在介电聚合物中超高能量密度 靠近玻璃过渡温度
Yuting Wan1, Hang Luo1, Zhongna Yan2
1State Key Laboratory of Powder Metallurgy, Central South University, Changsha, Hunan, 410083, P. R. China.
Advanced materials (Deerfield Beach, Fla.)
|August 23, 2025
概括
一个新的分子扭曲策略增强介电聚合物用于高温电容储能. 这种设计阻断了电子迁移,使高级应用在玻璃过渡温度 (Tg) 附近的性能稳定.
科学领域:
- 材料科学
- 聚合物化学
- 能量储存
背景情况:
- 高工作温度 (To) 对介电聚合物在储能方面至关重要,特别是对于新能源汽车和动力电子产品.
- 现有的高玻璃过渡温度 (Tg) 聚合物如卡普顿聚合物由于电子移位而呈现低To (<150°C).
- 由于链内伊米德环平面化和链间捐赠体-接受体 (D-A) 堆叠,导致高温下泄漏电流的升高.
研究的目的:
- 为高温介电聚合物开发分子设计策略,这些聚合物在Tg附近保持高电阻.
- 阻断链内和链间电子迁移路径,从而提高热稳定性和能量储存性能.
- 引入一种在高温下克服限制的介电聚合物设计范式.
主要方法:
- 提出了一种分子扭曲的结构锁定策略来破坏电子移位路径.
- 利用密度功能理论 (DFT) 计算来分析聚胺中的电子移位机制.
- 合成并描述了一种包含分子扭曲设计的新型介电聚合物.
主要成果:
- 设计的聚合物在250°C时表现出6.8 × 10^13 Ω m^-1的超高电阻,明显超过PEI在50°C时的电阻.
- 分子扭曲有效地破坏了链内胺环平面化和链间D-A面对面堆叠.
- 实现了4.3Jcm^3的超高放电能量密度,其性能优于现有的高Tg介电聚合物.
结论:
- 分子扭曲构造锁定策略在制造具有抑制电子迁移的高温介电聚合物方面是有效的.
- 这种聚合物具有特殊的电阻性和能量密度,使其适用于高温储能应用.
- 这项研究提供了一个有价值的设计原则,用于克服先进电子设备中介电聚合物的温度限制.
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