Preparation And Analysis Of Graphite Foams Infiltrated With Phase Change Materials For Energy Strorage

Graphite foam infiltrated with phase change materials for energy storage is a newcomposite material with graphite foam as skeleton and phase change materials as fillingmaterial. It has a characteristic that can transfer heat quickly. It overcome the shortcomings ofpure phase change material, such as low thermal conductivity, solid-liquid flow and unshaped.It can be used for thermal management of aerospace cabin electronic device.In this paper, two level manufacturing methods were used for preparation of graphitefoam infiltrated with phase change material. The first step was the preparation of highthermal conductive graphite foam, and the second step was making the phase changematerials fill into the graphite foam by the way of infiltration method. The mainly contentresearches of this paper are as follows:1. The11kinds of phase change materials with proper phase change temperature andlarge latent heat were chosen. According to the results of DSC and TGA testing, comparingthe latent, overcool and heat stability, and comprehensively considered, twenty alkenes,acetamide, xylitol and erythritol were finally chosen.2. The template method was used for preparation of graphite foam, which AR mesophasepitch was as raw materials and polyurethane foam was as template. By means of heattreatment the template was removed. After carbonization and graphitization, the graphite foamwas finished. At the same time, the characteristics of graphite foam were investigated. Theresults show that, the graphite foam was possessed of high porosity and graphitization degree,and the its thermal conductivity coefficient is up to54.4W/(m K), it also had certainmechanical strength.3. The melt infiltration method was used for making the liquid phase change material fillinto the3D pore structure of graphite foam. Compared to the infiltration effect of two cases ofwithout pressure and vacuum, it is clearly that vacuum infiltration can obtain better result. Atthe same time, the effects of time and temperature for infiltration effect, the results showedthe effects were not obvious. The pore structure of graphite foam is the seriously influencingfactor of infiltration, the greater porosity the better infiltration effect. The viscosity of theliquid phase change material was also considered, reducing viscosity was beneficial toinfiltrate. At last, the characteristics of the composite phase change material were analyzed, and heat storage capacity, stability, mechanical properties and so on were considered.4. By the means of numerical simulation, the effects of the composite phase changematerials in two typical phase change temperature control device application of spacecraftwere validated, the results showed that the temperature was controlled well.