Sintered Capacitor Electrode Surface for Adhesion and Wetting

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Solution Overview

Problem

Capacitors with high volume efficiency face issues such as reduced lifetime, delamination of sintered electrodes, gas generation due to bare metal oxidation, and difficulty in electrolyte wetting, particularly in sintered anodes.

Innovation Solution

Surface modification of the substrate with protrusions and indentations, combined with passivating compounds and impregnating agents, enhances adhesion and wettability, reducing delamination and gas generation, and improving electrolyte interaction.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Volume of stationary object

If sintered electrodes are used to increase volume efficiency, then volume efficiency is improved, but adhesion between electrode and substrate deteriorates causing delamination

Engineering Contradiction:

Improvevolume efficiencyVSAvoidadhesion

Core Design Contradiction:

Volume of stationary objectVSStrength

Solution Approach 1:

The substrate surface is pre-modified with protrusions and indentations before applying the sintered electrode material. This preliminary surface preparation creates mechanical interlocking features that prevent delamination while maintaining high volume efficiency of the sintered electrode structure.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The substrate surface is given non-uniform local properties through protrusions and indentations at specific locations. These localized structural variations enhance adhesion in critical areas without compromising the overall volume efficiency of the sintered electrode.

Inventive Principle:

Principle #3Local quality

2Volume of stationary object

If sintered electrodes with high volume efficiency are used, then volume efficiency is improved, but lifetime is reduced

Engineering Contradiction:

Improvevolume efficiencyVSAvoidlifetime

Core Design Contradiction:

Volume of stationary objectVSDuration of action of stationary object

Solution Approach 1:

Passivating compounds are applied in advance to form protective layers on the sintered electrode surface before operation. This preliminary protection prevents degradation mechanisms that would otherwise reduce lifetime, allowing the high volume efficiency structure to maintain its performance over extended periods.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

Protective compounds are introduced beforehand to cushion against harmful effects during operation. These compounds preemptively protect the sintered electrode structure from degradation, ensuring both high volume efficiency and extended lifetime are achieved simultaneously.

Inventive Principle:

Principle #11Beforehand cushioning (Prior cushioning)

3Volume of stationary object

If sintered electrodes are used to improve volume efficiency, then volume efficiency is improved, but gas generation increases due to bare metal oxidation

Engineering Contradiction:

Improvevolume efficiencyVSAvoidgas generation

Core Design Contradiction:

Volume of stationary objectVSObject-generated harmful factors

Solution Approach 1:

Passivating compounds are applied beforehand to form protective layers on exposed metal surfaces of the sintered electrode. This preliminary passivation prevents oxidation reactions that would generate gas, allowing the high volume efficiency structure to operate without harmful gas generation.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The passivating compounds convert the potentially harmful oxidation process into a beneficial protective layer formation. Instead of allowing bare metal to oxidize and generate gas, the compounds facilitate controlled formation of protective oxide layers that prevent further degradation and gas generation.

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

4Volume of stationary object

If sintered electrodes are used to increase volume efficiency, then volume efficiency is improved, but electrolyte wettability deteriorates

Engineering Contradiction:

Improvevolume efficiencyVSAvoidelectrolyte wettability

Core Design Contradiction:

Volume of stationary objectVSEase of operation

Solution Approach 1:

Impregnating agents are applied in advance to modify the surface properties of the sintered electrode. This preliminary treatment enhances electrolyte wettability before the electrode enters service, ensuring proper electrolyte distribution and contact while maintaining the high volume efficiency of the sintered structure.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The surface properties of the sintered electrode are modified by changing parameters such as surface energy and porosity through impregnating agents. These parameter changes improve electrolyte wettability without altering the overall volume efficiency of the sintered electrode structure.

Inventive Principle:

Principle #35Parameter changes

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 solution increases volume efficiency, reduces delamination and gas formation, and enhances electrolyte wetting, leading to improved capacitor performance and reduced thickness of separator layers.

Implementation Method 1

it may be achieved by sintering of valve metal particles, i.e. by a heating or annealing step that merges or fuses the particles

Methodology Applied

Scientific EffectSintering: Sintering

Implementation Method 2

at least a portion of the sintered body is modified by adsorbing a compound to crack sites or at least sites that at least partially lack an oxide layer

Methodology Applied

Scientific EffectAdsorption: Adsorption

Implementation Method 3

an impregnating compound that is configured to impregnate a portion of the surface of an electrode

Methodology Applied

Scientific EffectImpregnation: Absorption (physical)

Data Source

PatentUS20260011511A1Electrode, electrolyte, capacitive element, capacitor and processes of manufacturing or modifying or impregnating an electrode

Publication Date: 2026.01.08 TDK ELECTRONICS AG

AI summary

According to the application, an electrode is provided having a substrate and a sintered body on a first main surface of said substrate. The substrate comprises a first valve metal. The sintered body comprises merged or sintered particles that comprise a second valve metal. The first main surface of the substrate is surface-modified