Wang Tian-Yu, Li Xiao-Fen, Jie Ziyao, Liu Bai-Xin, Zhang Guixin, Liu Jian-Bo, Dang Zhi-Min, Wang Zhong Lin
State Key Laboratory of Control and Simulation of Power System and Generation Equipment, Department of Electrical Engineering, Tsinghua University, Beijing 100084, China.
Key Laboratory of Advanced Materials (MOE), School of Materials Science and Engineering, Tsinghua University, Beijing 100084, China.
Nano Lett. 2023 Sep 27;23(18):8808-8815. doi: 10.1021/acs.nanolett.3c01987. Epub 2023 Jul 17.
The development of advanced electrical equipment necessitates polymer dielectrics with a higher electric strength. Unfortunately, this bottleneck problem has yet to be solved because current material modification methods do not allow direct control of deep traps. Here, we propose a method for directly passivating deep traps. Measurements of nanoscale microregion charge characteristics and trap parameters reveal a significant reduction in the number of deep traps. The resulting polymer dielectric has an impressively high electrical strength, less surface charge accumulation, and a significantly increased flashover voltage and breakdown strength. In addition, the energy storage density is increased without sacrificing the charge-discharge efficiency. This reveals a new approach to increasing the energy storage density by reducing the trap energy levels at the electrode-dielectric interface. We further calculated and analyzed the microscopic physical mechanism of deep trap passivation based on density functional theory and characterized the contributions of orbital composition and orbital hybridization.
先进电气设备的发展需要具有更高电气强度的聚合物电介质。不幸的是，由于目前的材料改性方法无法直接控制深陷阱，这个瓶颈问题尚未得到解决。在此，我们提出一种直接钝化深陷阱的方法。纳米级微区电荷特性和陷阱参数的测量结果表明深陷阱数量显著减少。由此得到的聚合物电介质具有令人印象深刻的高电气强度、更少的表面电荷积累以及显著提高的闪络电压和击穿强度。此外，在不牺牲充放电效率的情况下提高了储能密度。这揭示了一种通过降低电极 - 电介质界面处的陷阱能级来提高储能密度的新方法。我们基于密度泛函理论进一步计算和分析了深陷阱钝化的微观物理机制，并表征了轨道组成和轨道杂化的贡献。
