Button Cell Centrifugation for Anode Contact

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Solution Overview

Problem

The existing methods for producing button cells often result in uneven distribution of anode material on the separator, leading to random fluctuations in internal resistance due to the positioning challenges during assembly.

Innovation Solution

A centrifugation process using a coiled plastic band with cup-shaped receptacles ensures that the anode material is pressed against the separator by centrifugal force, improving contact and reducing resistance fluctuations, and the band itself serves as a storage and transport medium, eliminating the need for separate packaging.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If the cell cover is positioned with the opening edge upwards during assembly, then the anode material can be filled, but the anode material does not lie evenly on the separator leading to random fluctuations in internal resistance

Engineering Contradiction:
Improveease of anode material fillingVSAvoiduniformity of anode material distribution
Core Design Contradiction:
Ease of manufactureVSManufacturing precision

Solution Approach 1:

The patent applies preliminary action by positioning the anode material on a support ring before assembly, and then using centrifugal force during rotation to press the anode material against the separator. This pre-positioning combined with subsequent centrifugal pressing ensures even distribution without requiring the cell cover to be held in a specific orientation during filling.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent introduces dynamic rotation of the assembled button cells to apply centrifugal force. This dynamic approach transforms the static assembly problem into a dynamic process where rotation speed can be controlled to achieve optimal anode material distribution against the separator, eliminating the need for precise manual positioning.

Inventive Principle:
Principle #15Dynamics

2Reliability

If button cells are arranged on centrifuge trays covered with cover plates, then the cells cannot slip off, but the trays require separate packaging and take up more space

Engineering Contradiction:
Improveprevention of cell slippingVSAvoidpackaging structure complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent makes the storage and transport medium multi-functional by designing it to serve both as the centrifugation container and as the final storage/transport packaging. The recesses in the medium hold the button cells during centrifugation and continue to protect them during storage and transport, eliminating the need for separate packaging steps and reducing overall complexity.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The patent merges the centrifuge tray function with the storage and transport medium into a single integrated component. Instead of using separate trays that require additional packaging, the storage medium itself is designed with recesses that perform both centrifugation and storage functions, simplifying the overall process and reducing space requirements.

Inventive Principle:
Principle #5Merging (Combining)

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 method achieves improved contact between the anode, separator, and cathode, resulting in consistently low and stable internal resistance, and provides a compact, efficient storage and transport solution for button cells.

Implementation Method 1

the anode material is pressed against the separator by the effect of the centrifugal force occurring during centrifugation

Methodology Applied
Scientific EffectCentrifugal force: Centrifugal Force

Data Source

PatentEP2792616B1Method for the production and storage of button cells
Publication Date: 2016.06.29 VARTA MICROBATTERY GMBH
  • EP2792616B1 patent drawingFigure 1(A)~1(B)
  • EP2792616B1 patent drawingFigure 2(A)~2(C)

AI summary

A method for producing button cells from the components cell cup and cell cap, cathode, anode, separator, seal, and electrolyte is described, comprising the assembly of said components into button cells and a subsequent centrifugation process for the purpose of improving the contact between the anode, separator, and cathode of the assembled cells. The method is particularly characterized by the fact that a belt with cup-shaped recesses is provided for the centrifugation process, the assembled cells are positioned in the recesses, and the belt is arranged, preferably in a spirally wound form, around an axis and set into rotation around this axis, so that the centrifugal force generated presses the anode against the separator.Furthermore, a storage and transport medium for button cells is described, comprising a belt with cup-shaped recesses in which the button cells are arranged, and a cylindrical winding core on which the belt is wound.