Secondary Battery Terminal Joint With Projection-Aligned Welding

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Solution Overview

Problem

Poor fit between the current collector and the terminal plate in prismatic secondary batteries can degrade the electrical characteristics of the battery.

Innovation Solution

A secondary battery design featuring a current collector with a protruding portion and a projection that extends through a hole in the terminal plate, allowing for precise welding and contact between the collector and the terminal plate, reducing welding defects.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a current collector is directly connected to a terminal plate in a prismatic secondary battery, then the electrical connection is established, but the fit between the current collector and terminal plate may be poor, degrading electrical characteristics

Engineering Contradiction:
Improveelectrical connection reliabilityVSAvoidfit precision between current collector and terminal plate
Core Design Contradiction:
ReliabilityVSManufacturing precision

Solution Approach 1:

A projection is formed on the current collector before assembly, which preliminarily positions the current collector relative to the terminal plate. The projection fits into a corresponding recess in the terminal plate, ensuring precise alignment and contact before welding occurs, thereby improving both fit precision and electrical connection reliability.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The projection acts as an intermediary element between the current collector and terminal plate. This intermediate structure facilitates precise positioning and stable contact, mediating the connection between the two components and eliminating the poor fit problem that would otherwise occur with direct connection.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If welding is performed to connect the current collector and terminal plate, then electrical connection is improved, but welding defects may occur reducing battery reliability

Engineering Contradiction:
Improveelectrical connection reliabilityVSAvoidwelding defects
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The projection and recess structure is formed before welding to preliminarily secure the current collector to the terminal plate. This preliminary mechanical connection ensures proper positioning and reduces stress on the weld joint, allowing welding to be performed more easily and reducing the occurrence of welding defects such as incomplete penetration or misalignment.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The projection-recess mechanical connection serves as a cushioning structure that absorbs positioning errors and stress during the welding process. This beforehand cushioning prevents welding defects by maintaining stable contact between the current collector and terminal plate throughout welding, thereby improving weld quality and reducing harmful welding defects.

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

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 improves the reliability of the secondary battery by ensuring consistent electrical connection and reducing welding defects, enhancing the overall performance and integrity of the battery.

Implementation Method 1

a welding area coupled to the protruding portion by welding, and the welding area is positioned around the projection

Methodology Applied
Scientific EffectWelding: Welding

Data Source

PatentEP4604230A1Secondary battery
Publication Date: 2025.08.20 SAMSUNG SDI CO LTD
  • EP4604230A1 patent drawingFigure 1~2
  • EP4604230A1 patent drawingFigure 3
  • EP4604230A1 patent drawingFigure 4

AI summary

A secondary battery includes an electrode assembly, a subplate connected to the electrode assembly. The secondary battery also includes current collector having a planar portion coupled to the subplate, a protruding portion protruding from the planar portion, and a projection provided on a top surface of the protruding portion. A terminal plate is coupled to the current collector and a hole is formed in the terminal plate, wherein the projection extends through the hole.