Experimental study on the thermal behaviors of lithium-ion batteries under discharge and overcharge conditions

Iron oxide modified montmorillonite (MMT) as flame retardant was used to polyvinyl chloride (PVC), and the flame retardant and smoke-suppressant properties of the PVC were investigated by the smoke density rating and cone calorimeter tests (CONE), and the thermal degradation behaviors of PVC were studied by thermogravimetric analysis (TG) in air atmosphere. The activation energies for the first stage of thermal degradation were obtained following the equation of Kissinger. The mechanical properties testing resultant data showed that iron oxide modified MMT had little effect on the tensile strength of the sample. The CONE result indicated that iron oxide modified MMT could reduce the heat release rate in flame retardant PVC: a more compact char residue formed on the surface of the sample including iron oxide modified MMT during the combustion process. The TG result showed that the sample with modified iron oxide MMT had higher thermal stability than the pure PVC. Besides, the PVC treated with modified MMT showed high activation energy.