Effective Thermal Conductivity of Lithium‐Ion Battery Electrodes in Dependence on the Degree of Calendering

Abstract

The thermal conductivity represents a key parameter for the consideration of temperature control and thermal inhomogeneities in batteries. A high‐effective thermal conductivity will entail lower temperature gradients and thus a more homogeneous temperature distribution, which is considered beneficial for a longer lifetime of battery cells. Herein, the impact of the microstructure within the porous electrode coating obtained by different compression rates and its thermal contact to the current collector is investigated as both factors significantly determine the overall conduction through the electrode. The effective thermal conductivity of two graphite anodes and two lithium nickel manganese cobalt oxide cathodes is evaluated at different compression rates. It is found that the thermal conductivity does not have a monotone dependence on the porosity with changing compression rates. The results show a strong correlation with the adhesion strength, thus a significant impact of the thermal contact resistance between the coating and current collector is assumed.

Using resistor network models to predict the transport properties of solid-state battery composites

“…This thermal conductivity lies within the typical range for sulfidic solid-state electrolytes. 21,30 With a value of 0.71 ± 0.04 W m -1 K -1 , NCM83 shows the highest thermal conductivity of the investigated series in agreement with the thermal conductivities of calendared NCM cathodes reported by Gandert et al 44 An increase in effective thermal conductivity with increasing NCM83 volume fraction is observed.…”

Using resistor network models to predict the transport properties of solid-state battery composites

“…This thermal conductivity lies within the typical range for sulfidic solidstate electrolytes. 21,30 With a value of 0.71 ± 0.04 W m -1 K -1 , NCM83 shows the highest thermal conductivity of the investigated series in agreement with the thermal conductivities of calendared NCM cathodes reported by Gandert et al 44 An increase in effective thermal conductivity with increasing NCM83 volume fraction is observed.…”