Battery Cell Pressure Relief Structure With Multi-Stage Score Grooves
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Solution Overview
Problem
Existing battery cell pressure relief apparatuses have poor long-term reliability due to the risk of cracks forming during the score groove formation process, leading to premature failure even when internal pressure is within normal ranges.
Innovation Solution
A multi-stage score groove structure is adopted for the pressure relief apparatus, reducing the forming force on the pressure relief portion and minimizing the risk of cracks. This design includes three levels of score grooves, with second score grooves arranged on the bottom surface of the third score groove to enhance pressure relief and simplify the forming process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a single deep score groove is formed in the pressure relief portion, then the pressure relief effect is achieved, but the forming force is too large which causes cracks and reduces reliability
Solution Approach 1:
The single deep score groove is divided into multiple shallow score grooves arranged in sequence from the first surface to the second surface of the pressure relief portion. This segmentation reduces the forming force required for each individual groove while achieving the same pressure relief effect through cumulative shallower cuts, thereby preventing cracks and improving reliability.
2Reliability
If multiple shallow score grooves are formed sequentially, then the forming force is reduced and crack risk decreases, but the structural complexity increases
Solution Approach 1:
The pressure relief portion is segmented with multiple score grooves at different depths and positions, creating a staged relief mechanism that reduces forming force while maintaining structural integrity.
Solution Approach 2:
Instead of adding complexity in the planar dimension, the score grooves are arranged in the thickness direction (from first surface to second surface), utilizing the third dimension to distribute the forming force across multiple shallower cuts rather than one deep cut.
3Reliability
If the score grooves are arranged from the first surface to the second surface, then the forming force is distributed and crack risk is reduced, but the pressure relief area may be insufficient
Solution Approach 1:
Multiple score grooves are distributed across the pressure relief portion from the first surface to the second surface, creating multiple rupture points that collectively provide sufficient pressure relief area while maintaining reduced forming force at each location.
Solution Approach 2:
Each score groove is positioned at a specific location and depth to optimize both the local forming force distribution and the overall pressure relief area. The grooves are strategically arranged to ensure adequate relief area is achieved without requiring excessive depth or width at any single location.
Data Source
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Figure 3
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AI summary
A pressure relief apparatus, a battery cell, a battery, and an electrical device are provided in embodiments of the present application, which belong to the field of battery technologies. The pressure relief apparatus includes a pressure relief body and a plurality of score grooves. The pressure relief body includes a pressure relief portion, and the pressure relief portion has a first surface and a second surface opposite to each other in a thickness direction thereof. A plurality of score grooves are sequentially arranged at the pressure relief portion in a direction from the first surface to the second surface, wherein in two adjacent score grooves in the thickness direction, a maximum width of a score groove far away from the first surface is less than a minimum width of a score groove close to the first surface. The pressure relief apparatus in such a structure adopts a multi-level score groove structure, which can reduce a forming force received by the pressure relief portion when forming each level of score groove, reduce the risk of generating cracks of the pressure relief portion. The pressure relief apparatus is less likely to fail due to the generation of cracks in a position of the pressure relief portion where the score groove is provided, and the long-term reliability of the pressure relief apparatus is improved.