Separator-Based Battery Lamination for Precise Electrode Alignment

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Solution Overview

Problem

Existing methods for manufacturing lithium-ion batteries fail to address the alignment of anode and cathode materials during the lamination process, leading to misalignment issues that can reduce battery lifetime, increase the risk of short circuits, and thermal runaway.

Innovation Solution

The method involves applying active materials directly to both sides of a separator sheet to form stack parts, ensuring precise alignment and uniform anode overhang by laminating these parts onto a current collector, thereby maintaining consistent anode overhang and reducing misalignment.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If active materials are first applied to current collectors and then laminated onto separators, then the manufacturing process is simpler, but misalignment occurs between electrodes leading to reduced battery lifetime and safety

Engineering Contradiction:
Improvemanufacturing process simplicityVSAvoidelectrode alignment precision
Core Design Contradiction:
Ease of manufactureVSManufacturing precision

Solution Approach 1:

The separator is pre-cut with alignment features (such as tabs or notches) before the lamination process. This preliminary preparation ensures that when electrodes are subsequently laminated onto the separator, the anode material automatically aligns correctly with the cathode material, preventing misalignment and ensuring proper anode overhang without requiring complex real-time alignment controls during assembly.

Inventive Principle:
Principle #10Preliminary action

2Ease of manufacture

If electrodes are laminated onto separators after formation, then the manufacturing process follows conventional steps, but unintentional misalignment eliminates anode overhang and increases short circuit risk

Engineering Contradiction:
Improveconventional manufacturing processVSAvoidbattery safety and performance
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The separator serves as an intermediary component that mediates the alignment between the anode and cathode. By incorporating alignment features directly into the separator structure, it acts as a reference framework that guides the positioning of both electrodes during lamination, ensuring correct alignment and maintaining the necessary anode overhang to prevent short circuits and thermal runaway.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Reliability

If precise anode overhang is maintained through improved lamination alignment, then battery safety improves, but manufacturing complexity increases

Engineering Contradiction:
Improvebattery safetyVSAvoidmanufacturing process complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

Alignment features are pre-formed on the separator during separator manufacturing, before the electrode lamination process. This preliminary action transfers the alignment function to the separator itself, eliminating the need for complex real-time alignment mechanisms during assembly and reducing manufacturing complexity while ensuring consistent anode overhang and battery safety.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP4675688A1Battery manufacturing method and corresponding battery
Publication Date: 2026.01.07 LG ENERGY SOLUTION LTD
  • EP4675688A1 patent drawingFigure 1
  • EP4675688A1 patent drawingFigure 2
  • EP4675688A1 patent drawingFigure 3

AI summary

Disclosed is a battery manufacturing method. A first stack part (10) is formed by applying a positive active material on one of two main surfaces of a first separator sheet (2.1) and applying a negative active material on the other one of the two main surfaces of the first separator sheet. A second stack part (20) is formed by applying the positive active material onto one of two main surfaces of a second separator sheet (2.2) and applying the negative active material onto the other one of the two main surfaces of the second separator sheet. The first stack part and the second stack part are stacked upon each other with a current collector plate interposed between the first stack part and the second stack part.