Comparative study on substitute triggering approaches for internal short circuit in lithium-ion batteries

Internal short circuit is among the most common causes of thermal runaway in lithium-ion batteries. Substitute triggering approaches are of great significance to internal short circuit research. This paper compares the performance of five substitute triggering approaches for internal short circuit, including (1) triggering with phase-change materials, (2) shape-memory alloys, (3) using artificially induced dendrite growth, (4) equivalent resistance, and (5) nail penetration. The thermal-electrical coupled features, controllability, similarity to real accidents and repeatability of the test are discussed by experimental and modelling analysis. The results show that the triggering approaches with phase-change materials and shape-memory alloys are controllable to trigger specific types of the internal short circuit but complex in experimental preparation. The triggering approach by artificially induced dendrite growth may best simulate the self-induced internal short circuit in real-time applications but with poor controllability. The triggering approach using equivalent resistance can be beneficial for calibrating the electrochemical-thermal coupled model, but no real internal short circuit in tests. Nail penetration is the easiest one to be conducted but has poor repeatability. The four classes of the internal short circuit are analyzed to reveal the relationship between physic phenomenon and thermal runaway. This paper guides the study of internal short circuit mechanism and safety evaluation.