Post-doctoral position: Silicon-based Lithium-ion batteries

A 24-month (+12m) post-doctoral position is offered at the Institute of Grenoble Interdisciplinary Research (IRIG, France). IRIG is a joint CEA-UGA research institute. It is a major actor in fundamental research on nanomaterials with extended research programs on energy conversion and storage.

The post-doctoral position is offered in the framework of the 4-years ECO2LIB European H2020 project dedicated to develop Silicon-based Lithium-ion batteries with improved operation time, led by Varta (Germany). Our task is to provide understanding of ageing mechanisms in composite electrodes by means of cutting-edge operando scattering and imaging techniques at world-class Large Scale Facilities, coupled with electrochemical characterizations.

Context.

Nowadays, lithium ion batteries (LiBs) are present in many applications such as mobile phones, computers and electric vehicles [1]. The usual anode material is graphite but silicon has recently appeared as a very promising candidate for the next generation of LiBs: its energy density is about ten times higher (~ 4000 mAh/g) than that of graphite (∼ 330 mAh/g), its discharge potential relative to Li+/Li is low (improving the battery safety), its raw cost is very low and a dedicated industry already exists (micro-electronics). Although cycling performances have been greatly improved in the last years, the practical use of Si in LiB has been hindered by limitations due to the mechanical failure of the electrode consecutive to the large volume changes upon lithiation. Different strategies have been proposed to minimize these effects, e.g. the use of i) composite materials by combining Si active particles with another active or inactive material, ii) nanosized crystalline Si particles (Si NPs) to accommodate large stress and strain without cracking, and iii) the prelithiation to control the Solid Electrolyte Interphase (SEI) impact and compensate Lithium trapping. To date, however, none of these strategies resulted in satisfactory cyclability.

Objectives.

Our project aims at gaining knowledge on the ageing mechanisms in new nanostructured Silicon/Graphite composite anodes for lithium ion batteries to determine the limiting processes by quantifying structural and electrochemical evolutions during cycling. We will employ diffraction/scattering tools as SAXS/WAXS (see our recent work C. Berhaut et al, ACS Nano 2019), XRD (S. Tardif et al, ACS Nano 2017), and advanced 3D techniques as synchrotron tomography and neutron imaging. The experiments will be performed on home-made battery cells and/or industrial cells provided by VARTA, on beamlines located at the European Synchrotron Radiation Facility (ESRF) and Institut Laue Langevin (ILL) in Grenoble. We expect to provide a detailed understanding of complex mechanisms occurring during the charge and the discharge of the fresh and aged Lithium-ion battery, which are critical for improving the performances of the device.

Hosting teams
The post doctorate fellow will benefit from the know-how gained at IRIG (www.irig.cea.fr) over the past years on operando electrode characterization and more particularly on Silicon materials for batteries. In the present project we will capitalize on this expertise, and benefit from the environment of the H2020 European Project ECO2LIB (www.eco2lib.eu) in which our teams are involved as WP leader for characterization. The applicant will evolve in a multidisciplinary environment and interact with the electrochemists, chemists and physicists of IRIG, as well as with our European academic and industrial partners.

Applicant profile
The post doctorate fellow will be in charge of i) designing/testing the battery cells for scattering experiments (X-ray and/or neutron), ii) performing basic electrochemical characterizations, iii) planning/realizing the scattering experiments, and iv) analyzing/interpreting the sets of data. Therefore, we are looking for aphysicist and/or electrochemist highly motivated by advanced characterization of nanomaterials and in-depth quantification of their evolution in the course of cycling. Previous working experience in energy storage (e.g. Li-ion batteries) research would be a strong asset. Experience in X-ray/neutron scattering techniques would be highly appreciated, but is not mandatory if the applicant has some background and/or strong interest in physical characterization.

Application: Please join a CV, a cover letter and two recommendation letters.

Contacts: Dr. Samuel Tardif
CEA/Grenoble, DRF/IRIG/MEM
Phone: 33(0)4.38.78.28.19
E-mail: samuel.tardif@cea.fr
Dr. Sandrine Lyonnard
CEA/Grenoble, DRF/IRIG/SyMMES
Phone : 33(0)4.38.78.29.66
E-mail : sandrine.lyonnard@cea.fr

Please join a CV, a cover letter and two recommendation letters.