Monday, 1 October 2018: 11:40
Galactic 5 (Sunrise Center)
Safety assessments of lithium-ion cells have been estimated by the judgment of the possibility of explosion and/or ignition of the tested cells. However, existing judgment of the safety is mainly based on the qualitative assessment so that quantitative evaluation approach is required. We developed a forced destruction system in which pressure change in event can quantitatively estimate using a pressure tight housing surrounding the test cell. We report the comparative results of the overcharged tests using LiFePO4/Graphite (LFP/Gr, 64 Wh), LiNi0.8Co0.15Al0.05O2/Gr (NCA/Gr, 15 Wh), and LiCoO2/Li4Ti5O12 (LCO/LTO, 10 Wh) systems. The increase in pressure (DPe) at overcharged state reflected well the electrode chemistry. DPe of the LFP/Gr system (2.6 kPa/Wh) was lower than that of the NCA/Gr system (7.0 kPa/Wh). The difference was derived from the cathode stability at the overcharge state. DPe of the LCO/LTO system (4.6 kPa/Wh) was lower than that of the NCA/Gr system. The stability of the LTO anode contributed the lower DPe of the LCO/LTO system than that of the NCA/Gr system. As presented above, we can quantitatively estimate the abuse event of the lithium-ion batteries with various chemistries and capacities by using developed forced destruction system.