The Institute of Environmental and Sustainable Chemistry at the Technical University of Braun-schweig offers a doctoral position (PhD) in cooperation with a research project of the Gesell-schaft für Anlagen- und Reaktorsicherheit (GRS)mbH.
Dynamics of electrolytes:
mobility and dielectric interactions of ions in aqueous solutions
The work will be conducted at the Repository Safety Research Division, Process Analyses De-partment of GRS, Braunschweig, Germany.
The research activities are focused in the experimental determination of the ion mobility in concentrated electrolytes in free and porous media and their theoretical modelling. The experimental work includes determination of the dielectric properties of electrolytes in a wide frequency range by means of electro-chemical impedance and time domain reflectometry. The combination of experiment and theory is ex-pected to gain new understanding of electrostatic and chemical interactions influencing the ion move-ment in an electric field, of large relevance in the fields of energy storage, separation membranes, bio-logical and environmental systems. Start of activities by August, 1st 2013.
Tasks: - construction and operation of electrochemical impedance and TDR- equipments
- modeling of transport properties (ion mobility and diffusion: mean sphere approximation theory)
- application of mobility data to the diffusion problem in relevant technologi-cal systems
- cooperation work with the Karlsruhe Institute of Technology (KIT) in the analysis of ion chemistry
Requirements: - master/diploma in chemistry or physics
- founded knowledge in physical chemistry and elemental knowledge of electrical circuitry
- experience with calculus software
- feel like to start in a new research field
- creativity, commitment and team work capability
For further information and sending of applications (including a cover letter and a curriculum vitae) refer to:
Prof. Dr. Uwe Schröder
Institut für Ökologische und Nachhaltige Chemie
38106 Braunschweig, Germany
Tel: +49-(0)531 391 8425
« Ionic liquids for high voltage Li-ion batteries »
This project is focused on the conception and development of new electrolytes based on room temperature ionic liquids (RTIL) which will be used in high voltage lithium-ion batteries with potential application in electric vehicles (EV). The RTIL consisting principally of only one cation and anion pair exhibit several advantages when compared to molecular solvents: low to no vapor pressure below 100°C, many possible combinations of ions (known as the designer solvent), high electrochemical stability (up to 5.7 V), non-flammable behaviour, ability to exclude water, high conductivity and high solubility of metal salts. Their electrochemical stability depends on the nature of the cation, which is responsible of oxidation processes, and the nature of the anion which influences the reduction of electrolyte.
In this project, the postdoctoral fellow will:
- investigate a development of new electrolytes based on ionic liquids for high voltage lithium-ion batteries,
- analyse the evolution of the electrolytes during the cycling,
- study the interfacial mechanisms on electrode/electrolyte interfaces,
- optimise the performances of new electrolytes by their modifications.
These studies of new electrolytes will be performed by means of classical electrochemical techniques i.e. Cyclic Voltammetry (CV), Electrochemical Impedance Spectroscopy (EIS) as well as by surface analytical techniques i.e. X-ray Photoelectron Spectroscopy (XPS), Time-of-Flight Secondary Ion Mass Spectrometry (TOF-SIMS) and Scanning Electron Microscopy (SEM).
The postdoctoral position, for a period of 12 months, will be held in the Institut de Recherche de Chimie Paris, CNRS - Chimie ParisTech (UMR 8247), Paris (group of PCS of. P. Marcus and I2E of M. Cassir) in collaboration with Renault S.A. granting this project.
Prior experience in electrochemistry (batteries) and physical chemistry is required. The experience in lithium batteries, ionic liquids and surface analytical techniques (XPS, TOF-SIMS) will be highly appreciated. The post-doc will be awarded to the successful applicant according to the local conditions and salary scales. For information please e-mail the contact shown below.
Application deadline: 26 May 2014.
Approximate starting date: June-July 2014