Tuning the Frequency Response of Fractional-Order Microsupercapacitors

双电层电容器（EDLC）是电化学电容器的一个子集，可以在直流和相对远离直流的频率下存储和传递电能，其有效电容介于铝电解电容器和二次电池之间。它们主要用于传统的能量存储应用中作为二次电源，例如微处理器和太阳能电池。它们也被证明是振荡器和滤波器电路、分数阶控制器和分数阶谐振器中的高效能量器件。然而，由于它们的电极的性质和多孔结构以及它们的电极/电解质相的界面电化学，它们的性能指标的许多基本方面仍然没有很好地理解，并且合理的设计实际上是不存在的。特别是，EDLC在远离直流工作时表现出耗散、电容性行为，阻抗角在-90度和0度之间。在本项目中，将设计和制造基于结构化2D和3D电极阵列的小型化EDLC，目的是理解和控制其非理想的分数阶行为。我们将开发和研究掺杂电解质的影响，以调整电场诱导的离子传输中存在的物理障碍。预期的结果是一个通用的程序和设计规则，以适用于微调和控制的阻抗相移的EDLC和他们的能量功率性能。使用平均场泊松-能斯特-普朗克模型进行建模和仿真，以提供对器件频率响应的基本理解。还将结合基于RC的电路开发使用分数阶数学工具和等效电路模型的系统级建模。将验证EDLC的可控分数阶行为，并展示其频域应用。该项目将有助于佛罗里达国际大学的研究，教育和多样性的目标。该项目的目标是解决缺乏知识的频域指标和性能的分数阶电容器使用实验和建模方法。我们的目标是研究以下内容：（1）电极-电解质界面规格和电解质参数，使调谐的电特性的EDLC在一个扩展的频率带宽：（2）电动效应发生在EDLC的支持电解质，以及它们如何影响的频域指标的设备;（3）使用3D电路互连和有限元方法建模以理解整体电特性;（4）双电层电容器的频率响应及其在（频域）滤波和（时域）该奖项反映了NSF的法定使命，并已被认为是值得通过评估使用基金会的知识产权的支持。优点和更广泛的影响审查标准。

Electric double-layer capacitors (EDLC) are a subset of electrochemical capacitors that can store and deliver electrical energy at dc and relatively far-from-dc frequencies with effective capacitance between that of aluminum electrolytic capacitors and secondary batteries. They are mostly employed in conventional energy storage applications as secondary power source, such as microprocessors and solar batteries. They have also been demonstrated as efficient energy devices in oscillators and filters circuits, fractional-order controllers, and fractional-order resonators. However, because of the nature and porous structure of their electrodes and the interfacial electrochemistry of their electrodes/electrolyte phase, many fundamental aspects of their performance metrics are still not well understood, and rational design is practically nonexistent. In particular, EDLCs exhibit a dissipative, resistive-capacitive behavior when operating away from dc with an impedance angle anywhere between -90 and 0 deg. In this project, miniaturized EDLCs based on structured 2D and 3D electrode arrays will be designed and fabricated with the objective of understanding and controlling their non-ideal, fractional-order behavior. We will develop and study the effect of doped electrolytes in order to tune the electric-field-induced ionic transport in the presence of physical obstacles. The expected outcome is a general procedure and design rules to apply in order to fine-tune and control the impedance phase shift of EDLCs and their energy-power performance. Modeling and simulation using mean-field Poisson-Nernst-Plank model will be carried out in order to provide a fundamental understanding of the frequency response of the devices. System-level modeling using fractional-order mathematical tools and equivalent circuit models will also be developed in connection with RC-based circuitry. The controllable fractional-order behavior of the EDLCs will be verified and their frequency-domain application will be demonstrated. This project will contribute to the research, education, and diversity goals of Florida International University.The objectives of this project are to tackle the lack of knowledge on the frequency-domain metrics and performance of factional-order capacitors using both experimental and modeling approaches. We aim to investigate the following: (1) electrode-electrolyte interface specifications and electrolyte parameters that enable the tuning of the electrical characteristics of an EDLC over an extended frequency bandwidth; (2) the electro-kinetic effects taking place in the supporting electrolyte of an EDLC, and how they affect the frequency-domain metrics of the device; (3) modeling using 3D-circuit interconnects and finite-element methods to understand the overall electric characteristics; and (4) the frequency response of the EDLCs and their application in (frequency-domain) filtering and (time-domain) memory applications.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.