Trident™ Thermal Conductivity Application Highlight: Characterization of a Battery Pouch’s Anisotropic Thermal Conductivity
This Application Highlight illustrates C-Therm’s FLEX Transient Plane Source (TPS) system being utilized to investigate the anisotropic thermal conductivities of a lithium pouch battery cell using the Single-Sided Utility.
Battery cells emit heat as they discharge electricity. Improper thermal management in a battery system can lead to capacity degradation, reduced efficiency, accelerated aging, and, in extreme cases, catastrophic safety hazards such as thermal runaway. A comprehensive characterization of the battery’s thermal properties, including thermal conductivity, is essential for successful thermal management.
Figure 1. Swollen Lithium Pouch Battery: One of the Consequences of Improper Thermal Management
Due to the multilayered structure of batteries, their thermal-conductivity profiles are usually anisotropic; heat transfer in the through-plane (Z) direction is often overpowered by that in the in-plane (R) direction. The separation of these two thermal conductivity directionalities is made possible by C-Therm’s FLEX TPS thermal conductivity sensor. It should be noted that the through-plane direction is influenced by thermal contact resistance between the cell layers. As such, mechanical pressure, surface roughness, etc., will directly influence the effective thermal conductivity.