Battery Cell Tab Alignment via Variable Height Current Collectors

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Solution Overview

Problem

The manufacturing of cylindrical electric battery cells is hindered by the difficulty in aligning current collection tabs, leading to angular offsets and reduced performance, which can result in scrap production and affect industrial production rates.

Innovation Solution

The design incorporates current collection tabs with specific dimensions and arrangements, including varying heights and separation distances between tabs, to ensure near-certain alignment and overlap, thereby facilitating effective electrical contact.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If current collection tabs are attached to electrode sheets, then electrical connection is enabled, but production rate decreases and defect risk increases

Engineering Contradiction:
Improveelectrical connection reliabilityVSAvoidproduction rate
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The patent extracts the current collection function from separate attachable tabs and integrates it directly into the electrode sheet structure through precision cutting. The tabs are formed as integral parts of the electrode sheets during the winding process, eliminating the need for separate attachment operations and reducing defect risks associated with tab attachment.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent merges the current collection tabs with the electrode sheets by forming them as integral parts through cutting. This combination ensures reliable electrical connection while simplifying the manufacturing process, as the tabs and electrodes become a unified structure that is wound together in a single operation.

Inventive Principle:
Principle #5Merging (Combining)

2Reliability

If tabs are folded and fixed after winding, then electrical connection is achieved, but the process becomes tedious and difficult to automate

Engineering Contradiction:
Improveelectrical contactVSAvoidmanufacturing ease
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The patent applies preliminary action by pre-forming the current collection tabs as integral parts of the electrode sheets before the winding process. The tabs are cut and positioned in advance with precise dimensions and spacing, so that they naturally align and contact during winding, eliminating the need for post-winding folding and fixing operations.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent enables self-service by designing the electrode sheets with built-in current collection tabs that automatically align and make electrical contact during the winding process. The precise geometric relationships between tabs (length between 50%-150% of separation distance, varying heights) ensure that tabs from different electrodes self-align and contact without external intervention.

Inventive Principle:
Principle #25Self-service

3Ease of manufacture

If cuts are made on electrode sheets to form tabs, then tabs are formed without additional components, but alignment precision becomes difficult to ensure

Engineering Contradiction:
Improvetab formationVSAvoidtab alignment
Core Design Contradiction:
Ease of manufactureVSManufacturing precision

Solution Approach 1:

The patent applies local quality by varying the dimensions of current collection tabs in different regions of the electrode sheets. Tabs in different series have different heights and lengths, creating a hierarchical structure where larger tabs provide primary contact points and smaller tabs provide secondary contact points. This local variation in tab quality ensures precise alignment and reliable electrical contact throughout the wound structure.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent uses parameter changes by systematically varying tab length, height, and separation distance according to specific geometric relationships. The tab length is set between 50%-150% of the separation distance, and heights vary across different series, creating a controlled parameter distribution that ensures precise alignment and overlap during winding, transforming the alignment challenge into a predictable geometric relationship.

Inventive Principle:
Principle #35Parameter changes

4Ease of manufacture

If tab dimensions are standardized, then manufacturing is simplified, but alignment certainty and overlap are reduced

Engineering Contradiction:
Improvemanufacturing simplicityVSAvoidalignment certainty
Core Design Contradiction:
Ease of manufactureVSManufacturing precision

Solution Approach 1:

The patent applies asymmetry by introducing deliberate dimensional variations in tab heights and lengths across different series, rather than using uniform standardized dimensions. This asymmetric design creates a hierarchical contact structure where tabs of different sizes interlock and overlap in a controlled manner, ensuring precise alignment and reliable electrical contact while maintaining manufacturing simplicity through systematic geometric relationships.

Inventive Principle:
Principle #4Asymmetry

Data Source

PatentEP4537420B1Cell for an electric battery and method for manufacturing same
Publication Date: 2025.06.04 VERKOR SA
  • EP4537420B1 patent drawingFigure 1~2
  • EP4537420B1 patent drawingFigure 3~4
  • EP4537420B1 patent drawingFigure 5

AI summary

The invention relates to an electric battery cell comprising at least one consecutive stack of a sheet: - of a first positive electrode (2) comprising an upper edge (4); - a first insulating separator; - a second negative electrode (3) comprising a lower edge (5); and - a second insulating separator, the at least one stack being rolled up on itself about a central axis (Y) so as to form a cylinder, the first electrode (2) and the second electrode (3) each comprising at least two series (6) of current collector tabs (7), each series (6) comprising at least two current collector tabs (7) having a given height (9), in which cell in a given series (6) the current collector tabs (7) are substantially the same height (9) and the height (9) of the current collector tabs (7) differs from one series (6) to the next.