Battery Lid Sealing Structure for Leak-Resistant Pouch Packaging
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing electrical storage devices, such as all-solid-state batteries, face challenges in maintaining a sealed state due to inadequate joining of the exterior film and lid, which can lead to leakage and reduced battery performance.
Innovation Solution
The electrical storage device incorporates a design with a first sealed portion where the exterior film surfaces are sealed, and a second sealed portion where the lid and exterior film surfaces are sealed, with a sealing strength of 40 N/15 mm or more, and includes features like resin lumps and a specific ratio of lid wrapping portion to lid seal surface to enhance sealing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the exterior film and lid are joined using conventional heat-sealing methods, then the sealing process is simple and fast, but the sealing strength is insufficient to maintain a reliable sealed state
Solution Approach 1:
The sealing structure is divided into two distinct sealed portions: a first sealed portion where exterior film surfaces are sealed together, and a second sealed portion where the lid and exterior film surfaces are sealed. This segmentation allows each portion to be optimized for its specific function, with the second sealed portion achieving a sealing strength of 40 N/15 mm or more while keeping the overall structure manageable.
Solution Approach 2:
The exterior film includes a heat-sealable resin layer that is sealed to the lid, and the main components of the materials for forming the heat-sealable resin layer and the lid are the same. This composite material approach ensures strong adhesion and sealing strength at the interface between the lid and exterior film, achieving the required 40 N/15 mm or more sealing strength.
2Reliability
If the lid wrapping portion is made too long to ensure adequate sealing coverage, then sealing coverage is improved, but the ratio of lid wrapping portion to lid seal surface becomes excessive and may cause sealing defects
Solution Approach 1:
The patent specifies that the ratio of the length of the lid wrapping portion to the length of the lid seal surface is 103% or less. This precise parameter control ensures adequate sealing coverage while preventing excessive wrapping that could cause sealing defects. The parameter optimization balances coverage requirements with manufacturing precision.
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
This design effectively maintains the sealed state of the electrode assembly within the outer packaging, preventing leakage and ensuring the longevity and performance of the electrical storage device.
Implementation Method 1
The exterior film includes a heat-sealable resin layer that is sealed to the lid
Data Source
AI summary
This power storage device includes an electrode body and an exterior body sealing the electrode body, wherein: the exterior body includes an exterior film wound on the electrode body so as to have an opening, a lid disposed in the opening, a first sealing part where mutually facing surfaces of the exterior film are sealed, and a second sealing part where mutually facing surfaces of the lid and the exterior film are sealed; and the sealing strength of the second sealing part is 40 N/15 mm or higher.