Investigation into thermal runaway of Li-ion batteries

Li-ion cells with the dimension 18650 are charged to defined states of charge and placed in a specially designed sample holder to fix them in place during the test series in the electrically heated stainless steel tubular reactor. The sample holder contains thermocouples and voltage sensing connectors to monitor the cell during the heat ramp experiment. During the thermal runaway several characteristic phases are observed like melting of the separator, evaporation of the electrolyte and cell disintegration. The characterisations of the cells are performed by online monitoring of cell temperature and voltage as well as gas sampling during the test.