Comparison of oxygen consumption calorimetry and thermochemistry theory on quantitative analysis of electrolyte combustion characteristics

In this paper, the combustion characteristics of electrolyte containing carbonate and carboxylate solvents ethylene carbonate/dimethyl carbonate/ethyl methyl carbonate (EC/DMC/EMC) and EC/DMC/ethyl acetate (EC/DMC/EA) were studied by using the cone calorimeter. The results showed that when replacing EMC with EA, the flash point of EC/DMC/EA blend increased by 2.2 degrees C and the ignition temperature rose by 2.1 degrees C. When the external heat flux gained from 15 kW/m(2) to 35 kW/m(2), the difference between the peak heat release rate (pHRR) of the two samples widened from 57.3 kW to 111.1 kW, while the relative value did not change significantly, from 19.3% to 20.6%. In addition, the addition of EA increased the fire growth index (FGI) value of the electrolyte by 19.8% on average, which accelerated the fire development process. According to the results of flame temperature, after adding EA, the flame temperature decreased in the whole combustion process at 15 kW/m(2), which reduced by 5.3% and 34.1%, respectively in the two steps. As the heat flux increased, the reduction amplitude declined. Thermochemistry (TC) theory was applied to verify the HRR values and change trend by calculating the theoretical heat release from normalized electrolyte molecules, and the results has been compared with those obtained from the cone calorimeter experiments based on the principle of oxygen consumption (OC) calorimetry, while HRR curves exported from the two methods were with the similar value and trend.

Automated summary

The combustion characteristics of electrolytes containing carbonate and carboxylate solvents were studied in this paper using a cone calorimeter. The findings showed that replacing EMC with EA increased the flash point and ignition temperature of the blend. Additionally, the addition of EA led to an increase in the pHRR difference and FGI value, as well as a decrease in flame temperature. The results from Thermochemistry theory were consistent with those obtained from cone calorimeter experiments.