Understanding pH evolution in water in salt electrolyte
Grenoble, Isère
CDD
Temps-plein
Il y a 12 jours
Offer DescriptionDeveloping safer batteries is the ultimate goal of current research in the field of battery technology. Water-based electrolyte could easily replace flammable organic electrolyte providing enhanced safety, a topic so far under investigated in the literature. Unfortunately, water-based electrolyte suffers from poor energy density due to the very narrow electrochemical stability windows.With aqueous electrolyte, we are facing the oxygen and hydrogen evolution reaction leading to pH fluctuation in the battery causing electroactive materials degradation, and poor electrochemical performance. Based on an interdisciplinary approach, the project will aim to drastically enhanced the safety and the energy density of water-in-salt system with an in-depth investigation of highly concentrated water-in-salt electrolytes to understand the main limitations of such technology.Cycling an aqueous battery at the edge of the electrochemical stability window over many consecutive cycles is expected to give rise to local pH gradients in the electrolyte over time, and these gradients modify locally the electrochemical stability window as described by the Nernst equation. The electrode materials must be able to tolerate these variations to guarantee long-term cycling stability of the full system. In addition, an understanding of the evolution of pH gradients is critical, as it determines the electrode potentials with respect to the stability window of the electrolyte.This project aims to understand the water-in-salt approach, especially the pH fluctuation using advanced operandi techniques such as scanning electrochemical microscope (SECM) and model electrode materials. For the former, a new apparatus is available on our laboratory providing state-of-the-art equipment to carry this first part of the research. The second one deals with the development of specific coating being able to resist pH fluctuation during cycling.Funding category: Autre financement publicPHD Country: FranceRequirementsSpecific RequirementsFor the LEPMI laboratory, we are looking for a PhD student to work on understanding the limitation of water-in-salt system. Coating of the active materials will be also proposed to improve the chemical stability at the interface. Advanced electrochemical characterizations (CV, GCPL, GITT, PITT) will be used to assess the electrochemical performance and understand the intrinsic limitation of the dedicated system. AOperando techniques (at the laboratory scale and Grenoble large-scale facilities) will be also employed.The applicant should hold a master degree or engineering degree in Material Science, Chemistry, Physics or related field. Knowledge in electrochemistry and batteries is required. We are offering a 3 years contract.To apply to this position please send your CV and cover letter to Dr. Claire Villevieille ( ).Additional InformationWork Location(s)Number of offers available 1 Company/Institute CNRS-LEPMI Country France City GrenobleWhere to apply WebsiteContact WebsiteSTATUS: EXPIRED