Battery Pack Heat Seal Adhesive Layer Thickness Reduction
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Solution Overview
Problem
Existing battery packs with multiple laminating films and heat seal adhesive films face issues of excessive thickness, reduced volumetric efficiency, and increased risk of folding and bending during manufacturing, leading to decreased yield and efficiency.
Innovation Solution
A battery pack design utilizing a thinner heat seal adhesive layer, specifically an ethylene-vinyl acetate copolymer layer with a thickness between 1 μm and 20 μm, is applied between packaging components to reduce thickness and improve adhesion, eliminating the need for a separate heat seal adhesive film and minimizing the risk of folding and bending.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If multiple laminating films and heat seal adhesive films are used to package the battery element, then the battery element is well protected and secured, but the overall thickness of the battery pack increases and volumetric efficiency decreases
Solution Approach 1:
The patent merges the heat seal adhesive film with one of the laminating films by forming a heat seal adhesive layer on the surface of the inner resin layer of the laminating film. This integration eliminates the need for a separate heat seal adhesive film, reducing the overall thickness while maintaining both the protective and sealing functions.
Solution Approach 2:
The patent uses thin film structures, specifically a heat seal adhesive layer with thickness of 1 μm or more and 20 μm or less, formed on the laminating film. This thin film approach provides sufficient adhesion and sealing functionality while minimizing thickness contribution to the overall battery pack.
2Reliability
If heat seal adhesive film is used to bond laminating films, then good adhesion is achieved, but the risk of folding and bending during manufacturing increases
Solution Approach 1:
By integrating the heat seal adhesive layer directly onto the laminating film's inner resin layer, the patent eliminates the separate heat seal adhesive film that causes folding and bending. The adhesive layer remains fixed to the laminating film throughout the manufacturing process, preventing displacement and folding issues.
Solution Approach 2:
The heat seal adhesive layer is preliminarily formed on the inner resin layer of the laminating film before the packaging process. This preliminary formation ensures the adhesive is already in position and fixed, eliminating the risk of folding and bending that occurs when handling separate adhesive films during assembly.
3Reliability
If separate heat seal adhesive film is used, then adhesion function is provided, but the device complexity and number of components increases
Solution Approach 1:
The patent combines the heat seal adhesive function with the laminating film structure by forming a heat seal adhesive layer on the inner resin layer. This merging reduces the number of separate components from multiple films to an integrated multi-layer structure, simplifying the overall device while maintaining the adhesion function.
Solution Approach 2:
The laminating film structure is enhanced to perform multiple functions: the inner resin layer provides structural support and the heat seal adhesive layer formed on it provides adhesion functionality. This multi-functional integration eliminates the need for separate dedicated adhesive films.
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
The solution results in a thinner battery pack with improved volumetric efficiency and increased production yield by reducing the thickness of the heat seal adhesive layer and eliminating the need for a separate adhesive film, enhancing manufacturing accuracy and reducing defects.
Implementation Method 1
both ends of the second packaging component are abutted on the outer bottom surface of the recess of the first packaging component, and the first outer resin layer and the second inner resin layer are bonded by a heat seal adhesive layer having a thickness of 1 μm or more and 20 μm or less which is preliminarily formed on the first packaging component or the second packaging component
Data Source
AI summary
A battery pack including a battery cell, a circuit board electrically connected to the battery cell, a first cover, and a second cover. The battery cell includes a battery element, a rectangular first packaging component, a recess, and a rectangular second packaging component. The battery element is housed in the recess, the first packaging component and the second packaging component are stacked so that the second packaging component covers the opening of the recess, the periphery of the opening is sealed, both ends of the second packaging component are abutted at the outer bottom surface of the recess of the first packaging component, and the first outer resin layer and the second inner resin layer are bonded by heat seal adhesive layer.