An improved method for measurement of radial thermal conductivity of cylindrical bodies

Abstract

Li-ion cells are ubiquitously found in day to day electronic devices due to their high power density storage capacity. These batteries are known to exhibit sharp reduction in performance at high temperature. Due to this, several attempts have been made in the past to measure thermal properties of the Li-ion cell. This work improves upon past measurements by showing that heat loss during measurements is non-negligible, and by developing an analytical model to account for such heat loss. Experimental measurements carried out on multiple materials demonstrate non-negligible heat loss. When accounted analytically, these data result in thermal conductivity values that are in close agreement with independently-measured values for Acrylic and Delrin. A D-optimality criterion is used for improving measurement accuracy. Measurements are also carried out on a Li-ion cell in order to accurately determine its radial thermal conductivity. The accurate measurement of thermal properties enabled by this work may facilitate improved thermal design of Li-ion based energy conversion and storage devices.