Reduced Thermal Mathematical Model Generation of a Li-ion Battery Block

As a part of the power subsystem in spacecraft, batteries face a less severe environment, but they are sensitive to thermal changes under strict thermal requirements. In order to understand the thermal behavior, the best and cost-effective method is to use a structural thermal representative of the design, apply flight-like conditions, and create a simulation model. In order to fulfill this task, a thermal balance test was applied to a newly developed Li-ion battery’s structural thermal model in this study. The thermal control hardware was designed identical to the flight model, and the tests were conducted on eight scenarios simulating the thermal environment in space. A reduced thermal mathematical model was derived using the experimental data inversion. First, the battery parts that indicate similar temperatures were assumed as a unique node, and each part of the structural thermal model was represented by a single node; the heat exchange between each node was modeled by linear conductors. Due to high temperature differences in higher temperature simulations, the model was updated with radiation conductors, which was called hybrid modeling. It was seen that the final mathematical correlation was satisfied with test cases 4 to 8, which cover the operational and non-operational temperature limits of the Li-ion battery.