Abstract: In order to study the explosion characteristics of mixed dust from lithium iron phosphate batteries, the Siwek-20 L explosion test device was used to investigate the lower explosion limit, the pressure generated by the explosion, the rate of increase in explosion pressure and the explosion index of lithium iron phosphate battery dust. At the same time, the thermal stability of the organic components of lithium iron phosphate batteries was analyzed by means of a thermogravimetric analyzer. The results show that in the organic components of lithium iron phosphate batteries, polypropylene begins to decompose at 257.55 ℃, and the mass loss rate reaches 98.70% when it rises to 440.60 ℃. Polyvinylidene fluoride exhibits good thermal stability below 400.00 ℃. When the temperature rises to 402.73~504.89 ℃, its weight loss rate increases significantly, with a mass loss rate of approximately 62.63%. The lower explosive limit concentration of lithium iron phosphate battery dust with a median particle size (D50) of 17.69 μm is 660~680 g/m³, the maximum explosion pressure is 0.439 MPa, the maximum pressure rise rate is 18.752 MPa/s, the maximum explosion index is 5.09 MPa•m/s. According to the ISO 6184-1∶1985 classification standard, the explosion hazard level is St 1, and the explosion attribute is weak.

Key words: lithium iron phosphate battery dust, explosion pressure, rate of explosion pressure rise, explosion index, thermal stability