The Thermal Properties of CH3COONa•3H2O as Suitable Energy Storage Materials Enhanced by BNNSs

Sodium acetate trihydrate (CH3COONa•3H2O, SAT), as one kind of medium and low temperature inorganic hydrated salts, has high latent heat and suitable phase transition temperature. However, there are some problems such as supercooling, phase separation and poor cycle stability. In this paper, boron nitride nanosheets (BNNSs) and alumina (Al2O3) were used as nucleating agents, sodium carboxymethyl cellulose (CMC) was used as the thickener to inhibit the supercooling and phase separation of SAT successfully. BNNSs can also improve the thermal conductivity of SAT. It was found that the addition of 0.5 wt% Al2O3 can reduce the supercooling to 5.11 ℃ of SAT, and the addition of 1 wt% CMC can inhibit the phase separation phenomenon of SAT. The addition of BNNSs can further reduce the supercooling of SAT (0.63 ℃) and enhance the heat transfer characteristics of SAT (1.570 W•m-1 •K-1). The prepared composite has good thermal storage performance and cycle stability.