Folded Insulation Sheet Assembly for Stable Bare Cell Wrapping

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Solution Overview

Problem

Existing energy storage devices face issues with low wrapping efficiency and stability due to separate insulating sheets that require multiple processes and seam warping, leading to potential safety risks from bonding failures.

Innovation Solution

A protective film assembly with an integrated insulation sheet featuring fold structures that divide into multiple regions, allowing for seamless wrapping and increased bonding areas, ensuring structural stability and improved insulation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If separate insulating sheets are used for wrapping the bare cell, then the insulation protection is achieved, but the wrapping efficiency is low and the bonding area is small

Engineering Contradiction:
Improveinsulation protectionVSAvoidwrapping efficiency
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The patent combines multiple separate insulating sheets (bottom insulating sheet, main wrapping sheet, and auxiliary wrapping sheet) into a single integrated insulating sheet with one body. This integrated sheet includes a bottom surface covering region, a main surface covering region, and first and second side surface covering regions that are all connected as one piece, eliminating the need for multiple separate components and improving wrapping efficiency while maintaining insulation protection.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The integrated insulating sheet is divided into multiple functional regions (bottom surface covering region, main surface covering region, first side surface covering region, second side surface covering region) through fold structures. These regions are segmented to cover different surfaces of the bare cell while remaining part of a single integrated structure, allowing efficient wrapping without requiring multiple separate sheets.

Inventive Principle:
Principle #1Segmentation

2Reliability

If multiple separate wrapping sheets are used, then the insulation coverage is complete, but the seams between sheets are prone to warping and bonding failure

Engineering Contradiction:
Improveinsulation coverageVSAvoidwrapping stability
Core Design Contradiction:
ReliabilityVSStability of the object's composition

Solution Approach 1:

By merging multiple separate wrapping sheets into a single integrated insulating sheet, the patent eliminates the seams and joints that exist between separate sheets. The integrated structure ensures uniform wrapping without warping at connection points, as there are no separate components to bond together, thereby improving wrapping stability while maintaining complete insulation coverage.

Inventive Principle:
Principle #5Merging (Combining)

3Reliability

If separate insulating sheets are used, then the insulation function is achieved, but the bonding area is small leading to bonding failure

Engineering Contradiction:
Improveinsulation functionVSAvoidbonding area
Core Design Contradiction:
ReliabilityVSArea of stationary object

Solution Approach 1:

The integration of multiple insulating sheet functions into one single insulating sheet creates continuous bonding surfaces without interruption. The first and second side surface covering regions overlap after bending, forming extensive bonding areas that are free from the limitations of separate sheet connections, thereby ensuring reliable bonding while maintaining insulation function.

Inventive Principle:
Principle #5Merging (Combining)

4Reliability

If multiple separate insulating sheets and zoned wrapping processes are used, then the insulation protection is achieved, but the manufacturing complexity is high

Engineering Contradiction:
Improveinsulation protectionVSAvoidmanufacturing complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent simplifies manufacturing by combining multiple insulating sheets and zoned wrapping processes into a single integrated insulating sheet that can be wrapped in one operation. The integrated sheet includes all necessary regions (bottom, main, and side surface covering regions) connected together, eliminating the need for separate component collection, sorting, and zoned wrapping processes, thereby reducing manufacturing complexity while maintaining insulation protection.

Inventive Principle:
Principle #5Merging (Combining)

Data Source

PatentEP4618257A1Protective film assembly and energy storage device
Publication Date: 2025.09.17 SHENZHEN HITHIUM ENERGY STORAGE CONTROL TECHNOLOGY CO LTD
  • EP4618257A1 patent drawingFigure 1
  • EP4618257A1 patent drawingFigure 2~3
  • EP4618257A1 patent drawingFigure 4~5

AI summary

The present disclosure discloses a protective film assembly, applied to an electrode assembly (300) of an energy storage device (1000), and including an insulation sheet (100) for wrapping the electrode assembly (300) , and arranged between a housing of the energy storage device (1000) and the electrode assembly (300). The insulation sheet (100) is integrated, and is provided with a plurality of fold structures (150) , which divide the insulation sheet (100) into a bottom surface covering region (140) clinging to a bottom of the electrode assembly (300), a main surface (110) covering region clinging to a main surface of the electrode assembly (300), and a first side surface (120) covering region and a second side surface (130) covering region clinging to side surfaces of the electrode assembly (300). The first side surface (120) covering region includes a first covering sub-region (121) and a second covering sub-region (122) which can overlap each other; the second side surface (130) covering region includes a third covering sub-region (131) and a fourth covering sub-region (132) which can overlap each other; a maximum sizes of the first covering sub-region (121) and the second covering sub-region (122) in a thickness direction and height direction of the electrode assembly are equal, so that the first covering sub-region (121) and the second covering sub-region (122) have a high matching degree and a large bonding area. The present disclosure further discloses an energy storage device (1000).