Composite Current Collector Sealing Without Adhesive Heat Damage
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Solution Overview
Problem
The adhesion strength of the adhesive layer in power storage devices is reduced due to heat transfer during the welding of sealing members to the electrodes, leading to potential damage to the electrodes.
Innovation Solution
The power storage device incorporates an adhesive layer with a higher heat-resistant temperature than the sealing members, ensuring that the adhesion strength is maintained even when heat is transferred during welding, thereby preventing damage to the electrodes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the sealing member is welded to the electrode surface, then the sealing performance is improved, but the adhesion strength of the adhesive layer is reduced due to heat transfer
Solution Approach 1:
The patent changes the temperature parameter by ensuring the adhesive layer can withstand temperatures up to 150°C or higher, which is above the melting point of the sealing member material. This allows the sealing member to be welded without damaging the adhesive layer's bonding capability.
Solution Approach 2:
The current collector uses a composite structure with multiple metal foils and an adhesive layer in between. This composite design allows the adhesive layer to maintain its bonding function while the metal foils conduct heat away from the adhesive during sealing member welding.
2Force
If heat is applied during welding of the sealing member, then the sealing member bonds to the electrode, but the adhesive layer deteriorates due to excessive heat
Solution Approach 1:
The adhesive layer is designed with a glass transition temperature or melting point of 150°C or higher, allowing it to maintain structural integrity during the welding process which typically occurs at lower temperatures. This parameter change ensures the adhesive layer does not deteriorate during sealing member bonding.
3Strength
If the adhesive layer has high heat resistance, then the adhesion strength is maintained during welding, but the manufacturing complexity increases
Solution Approach 1:
The patent specifies clear temperature parameter thresholds (glass transition temperature or melting point of 150°C or higher) for the adhesive layer material selection. This quantitative criterion simplifies the material selection process while ensuring the adhesive layer maintains its bonding strength during welding operations.
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 inhibits damage to the electrodes by maintaining adhesion strength, enhancing the structural integrity of the power storage device.
Implementation Method 1
an adhesive layer provided between the first metal foil and the second metal foil, the adhesive layer bonding the first metal foil and the second metal foil with each other
Implementation Method 2
heat in the welding of the sealing member to the electrode is transferred to an adhesive layer
Data Source
AI summary
A power storage device includes: an electrode including: a current collector having a surface; and a positive active material layer provided on the surface of the current collector; and a sealing member provided on the surface of the current collector, the sealing member surrounding the positive active material layer in a stacking direction. The current collector includes: a first metal foil including the surface; a second metal foil provided opposite to the positive active material layer with respect to first metal foil; and an adhesive layer provided between the first metal foil and the second metal foil, the adhesive layer bonding the first metal foil and the second metal foil with each other. The sealing member includes: a seal portion welded to the surface; and another seal portion welded to a side face of the current collector including a side face of the adhesive layer.