Effect of embedding sodium acetate trihydrate on the Ag anode in an electrical nucleation cell of a supercooled latent heat storage material

Abstract

Electrical nucleation was investigated by using a Ag anode with sodium acetate trihydrate crystals embedded on the surface in a supercooled aqueous solution of sodium acetate (45–54 wt%) as a latent heat storage device. Rapid electrical nucleation was achieved by applying a direct-current voltage of greater than 1.4 V. When the voltage was set to greater than 1.8 V, the induction time of the electrical nucleation increased as the number of operations increased. The Ag anode life increased when the voltage was less than 1.8 V. When the voltage was 2.0 V, the anode resistance increased as the number of operations increased, with the anode surface deteriorating and forming silver oxide. The repeat life of electrical nucleation at voltages less than 1.8 V was about two times longer than that at voltages greater than 1.8 V. The repeat performance of electrical nucleation and the stability of the supercooled solution were found to depend on the surface roughness, Ra, of the Ag anode. The Ra value was optimized to be in the range 0.6 ≤ Ra ≤ 1.0 µm.