Flexible TiO2-Polymer Capacitors With High Permittivity and Low Loss
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Solution Overview
Problem
Conventional dielectric capacitors face limitations in achieving high energy density and low dielectric loss due to low dielectric constants of polymers and low breakdown fields of ceramics, with temperature and frequency-dependent properties hindering their practical applications.
Innovation Solution
Development of a multilayer and flexible capacitor using metal-ion doped TiO2 ceramic powders embedded in a polymer matrix, specifically using Er and Nb-doped TiO2 ceramic powders with a fluoropolymer matrix, where the polymer is physically or chemically adsorbed to the ceramic powders, and the composite is fabricated through hydroxylation, solution casting, and hot pressing to enhance dielectric properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If conventional dielectric capacitors use polymer materials, then flexibility and ease of manufacture are improved, but dielectric constant and energy density deteriorate
Solution Approach 1:
The patent creates a composite material system combining polymer matrix (providing flexibility and ease of manufacture) with ceramic fillers (providing high dielectric constant). The composite structure allows simultaneous achievement of processability and high dielectric performance, resolving the contradiction between ease of manufacture and dielectric constant.
2Quantity of substance
If conventional dielectric capacitors use ceramic materials, then dielectric constant is improved, but breakdown field and manufacturing complexity worsen
Solution Approach 1:
By embedding ceramic particles within a polymer matrix, the patent achieves high dielectric constant from the ceramic while the polymer provides structural integrity and simplifies manufacturing. The composite approach allows ceramic benefits without the associated manufacturing complexity.
Solution Approach 2:
The patent distributes ceramic fillers locally within the polymer matrix, concentrating high dielectric constant regions where needed while maintaining overall structural simplicity. This local quality approach allows high dielectric performance without requiring complex ceramic processing throughout the entire device.
3Quantity of substance
If CP materials like BaTiO3 are used, then dielectric constant is improved, but temperature stability deteriorates
Solution Approach 1:
The patent modifies the properties of CP materials through metal-ion doping (e.g., Nb, Ta, W doping in TiO2) to alter the phase transition temperature and broaden the temperature range over which high dielectric constant is maintained. This parameter change approach enables temperature-stable CP behavior.
Solution Approach 2:
By combining CP ceramic fillers with polymer matrix, the patent creates a composite where the polymer's inherent temperature stability compensates for the ceramic's temperature-dependent dielectric constant, achieving overall temperature-stable performance while maintaining high dielectric constant.
4Quantity of substance
If CP materials like CCTO are used, then dielectric constant is improved, but dielectric loss worsens
Solution Approach 1:
The patent employs metal-ion doping to modify the electronic and defect structure of CP materials, reducing dielectric loss by controlling oxygen vacancies and improving charge carrier behavior. This parameter optimization allows simultaneous achievement of high dielectric constant and low dielectric loss.
Solution Approach 2:
The patent creates core-shell structures or surface-modified ceramic particles where the core provides high dielectric constant while the shell or surface treatment reduces dielectric loss. This local quality differentiation resolves the contradiction between high dielectric constant and low dielectric loss.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The resulting composite capacitors exhibit a high dielectric constant of up to 300, negligible dielectric loss, and a high energy density of 8.9 J/cm3 at a breakdown field of 82 MV/m, offering improved reliability and performance for energy storage applications.
Implementation Method 1
a part of the polymer matrix is exposed and adsorbed to the surface of the ceramic powders
Implementation Method 2
Surface hydroxylated ceramic fillers, embedded in copolymer matrix
Data Source
AI summary
Disclosed is polymer-ceramic composite material with colossal permittivity, comprising polymer matrix and ceramic powders embedded in the polymer matrix, wherein a part of the polymer matrix is exposed and adsorbed to the surface of the ceramic powders, and the polymer is electrically insulating. This invention simultaneously achieves large dielectric constant, negligible dielectric loss and high energy density in flexible composite capacitors based on metal-ion co-doped colossal permittivity materials. The host oxides used in this CP system is friendly to the environment, non-toxic and abundant. Additionally, the process developed is relatively simple, low cost and suitable for mass production-scale. Therefore, these composite capacitors have great technological potential for many applications. Compared to the conventional ceramic materials, composites of this invention are lightweight, scalable and easily fabricated into complex shapes towards miniaturization of the compact systems. The additional flexibility feature also possesses broad application prospects in modern electronic and energy storage devices.