萘四甲酸二酐改性的聚醚酰亚胺共聚薄膜高温储能性能研究

In ordcr to tackle the issue ol a significant decrease in diclcctric cncrgy storage Performance of poly (cthcrimidc) (PEI) at high temperature (T>100°C) and in high electric field (E >400 MV/m) due to the increase of conduetivity loss, a copolymerization modification method based on high electron affinity monomer was proposed to improve the high temperature energy storage Performance of PEI. A series of NTCDA-PEI (nPEI) films were prepared by copolymerization of 1,4,5, 8-naphthalenetetracarboxylic dianhydridc (NTCDA) monomers and conventional PEI monomers. The effects of different NTCDA copolymerization ratios on thermal properties, dielectric properties,brcakdown properties and energy storage properties of thc materials were studied. In addition, by leveraging the hopping conductance model and the thermal Stimulation current measurement, the internal mechanism of the influence of the conductance and trap characteristics on the energy storage Performance of thc copolymer films was analyzed. The results showed that thc copolymerized films introduced more electron traps, effectively suppressed the carricr migration at high temperaturc, realized the decrease of conduetive current and the increase of brcakdown clcctric ficld strength, and then improved the discharge energy density and charge and discharge efficiency of nPEl films at high temperature. When the NTCDA's molar content was 1. 5%, thc Performance of the copolymerized film was the best at 150 °C, and the breakdown strength was 574. 35 MV/m, which is 14. 0% higher than that of pure PEI. The maximum discharge energy density was 6. 38 J/cm3, which is 50. 8% higher than that of pure PEI. The charge and discharge efficiency increased from 52. 2% of pure PEI to 88. 7%. This study provides a Solution for the development of energy storage devices suitable for high temperature environments.