Experimental and Computational Research on the Thermal Conductivities of Li/SOCl₂Batteries

Abstract

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/SOCl 2 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/SOCl 2 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/SOCl 2 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.

Measurement of Multiscale Thermal Transport Phenomena in Li-Ion Cells: A Review

“…There have been a few experimental measurements reported in literature for the cell-level thermal property measurements. Some of these are based on primarily thermal methods [56][57][58][59], whereas others are based on the coupling between thermal transport and electrochemical properties [60,61]. It is important for such measurements to account for anisotropy due to the rolled/folded nature of the electrode roll.…”

“…The axial thermal conductivity of a Li-ion cell has also been measured using a comparative method to obtain the heat flow through a battery indirectly, while preventing heat loss via thermal compensation [56]. The thermal compensation system consists of a heater which reduces the radial temperature gradient to minimize the radial heat losses.…”

“…In this work, the radial thermal conductivity was estimated to be around 1.0 W/m K from the known thermal conductivities of the electrode stack components, ignoring the thermal contact resistances. Axial thermal conductivity was reported to range from 6.83 to 4.25 W/m K over an entire discharge process [56].…”