In order to reduce CO2 emissions and fossil fuel dependence the development and uptake of electric vehicles play a key role. Achieving performances acceptable for a wide range of users, and not only for the early adapters, requires the development of innovative energy storage with higher energy density, higher safety and lower environmental impact. The SiLithium project focuses on the analysis and the improvement of safety and environmental issues.
The aim of the research project is the development of a standardized test method for the characterization of the gaseous emissions of lithium-ion cells. For this purpose, a dedicated measuring station to characterize the gaseous products generated during the cycling operation and misuse conditions is planned. The qualitative and quantitative analysis of gases released during accidents is of great importance, since their potential hazard has not been studied systematically.
The work program combines two important aspects for the development of batteries:
First, a test site set up and the associated measurement methodology will be developed to characterize the gaseous emissions of Li-ion cells qualitatively and quantitatively. An accurate and reliable quantitative measurement of small gas volumes resulting in the investigation of EL-Press laboratory cell is challenging. Two alternative measurement concepts - based on an in situ spectroscopic (FTIR) measurement or on a chromatographic separation and determination (by GC / MS) – will be investigated, developed, validated and finally compared and evaluated. The goal is a standardized method with a wide application for the characterization of rechargeable Lithium ion batteries. The method is also the basis for toxicological and environmental assessment of the released gases during misuse conditions of Lithium ion batteries.
Second, Li-ion cells with silicon as a new anode material are aimed to be developed. Due to the high energy density achievable there are great hopes in silicon powders as anode material for Li-ion batteries. For this purpose porous Silicon powder, developed in an etching process, is planned. Then it is polymerized with a conductive polymer in order to avoid or at least cushion the strong volume change of the silicon during its intercalation processes. This will aid in increasing the battery life. These new lithium-ion battery with Silicon as an anode material is evaluated according to the LCA (Life Cycle Assessment) and eco-design concepts.
This project provides, on the one hand, a significant contribution to the development of highly efficient, safe and environmentally friendly Li-ion batteries, on the other hand it will lead to the development of a standardized method for the analysis of gaseous emissions of rechargeable Li-ion cells.
Findings of the study are published by a final report (short version, German only) which is available online via the Federal Ministry for Transport, Innovation and Technology (BMVIT):