Lead Lanthanum Zirconate Titanate Relaxor Ferroelectric Thin Films Capacitors for Energy Storage
For stationary energy storage and vehicle propulsion, the demand for high efficient electric energy storage technology is on the rise. Capacitors, having orders of magnitude higher power density and life cycles compared with batteries, are able to smooth out momentary fluctuations and supply stable energy from renewable sources, to prolong the lifetime of batteries and improve the reliability of electric systems in hybrid vehicles. They also used to meet peak power needs in hybrid electric vehicles (HEVs), and keep internal combustion engines operating at optimized energy efficiency. Although capacitors have already been adopted widely in HEVs, more attention is now being directed toward improving the overall performance while reducing the size, weight, and cost of power electronics.
Some of the desired improvements include high energy density, low electrical and thermal losses, better packaging, and improved reliability and lifetime. Thin-film ferroelectric relaxor capacitors demonstrate many attractive properties, such as high capacitance, low dielectric loss, high breakdown strength, and are capable of operating at high temperature under the hood. These properties makes relaxor ferroelectric capacitors a prime candidate to replace currently used polymer capacitors because it reduces size of the capacitor and does not require separate coolants. This presentation will discuss the performance of lead lanthanum zirconate titanate (PLZT) relaxor ferroelectric thin films on different combinations of bottom electrode (Pt, LaNiO3) and substrate (Ni, Si) for a more cost-effective solution to develop volumetrically efficient capacitors with high capacitance density, energy density, and energy storage efficiency.