Scalable Polyimide‐Organosilicate Hybrid Films for High‐Temperature Capacitive Energy Storage
Scalable Polyimide‐Organosilicate Hybrid Films for High‐Temperature Capacitive Energy Storage
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用于高温电容储能的可扩展聚酰亚胺-有机硅酸盐混合薄膜
DOI：
10.1002/adma.202211487
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发表时间：
2023
期刊：
影响因子：
--
通讯作者：
Hong Wang
中科院分区：
文献类型：
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作者：
Jiufeng Dong;Li Li;P. Qiu;Yupeng Pan;Yujuan Niu;Liang Sun;Zizhao Pan;Yuqi Liu;Lijun Tan;Xinwei Xu;Chen Xu;G. Luo;Qing Wang;Hong Wang
高温聚合物电介质在下一代微电子和电力系统中具有广阔的应用前景。然而，介电聚合物在高温下的电容能量密度受到载流子激发和传输的严重限制。在此，提出了一种分子工程策略，通过将氨基多面体低聚倍半硅氧烷（NH2-POSS）与聚酰亚胺（PI）的链端键合来调节聚合物中的体积限制传导。实验研究和密度泛函理论（DFT）计算表明，宽带隙Eg≈6.6 eV的末端基团NH2-POSS增加了PI的能带能级，并诱导杂化膜中局部深陷阱的形成，从而显着抑制载流子传输。在200℃时，混合薄膜同时表现出3.45 J cm−3的超高放电能量密度和2.74 J g−1的高重量能量密度，充放电效率>90%，远远超过介电聚合物和几乎所有其他聚合物纳米复合材料所实现的充放电效率。此外，NH2-POSS封端的PI薄膜在200℃下表现出优异的充放电循环性能（>50000）和功率密度（0.39 MW cm−3），使其成为高温高能量密度电容器的有希望的候选者。这项工作代表了一种新颖的策略，可扩展聚合物电介质，在恶劣环境下运行具有卓越的电容性能。
High‐temperature polymer dielectrics have broad application prospects in next‐generation microelectronics and electrical power systems. However, the capacitive energy densities of dielectric polymers at elevated temperatures are severely limited by carrier excitation and transport. Herein, a molecular engineering strategy is presented to regulate the bulk‐limited conduction in the polymer by bonding amino polyhedral oligomeric silsesquioxane (NH2‐POSS) with the chain ends of polyimide (PI). Experimental studies and density functional theory (DFT) calculations demonstrate that the terminal group NH2‐POSS with a wide‐bandgap of Eg ≈ 6.6 eV increases the band energy levels of the PI and induces the formation of local deep traps in the hybrid films, which significantly restrains carrier transport. At 200 °C, the hybrid film exhibits concurrently an ultrahigh discharged energy density of 3.45 J cm−3 and a high gravimetric energy density of 2.74 J g−1, with the charge‐discharge efficiency >90%, far exceeding those achieved in the dielectric polymers and nearly all other polymer nanocomposites. Moreover, the NH2‐POSS terminated PI film exhibits excellent charge‐discharge cyclability (>50000) and power density (0.39 MW cm−3) at 200 °C, making it a promising candidate for high‐temperature high‐energy‐density capacitors. This work represents a novel strategy to scalable polymer dielectrics with superior capacitive performance operating in harsh environments.