Foldable Current Collector With Asymmetric Fold for Compact Assembly

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Solution Overview

Problem

Existing current collectors for prismatic battery cells face challenges in achieving compactness and ease of assembly while minimizing material stress during folding, often requiring additional means to maintain wings in a parallel position.

Innovation Solution

A current collector design with an asymmetric fold portion that allows closer wing alignment without overstressing the material, facilitated by a folding tool applied to a specific flat face, enabling controlled plastic deformation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Volume of moving object

If the fold portion is plastically folded to bring the two wings parallel, then the current collector becomes more compact, but the material experiences significant stress and elastic springback

Engineering Contradiction:
Improvecompactness of current collectorVSAvoidstress on sheet metal material
Core Design Contradiction:
Volume of moving objectVSStress or pressure

Solution Approach 1:

The fold portion is designed with an asymmetric cross-sectional shape that is not symmetric about the fold axis. This asymmetric geometry allows the material to fold more easily with reduced stress concentration, while still achieving the desired parallel configuration of the two wings. The asymmetric shape optimizes the distribution of plastic deformation during folding.

Inventive Principle:
Principle #4Asymmetry

Solution Approach 2:

The fold portion is pre-formed with a specific asymmetric cross-sectional shape before the final folding operation. This preliminary shaping prepares the material to undergo plastic deformation more smoothly during the folding process, reducing the stress required to achieve the parallel wing configuration and minimizing elastic springback.

Inventive Principle:
Principle #10Preliminary action

2Manufacturing precision

If the fold portion cross-section is made symmetric, then the folding is easier to control, but the material stress increases and compactness is reduced

Engineering Contradiction:
Improvecontrol of folding processVSAvoidcompactness of current collector
Core Design Contradiction:
Manufacturing precisionVSVolume of moving object

Solution Approach 1:

The fold portion employs an asymmetric cross-sectional shape that is optimized to balance manufacturing control with material stress reduction. The asymmetric geometry provides sufficient control during the folding process while enabling greater compactness in the final parallel configuration compared to symmetric designs.

Inventive Principle:
Principle #4Asymmetry

3Stability of the object's composition

If additional means are added to maintain wings parallel, then the wings stay in final position, but the device complexity increases

Engineering Contradiction:
Improvemaintenance of parallel wing positionVSAvoidcomplexity of current collector structure
Core Design Contradiction:
Stability of the object's compositionVSDevice complexity

Solution Approach 1:

The fold portion is designed to maintain the parallel position of the two wings through its own geometric properties and material deformation characteristics, without requiring additional external means such as hooks or retaining structures. The asymmetric cross-sectional shape and controlled plastic deformation enable the structure to self-maintain its final configuration.

Inventive Principle:
Principle #25Self-service

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 design achieves a more compact and easily assembled current collector with reduced material stress, ensuring efficient electrical connection and improved manufacturing control.

Implementation Method 1

The fold portion is subsequently plastically folded such that the first wing rotates relative to the second wing about the fold axis

Methodology Applied
Scientific EffectPlastic deformation: Plasticity

Implementation Method 2

the two wings tend to elastically spring back towards an intermediate position between the initial and final positions

Methodology Applied
Scientific EffectElastic springback: Elasticity

Data Source

PatentEP4510359B1Foldable current collector, battery cell subassembly and method of assembly
Publication Date: 2026.03.11 AUTOMOTIVE CELLS CO SE
  • EP4510359B1 patent drawingFigure 1~2
  • EP4510359B1 patent drawingFigure 3~4

AI summary

A current collector (12) for connecting two components (14, 16) of a battery cell, namely a set of electrode tabs (14) and a terminal foot (16), comprises a sheet metal piece having a first wing (20), a second wing (22) and at least one fold portion (24) linking the first wing (20) to the second wing (22). The first wing (20) has a first flat face (30) located in a first plane (200), the second wing (22) has a second flat face (36) located in a second plane (300), the fold portion (24) defines a fold axis (100) which is parallel to the first flat face (30) and to the second flat face (36), the first flat face (30) is oriented in a first rotation direction (110) about the fold axis (100) and the second flat face (36) is oriented in a second rotation direction (120) about the fold axis, opposed to the first rotation direction (110). The fold portion (24) is entirely located on one side of the first plane (200) oriented in the second rotation direction (120) and crosses the second plane twice (300).