Study On Dielectric Energy Storage Performance Of Large Area Polymer Composites

At present,the research of dielectric energy storage materials is often devoted to obtaining higher energy storage,ignoring the most important point in the application.The premise and fundamental of a mature application material is stable performance.In order to study the performance stability of the film,a large-area composite film was prepared.Polymer dielectric energy storage materials are often unable to obtain high energy storage due to the limitation of dielectric constant,blocking the pace of research.In order to obtain a dielectric material with high energy storage,high efficiency and good high temperature resistance,the polymer material PVDF with relatively high dielectric constant as the substrate,adding high temperature resistance of linear polymer PMMA,ABS prepared composite materials.The addition of PMMA and ABS enables the composite material to have high efficiency and a certain degree of high temperature resistance while having high dielectric properties,which can cater to electronic components that work under contemporary high temperature requirements,such as inverters in hybrid vehicles.This thesis studies the stability of the electrical properties of the composite film from three aspects,and conceives a multilayer film capacitor from the multilayer ceramic capacitor,which has the characteristics of small size and light weight.The main research is as follows:1.Add polymer PMMA to high-dielectric PVDF,mix with a certain volume fraction to obtain a composite material and cast a large-area composite film.Comparing the performance of the composite film and the cast-out large area PVDF film,it is found that the energy storage efficiency of the composite film has been effectively improved.The energy storage efficiency of PVDF is 57.7%,and the energy storage efficiency of PMMA/PVDF composite is 84.9%.In order to study the stability of the electrical properties of the composite film,three aspects of the application of electrodes with different effective areas,the film in different areas,and the flexibility of the film were studied and tested.Research shows that among the five electrodes with different areas,the maximum difference in energy storage at the same field strength（300 MV/m）is only 0.18 J/cm³,the maximum difference in efficiency is only 2.5%,and the maximum difference in energy storage at a temperature of 90 ^oC is 0.61 J/cm³.In 9 tests in different areas of the large-area film,the same field strength（200 MV/m）energy storage fluctuates by 0.17 J/cm³,the efficiency fluctuates by 1.4%,and the energy storage at a temperature of 90 ^oC fluctuates by 0.15 J/cm³,and the efficiency A change of 2.8%.2.Compared with PVDF,the large-area ABS/PVDF composite film prepared under the same process has a 29.3%increase in efficiency of the composite film.Among the five electrodes with different areas,the maximum difference in energy storage at the same field strength（300 MV/m）is 0.72 J/cm³,and the maximum difference in energy storage at a temperature of 90 ^oC is 0.79 J/cm³.In the test of 9different areas of the large-area film,the energy storage at the same field strength（200MV/m）fluctuates by 0.09 J/cm³,the efficiency fluctuates by 1.5%,and the energy storage at a temperature of 90 ^oC fluctuates by 0.14 J/cm³,and the efficiency a change of 0.9%.3.By studying the design scheme and process of the multilayer capacitor,a multilayer capacitor with 10 layers is designed and prepared.The study found that the capacitance of the film capacitors with 10 layers was greatly improved.The capacitance value of the PMMA/PVDF single-layer composite film is about 7.36×10^-12F at a frequency of 1 k Hz,and the capacitance value of the laminated capacitor is about 3.96×10^-8 F.The capacitance has been greatly improved,and the capacitance of ABS/PVDF laminated capacitor has also been improved to some extent.