Button Battery Lid Alignment for Leak-Resistant Welding

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Solution Overview

Problem

The existing button battery manufacturing process faces challenges with the double-wall configuration, which results in wasted space and difficulties in achieving a perfect weld connection due to the need for precise alignment and small dimensions, leading to potential leakage issues.

Innovation Solution

A button battery design featuring a cup-shaped container and a lid with complementary conical portions for self-alignment and a uniformly conductive lid for improved sealing, allowing for precise alignment and stable welding, reducing the need for a double-wall configuration and enhancing sealing efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a double-wall configuration with gasket or glue is used for sealing, then electrical insulation is achieved, but space is wasted and manufacturing complexity increases

Engineering Contradiction:
Improveelectrical insulationVSAvoidbattery volume
Core Design Contradiction:
ReliabilityVSVolume of stationary object

Solution Approach 1:

The patent merges the electrical insulation function with the sealing function by making the lid's peripheral portion itself electrically insulating while providing the seal, eliminating the need for separate gaskets or glue layers. This integration removes the double-wall configuration and reduces overall battery volume.

Inventive Principle:
Principle #5Merging (Combining)

2Reliability

If laser welding is used to fix the lid to the cup rim, then sealing is achieved, but alignment precision requirements are extremely high and manufacturing difficulty increases

Engineering Contradiction:
Improvesealing qualityVSAvoidalignment precision
Core Design Contradiction:
ReliabilityVSManufacturing precision

Solution Approach 1:

The patent incorporates preliminary alignment features (conical alignment portions and positioning protrusions) into the lid and cup structure before the welding process. These features pre-establish the correct relative position and orientation of the lid and cup, ensuring accurate alignment is achieved automatically during assembly, thereby reducing the precision requirements for the subsequent welding operation.

Inventive Principle:
Principle #10Preliminary action

3Ease of manufacture

If the lid is uniformly conductive, then manufacturing is simplified and welding is improved, but electrical insulation between contacts must be achieved differently

Engineering Contradiction:
Improvelid manufacturingVSAvoidelectrical insulation
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The patent segments the lid into functionally distinct portions: a centrally located conductive portion for electrical contact and a peripherally located insulating portion for both sealing and electrical insulation. This segmentation allows each portion to be optimized for its specific function while together they form an integrated lid structure that simplifies manufacturing compared to alternative approaches.

Inventive Principle:
Principle #1Segmentation

Data Source

PatentEP4407727A1A button battery
Publication Date: 2024.07.31 RENATA
  • EP4407727A1 patent drawingFigure 1
  • EP4407727A1 patent drawingFigure 2~4b
  • EP4407727A1 patent drawingFigure 5a~7

AI summary

A button battery according to the invention comprises a first component (1) in the form of a cup-shaped container, an electrode assembly (4) inserted in the container, and furthermore a lid-shaped second component (10) fixed along its outer edge to the upper rim of the sidewall (3) of the container. Either the first or the second component comprises three portions: an electrically conductive central portion (11), an electrically conductive peripheral portion (12) and an electrically insulating intermediate portion (13) that separates and insulates the central portion from the peripheral portion. The sidewall (3) of the first component and the edge of the second component (10) are shaped so as to comprise complementary conical portions (22, 25) which are in mutual contact in the assembled battery. Said complementary conical portions enable the self-alignment of the lid (10) to the rim of the sidewall (3) during assembly of the battery, and further aid in maintaining the lid onto the container during the sealing process which may be a process of welding the lid to the container along a common perimeter. According to preferred embodiments, the edge of the lid (10) and the rim of the sidewall (3) are further provided with step portions (23, 25) configured to define a stop for the insertion of one conical portion into the other.