Dual Tantalum Anode Capacitor Nested Separator Design

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Solution Overview

Problem

Existing dual anode capacitor designs face challenges in sealing and preventing direct physical contact between anode and cathode active materials, leading to potential short circuits, particularly in complex separator envelope designs.

Innovation Solution

A 'bag-in-a-bag' separator design is implemented, where a cathode current collector with active material is housed in a first separator envelope between side-by-side anodes, and the entire assembly is then contained in a second separator envelope, preventing direct contact and using a conductive casing as the cathode terminal, while allowing for independent charging of anodes.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a dual separator envelope design is used to prevent contact between anode and cathode, then reliability is improved, but device complexity increases

Engineering Contradiction:
Improveprevention of short circuitVSAvoidseparator envelope structure
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent implements a nested separator envelope structure where a first separator envelope contains the cathode current collector and active material, which is then placed inside a second separator envelope that contains the anode pellets. This nested configuration provides redundant isolation barriers, ensuring that even if one envelope fails, the other continues to prevent contact between anode and cathode, thereby enhancing reliability while maintaining a systematic approach to complexity management.

Inventive Principle:
Principle #7Nested doll (Nesting)

Solution Approach 2:

The separator system is divided into two distinct functional segments: the first separator envelope specifically contains the cathode assembly and prevents its contact with anodes, while the second separator envelope contains the entire cathode assembly and provides an additional barrier. This segmentation allows each envelope to be optimized for its specific protective function, improving overall reliability through distributed protection rather than relying on a single complex separator structure.

Inventive Principle:
Principle #1Segmentation

2Reliability

If each anode is housed in its own separator envelope, then reliability is improved, but ease of manufacture deteriorates

Engineering Contradiction:
Improveisolation of anodesVSAvoidsealing and trimming process
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The patent combines multiple anode pellets into a single shared second separator envelope rather than housing each anode in a separate envelope. This merging approach maintains the reliability benefit of separator isolation while dramatically simplifying the manufacturing process. The cathode current collector and active material remain in their own first separator envelope, but the anodes are collectively contained, reducing the number of sealing and trimming operations required during assembly.

Inventive Principle:
Principle #5Merging (Combining)

3Reliability

If a second separator envelope is added around the first envelope, then reliability is improved, but device complexity increases

Engineering Contradiction:
Improveprevent short circuit contactVSAvoiddouble envelope structure
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent employs a nested envelope configuration where the first separator envelope containing the cathode assembly is placed inside the second separator envelope that contains the anode pellets. This nesting arrangement provides layered protection against short circuits while utilizing the internal space efficiently. The concentric structure ensures that even if one envelope is compromised, the other maintains isolation, enhancing reliability without requiring separate external housing structures.

Inventive Principle:
Principle #7Nested doll (Nesting)

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 design effectively prevents short circuits and allows for flexible charging of anodes, enhancing the safety and performance of dual anode capacitors by maintaining electrical isolation between anode and cathode active materials.

Implementation Method 1

the first separator envelope housing the cathode current collector/cathode active material subassembly is positioned between side-by-side anodes and this electrode assembly is then contained in a second separator envelope

Methodology Applied
Scientific EffectPhysical containment: Physical Containment

Implementation Method 2

A working electrolyte filled into the casing serves as an ionic transport for charging and discharging the capacitor

Methodology Applied
Scientific EffectIonic transport: Ion Exchange

Data Source

PatentEP3171378B1High voltage capacitor having a dual tantalum anode/cathode current collector electrode assembly housed in a dual separator envelope design
Publication Date: 2021.12.22 GREATBATCH LTD
  • EP3171378B1 patent drawingFigure 1
  • EP3171378B1 patent drawingFigure 2~2B
  • EP3171378B1 patent drawingFigure 3

AI summary

A capacitor having at least two side-by-side anodes with a cathode current collector disposed between the anodes and housed inside a casing is described. Cathode active material is supported on the opposed major faces of the current collector and the current collector/cathode active material subassembly is housed in a first separator envelope. The first separator envelope is positioned between the side-by-side anodes and this electrode assembly is then contained in a second separator envelope. The two anodes can be connected in parallel inside or outside casing, or they can be unconnected to each other. There is also cathode active material supported on inner surfaces of the casing in a face-to-face alignment with an adjacent one of the anodes. That way, the second separator envelope also prevents direct physical contact between the anode pellets and the cathode active material supported on the casing sidewalls.