Chi Fengyao, Hu Yajie, He Wenya, Weng Chuanxin, Cheng Huhu, Li Chun, Qu Liangti
Key Laboratory of Organic Optoelectronics & Molecular Engineering, Ministry of Education, Department of Chemistry, and State Key Laboratory of Tribology, Department of Mechanical Engineering, Tsinghua University, Beijing, 100084, P. R. China.
Small. 2022 May;18(18):e2200916. doi: 10.1002/smll.202200916. Epub 2022 Mar 30.
The filtering capacitor plays an essential role in the ever-increasing electronics for current stability in complicated environments. However, because of the low specific capacitance and bulky volume, current filtering devices have difficulty satisfying the harsh temperature environment and small size for supercomputers, electric vehicles, aircraft and so on. Therefore, an ultra-fast electrochemical capacitor is developed on the basis of vertically oriented graphene iongel electrodes (GI-EC), which demonstrates excellent alternate current line-filtering performance with both hot tolerance of up to 150 °C and a wide voltage window of 4 V. Because of the particularly oriented graphene nanosheets induced fast ion transport, this ionic electrochemical capacitor displays a high areal specific energy density of 1784 µF V cm with a phase angle of -80.0° (120 Hz) at 150 °C, which is greater than most of the reported electrochemical capacitors. Moreover, it can filter arbitrary waveforms to smooth direct current signals and works well with a wide frequency range from 10 to 10 Hz. The easy integration of GI-ECs in series or parallel can also further deliver desired capacitances or high voltages. The GI-EC with high-rate performance, wide voltage window, and high-temperature adaptability presents a great promise for universally applicable filtering capacitors.
滤波电容器在日益复杂的电子设备中对于稳定电流起着至关重要的作用。然而，由于比电容低且体积庞大，当前的滤波装置难以满足超级计算机、电动汽车、飞机等对恶劣温度环境和小尺寸的要求。因此，基于垂直取向的石墨烯离子凝胶电极（GI-EC）开发了一种超快速电化学电容器，它展示出优异的交流线路滤波性能，耐热高达150°C，电压窗口宽达4V。由于特别取向的石墨烯纳米片促进了快速离子传输，这种离子电化学电容器在150°C时具有1784µF V cm的高面积比能量密度以及-80.0°（120Hz）的相角，这比大多数已报道的电化学电容器都要高。此外，它能够过滤任意波形以平滑直流信号，并且在10至10Hz的宽频率范围内都能良好工作。GI-EC易于串联或并联集成，还能进一步提供所需的电容或高电压。具有高倍率性能、宽电压窗口和高温适应性的GI-EC为通用滤波电容器展现出了巨大的前景。
