Secondary Battery Terminal Crimp Structure for Strong Metal Joining

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Solution Overview

Problem

Existing methods for joining electrode terminals and intermediate members in secondary batteries, such as ultrasonic joining, require high junction energy, leading to surface roughness and deformation, which complicates assembly and production.

Innovation Solution

A terminal design where two metal members are crimped together without a through hole, ensuring mechanical strength and allowing for metal joining at opposing surfaces, thereby achieving strong junctions and efficient conduction without the need for post-treatment.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If ultrasonic joining is used to join electrode terminal and intermediate member, then junction strength is improved, but surface roughness and deformation occur requiring post treatment

Engineering Contradiction:
Improvejunction strengthVSAvoidsurface roughness
Core Design Contradiction:
StrengthVSManufacturing precision

Solution Approach 1:

The patent divides the joining process into two distinct stages: first crimping to establish mechanical interlocking and initial strength, then applying ultrasonic energy only to specific areas needing metallurgical bonding. This segmentation allows each method to perform its optimal function without the drawbacks of using either method alone.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The crimping operation is performed as a preliminary action before ultrasonic joining. This preliminary mechanical interlocking provides initial strength and positions the components correctly, so that subsequent ultrasonic treatment only needs to provide the metallurgical bond without causing excessive deformation.

Inventive Principle:
Principle #10Preliminary action

2Strength

If large junction energy is applied to ensure junction strength, then conduction and junction strength are improved, but surface roughness and deformation are caused

Engineering Contradiction:
Improvejunction strengthVSAvoidpost treatment complexity
Core Design Contradiction:
StrengthVSDevice complexity

Solution Approach 1:

Instead of applying ultrasonic energy uniformly across the entire joining surface, the patent applies it only partially to specific areas where metallurgical bonding is needed. This partial action achieves the required junction strength while minimizing surface deformation and eliminating the need for post-treatment flattening operations.

Inventive Principle:
Principle #16Partial or excessive action

3Ease of manufacture

If crimping is performed via through hole, then assembly is simplified, but mechanical strength and conduction are reduced

Engineering Contradiction:
Improveassembly easeVSAvoidmechanical strength
Core Design Contradiction:
Ease of manufactureVSStrength

Solution Approach 1:

The patent extracts the through hole from the design and replaces it with an end-face crimping configuration. The intermediate member is crimped directly onto the end face of the electrode terminal, eliminating the need for holes while providing superior mechanical strength and electrical conduction through direct end-to-end contact.

Inventive Principle:
Principle #2Taking out (Extraction)

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 crimped structure without a through hole ensures mechanical strength and allows for effective metal joining, resulting in improved conduction and junction strength between the terminal and bus bar, while eliminating the need for post-treatment to flatten the surface.

Implementation Method 1

the first member and the second member have metal junction surfaces metal-joined to each other at opposing surfaces thereof after the first member and the second member have been previously crimped, wherein the metal joining is performed by ultrasonic joining, diffusion joining, frictional pressure contact, or laser welding

Methodology Applied
Scientific EffectUltrasonic joining: Ultrasonic Vibration

Implementation Method 2

the first member and the second member have metal junction surfaces metal-joined to each other at opposing surfaces thereof after the first member and the second member have been previously crimped, wherein the metal joining is performed by ultrasonic joining, diffusion joining, frictional pressure contact, or laser welding

Methodology Applied
Scientific EffectDiffusion joining: Diffusion Welding

Implementation Method 3

the first member and the second member have metal junction surfaces metal-joined to each other at opposing surfaces thereof after the first member and the second member have been previously crimped, wherein the metal joining is performed by ultrasonic joining, diffusion joining, frictional pressure contact, or laser welding

Methodology Applied
Scientific EffectFrictional pressure contact: Friction Welding

Implementation Method 4

the first member and the second member have metal junction surfaces metal-joined to each other at opposing surfaces thereof after the first member and the second member have been previously crimped, wherein the metal joining is performed by ultrasonic joining, diffusion joining, frictional pressure contact, or laser welding

Methodology Applied
Scientific EffectLaser welding: Laser Beam Welding

Data Source

PatentEP3972044B1Secondary battery and terminal for secondary battery and manufacturing method thereof
Publication Date: 2025.04.23 PRIME PLANET ENERGY & SOLUTIONS INC
  • EP3972044B1 patent drawingFigure 1
  • EP3972044B1 patent drawingFigure 2
  • EP3972044B1 patent drawingFigure 3

AI summary

A terminal including two members excellent in junction strength and conduction is provided. The terminal herein disclosed is a terminal forming any of a positive electrode and a negative electrode of a secondary battery, and has a first member and a second member each made of a metal. The first member is formed in a sheet shape, and the second member has a crimped part opposed to the first member. Herein, at one surface of the first member, the crimped part of the second member is crimped with the first member not via a through hole, and the opposing surfaces of the first member and the second member have the metal junction surfaces metal-joined to each other.