Enhancement of Energy-Storage Density in PZT/PZO-Based Multilayer Ferroelectric Thin Films

PbZr0.35Ti0.65O3 (PZT), PbZrO3 (PZO), and PZT/PZO ferroelectric/antiferroelectric multilayer films were prepared on a Pt/Ti/SiO2/Si substrate using the sol–gel method. Microstructures and physical properties such as the polarization behaviors, leakage current, dielectric features, and energy-storage characteristics of the three films were systematically explored. All electric field-dependent phase transitions, from sharp to diffused, can be tuned by layer structure, indicated by the polarization, shift current, and dielectric properties. The leakage current behaviors suggested that the layer structure could modulate the current mechanism, including space-charge-limited bulk conduction for single layer films and Schottky emission for multilayer thin films. The electric breakdown strength of a PZT/PZO multilayer structure can be further enhanced to 1760 kV/cm, which is higher than PZT (1162 kV/cm) and PZO (1373 kV/cm) films. A recoverable energy-storage density of 21.1 J/cm3 was received in PZT/PZO multilayers due to its high electric breakdown strength. Our results demonstrate that a multilayer structure is an effective method for enhancing energy-storage capacitors.

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Modulation and mechanism of spatial structure for multi-layer cyanate ester resin composites to achieve remarkably increased energy storage density and decreased dielectric loss

Journal of Composite Materials ◽

10.1177/0021998320951888 ◽

2020 ◽

pp. 002199832095188

Author(s):

Xiaobao Zhang ◽

Li Yuan ◽

Guozheng Liang ◽

Aijuan Gu

Keyword(s):

Energy Storage ◽

Dielectric Loss ◽

Spatial Structure ◽

Breakdown Strength ◽

Layer Structure ◽

Single Layer ◽

Cyanate Ester ◽

Energy Storage Density ◽

Spatial Structures ◽

Storage Density

Overcoming sticky problems of large dielectric loss and poor breakdown strength ( Eb) is prerequisite of actual applications for high dielectric constant polymer composites. Herein, three kinds of multi-layer structure composites with different spatial structures (2MP-CE/CNT, CE/CNT-2MP-CE/CNT, MP-CE/CNT-MP) were prepared based on carbon nanotubes (CNTs), cyanate ester (CE) resin and mica paper (MP). Compared with traditional single-layer CE/CNT composite, multi-layer CE/CNT-2MP-CE/CNT composites, of which the middle layer is two pieces of MPs with a thickness of 60 µm, while both bottom and top layers are CE/CNT composite, simultaneously achieve 105 reduction in dielectric loss and 18.1 times increase in energy storage density ( Ue). Through modulating two sheets of MPs and CE/CNT as top and bottom layer, respectively, 2MP-CE/CNT composite with 60 μm MPs has the largest breakdown strength ( Eb), its Eb and Ue are severally about 7.1 and 19.5 times of those of CE/CNT composite. The relationship and mechanism between spatial structure and integrated performance such as dielectric properties, Eb and Ue of composites were systematically investigated. The attractive integrated performances of CE/CNT-2MP-CE/CNT and 2MP-CE/CNT composites are attributed to their unique composition and spatial structures, which bring special micro-capacitance and interfacial polarization, and thus leading to outstanding performances. Therefore, this investigation provides a strategy for getting desirable performances through building composites with specific spatial structure.

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