Sintered Electrode Foil for Stable High-Capacitance Electrolytic Capacitors
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Solution Overview
Problem
Existing electrolytic capacitors face limitations in increasing capacitance due to the environmental and economic burdens of chemical etching treatments, and the resulting foil strength decreases, leading to unstable capacitance.
Innovation Solution
The use of a sintered foil with a metal sintered material on the electrode surface and an electrolytic solution viscosity of 400 cP or less, combined with fine sintered particles of 5.0 μm or less, to enhance specific surface area and stabilize capacitance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If chemical etching treatment is used to increase specific surface area, then capacitance increases, but environmental load and economic burden increase
Solution Approach 1:
The invention changes the parameter of surface treatment method from chemical etching to sintering of metal powder. By controlling sintering temperature and metal powder characteristics, the specific surface area is increased without using harmful chemicals, thus resolving the contradiction between capacitance enhancement and environmental protection
Solution Approach 2:
The invention replaces the chemical etching process with a thermal sintering process. Instead of using chemical reactions to create surface pores, mechanical/thermal energy is applied to fuse metal powder particles, creating a porous structure that increases surface area without chemical waste
2Quantity of substance
If chemical etching treatment is used to increase specific surface area, then capacitance increases, but foil strength decreases
Solution Approach 1:
The invention changes the surface treatment parameter from chemical dissolution to thermal sintering. The sintering process fuses metal powder particles together, creating strong interparticle bonds that maintain foil strength while simultaneously creating pores that increase specific surface area
Solution Approach 2:
The invention uses a composite structure where metal powder particles are sintered together to form a porous coating on the foil. This composite structure provides both high surface area for capacitance and strong interparticle bonding for mechanical strength
3Quantity of substance
If sintered foil is used to increase specific surface area, then capacitance increases, but capacitance stability becomes insufficient
Solution Approach 1:
The invention optimizes multiple parameters including electrolyte viscosity (400 cP or less), metal powder particle size (5.0 μm or less), and sintering temperature. This combination of parameter optimizations ensures that the increased surface area translates into stable capacitance performance
Solution Approach 2:
The invention establishes a relationship between electrolyte viscosity and sintered particle size, where the electrolyte viscosity is controlled to be 400 cP or less to ensure proper penetration and wetting of the fine sintered particles, thereby maintaining stable capacitance
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
This approach achieves a high and stable capacitance in electrolytic capacitors, maintaining performance over time without significant decreases, reducing environmental and economic burdens.
Implementation Method 1
forming a sintered material film composed of the sintered material on a surface of a base material
Implementation Method 2
the viscosity μ [cP] of the electrolytic solution at 25 [° C.] is 400 [cP] or less
Data Source
AI summary
An electrolytic capacitor has a capacitor element having an anode foil having a dielectric layer formed thereon, a cathode foil and a separator placed between the anode foil and the cathode foil and an electrolytic solution impregnated in the capacitor element. The anode foil or the cathode foil is obtained by forming a sintered material of a composition containing a metal powder in a foil form (is composed of a foil-form sintered material) or forming a sintered material film composed of the sintered material on a surface of a base material, and the viscosity μ [cP] of the electrolytic solution at 25 [° C.] is 400 [cP] or less.