The Research Of The Solid-solid Phase Change Material (C_nH_2n+1)₂MCl₄ And Its Binary Systems For Energy Storage

Energy usage is a driving force of the development of our human society. Now the worldwide energy resource crisis urges the new energy exploiting and the energy save technology however the energy storage technology is one of the key factors to the problem solving. Using solid-solid phase change material to store energy has so many advantages to the other materials .But there are few suitable these materials for practice usage now. A set of materials with formula (C_nH_2n+12MCl₄ is a typical solid-solid phase change material and it possess almost all the merits of the solid-solid phase change materials .The only fault of the material for practice usage is its higher price and lower enthalpies . So it is obviously valuable to promoter the property price ratio of the materials. For this reason we take element analysis, X-ray diffraction, IR spectra at various temperatures and differential scanning calorimetric (DSC) as experimental methods and study the solid-solid phase change materials and their binary systems systemically in four sections for the dissertation.In the first section a new serial materials of this kind has been synthesized and element analysis, X-ray diffraction and IR spectra technology were used to represent them. Differential scanning calorimetric (DSC) and thermal analysis kinetics (TAK) results shown some of these materials have the proper property for energy storage. It enlarges the scope of the materials and is worth to understand the relations between the structure and the property of these materials.In the second section the binary systems of the materials with different metals ion were prepared. The interlayer data of the binary systems of the materials were inferred from the X-ray diffraction results which having been gotten earlier. The results of differential scanning calorimetric indict that the enthalpies of the binary systems of the two associated octahedral metal ion compounds divide in phase change temperature range while the single tetrahedral ion binary systems convene. Addition to the TAK results this phenomenon is useful to better the energy storageproperly of this kind of materials.In the third section the binary systems of the materials of different chains were prepared. Differential scanning calorimetric (DSC) was used to determine the phase change temperatures of the CisCoCl/CioCoCl and C12C0CI/C10C0CI binary systems at different components. Aided by the X-ray diffraction and IR spectra at various temperatures two phase diagram were established. Some data of the energy storage properties of these materials were determined.In the last section the feature of the phase change of the materials was treated theoretically. The mechanics of the phase change of the materials was discussed .And a relation between the possible limit enthalpies and the chains n was given. The factors that make the boundaries of the quality that we want to promoter are illustrated. All the results will be beneficent to find the alterative materials with higher property price ratio.