The through-plane thermal diffusivity was measured for the electrodes using laser flash analysis (LFA 467 HyperFlash, Netzsch). This measurement was carried out at temperatures of -5 °C, 10 °C, 25 °C, 40 °C, and 55 °C using a nitrogen purge gas. For this measurement samples of 20 mm x 20 mm were used, each sample was measured five times at each temperature.