Battery Cell Cover Structure for Corner Sealing Stability

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Solution Overview

Problem

Existing battery cell designs face challenges in maintaining effective sealing at the corner portions of the cover member and preventing displacement due to factors like vibration or vacuuming, which can lead to issues such as short-circuiting of current collectors.

Innovation Solution

The battery cell design incorporates a cover member with protruding portions at the corners that are perpendicular to the battery element's end surface, enhancing sealing and suppressing displacement by pressing against the element, while allowing current collectors to overlap and be accommodated in gaps, with specific area and thickness ratios optimized for improved sealing and space utilization.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If the exterior film is simply wound around the battery element and the cover member, then the manufacturing process is simple, but the sealing property of the corner portion of the cover member deteriorates

Engineering Contradiction:
Improvesimplicity of exterior film winding processVSAvoidsealing property of corner portion
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The cover member is divided into a flat plate portion and a side plate portion that protrudes from it. This segmentation creates distinct functional zones: the flat plate provides a stable base for exterior film winding, while the side plate extends to improve sealing at the corner portions where the exterior film makes contact.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The side plate protrudes in a direction extending from the flat plate, adding a dimensional element that allows the exterior film to wrap around and contact both the flat plate and the side plate. This creates enhanced sealing at the corner portions without complicating the winding process itself.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Device complexity

If the exterior film is simply wound around the battery element and the cover member, then the device structure is simple, but the displacement of the cover member cannot be suppressed

Engineering Contradiction:
Improvesimplicity of cover member structureVSAvoidposition stability of cover member
Core Design Contradiction:
Device complexityVSStability of the object's composition

Solution Approach 1:

The cover member is segmented into a flat plate portion and a side plate portion. The side plate acts as a stabilizing element that prevents displacement by providing additional contact points and structural support, while the flat plate maintains the primary covering function.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The side plate has a curved surface that allows the exterior film to wrap around smoothly. This curvature design enables the film to conform to the shape while the side plate maintains its position, preventing displacement during operation or vacuuming processes.

Inventive Principle:
Principle #14Spheroidality (Curvature)

3Reliability

If the protruding portion is added to the cover member, then the sealing property of the corner portion is improved, but the device complexity increases

Engineering Contradiction:
Improvesealing property of corner portionVSAvoidcomplexity of cover member structure
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The cover member is divided into functional segments: the flat plate portion for basic covering and the side plate protruding portion for enhanced sealing. This segmentation allows each part to perform its specific function efficiently without requiring complex integrated designs.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The side plate extends in a direction from the flat plate, utilizing an additional spatial dimension to achieve improved sealing. This approach adds functionality without requiring complex modifications to the existing flat plate structure, maintaining relative simplicity while enhancing performance.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Data Source

PatentEP4704224A1Battery cell
Publication Date: 2026.03.04 AESC JAPAN LTD
  • EP4704224A1 patent drawingFigure 1
  • EP4704224A1 patent drawingFigure 2
  • EP4704224A1 patent drawingFigure 3

AI summary

The battery cell (10) includes a battery element (100), a front cover member (210) that covers an end surface of the battery element (100), and an exterior film (300) wound around the battery element (100) and the front cover member (210). The front cover member (210) includes at least one corner portion covered with the exterior film (300) and a front protruding portion (214) that protrudes from at least a part of the corner portion. The front protruding portion (214) and the end surface of the battery element (100) are arranged in a direction perpendicular to the end surface of the battery element (100).