Electrode Assembly Fixing Structure for Stable Secondary Batteries

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Solution Overview

Problem

Secondary batteries face instability issues due to electrode plate tearing and substrate tab breakage during repeated charging and discharging, which affects cell stability and requires a method to securely fix the electrode assembly within the case.

Innovation Solution

The use of fixing members, such as tapes or spray coatings made of polystyrene or polyethylene, attached to various surfaces of the electrode assembly to securely position it within the case, including central, end, and side surfaces, ensuring electrical insulation and preventing movement.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If fixing members are attached to the electrode assembly, then the electrode assembly is securely fixed within the case, but the device complexity increases

Engineering Contradiction:
Improveelectrode assembly stabilityVSAvoidstructure complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The fixing member is implemented as a thin film structure with adhesive layers that conform to the electrode assembly surface. This flexible film approach provides secure fixation without requiring rigid structural components, thus maintaining reliability while minimizing added complexity.

Inventive Principle:
Principle #30Flexible shells and thin films

Solution Approach 2:

The fixing member acts as an intermediary element between the electrode assembly and the case. It includes an adhesive layer that mediates the bonding interface, allowing secure fixation while isolating the electrode assembly from direct mechanical constraints, thereby simplifying the overall structure.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If fixing members are attached to the electrode assembly, then movement is prevented, but the manufacturing process becomes more complex

Engineering Contradiction:
Improveelectrode assembly stabilityVSAvoidmanufacturing process simplicity
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The adhesive layer of the fixing member is pre-applied to the electrode assembly before assembly into the case. This preliminary action ensures proper positioning and fixation during the manufacturing process, preventing movement without requiring complex post-assembly operations or specialized manufacturing equipment.

Inventive Principle:
Principle #10Preliminary action

3Shape

If the fixing member thickness matches the active material thickness, then the surface is flush and compact, but the fixing strength is reduced

Engineering Contradiction:
Improvesurface flatnessVSAvoidfixing strength
Core Design Contradiction:
ShapeVSStrength

Solution Approach 1:

The fixing member utilizes a thin film adhesive structure that achieves sufficient fixation strength through adhesive bonding rather than mechanical interlocking. The film conformally coats the electrode assembly surface, providing a flush appearance while maintaining adequate fixing strength through the adhesive properties of the polymer material.

Inventive Principle:
Principle #30Flexible shells and thin films

Data Source

PatentEP4297154A1Secondary battery
Publication Date: 2023.12.27 SAMSUNG SDI CO LTD
  • EP4297154A1 patent drawingFigure 1
  • EP4297154A1 patent drawingFigure 2~3
  • EP4297154A1 patent drawingFigure 4

AI summary

A secondary battery, including an electrode assembly including a plurality of first electrode plates coated with a first active material, a plurality of second electrode plates coated with a second active material, and a separator positioned between each of the plurality of first electrode plates and each of the plurality of second electrode plates, and a case accommodating the electrode assembly through an internal space, wherein the electrode assembly includes a fixing member on at least one surface in contact with the case.