Li-ion batteries play an ever-increasing role in our daily life. Therefore, it is important to understand the potential risks involved with these devices. In this work we demonstrate the thermal runaway characteristics of three types of commercially available Li-ion batteries with the format 18650. The Li-ion batteries were deliberately driven into thermal runaway by overheating under controlled conditions. Cell temperatures up to 850 C and a gas release of up to 0.27 mol were measured. The main gas components were quantified with gas-chromatography. The safety of Li-ion batteries is determined by their composition, size, energy content, design and quality. This work investigated the influence of different cathode-material chemistry on the safety of commercial graphite-based 18650 cells. The active cathode materials of the three tested cell types were (a) LiFePO 4 , (b) Li(Ni 0.45 Mn 0.45 Co 0.10)O 2 and (c) a blend of LiCoO 2 and Li(Ni 0.50 Mn 0.25 Co 0.25)O 2 .

Destructive thermal ramp experiments with commercial Li-ion batteries at different state of charge were made. Produced gases were quantified and a causing chemical reaction system is proposed.

Lithium-ion batteries (LIBs) are gaining importance in the automotive sector because of the potential of electric vehicles (EVs) to reduce greenhouse gas emissions and air pollution. However, there are serious hazards resulting from failing battery cells leading to exothermic chemical reactions inside the cell, called thermal runaway (TR). Literature of quantifying the failing behavior of modern automotive high capacity cells is rare and focusing on single hazard categories such as heat generation. Thus, the aim of this study is to quantify several hazard relevant parameters of a failing currently used battery cell extracted from a modern mass-produced EV: the temperature response of the cell, the maximum reached cell surface temperature, the amount of produced vent gas, the gas venting rate, the composition of the produced gases including electrolyte vapor and the size and composition of the produced particles at TR. For this purpose, overtemperature experiments with fresh 41 Ah automotive lithium NMC/LMO—graphite pouch cells at different state-of-charge (SOC) 100%, 30% and 0% are performed. The results are valuable for firefighters, battery pack designers, cell recyclers, cell transportation and all who deal with batteries.

In order to understand the lithium-ion battery (LIB) failing behavior and to prevent failures and their consequences, different LIB safety tests, also called abuse tests, have been developed. This paper focuses on thermal runway (TR) triggered by overtemperature, overcharge and nail-penetration. It shows the setup and the results of the three different TR triggers on two different cell types in a custom-made TR reactor. The investigated cell types are state-of-the-art automotive pouch and hard case cells. The results are discussed in three main categories: thermal behavior, vent gas production and vent gas composition. The results and findings are supposed to be valuable for battery pack designer, car manufacturer and testing institutions for the development of future battery testing facilities and regulations.

Damaged or heavily over-heated Li-ion batteries in electric vehicles can transit into a thermal runaway reaction with further heat and gas release.