Pouch-Type Battery Case Structure for Higher Energy Density

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Solution Overview

Problem

Existing pouch-type secondary batteries face limitations in energy density due to manufacturing constraints, particularly in the formation process, which restricts the thickness and size, making it difficult to improve performance.

Innovation Solution

A pouch-type case with an opening between case units and a sealing member is used, along with a recessed portion in the case sheet to accommodate various electrode sizes, allowing for efficient embedding of the electrode assembly and improved sealing.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Volume of moving object

If a pouch-type case with stacked layers is used, then the case structure is formed, but the elongation by pressing and heating is limited, restricting thickness and size

Engineering Contradiction:
Improvebattery thicknessVSAvoidmanufacturing process flexibility
Core Design Contradiction:
Volume of moving objectVSEase of manufacture

Solution Approach 1:

The case is divided into a body portion and a lid portion that are separately formed and then assembled together. The body portion includes a bottom wall and side walls, while the lid portion includes a top wall and side walls, allowing independent formation and optimization of each segment.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The electrode assembly is inserted into the case through an opening formed in the lid portion, and then the sealing member is inserted to seal the opening. This nested assembly approach allows for flexible manufacturing and assembly processes.

Inventive Principle:
Principle #7Nested doll (Nesting)

2Productivity

If the case structure is limited in process steps, then manufacturing is simplified, but energy density improvement becomes difficult

Engineering Contradiction:
Improveenergy densityVSAvoidcase structure complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The case is segmented into body and lid portions that can be manufactured independently using different processes and then assembled, allowing optimization of each part for specific functions while maintaining overall manufacturing efficiency.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

A sealing member is introduced as an intermediary component that connects the body portion and lid portion, provides sealing function, and allows for flexible assembly while maintaining structural integrity.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Length of stationary object

If pressing and heating elongation is limited, then case integrity is maintained, but thickness and size are restricted

Engineering Contradiction:
Improvecase thicknessVSAvoidcase dimensional control
Core Design Contradiction:
Length of stationary objectVSManufacturing precision

Solution Approach 1:

By dividing the case into separately formed body and lid portions, each segment can be manufactured with precise dimensional control in its optimal thickness range, then assembled to achieve the desired total thickness without requiring excessive pressing and heating of a single layered structure.

Inventive Principle:
Principle #1Segmentation

Data Source

PatentEP4668428A1Secondary battery and method for manufacturing secondary battery
Publication Date: 2025.12.24 LG ENERGY SOLUTION LTD
  • EP4668428A1 patent drawingFigure 1
  • EP4668428A1 patent drawingFigure 2
  • EP4668428A1 patent drawingFigure 3

AI summary

A secondary battery according to an embodiment of the present disclosure may include a pouch-type case having an opening between a pair of case units, an electrode assembly inserted into the case through the opening, and a sealing member provided to cover the opening and seal the case.