Investigation of the electro-mechanical behavior of automotive high voltage busbars under combined electrical load with varying indenter geometry and environmental conditions

As high voltage systems for electrified vehicles and their electronic components exhibit hazardous potential during abuse situations, their development needs special consideration. Battery busbars, representing current-carrying components, pose a special threat in the event of a vehicle crash. While the behavior of Li-Ion cells under different crash loads has already been investigated, there is no detailed knowledge about the electro-mechanical behavior of busbars during crash situations. Therefore, this paper focuses on combining mechanical and electrical loads on thermoplastic-insulated battery busbars. The conducted experimental work includes mechanical penetration of the insulation with various indenter geometries. Simultaneously, a high electrical potential was applied between the indenter and the conducting copper of the busbar. To detect the failure of the busbar, which is considered an electrical short circuit, insulation resistance was measured. Furthermore, the investigation includes the influence of humidity and lower voltage on the electro-mechanical behavior to simulate operating conditions. The results of this paper contribute to current knowledge in meeting the challenges that arise in developing safe vehicle batteries. The critical load limits and failure behavior can be used to improve the prediction accuracy of hazardous situations for the development and design process of high voltage battery systems.