Wang Baotieliang, Zou Jiawei, Liu Bo, Wang Zhaoyang, Li Bei, Xu Donghua, Li Qi, Luan Shifang
State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, China.
School of Applied Chemistry and Engineering, University of Science and Technology of China, Hefei 230026, China.
Mater Horiz. 2025 Jun 30;12(13):4841-4850. doi: 10.1039/d4mh01687d.
Advancements in microelectronics and electrical power systems require dielectric polymeric materials capable of maintaining high discharged energy density and charge-discharge efficiency over a wide temperature range. Intrinsic polar polymers with enhanced dielectric constants are crucial for achieving high energy density and are extensively utilized at room temperature. However, the compatibility of high energy density and efficiency remains a significant challenge. Most polar polymer dielectric films suffer a considerable drop in capacitive performance as the temperature rises, with efficiency falling below 50%, and the waste Joule heat generated from conduction loss may lead to a vicious cycle. Herein, a new strategy of restraining dipole interactions in polar polymers is proposed to achieve optimal molecular chain stacking configurations, significantly decreased conductivity, and deeper charge trap sites, thus exhibiting enhanced energy density with outstanding efficiency at elevated temperatures. Remarkably, an energy density of 4.61 J cm at an ultra-high efficiency above 95% was achieved, as well as cycling stability exceeding 150 000 cycles with an energy density of 2.4 J cm at 150 °C, surpassing current high polar polymers and most advanced polymer composites. This discovery presents a promising solution for preserving high capacitive performance in polar polymeric materials at elevated temperatures.
微电子和电力系统的发展需要能够在很宽的温度范围内保持高放电能量密度和充放电效率的介电聚合物材料。具有增强介电常数的本征极性聚合物对于实现高能量密度至关重要，并且在室温下被广泛使用。然而，高能量密度和效率的兼容性仍然是一个重大挑战。大多数极性聚合物介电膜随着温度升高电容性能会大幅下降，效率降至50%以下，并且传导损耗产生的废焦耳热可能会导致恶性循环。在此，提出了一种抑制极性聚合物中偶极相互作用的新策略，以实现最佳的分子链堆积构型、显著降低的电导率和更深的电荷陷阱位点，从而在高温下表现出增强的能量密度和出色的效率。值得注意的是，在高于95%的超高效率下实现了4.61 J/cm³的能量密度，以及在150°C下能量密度为2.4 J/cm³时超过150000次的循环稳定性，超过了目前的高极性聚合物和大多数先进的聚合物复合材料。这一发现为在高温下保持极性聚合物材料的高电容性能提供了一个有前景的解决方案。
