Battery Packaging Laminate Suppressing Curling and Enhancing Insulation
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Solution Overview
Problem
Conventional battery packaging materials face challenges in maintaining insulating properties, particularly in high-humidity environments, leading to electrolyte leakage and reduced durability, especially in large capacity batteries like those for vehicles, where curling issues also impact production efficiency.
Innovation Solution
A battery packaging material laminate configuration comprising a polyester film layer, an aluminum alloy foil layer, and a heat-sealable resin layer, with specific thickness ranges and dielectric breakdown voltage, is developed to suppress curling and enhance surface insulating properties, effectively preventing electrolyte leakage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Weight of moving object
If polyamide film is used as base substrate layer, then weight reduction and ease of processing are improved, but insulating properties deteriorate especially in high humidity environment
Solution Approach 1:
The patent uses a composite structure consisting of a polyamide film base layer combined with a heat-sealable resin coating layer. This composite material approach allows the packaging to maintain the weight advantages and processability of polyamide film while the resin coating provides enhanced insulating properties and moisture resistance, resolving the contradiction between lightweight design and electrical insulation reliability.
2Ease of manufacture
If polyamide film is used as base substrate layer, then ease of manufacture is improved, but insulating properties deteriorate in high humidity environment leading to electrolyte leakage
Solution Approach 1:
The patent combines polyamide film with a heat-sealable resin coating to create a composite packaging material. The polyamide film provides ease of manufacture and good formability, while the resin coating layer supplies the necessary insulating properties and moisture barrier characteristics, preventing electrolyte leakage even in high humidity environments.
3Adaptability or versatility
If film-shaped laminate is used instead of metallic packaging, then shape diversification and weight reduction are improved, but insulating properties and durability in harsh environment deteriorate
Solution Approach 1:
The patent employs a composite laminate structure with polyamide film base layer and heat-sealable resin coating. This composite design enables shape diversification and weight reduction characteristic of film materials while the resin coating provides the insulating properties and environmental durability typically associated with metallic packaging, thus resolving the contradiction between versatility and reliability.
4Reliability
If heat-sealable resin layer thickness is increased to improve sealing, then sealing performance is improved but curling increases reducing production efficiency
Solution Approach 1:
The patent optimizes the thickness parameter of the heat-sealable resin coating layer to a specific range (5-20 μm). This parameter optimization achieves adequate sealing performance while minimizing curling of the packaging material, thereby maintaining high production efficiency. The precise control of coating thickness resolves the contradiction between sealing quality and manufacturing productivity.
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 effectively suppresses curling and ensures sufficient surface insulating properties, reducing electrolyte leakage and improving the durability and production efficiency of large capacity batteries.
Implementation Method 1
heat-sealable resin layers are thermally welded to obtain a battery with battery elements stored in the battery packaging material
Implementation Method 2
an adhesive film 12 is interposed between the metal terminal 11 that is electrically connected to an electrode of a battery element 40 and the battery packaging material 10
Data Source
AI summary
A battery packaging material is configured from a laminate including, at a minimum, a polyester film layer, an aluminum alloy foil layer, and a heat fusible resin layer in the stated order. The thickness of the polyester film layer is 23-27 μm (inclusive), the thickness of the aluminum alloy foil layer is 27-43 μm (inclusive), the thickness of the heat fusible resin layer is 70-100 μm (inclusive), and the insulation breakdown voltage of the surface of the polyester film layer side is 13 kV or greater.