High density capacitors: bridging the performance gap between conventional capacitors and electric double layer capacitors

高密度电容器：缩小传统电容器和双电层电容器之间的性能差距

• 批准号: 1611060
• 负责人: Zhaoyang Fan
• 金额: $ 34.96万
• 依托单位: Texas Tech University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-08-01 至 2020-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1611060&HistoricalAwards=false
• 关键词: density; capacitors; bridging; performance; gap

The low capacitance density of electrolytic capacitors is becoming a limiting factor on circuit board profile and circuit performance. The capacitance density of the current generation of electric double layer supercapacitors is several orders of magnitude higher, but they are limited to a charge-discharge rate of about 1 second, or a characteristic frequency of 1 hertz, and thus not suitable for those circuit applications requiring capacitors that must run in the hundreds of hertz to kilohertz range. In other words, there exists a significant performance gap, in terms of capacitance/frequency, between currently available supercapacitor and traditional circuit capacitor technologies. The proposed research addresses this performance gap through studies aimed at developing ultrafast supercapacitors with novel nanostructured electrodes and a high capacitance density that run in the hundreds of hertz to kilohertz range and are suitable for circuit applications. This research, if successful, will bring about disruptive change in capacitor design and ground-breaking applications in crucial circuit functions like decoupling, timing, filtering, and power supply and conditioning. The proposed nanostructured electrodes can additionally be utilized in battery and electrocatalyst applications. Education and outreach activities are integrated in this project for the training of undergraduate and graduate students. In addition to supported Research Experiences for Undergraduates program students, several undergraduate students will be involved in the project through their Project Lab course work, to inspire their interest in advanced studies. Attention will be paid to recruiting female and minority students, particularly first-generation college students, to secure diversity and broad participation. An outreach component on nanomaterials for energy technologies will be developed to educate students who will serve as ambassadors in subsequent outreach efforts coordinated by the T-STEM Center of Texas Tech University.The proposed research will characterize and demonstrate high-density capacitors running in the hundreds of hertz to kilohertz frequency range. This represents a disruptive advance in capacitor technology for compact and efficient ultrafast electric double layer capacitors as discrete components, for line-frequency alternating current filtering, and on-chip integrated high-density micro-capacitor needs. The proposed electrode is based on perpendicularly edge-oriented multilayer graphene grown on a cellulose nanofiber scaffold. This novel material has a shallow, straight forward, wide-open pore structure that ensures high frequency response while its large specific surface area and especially high density of fully exposed graphene edges offer the possibility of large capacitance. Edge-oriented multilayer graphene growth and cellulose fiber carbonization into carbon nanofiber are implemented in a process that requires only a few minutes' time. The ultrafast electric double layer capacitors based on this new material could allow at least two orders of volume reduction compared to low-voltage aluminum electrolytic capacitors for filtering. The resulting freestanding electrodes can also be transferred to a substrate or an integrated circuit chip for in-package or on-chip capacitor integration. This project comprises comprehensive nanomaterial and charge storage studies, device modeling, fabrication and performance testing. If successful, it will ultimately bridge the frequency/capacitance gap between existing circuit capacitors and supercapacitors. The outcomes of this study will in addition enhance understanding in the areas of related materials and devices.

电解电容器的低电容密度正在成为电路板轮廓和电路性能的限制因素。当前一代的双电层超级电容器的电容密度高几个数量级，但它们限于约1秒的充电-放电速率或1赫兹的特征频率，因此不适合于需要必须在数百赫兹至千赫兹范围内运行的电容器的那些电路应用。换句话说，在电容/频率方面，目前可用的超级电容器和传统的电路电容器技术之间存在显著的性能差距。拟议的研究通过旨在开发具有新型纳米结构电极和高电容密度的超快超级电容器的研究来解决这一性能差距，这些超级电容器在数百赫兹至千赫兹范围内运行，适用于电路应用。这项研究如果成功，将给电容器设计带来颠覆性的变化，并在关键电路功能（如去耦、定时、滤波、电源和调节）中带来突破性的应用。所提出的纳米结构电极可以另外用于电池和电催化剂应用中。教育和推广活动被纳入该项目，以培训本科生和研究生。除了支持本科生项目学生的研究经验外，一些本科生将通过他们的项目实验室课程工作参与该项目，以激发他们对高级研究的兴趣。将注意招收女生和少数民族学生，特别是第一代大学生，以确保多样性和广泛参与。将开发一个关于能源技术纳米材料的推广部分，以教育学生，他们将在德克萨斯理工大学T-STEM中心协调的后续推广工作中担任大使。拟议的研究将描述和展示在数百赫兹至千赫兹频率范围内运行的高密度电容器。这代表了电容器技术的突破性进步，适用于作为分立元件的紧凑高效超快双电层电容器、工频交流滤波以及片上集成高密度微型电容器需求。所提出的电极是基于垂直边缘取向的多层石墨烯生长在一个纤维素纤维支架。这种新型材料具有浅的、直的、敞开的孔结构，确保了高频响应，同时其大的比表面积和特别高的完全暴露的石墨烯边缘的密度提供了大电容的可能性。边缘取向的多层石墨烯生长和纤维素纤维碳化成碳纳米管的过程仅需几分钟的时间。与用于滤波的低压铝电解电容器相比，基于这种新材料的超快双电层电容器可以允许至少两个数量级的体积减小。所得到的独立式电极也可以被转移到衬底或集成电路芯片上，用于封装内或芯片上电容器集成。该项目包括全面的纳米材料和电荷存储研究，器件建模，制造和性能测试。如果成功，它将最终弥合现有电路电容器和超级电容器之间的频率/电容差距。此外，本研究的结果将增强对相关材料和器械领域的理解。

项目成果

Prussian blue based vertical graphene 3D structures for high frequency electrochemical capacitors

• DOI: 10.1016/j.ensm.2020.07.016
• 发表时间: 2020-11-01
• 期刊: ENERGY STORAGE MATERIALS
• 影响因子: 20.4
• 作者: Li, Wenyue;Azam, Sakibul;Fan, Zhaoyang
• 通讯作者: Fan, Zhaoyang

Vertically edge-oriented graphene on plasma pyrolyzed cellulose fibers and demonstration of kilohertz high-frequency filtering electrical double layer capacitors

• DOI: 10.1016/j.carbon.2018.10.012
• 发表时间: 2019-01-01
• 期刊: CARBON
• 影响因子: 10.9
• 作者: Islam, Nazifah;Hoque, Md Nadim Ferdous;Fan, Zhaoyang
• 通讯作者: Fan, Zhaoyang

High-frequency electrochemical capacitors based on plasma pyrolyzed bacterial cellulose aerogel for current ripple filtering and pulse energy storage

• DOI: 10.1016/j.nanoen.2017.08.015
• 发表时间: 2017-10-01
• 期刊: NANO ENERGY
• 影响因子: 17.6
• 作者: Islam, Nazifah;Li, Shiqi;Fan, Zhaoyang
• 通讯作者: Fan, Zhaoyang

ZIF-67-derived edge-oriented graphene clusters coupled with carbon nanotubes containing encapsulated Co nanoparticles for high-frequency electrochemical capacitors

• DOI: 10.1039/c9se00503j
• 发表时间: 2019-10
• 期刊: Sustainable Energy & Fuels
• 影响因子: 5.6
• 作者: Wenyue Li;Nazifah Islam;S. Azam;Zhen Xu;J. Warzywoda;Zhaoyang Fan

Fast supercapacitors based on vertically oriented MoS2 nanosheets on plasma pyrolyzed cellulose filter paper

• DOI: 10.1016/j.jpowsour.2018.08.049
• 发表时间: 2018-10-01
• 期刊: JOURNAL OF POWER SOURCES
• 影响因子: 9.2
• 作者: Islam, Nazifah;Wang, Shu;Fan, Zhaoyang
• 通讯作者: Fan, Zhaoyang