To get Finns excited about electric cars, we first need batteries
Electric cars will only be driving around city streets in Finland after powerful enough batteries have been developed for them. The batteries must be compatible with future charging networks and the cold climate of Finland. Researchers from Aalto University are seeking a solution to the problem and analysing lithium-ion batteries with the aim to find a model suitable for the conditions in Finland.
The research work, conducted at the Department of Chemistry, began in early 2012 and is connected with the eSINi research project. According to post-doctoral researcher Tanja Kallio, the project aims to determine how the charging impacts different battery types and their durability. In an electric car, a battery is an expensive and important component. Turning the battery over to an outside party, such as an energy company, for charging and discharging requires certainty over the impacts of the procedure on the battery. Kallio thinks that free use of the batteries might be of interest to energy companies. Before creating such practices, it is important to make sure that they do not damage the battery.
"Lithium-ion batteries include a Battery Management System (BMS) that would normally manage the charging of the battery and prevent overcharging and other error situations. In case there is no certainty of interoperability between BMS and an external system, BMS cannot be included in the battery. Even then, the safety of the battery must be ensured", says Kallio.
Book-sized cell in a cooling cabinet
As the lithium-ion batteries studied in eSINi are made by several different manufacturers and the batteries contain a number of different chemistries, the Department of Chemistry offers its expertise for the analysis of the differences between battery types. While the department also carries out its own research on battery materials, the eSINi project focuses on batteries already on the market. The study explores whether it would be possible for Finns here to use a car manufactured in Spain, for example, including a lithium-ion battery.
According to professor Kyösti Kontturi, similar research projects have been carried out previously in different parts of the world, but the long winter and cold climate in Finland introduce a new element to the study. For this reason, results obtained elsewhere cannot be directly generalised here.
"In practice, the object studied in the laboratory at the Department of Chemistry is not an entire sample battery but a single cell that represents the whole battery within reasonable limits of current, voltage and power," explains Kallio. The material chemistry of the cell, roughly the size of a book, is examined for example using a climate cabinet with adjustable temperatures in order to determine the effect of cold weather on the battery. If, due to cold air, a certain battery type breaks down or does not work properly, it is dismantled and efforts are made to determine the reason for the malfunction.
The eSINi (Electrical Vehicle Charging Infrastructure for Urban Environments) research project aims to enable broad adoption of electric cars particularly in the Helsinki Metropolitan Area. In the project, the researchers plan and explore the need for different charging points and other infrastructure related to the cars.
The eSINi research project is part of a larger entity focusing on the designing of electric transport. It is a parallel research project to the Electric Traffic in Metropolitan Helsinki project, and its main funders are the EVE programme by Tekes and the Innovative City programme by the City of Helsinki.
- Filling up with electricity [sci.aalto.fi]