Multiphase TiO2 Ceramic Composition for High-k Low-Loss Stability
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current dielectric ceramic materials face challenges in achieving a high dielectric constant, low dielectric loss, and good frequency- and temperature-stability while maintaining high breakdown strength, which is crucial for high-energy storage devices and supercapacitors.
Innovation Solution
A multiphase ceramic material with a general formula of AxBnxTi1−(n+1)xO2, where A includes Nb, Ta, V, Mo, and Sb, and B includes In, Ga, Al, Co, Cr, and Sc, with a secondary phase of B2TiO5 evenly dispersed in a primary phase of A5+ and B3+ co-doped rutile TiO2, enhancing insulation resistivity and breakdown voltage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If ferroelectric materials like BaTiO3 are used to achieve high dielectric constant, then the dielectric constant is improved, but the dielectric constant becomes highly dependent on temperature
Solution Approach 1:
The patent employs a composite material system consisting of primary phase (A5+ and B3+ co-doped rutile TiO2) and secondary phase (B2TiO5). This composite structure combines the high dielectric constant of the primary phase with the temperature stability and electrical insulation properties of the secondary phase, resolving the contradiction between achieving high dielectric constant and maintaining temperature stability.
Solution Approach 2:
The secondary phase B2TiO5 is selectively distributed at the grain boundaries of the primary phase, creating local quality differentiation. The grain interior maintains high dielectric constant while the grain boundary region provides temperature stability and electrical insulation, thus resolving the contradiction through spatially differentiated functionality.
2Area of stationary object
If non-ferroelectric materials like CCTO, doped NiO and La2xSrxNiO4 are used to achieve high dielectric constant within wide temperature range, then the dielectric constant is improved, but the dielectric loss becomes very high
Solution Approach 1:
The patent creates a composite where the primary phase (A5+ and B3+ co-doped rutile TiO2) provides high dielectric constant, while the secondary phase (B2TiO5) dispersed at grain boundaries suppresses dielectric loss by blocking charge transfer pathways. This composite approach achieves both high dielectric constant and low dielectric loss simultaneously.
Solution Approach 2:
The secondary phase B2TiO5 acts as an intermediary at the grain boundaries, mediating the electrical properties between adjacent primary phase grains. It blocks the transfer of weakly bounded charges that would otherwise cause high dielectric loss, while allowing the high dielectric constant property to be maintained in the bulk material.
3Area of stationary object
If high dielectric constant is achieved, then the energy storage capacity is improved, but the breakdown strength needs to be maintained for high-energy storage devices
Solution Approach 1:
The composite structure with primary phase providing high dielectric constant and secondary phase providing high breakdown strength resolves this contradiction. The secondary phase B2TiO5 at grain boundaries acts as electrical insulation barriers, preventing premature breakdown while allowing the high dielectric constant of the primary phase to be utilized for energy storage.
Solution Approach 2:
The secondary phase B2TiO5 serves as an intermediary protective layer at grain boundaries, enhancing the overall breakdown strength of the ceramic material. This allows the material to withstand higher electric fields without breakdown, enabling the utilization of high dielectric constant for practical energy storage applications.
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 ceramic material exhibits a giant dielectric constant (>10,000) with low dielectric loss (<0.05) across a wide frequency and temperature range, and high insulation resistivity (>10^11 Ω·cm), suitable for high-energy storage devices and supercapacitors.
Implementation Method 1
the secondary phase exhibits excellent electrical insulation properties. The secondary phase is discontinuously and uniformly distributed around the grain boundary of the primary phase. Therefore, it can effectively block the transfer of weakly bounded charges, which contributes to increasing the working voltage and breakdown voltage of the material.
Implementation Method 2
The primary phase provides the multiphase ceramic material with the giant dielectric property. the multiphase ceramic material has a dielectric constant of higher than 10,000 at a frequency of 20 Hz to 2×106 Hz
Data Source
AI summary
The present invention discloses a multiphase ceramic material with a giant dielectric constant, wherein the multiphase ceramic material has a general formula of AxBnxTi1−(n+1)xO2; wherein A is at least one selected from the group consisting of Nb, Ta, V, Mo, and Sb, B is at least one selected from the group consisting of In, Ga, Al, Co, Cr, Sc, Fe (III), and a trivalent rare-earth cation; n is a molar ratio of B to A, 1<n≤5, 0<x≤0.1. The multiphase ceramic material possesses outstanding properties including a giant dielectric constant, a low dielectric loss, and excellent frequency- and temperature-stability. In particular, it exhibits a high insulation resistivity of higher than 1011Ω·cm and a high breakdown voltage, which implies it can be applied in high-energy storage devices and supercapacitors. This invention also provides a method to synthesize the multiphase ceramic material.