Composite materials for all-solid-state lithium-sulfur batteries

Lithium-sulfur batteries have a five times higher theoretical energy density than state-of-the-art Li-ion batteries. In addition, sulfur is abundant, inexpensive, and low in toxicity. However, the solubility of lithium polysulfides in liquid electrolytes limits the sulfur utilization rate, as well as the number of charge/discharge cycles. Research is currently focused on so-called “all-solid-state” technologies, in which the liquid electrolyte is replaced by an ion-conducting solid phase. Sulfur is then converted into Li2S in the solid state within the cathode, but other challenges arise, such as interfacial resistance between the solid electrolyte and the electrodes, as well as slower redox phenomena than in the liquid phase.
The proposed Ph.D. position consists in studying new materials for all-solid-state Li-S batteries, and more specifically a composite cathode material wherein interfaces will be optimized using various preparation methods, and redox kinetics will be accelerated using transition metals sulfides (TMS) with controlled characteristics.  Operando characterization techniques (X ray diffraction and tomography) will be helpful for the understanding of the process in complement to other electrochemical and physicochemical characterizations to determine the structure/property relationships leading to the most efficient TMS for this application. We are looking for a motivated candidate with a strong knowledge in materials synthesis and electrochemistry.
The thesis will be carried out in collaboration between IFPEN (Lyon) and the MATEIS laboratory, INSA Lyon.

Keywords: all-solid-state lithium sulfur battery, transition metal sulfide, solid electrolyte, thiophosphate, argyrodite

• Academic supervisor    Dr Eric MAIRE, MATEIS (INSA), ORCID: 0000-0003-1952-2602 
• Doctoral School     ED34, ED Matériaux de Lyon
• IFPEN supervisor    Dr Arnold LAMBERT, ORCID: 0000-0003-4169-5622
• PhD location    IFPEN, Lyon, France 
• Duration and start date    3 years, starting in the fourth quarter 2024 (Novembre 4)
• Employer    IFPEN
• Academic requirements    University Master degree in Materials Sciences, Chemistry     
• Language requirements    English level B2 (CEFR)     
• Other requirements    Knowledge in electrochemistry and work experience under inert atmosphere would be a plus .... 

To apply, please send your cover letter and CV to the IFPEN supervisor indicated below.