Battery Monocell Assembly With Alignment Openings for Precise Positioning

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Solution Overview

Problem

As battery cell size decreases, it becomes increasingly difficult to control the position of the cathode between separator layers, leading to reduced accuracy and efficiency, and handling individual monocells becomes challenging.

Innovation Solution

A method involving pre-cutting patterns in metal foils and separator sheets with alignment openings, allowing for precise alignment and assembly of monocells without lamination, ensuring correct positioning and stiffness for easy handling.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Volume of moving object

If the battery cell size is reduced, then the battery becomes more compact and versatile in shape, but it becomes increasingly difficult to control the position of the cathode between separator layers, leading to reduced manufacturing precision and handling difficulty

Engineering Contradiction:
Improvebattery cell sizeVSAvoidcathode positioning accuracy
Core Design Contradiction:
Volume of moving objectVSManufacturing precision

Solution Approach 1:

Alignment openings are pre-cut in the separator sheets and electrode foils before assembly. These openings are positioned at predetermined locations to guide the relative placement of components, ensuring accurate cathode positioning between separator layers even in miniaturized battery cells. This preliminary preparation eliminates the need for complex real-time alignment procedures during assembly.

Inventive Principle:
Principle #10Preliminary action

2Volume of moving object

If the battery cell size is reduced, then the battery becomes more compact, but handling and aligning individual monocells becomes more difficult

Engineering Contradiction:
Improvebattery cell sizeVSAvoidmonocell handling ease
Core Design Contradiction:
Volume of moving objectVSEase of operation

Solution Approach 1:

Multiple separator sheets are bonded together along their perimeters to form a integrated pocket structure that contains the cathode. This merging of separator sheets creates a single unified component that is easier to handle than individual thin separator sheets, particularly in miniaturized battery applications where handling precision is critical.

Inventive Principle:
Principle #5Merging (Combining)

3Strength

If lamination is used to increase monocell stiffness, then handling becomes easier, but the pressure and heat may damage the separator and electrodes, causing short circuiting or deficient electrolyte adsorption

Engineering Contradiction:
Improvemonocell stiffnessVSAvoidseparator and electrode integrity
Core Design Contradiction:
StrengthVSReliability

Solution Approach 1:

A metal foil is introduced as an intermediary structural element between the separator sheets and electrodes. The foil provides mechanical support and stiffness to the monocell structure, replacing the need for high-pressure lamination. This intermediary component achieves the desired structural strength without subjecting the separator and electrodes to damaging heat and pressure, thereby maintaining their integrity and preventing short circuits.

Inventive Principle:
Principle #24Intermediary (Mediator)

Data Source

PatentEP4645399A1A method for producing a monocell of a battery
Publication Date: 2025.11.05 RENATA
  • EP4645399A1 patent drawingFigure 1~2d
  • EP4645399A1 patent drawingFigure 3a~5b
  • EP4645399A1 patent drawingFigure 6~7

AI summary

Cut-out patterns are produced in a first coated metal foil (14), a second coated metal foil (20) and pair of separator sheets (25). From the first foil (14), the shape of the coated portion (6) of the first electrode is partially cut out along a cut-out lane (17). The cut-out is partial in the sense that said coated portion remains attached to the foil at the predefined position (19) of the first electrode tab. The cut-out pattern in the first foil additionally includes an alignment opening (18, 18a), while the cut-out patterns in the second foil and in the separator sheets also include respective alignment openings (23a, 26). The first foil (14) is inserted between the separator sheets (25) wherein at least one pair of alignment openings (26) in said separator sheets are mutually aligned to each other and to an alignment opening (18, 18a) in the first foil. The separator sheets are then bonded along the cut-out lane (17), to form a first assembly comprising a pocket (11) that contains the coated portion (6) of the first electrode. The second foil (20) is then placed on or under said first assembly, and the alignment opening (23a) in the second foil is aligned to the aligned openings in the first assembly The second foil is attached to the first assembly to obtain a second assembly (28). From the second assembly, the monocell is cut out according to a predefined shape.