Jelly-Roll Battery Cell Tab Bending for Compact Collector Joining

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Solution Overview

Problem

The connection between a current collector and an electrode non-coating portion in prismatic secondary batteries requires a connection space, which reduces the energy density of the battery.

Innovation Solution

The design minimizes the connection space by bending electrode assembly non-coating portions to couple with the current collector, arranging the welding face perpendicular to the winding axis, and optimizing the internal space usage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If the connection between current collector and electrode non-coating portion is made in a direction perpendicular to winding axis, then the connection structure is simple, but the connection space increases reducing energy density

Engineering Contradiction:
Improveconnection structureVSAvoidenergy density
Core Design Contradiction:
Device complexityVSQuantity of substance

Solution Approach 1:

The patent changes the connection direction from perpendicular to the winding axis (conventional approach) to parallel to the winding axis. This dimensional change allows the non-coating portions to be connected to the current collector in a direction that minimizes the required connection space, thereby increasing energy density while maintaining structural simplicity

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Quantity of substance

If connection space is reduced, then energy density increases, but manufacturing difficulty may increase

Engineering Contradiction:
Improveenergy densityVSAvoidmanufacturing ease
Core Design Contradiction:
Quantity of substanceVSEase of manufacture

Solution Approach 1:

The non-coating portions are pre-formed with bent shapes during the electrode assembly manufacturing process, before final assembly into the battery case. This preliminary formation of the bent configuration simplifies the subsequent assembly process and maintains manufacturing ease while achieving reduced connection space and increased energy density

Inventive Principle:
Principle #10Preliminary action

3Volume of stationary object

If welding face is arranged perpendicular to winding axis, then space efficiency increases, but damage risk during crushing increases

Engineering Contradiction:
Improvespace efficiencyVSAvoidsafety
Core Design Contradiction:
Volume of stationary objectVSReliability

Solution Approach 1:

The patent creates an asymmetric arrangement where the welding faces are positioned at opposite ends of the electrode assembly, perpendicular to the winding axis. This asymmetric configuration optimizes space efficiency while the distributed positioning at opposite ends provides structural symmetry in terms of load distribution, reducing damage risk during crushing

Inventive Principle:
Principle #4Asymmetry

Data Source

PatentEP4661129A1Secondary battery and method of manufacturing the same
Publication Date: 2025.12.10 SK ON CO LTD
  • EP4661129A1 patent drawingFigure 1~2
  • EP4661129A1 patent drawingFigure 3
  • EP4661129A1 patent drawingFigure 4~5

AI summary

The disclosure relates to a battery cell. More specifically, the disclosure relates to a battery cell minimizing a connection space between a non-coating portion forming an electrode assembly (100) and a current collector (220). The battery cell according to the disclosure can maximize the use efficiency of an internal space by minimizing a connection space between a non-coating portion of a jelly roll-shaped electrode assembly and a current collector (220). The battery cell according to the disclosure can increase a capacity by reducing a space loss inside a case (400) accommodating an electrode assembly (100). The battery cell according to the disclosure arranges a welding face of a current collector (220) perpendicular to a winding axis direction of an electrode assembly (100), and thus can reduce damage to the electrode assembly (100) when the battery cell is crushed and can improve safety.