High Temperature, High Energy Density and Low Loss Nano-Layered Polymer Films for Navy Pulsed Power Capacitors
Abstract
Full Proposal to ONR Code 332 Dielectric Films for Capacitors Program High Temperature, High Energy Density and Low Loss Nano-Layered Polymer Films for Navy Pulsed Power Capacitors Primary Offeror: Case Western Reserve University Technical Point of Contact: Principal Investigator: Professor Lei Zhu Department of Macromolecular Science and Engineering, Center for Layered Polymeric Systems (CLiPS), Case Western Reserve University, Cleveland OH 44106-7202 Tel. (216) 368-5861, Email: lxz121@case.edu Co-Principal Investigator: Professor Eric Baer Department of Macromolecular Science and Engineering, Center for Layered Polymeric Systems (CLiPS), Case Western Reserve University, Cleveland OH 44106-7202 Tel. (216) 368-4203, Email: exb6@case.edu Project Summary Through continued support by Office of Naval Research in the past years, multilayer film technology for Navy’s pulsed power applications have reach a stage that fundamental working mechanisms have been identified. These include both advantageous and disadvantageous dielectric properties. The advantageous properties include dipolar polarization of paraelectric amorphous dipoles and interfacial polarizations from various charge carriers such as real charges and impurity ions. The disadvantageous properties include ferroelectric switching of polar crystalline dipoles, migrational loss from impurity ions, and electronic conduction (especially at >100 °C). In this proposal, we aim to maximize the advantageous properties and minimize or eliminate the disadvantage properties, and finally achieve desired dielectric properties to meet Navy’s future needs; high energy density (>20 J/cm3 at breakdown), high temperature (e.g., 150 °C), and low loss (hysteresis loop <10%). First, by using a high glass transition temperature (Tg = 166 °C) polycarbonate (HTPC), the PC/poly(vinylidene fluoride) (PVDF) 70/30 (vol./vol.) 33- layer film can exhibit optimal dielectric performance up to 150 °C. Second, both real charge and impurity ion interfacial polarizations at the HTPC/PVDF interfaces can effectively “trap” injected charges (i.e., hot electrons) from metal electrodes, increasing volume resistivity, breakdown strength, and lifetime simultaneously. Third, adding an interphase/tie layer between HTPC and PVDF will provide multiple functions; improved interfacial adhesion, blocking charge injection from PVDF to HTPC, and locking in polarized impurity ions (i.e., ionic electret effect) to further reduce bulk conductivity. Fourth, we will study uniaxial and biaxial stretching of multilayer films, which have been proved to improve dielectric properties in all aspects. Finally, we will explore other high dielectric constant paraelectric polymers such as P(VDF-co-trifluoroethylene) [P(VDFTrFE)] and nylons to multilayer with PC or HTPC. The goal is to achieve even higher energy density and/or temperature capability. Various dielectric characterization methods, such as dielectric spectroscopy, D-E loop test, Weibull breakdown and lifetime analyses, leakage current study, and thermally stimulated current study will be employed to achieve our proposed goals. Submitted to: Dr. Paul Armistead and Dr. Michele Anderson, Office of Naval Research, Code 332
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Jun 03, 2016
- Source ID
- N000141612170
Entities
People
- Lei Zhu
Organizations
- Case Western Reserve University
- Office of Naval Research
- United States Navy