Electrode Assembly Tape Layout for Battery Thickness Balance

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Solution Overview

Problem

Existing secondary battery manufacturing processes face challenges in ensuring consistent thickness balance and adhesion of electrode active material layers, particularly in the sliding areas where slurry flow reduces layer thickness, leading to potential insertability issues and compromised battery quality.

Innovation Solution

A method involving the sequential attachment of top, body, and side tapes around the electrode assembly to enhance adhesion and thickness balance, specifically using synthetic resin tapes like PET, PP, or PI, ensuring the upper end portion has reduced active material layer thickness and improved insertability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If the electrode active material layer is coated on the current collector, then the battery capacity is improved, but the thickness balance and adhesion in sliding areas deteriorate

Engineering Contradiction:
Improvebattery capacityVSAvoidthickness balance
Core Design Contradiction:
Quantity of substanceVSManufacturing precision

Solution Approach 1:

The patent divides the current collector into multiple segments: a sliding area where the active material layer thickness is intentionally reduced, and non-sliding areas where the layer maintains normal thickness. This segmentation allows the battery to achieve high capacity in non-sliding areas while ensuring proper adhesion and thickness balance in sliding areas through the separate application of adhesive layers in those specific regions.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent applies different properties to different parts of the electrode structure. Specifically, the sliding area receives an additional adhesive layer application and has reduced active material thickness, while non-sliding areas maintain standard coating. This local differentiation resolves the contradiction by ensuring proper adhesion where needed without compromising overall battery capacity.

Inventive Principle:
Principle #3Local quality

2Quantity of substance

If the electrode active material layer thickness is increased, then the battery capacity is improved, but the insertability deteriorates due to poor adhesion in sliding areas

Engineering Contradiction:
Improvebattery capacityVSAvoidinsertability
Core Design Contradiction:
Quantity of substanceVSEase of operation

Solution Approach 1:

The patent applies adhesive layers to the sliding areas before assembling the battery components. This preliminary action ensures that when the electrode assembly is inserted into the battery case, the adhesive is already in place to prevent displacement of the active material layer, thereby improving insertability without reducing capacity.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

By segmenting the current collector into sliding and non-sliding areas with different thickness characteristics and applying adhesive selectively to sliding areas, the patent enables the electrode assembly to maintain high capacity while achieving proper insertability through differentiated structural properties.

Inventive Principle:
Principle #1Segmentation

3Productivity

If the slurry flow is increased to improve coating coverage, then the manufacturing efficiency is improved, but the thickness balance in sliding areas deteriorates

Engineering Contradiction:
Improvemanufacturing efficiencyVSAvoidthickness balance
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

The patent extracts or removes the active material layer from the sliding area, intentionally creating a region with reduced or no active material coating. This extraction allows the manufacturing process to maintain high efficiency with increased slurry flow while preventing thickness imbalance issues in sliding areas through the separate application of adhesive layers.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent implements local quality by creating a sliding area with distinct properties (reduced active material thickness and added adhesive layer) compared to non-sliding areas. This local differentiation enables efficient manufacturing with higher slurry flow rates while maintaining proper thickness balance through the selectively modified sliding region.

Inventive Principle:
Principle #3Local quality

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 tape attachment process enhances the adhesion and thickness balance of secondary batteries, improving insertability and heat exposure characteristics, thereby increasing the quality and performance of the battery cells.

Implementation Method 1

a second adhesive layer may then be applied to the sliding area of the negative electrode, thereby complementing the negative electrode in the sliding area

Methodology Applied
Scientific EffectAdhesion: Adhesive

Data Source

PatentEP4641725A1Secondary battery and method of manufacturing the same
Publication Date: 2025.10.29 SAMSUNG SDI CO LTD
  • EP4641725A1 patent drawingFigure 1~2
  • EP4641725A1 patent drawingFigure 3~4
  • EP4641725A1 patent drawingFigure 5

AI summary

A secondary battery and a method of manufacturing the same are disclosed. The method of manufacturing a secondary battery includes preparing an electrode assembly including a first electrode plate, a second electrode plate, and a separator, attaching a top tape to an upper end portion of the electrode assembly, attaching a bottom tape to surround a lower end portion of the electrode assembly, attaching a body tape to surround the upper end portion of the electrode assembly, and inserting the electrode assembly into a case, wherein each of the first and second electrode plates includes a current collector, an active material layer on the current collector, an uncoated portion at an end of the current collector adjacent to the electrode active material layer, and an electrode tab at an end portion of the uncoated portion.