Highly flexible ferroelectric PZT thick films on Cu/PI foil for flexible energy storage devices

Abstract

Electrostatic dielectric capacitors are difficult to integrate into flexible electronics because of their limited flexibility and the requirement for miniaturization and durability. Polymer-based composite dielectric capacitors have a small potential owing to their flexibility; however, their limited energy storage capability, low thermal stability, and the fact that they require strong electric fields impede their practicality. To overcome these issues, we fabricated ferroelectric ceramic-based highly flexible dielectric thick-film capacitors with high energy-storage densities by exploiting the synergistic advantages of aerosol deposition (AD) and intense pulsed light (IPL) photothermal treatment. The AD facilitated the fabrication of nanocrystalline (Pb(Zr, Ti)O3; PZT) thick films (6 mu m), whereas IPL annealing improved the crystallinity rapidly without damaging the economically viable flexible Cu/PI substrates. The flexible Pt/PZT/Cu/PI capacitors delivered outstanding voltage endurance of up to 600 V, recoverable energy density (Urec) of 17.5 J/cm3, and charge-discharge efficiency (eta) over 70 % at 1000 kV/cm. In addition, the polarization and energy storage properties of these flexible capacitors did not undergo significant degradation even after 104 mechanical bending cycles with a bending curvature radius of 1.7 mm and as many as 106 electric fatigue cycles. They also demonstrated excellent thermal stability up to 100 degrees C. Moreover, the capacitors rapidly discharged (tau 0.9 of 908 ns) an energy density of 13.0 J/cm3 with a peak power density of 33 MW/cm3 at a practical applied voltage of 300 V. This study provides an economically viable and scalable approach for fabricating flexible ferroelectric ceramic dielectric capacitors for future flexible energy storage technologies.