Molding Packaging Material Protection Coat Layer
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Solution Overview
Problem
Existing molding packaging materials for lithium-ion batteries face issues with electrolyte adhesion, surface swelling, scratches, and chemical resistance, leading to deterioration of outer appearance quality and increased production costs due to the use of polyamide films, which also suffer from moisture absorption and curling.
Innovation Solution
A molding packaging material with a structure comprising a heat-resistant outer substrate layer, a metallic foil layer, an inner sealant layer, and a protection coat layer made of a resin composition containing phenoxy resin and urethane resin, providing excellent moldability, chemical resistance, and scratch resistance, thereby preventing electrolyte adhesion and surface damage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a polyamide film is used as the outer layer of the packaging material, then the moldability is improved, but the chemical resistance deteriorates causing electrolyte adhesion and surface swelling
Solution Approach 1:
The patent applies composite materials by creating a multi-layer structure where a polyamide resin layer (providing moldability) is combined with a fluororesin layer (providing chemical resistance). The fluororesin layer is applied as a coating on the polyamide film, forming a composite structure that exhibits both good moldability from the polyamide base and excellent electrolyte resistance from the fluororesin coating, thereby resolving the contradiction between these two properties.
2Reliability
If a polyester resin layer and polyamide resin layer are coextruded via an adhesive resin layer, then the chemical resistance is improved, but the cost increases and moldability deteriorates
Solution Approach 1:
The patent segments the functional requirements by separating the moldability function (handled by the polyamide resin layer) from the chemical resistance function (handled by the fluororesin coating). This segmentation allows each layer to be optimized for its specific function without requiring complex coextrusion processes, thereby reducing manufacturing complexity while maintaining both properties.
3Strength
If a protection layer is added on the outside of the polyamide film, then the scratch resistance is improved, but the device complexity increases
Solution Approach 1:
The patent merges the protection function into the existing multi-layer structure by applying the fluororesin coating that simultaneously provides both chemical resistance (electrolyte resistance) and mechanical protection (scratch resistance). This merging of multiple protective functions into a single integrated layer reduces structural complexity compared to adding separate protection layers for each function.
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 enhances the packaging material's moldability, chemical resistance, and scratch resistance, reducing production costs by eliminating the need for masking tapes and preventing electrolyte-induced surface deterioration, while maintaining the integrity of the battery case during handling and sealing processes.
Implementation Method 1
a protection coat layer formed on a side opposite to the metallic foil layer side of the outer substrate layer, wherein the protection coat layer is made of a resin composition including a main resin containing a phenoxy resin and a urethane resin... providing excellent moldability, chemical resistance, and scratch resistance, thereby preventing electrolyte adhesion and surface damage
Implementation Method 2
a metallic foil layer arranged between the outer substrate layer and the inner sealant layer
Implementation Method 3
when a battery element is introduced in a molded packaging material and the battery element is sealed by heat sealing the edge part of the packaging material
Data Source
AI summary
A molding packaging material includes an outer substrate layer made of a heat-resistant resin, an inner sealant layer made of a thermoplastic resin, a metallic foil layer provided between the outer substrate layer and the inner sealant layer, and a protection coat layer formed on a side opposite to the metallic foil layer side of the outer substrate layer. The protection coat layer is made of a resin composition including a main resin containing a phenoxy resin and a urethane resin, and a curing agent, and has a thickness of 0.1 μm to 10 μm.