Wang Huan, Luo Hang, Guo Ru, Peng Jiajun, He Guanghu, Hu Deng, Yang Xiwen, Zhang Dou
Powder Metallurgy Research Institute, State Key Laboratory of Powder Metallurgy, Central South University, Changsha, Hunan, 410083, China.
Department of Mechanical and Automation Engineering, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong, 999077, China.
Small. 2025 Aug;21(33):e2504788. doi: 10.1002/smll.202504788. Epub 2025 Jun 20.
Advances in high-temperature-resistant polymer dielectric present a crucial opportunity for next-generation electrostatic energy storage in power electronics. However, the practical application of polymer dielectrics at elevated temperatures (above 150 °C) is largely limited due to the exponential increase in conduction loss under the high thermo-electric field. In this work, N and S atom-doped carbon polymer dots (NSCPDs) engineered dual-barrier to address the critical issue of conduction loss is utilized. Specifically, the doping elements of N and S heteroatoms enhance the NSCPDs' electron affinity and facilitate the formation of deeper traps with energy levels of 1.60 eV compared to pristine CPDs (1.07 eV). Furthermore, the Coulomb blocking effect induced by quantum-sized NSCPDs can capture electrons and tortuous the electron transport path. Therefore, this constructed "Coulomb blockage-trap barrier" dual energy barrier effectively suppresses carrier migration and lowers leakage current, enabling the 0.5 wt.% NSCPDs/PEI composite to attain a remarkable energy storage density of 3.49 J cm at 200 °C, which represents a 60% enhancement compared to pristine PEI (2.21 J cm). The composite simultaneously demonstrates excellent efficiency (η > 90%) and robust cycling stability over 10 cycles. This study provides a generalizable materials design paradigm for the development of high-temperature polymer dielectrics.
耐高温聚合物电介质的进展为电力电子领域的下一代静电能量存储提供了关键机遇。然而，由于在高温（高于150°C）下热电场上传导损耗呈指数增长，聚合物电介质在高温下的实际应用受到很大限制。在这项工作中，利用了氮和硫原子掺杂的碳聚合物点（NSCPDs）设计的双势垒来解决传导损耗这一关键问题。具体而言，氮和硫杂原子的掺杂元素增强了NSCPDs的电子亲和力，并促进了与原始CPDs（1.07 eV）相比能级为1.60 eV的更深陷阱的形成。此外，量子尺寸的NSCPDs诱导的库仑阻塞效应可以捕获电子并使电子传输路径弯曲。因此，这种构建的“库仑阻塞-陷阱势垒”双能量势垒有效地抑制了载流子迁移并降低了漏电流，使得0.5 wt.%的NSCPDs/PEI复合材料在200°C时能够获得3.49 J cm的显著储能密度，与原始PEI（2.21 J cm）相比提高了60%。该复合材料同时展现出优异的效率（η>90%）以及在10次循环以上的强大循环稳定性。这项研究为高温聚合物电介质的开发提供了一种可推广的材料设计范例。
