Excellence in Research - Collaborative: Hierarchical Multilayered Block Copolymer Dielectrics with Z-Gradient Nanofiller for Capacitive Energy Storage and Gate Dielectric

Jackson State University, Jackson MS

Investigators

Abstract

This project is jointly funded by the Historically Black Colleges and Universities Undergraduate Program - Excellence in Research program (HBCU-UP EiR) and the Established Program to Stimulate Competitive Research (EPSCoR). NON-TECHNICAL SUMMARY: There is much interest in use of lightweight polymer films for potential applications in flexible electronics related to portable energy storage devices, including batteries, capacitors, integrated solar cells and soft-actuation. In this regard, new approaches to high-energy density capacitive energy storage have recently demonstrated notable potential for high electrical energy storage using multilayered polymer films. Essentially the multiple interfaces within the multilayer act to sequentially block electrical breakdown of the dielectric polymer film that determines the upper limit of energy storage of the flexible capacitor. Recognizing that the breakdown follows an increasingly branched asymmetric pathway between electrodes (much like lightning bolts striking the earth), with the highest potential at the positive electrode, the work will systematically design and explore whether hybrid polymer multilayers (tetra-layered) can be structurally "reversed-engineered" with an asymmetry in polymer-layer breakdown properties that counters the asymmetric breakdown pathway. The approach aims to use self-assembling block copolymers for multilayer formation and combines it with the use of dispersed inorganic nanofillers to boost the energy storage capacity. Successful outcome can have a significant impact on the flexible electronics industry. This multidisciplinary team effort involves Howard University and Jackson State University (Historically Black College Universities) and University of Houston, a Minority Serving Institution, with significant amounts of intra and inter-institutional educational, training and research activities. The project will arrange a yearly rotational day-long conference on nanocomposites at each of the campuses to educate scientists, local teachers and local college bound students about the vast possibilities of nanotechnology. A trained cadre of talented nanotechnologists will be trained to address the challenges of the nation's workforce needs and produce peer reviewed scientific and technological publications that can be disseminated to the scientific community and broader society. The program aims to make web-accessible training protocols to prospective researchers in the field of nanoscience and nanoengineering. TECHNICAL SUMMARY; Fundamentally high energy densities and ultrafast charge-discharge rates (pulsed power) in solid state-flexible capacitors are of fundamental importance. The energy storage density is limited by the maximum electric field that can be applied across the electrodes. Current technologies for pulsed power applications utilize polymers as the dielectric of choice due to their high electrical resistance, low dielectric loss, self healing capability, formability and flexibility. However, these materials do not meet all of the requirements of the next-generation film dielectrics for high voltage and high energy density electronic devices. The planned work is based on the hypothesis that an anti-symmetric z-structured tetra-layered design of molecularly assembled capacitive elemental layers can precisely counter the asymmetry of the electrical treeing breakdown cascade from the positive to the negative electrode. The anti-symmetric film structure considers a tetra-layer with an extremely high breakdown prevention self-assembling multilayered block copolymer at the positive electrode where E-field strength is highest as per electrical treeing breakdown view-point. The subsequent layer is also a block copolymer structure with in-plane aligned nanosheets to forestall E-field cascade breakdown. The third layer is designed to contain high dielectric nanoparticles sequestered within a macroscopically ordered block copolymer layer, which also provides a strategy of gate dielectric for 2D semiconductor devices such as field-effect transistors and logic design with enhanced functionalities compared to the conventional dielectrics. Finally, a defect-free bottom polymer layer is used, which will prevent trickle-current to the negative electrode. A multidisciplinary team between Howard University and Jackson State University (Historically Black College Universities), and University of Houston, a Minority Serving Institution, will work towards training a cadre of talented nanotechnologists to face the challenges of the nation's workforce needs. Web modules on nanoscience and nanoengineering research for young and interested researchers and the general public will be made available. 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.