Current electrified vehicles predominantly use Li-ion battery systems. Li-ion battery features high energy density as well as good durability. However, critical operating conditions can lead to a thermal runaway reaction and intense heat evolution as well as to gas release. In the project ISALIB the intrinsic risk of thermal runaway depending on the used materials (anode type, cathode type, electrolyte) and the type of error (over temperature, over load and so on) is examined. The result is the comprehensive risk assessment of the relevant automotive applications for Li-ion batteries.