Experimental and computational research on the thermal conductivities of Li/SOCl₂ batteries

A modified steady-state thermal conductivity measurement method that adds a thermal compensation device (TCD) is proposed. Calibration experiments verify that the heat loss rate of the test apparatus is less than 5.0%. The thermal conductivities of the spirally wound cylindrical Li/SOCl2 batteries are measured at different discharge currents (1.0 A, 1.2 A, and 2.0 A) and at different depths of discharge (DOD) (0% DOD, 50% DOD, and 100% DOD). The measured values exhibit a dependence on the DOD and independence from the discharge current. To validate the test method, a model combining a statistical averaging method with a hybrid computing strategy is established to simplify the calculation model; the model considered influencing factors, such as physical uncertainty and the shape irregularity of the Li/SOCl₂ battery. The tendency for thermal conductivity to decrease when DOD increases demonstrates that the measurement and simulation are consistent. The analysis results indicate that the consumption coefficient (f) is an important factor for the thermal conductivity of a Li/SOCl₂ battery. At a constant DOD, the overall axial thermal conductivities decrease significantly when the consumption coefficient increases. Therefore, when designing batteries, the change in the thermal conductivities relative to the consumption coefficient and DOD should be monitored.