Li–S batteries are regarded as an attractive alternative to lithium-ion (Li-ion) batteries as they can potentially offer a significantly higher energy density, and their major component, sulfur, is abundant, light, cheap, and environmentally benign. However, one challenge has to be overcome, the so-called polysulfide shuttle effect of Li-S batteries causes progressive loss of active material from the cathode resulting in a short life span of the batteries. In a collaborative project with 2 international partners, we will investigate novel electrode and separator materials based on layered heterostructures derived from two-dimensional transition metal carbides, nitrides (MXenes) to immobilize lithium poly(sulfides). Your Tasks Your tasks involve the synthesis of nanocomposites of MXenes and Transition Metal Oxides, the characterization of their morphology with various techniques such as XRD, SEM, TEM, XANES and XPS. We expect to reveal the conversion kinetics of polysulfides through electrochemical characterization methods; fabrication of various heterostructures for electrodes and separators will be performed; detailed electrochemical tests will be carried out. Together with our project partners we will fabricate Li-S coin and pouch cells.
You are a highly motivated experimentalist with a Master degree in chemistry, chemical engineering, materials science or a related discipline. You have hands-on laboratory experience in fabricating and characterizing Li-S batteries and synthesizing MXenes and nano-heterostructures. Prior experience in polysulfides conversion research is an advantage. Very good communication skills in English are required, German language skills are beneficial.
The work will be carried out at Empa Dübendorf in the Laboratory of Functional Polymers, The successful candidate will be enrolled in the PhD program at the École Polytechnique Fédérale de Lausanne (EPFL). Review of applications begins immediately and will continue until the position is filled. The tentative start date is 1st October 2021 or upon mutual agreement.