Variation laws of heat storage performances and heat storage stability of ZrO2 electrolyte materials with temperature and time

ZrO2 electrolyte is one of key parts of solid electrolyte oxygen sensors. The heat storage performances and heat storage stability of ZrO2 electrolyte influence the performance of solid electrolyte oxygen sensors directly. Sensors work in high-temperature changing environment and the prominent non-harmonic effect of atomic vibration of ZrO2 electrolyte materials can influence heat storage performances and heat storage stability of sensor significantly. To improve performances and thermostability of electrolyte, non-harmonic vibration of atoms were taken into account in this study. The variation laws of heat capacity and heat storage stability of ZrO2 electrolyte materials with temperature and time were investigated by solid physical theories and methods. Moreover, influences of non-harmonic vibration of atoms were discussed. Results demonstrate that the Debye temperature achieves a linear growth as temperature rises due to the nonharmonic effect. The constant-volume specific heat presents a nonlinear growth as temperature rises and it shows an approximate negative exponential attenuation as time goes on. The constant-volume specific heat decreases due to the non-harmonic effect. The reduction amplitude increases firstly and then decreases with time, but it increases gradually as time goes on. Heat storage stability weakens firstly and then enhances with the increase of temperature and it is poorest at about 160K. Heat storage stability is weakened to a small extent due to the non-harmonic effect. The results are basically consistent with other literature results. Research conclusions can provide theoretical references to study stability and service life of solid electrolyte oxygen sensors.