Power Storage Casing Laminate for Formability and Piercing Resistance
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Solution Overview
Problem
Conventional packaging materials for power storage devices, such as stainless-steel laminates, compromise formability and production efficiency due to high rigidity, leading to decreased dimensional accuracy and piercing resistance.
Innovation Solution
A packaging material comprising a polyamide film base material layer with specific hot water shrinkage, elastic modulus, and breaking strength properties, combined with a barrier and sealant layer, to enhance formability and piercing resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If a stainless-steel laminate material is used as a packaging material to improve piercing resistance, then piercing resistance is improved, but formability deteriorates
Solution Approach 1:
The patent uses a composite laminate structure consisting of a polyamide film layer and a stainless steel foil layer. The polyamide film layer (5-20 μm thick) provides flexibility and formability, while the stainless steel foil layer (3-10 μm thick) provides piercing resistance. This composite structure resolves the contradiction by combining materials with complementary properties.
Solution Approach 2:
The patent specifies precise parameter ranges for the polyamide film layer: hot water shrinkage of 1.5-5.0% in both transverse and machine directions, elastic modulus of 1.0-3.0 GPa, and breaking strength of 200-400 MPa. By controlling these parameters, the material achieves optimal balance between formability and strength.
2Strength
If a stainless-steel laminate material is used to improve piercing resistance, then piercing resistance is improved, but production efficiency decreases
Solution Approach 1:
The patent optimizes the thickness of each layer to achieve the desired performance with minimal material usage. The polyamide film is 5-20 μm and the stainless steel foil is 3-10 μm, which provides sufficient piercing resistance while maintaining ease of processing and forming, thereby improving production efficiency.
3Strength
If a stainless-steel laminate material is used to improve piercing resistance, then piercing resistance is improved, but dimensional accuracy decreases
Solution Approach 1:
The patent specifies that the hot water shrinkage of the polyamide film layer must be 1.5-5.0% in both transverse and machine directions with a difference of less than 3.0%. This controlled shrinkage behavior ensures dimensional stability and accuracy during processing while maintaining the piercing resistance provided by the stainless steel layer.
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 polyamide film-based packaging material maintains moderate flexibility and strength, efficiently dispersing external forces and ensuring adequate piercing resistance, thereby improving formability and production efficiency.
Implementation Method 1
the base material layer is 1.5 GPa to 3 GPa in elastic modulus in both the transverse direction (TD) and the machine direction (MD)
Implementation Method 2
the base material layer is 320 MPa or more in at least one of a breaking strength in the transverse direction (TD) and a breaking strength in the machine direction (MD)
Implementation Method 3
the base material layer is 2.0% to 5.0% in hot water shrinkage in both a transverse direction (TD) and a machine direction (MD)
Data Source
AI summary
Provided is a packaging material for a power storage device excellent in workability and piercing resistance. The present invention relates to a packaging material for a power storage device, including a base material layer 51, a barrier layer 52 laminated on an inner side of the base material layer 51, and a sealant layer 53 laminated an inner side of the barrier layer 52. The base material layer 51 is formed of a polyamide film and is 2.0% to 5.0% both in hot water shrinkage in a transverse direction (TD) and a machine direction (MD), 1.5% or less in a difference between the hot water shrinkage in the TD and the MD, 1.5 GPa to 3 GPa in elastic modulus in both the TD and the MD, and 320 MPa or more in at least one of breaking strengths in the TD and the MD.