Composite phase-change material of encapsulating calcium chloride hexahydrate by calcium-based metal organic framework

Abstract

The invention relates to a composite phase-change material in which calcium chloride hexahydrate is encapsulated by a calcium-based metal-organic framework and a preparation method thereof, belonging to the field of phase-change materials. The composite phase change material of the present invention is composed of 65%-90% inorganic hydrate salt phase change material-calcium chloride hexahydrate and 10%-35% calcium-based metal organic framework. The feature of the present invention is that calcium chloride hexahydrate is confined in the nano-scale pores of the metal-organic framework, and the calcium chloride that cannot be completely dissolved after melting will deposit in the pores of the metal-organic framework, which can fully contact with water to ensure the next time The solidification and crystallization process proceeds smoothly without phase separation; the crystal form difference between the calcium-based metal-organic framework and calcium chloride hexahydrate is within 15%, and the metal-organic framework can be used as a nucleation matrix for calcium chloride hexahydrate crystallization , making the supercooling of calcium chloride hexahydrate within 2oC. The composite phase change material of the present invention solves the problems of leakage, supercooling and phase separation of calcium chloride hexahydrate, and at the same time can maintain stable performance in the air, and more importantly, the raw material is cheap, the process is simple, and the reaction conditions are mild , and its industrial production has high competitiveness.

Description

technical field [0001] The invention relates to a composite phase change material with excellent cycle performance and low supercooling degree and a preparation method thereof, which uses calcium chloride hexahydrate as an energy storage material, and a calcium-based metal organic framework as an encapsulation material and a nucleation matrix at the same time. Background technique [0002] As a clean and efficient thermal energy storage material, phase change materials have attracted widespread attention. Their unique energy storage constant temperature and high energy storage density characteristics make them have broad application prospects in solar energy utilization, building energy conservation, and temperature control of electronic devices. Among them, inorganic hydrated salt phase change materials have the advantages of high energy storage density, low cost, and high thermal conductivity, but their supercooling and phase separation phenomena limit their further widespr...

AI Technical Summary

Problems solved by technology

Among them, inorganic hydrated salt phase change materials have the advantages of high energy storage density, low cost, and high thermal conductivity, but their supercooling and phase separation phenomena limit their further widespread use.

Supercooling means that the inorganic hydrate salt cannot crystallize at a few degrees, tens of degrees or even tens of degrees below its phase transition temperature, so that the inorganic hydrate salt phase change material cannot crystallize and release heat at the required temperature, and even cannot Complete the melting-crystallization cycle; and phase separation means that after the inorganic hydrate salt is melted, the inorganic salt cannot be safely dissolved in the crystallization water and then precipitates to the bottom of the solution, which greatly reduces the service life of the inorganic hydrate salt phase change material, so it solves the problem of inorganic hydrate salt The supercooling and phase separation problems are the basis of its application

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