Combined Thermal Runaway Investigation of Coin Cells with an Accelerating Rate Calorimeter and a Tian-Calvet Calorimeter

Commercial coin cells with LiNi0.6Mn0.2Co0.2O2 positive electrode material were investigated using an accelerating rate calorimeter and a Tian-Calvet calorimeter. After cycling charging to the selected states of charge (SOCs), studied under thermal abuse conditions heat-wait-seek (HWS) method heating step 5 K threshold for self-heating detection 0.02 K/min. The onset temperature rise, i.e., runaway events, determined. morphology electrode, negative separator fresh tested compared scanning electron microscopy (SEM). Furthermore, microstructure chemical compositions individual components by X-ray diffraction (XRD) inductively coupled plasma optical emission spectrometry (ICP-OES), respectively. In calorimeter, SOCs (positive separator) heated up constant 0.1 °C/min (ramp mode). Simultaneously, heat flow signals recorded analyze generation. combination three different methods—the HWS ES-ARC, ramp mode on both calorimeter—together post-mortem analysis, give us complete picture processes leading runaway.