Battery Electrode Tab Curvature for Stress Relief at Connection Corners

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Solution Overview

Problem

Conventional electrode tabs in secondary batteries experience stress concentration at the connection corners, increasing the risk of being cut due to internal and external forces during manufacturing and use.

Innovation Solution

The electrode tab features a stress relief portion with a curved design, specifically a side surface cut into an arc shape with a predetermined radius of curvature, reducing stress concentration at the connection point between the electrode plate and the tab.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If the electrode tab connection portion is patterned with a right angle by cutting, then the manufacturing process is simple, but stress concentrates on the corner increasing the danger of being cut

Engineering Contradiction:
Improvemanufacturing process simplicityVSAvoidelectrode tab durability
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The patent applies curvature by cutting the side surface of the first tab portion into an arc shape with a predetermined radius of curvature. This curved design eliminates sharp corners where stress would concentrate, distributing stress more evenly across the connection portion between the electrode plate and electrode tab, thereby preventing cutting while maintaining manufacturing simplicity

Inventive Principle:
Principle #14Spheroidality (Curvature)

2Device complexity

If the electrode tab has a straight connection portion, then the structure is simple, but stress concentration occurs at the corner during manufacturing and use

Engineering Contradiction:
Improveelectrode tab structureVSAvoidstress concentration
Core Design Contradiction:
Device complexityVSStress or pressure

Solution Approach 1:

The patent introduces a curved side surface with arc-shaped cutting on the first tab portion, replacing the straight connection portion. This curvature fundamentally changes the stress distribution pattern, eliminating stress concentration at corners while adding minimal structural complexity to the electrode tab design

Inventive Principle:
Principle #14Spheroidality (Curvature)

Data Source

PatentEP4113733B1Battery cell including electrode tab having stress relief portion
Publication Date: 2025.11.19 LG ENERGY SOLUTION LTD
  • EP4113733B1 patent drawingFigure 1~2
  • EP4113733B1 patent drawingFigure 3~4
  • EP4113733B1 patent drawingFigure 5

AI summary

The present invention relates to a battery cell including an electrode assembly including a plurality of electrode plates and at least one separator interposed between the plurality of electrode plates, a case configured to receive the electrode assembly, electrode tabs formed at the electrode plates so as to protrude and extend therefrom, and an electrode lead joined to the electrode tabs while being electrically connected to the outside, wherein each of the electrode tabs includes a first tab portion connected to a corresponding one of the electrode plates and a second tab portion extending from the first tab portion, the electrode lead being joined to the second tab portion, and the first tab portion is provided with a stress relief portion configured to reduce stress in the electrode tab.