging. All the means available at CEA and partners concerning batteries/rheology will be used such as dispersion mixer, planetary mixer for inks, different means of electrode coating and calendering, possibility to extend the study to electrode extrusion, simple rheology and capillary rheometer, cycling benches and potentiostats, DRX, SEM, Raman, MET, porosimeter, specific surface measurement, ... Funding for this topic is still in discussion and not confirmed.

Download the offer (.zip)

See all positions