Resin Base Material Surface Roughness for Current Cut-Off Stability
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Solution Overview
Problem
Existing electrode current collectors with a lamination structure fail to effectively break the metal thin film during abnormal heat generation, leading to inadequate current cut-off function and increased costs due to additional safety measures.
Innovation Solution
An electrode current collector with a resin base material having a surface roughness of 2 µm or more and a metal thin film thickness of 2 µm or more, designed to enhance adhesion and deformation of the metal thin film upon resin melting, ensuring stable activation of the current cut-off function.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the surface roughness of the resin base material is increased to improve adhesion and current cut-off function activation, then the activation stability of the current cut-off function improves, but the manufacturing precision and surface quality control become more difficult
Solution Approach 1:
The patent applies parameter changes by specifying a minimum surface roughness value (Rz ≥ 2 μm) for the resin base material. This parameter modification transforms the surface properties to enhance adhesion between the resin and metal thin film, ensuring that when the resin melts during abnormal heat generation, it can effectively deform and break the metal thin film to activate the current cut-off function. The explicit parameter specification resolves the contradiction by establishing a clear manufacturing target that balances reliability improvement with manufacturability.
2Reliability
If additional current cut-off mechanisms are added to electrode terminals to prevent abnormal heat generation, then safety is improved, but device complexity and component costs increase
Solution Approach 1:
The patent applies the self-service principle by designing the electrode current collector to inherently possess current cut-off functionality through its own structural properties. The resin base material with enhanced surface roughness (Rz ≥ 2 μm) enables the metal thin film to effectively break during abnormal heat generation, allowing the current collector to self-activate the current cut-off function without requiring external safety mechanisms at the electrode terminals. This eliminates additional components and reduces device complexity while maintaining safety.
3Reliability
If the metal thin film thickness is increased to improve electroconductivity, then electrical performance improves, but the ease of breaking the metal thin film during abnormal heat generation decreases
Solution Approach 1:
The patent applies parameter changes by optimizing the surface roughness of the resin base material (Rz ≥ 2 μm) to compensate for increased metal thin film thickness. The enhanced surface roughness creates stronger adhesion and enables more effective stress transfer during resin melting, allowing thicker metal films (which provide better electroconductivity) to still break effectively when needed. This parameter adjustment resolves the contradiction by enabling thicker films to maintain both electrical performance and breakability.
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 enhanced surface roughness and film thickness improve the activation stability of the current cut-off function, preventing abnormal heat generation progression without the need for additional safety mechanisms, thus reducing component costs.
Implementation Method 1
the surface of the resin base material in contact with the metal thin film has a surface roughness Rz of 2 μm or more... the resin base material to be melted and deformed so as to pull the metal thm film at the time when abnormal heat generation occurs
Data Source
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Figure 3
AI summary
The present disclosure can improve activation stability of the current cut-off function of the electrode current collector. The electrode current collector 10 disclosed herein includes a sheet-like resin base material 12, and a metal thin film 14 provided on a surface 12a, 12b of the resin base material 12. In the electrode current collector 10 disclosed herein, the surface 12a, 12b of the resin base material 12 in contact with the metal thin films 14 has a surface roughness Rz of 2 µm or more. This can largely improve the adhesion between the resin base material 12 and the metal thin film 14. Thus, when abnormal heat generation occurs, the resin base material 12 is melted and deformed so as to pull the metal thin film 14, thereby breaking the metal thin films 14. As a result, the current cut-off function can be stably activated, and the progression of abnormal heat generation can be substantially prevented, as appropriate.