The research project "E-FLoA" aims to develop an operando analysis method for the rapid measurement of electrolyte decomposition and characterisation of electrolytes. Electrolytes have a central role in cell development, as they significantly influence the behaviour and ageing of lithium-ion batteries. The identification of electrolyte formulations with increased ageing stability can lead to decisive competitive advantages in cell production. Electrolyte decomposition is manifested by gas formation, drying out of the cell, or consumption of the electrolyte, and the formation of cover layers and reactive intermediates. These ageing processes occur in parallel with the main reactions both during charging and discharging and while the lithium-ion battery is at rest. The quantification of electrolyte degradation by means of classical ageing tests is a time-consuming measurement procedure that only provides initial results after months. Within this project's scope, a new measurement method for determining the calendrical ageing rate of lithium-ion batteries, the float current measurement, is therefore used to determine the electrolyte degradation reactions and optimised for the analysis of electrolytes. Chemical measurements support the further development of this method to characterise the dominant ageing factors in cell ageing and by quantum chemical reaction modelling for a more precise breakdown of the dominant reaction kinetics. The new analytical measurement method of electrothermal evaporation is also to be further developed within this framework.
The focus of this research project is thus on the influence of electrolytes on battery performance. In this context, electrolyte components will be varied to obtain a comprehensive overview of the influence of various solvents and additives on the electrolyte properties. The performance of ageing tests and investigations lead to a better understanding of the processes involved in electrolyte ageing and allow a validation of the model conception underlying the float current measurement. Furthermore, in combination with the chemical analytical methods used, they deepen the basic knowledge about electrolyte ageing. The complementary methods used in this project strengthen the knowledge of electrolyte decomposition and help in modelling behavioural models of lithium-ion batteries.
The expected further development of new measurement methods and the general increase in knowledge about electrolyte ageing will provide an essential foundation for the development of new cell materials in research and industry in Germany.
1st January 2021 to 31th December 2023
The E-FloA project is funded by the Federal Ministry of Education and Research (BMBF) under the funding code 03XP0349A as part of the BMBF competence cluster “Analytics & Quality Assurance – Aqua”.
- University of Münster / MEET
- RWTH Aachen