Filtern
Erscheinungsjahr
- 2023 (4)
Dokumenttyp
- Vortrag (2)
- Beitrag zu einem Tagungsband (1)
- Posterpräsentation (1)
Sprache
- Englisch (4)
Referierte Publikation
- nein (4)
Schlagworte
- Electrical Energy Storage (4) (entfernen)
Organisationseinheit der BAM
Eingeladener Vortrag
- nein (2)
The number of cars which use a battery for propulsion, like BEV (battery electric vehicle) or PHEV (plug-in hybrid electric vehicle), is increasing. Following, the probability of these car types being involved in car accidents will increase. In a worst-case accident scenario, the installed batteries could go under thermal runaway (TR). A TR could be initiated by various causes, e.g., high temperatures from outside, mechanical damage of the cells/modules/batteries or internal and external short circuits. During such an event, large amounts of heat and toxic and/or flammable gases are released. This poses a great hazard to people and property in the immediate vicinity. The paper describes a large-scale test series on the lithium-ion battery TR consequences of automobile cells and modules up to E = 6.85 kWh. Near field temperatures of ΔT > 800°C in a distance of l = 2 m were measured. During an overcharge test, fragment throwing distances of l > 30 m were detected. Subsequent gas explosions of the released gases were documented. Hydrogen fluoride (HF) was measured in all tests, from cell to module. The highestmeasured concentration was cHF = 76 ppm, which is significantly higher than the 30-min-level for AEGL 2 (acute exposure guideline level 2). Based on the experimentally determined consequences, concrete measures for the accident analysis are subsequently drawn.
The number of cars which use a battery for propulsion, like BEV (battery electric vehicle) or PHEV (plug-in hybrid electric vehicle), is increasing. Following, the probability of these car types being involved in car accidents will increase. In a worst-case accident scenario, the installed batteries could go under thermal runaway (TR). A TR could be initiated by various causes, e.g., high temperatures from outside, mechanical damage of the cells/modules/batteries or internal and external short circuits. During such an event, large amounts of heat and toxic and/or flammable gases are released. This poses a great hazard to people and property in the immediate vicinity. The paper describes a large-scale test series on the lithium-ion battery TR consequences of automobile cells and modules up to E = 6.85 kWh. Near field temperatures of ΔT > 800°C in a distance of l = 2 m were measured. During an overcharge test, fragment throwing distances of l > 30 m were detected. Subsequent gas explosions of the released gases were documented. Hydrogen fluoride (HF) was measured in all tests, from cell to module. The highest measured concentration was cHF = 76 ppm, which is significantly higher than the 30-min-level for AEGL 2 (acute exposure guideline level 2). Based on the experimentally determined consequences, concrete measures for the accident analysis are subsequently drawn.
Every technical system has a failure rate, including a lithium-ion battery. To minimize the effects in the event of a thermal runaway, it is necessary to know what consequences to expect. In the talk, current results from tests on the thermal runaway behaviour of lithium-ion batteries will be presented and conclusions drawn for the handling of those.
Thermal runaway investigations were performed by subjecting single and double NMC pouch cells to thermal abuse condition inside an air-tight reactor vessel with an internal volume of 100 dm³. The study was divided into two series. The findings revealed the thermal runaway-induced explosion in the cells results in a rate of temperature increase greater than 10 K/s. The highest gaseous production was achieved at a range of 90 – 100% SOC and higher battery capacities 0.79 L/Wh (Series 1, 10 Ah cell) and 0.87 L/Wh (Series 2, 32 Ah cell). The investigation showed between 25 m³ and 84 m³ of explosible gas mixture could be released from electric vehicles of nominal useable electrical energy from 32 kWh up to 108 kWh at thermal runaway. It was also found that, the release of these explosible gases could undergo a secondary explosion.