Battery Cell Connection Portion for Sealing and Pressure Relief
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Solution Overview
Problem
Existing battery technologies face safety concerns due to inadequate sealing structures between the casing and cover body, leading to potential electrolytic solution leakage and safety issues during thermal runaway.
Innovation Solution
A battery cell design featuring a casing and cover body with a connection portion that includes a first region and a second region, where the second region has lower strength than the first region, allowing for directional pressure relief by breaking under internal pressure or temperature thresholds, thereby enhancing safety.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the connection portion between casing and cover body is made with uniform strength, then the sealing structure is simple and easy to manufacture, but the battery cell cannot release internal pressure effectively during thermal runaway
Solution Approach 1:
The connection portion is designed with non-uniform strength distribution, featuring a first region with higher strength and a second region with lower strength. This local quality differentiation allows the connection portion to maintain overall sealing integrity while providing a specific weak point for controlled pressure release during thermal runaway events.
Solution Approach 2:
The connection portion is segmented into multiple regions with different strength characteristics. The first region provides strong sealing connection, while the second region serves as a pressure relief path. This segmentation enables the connection portion to perform multiple functions simultaneously.
2Strength
If the connection portion is made with high strength throughout, then the sealing effect between casing and cover body is improved, but the battery cell cannot release internal pressure during thermal runaway
Solution Approach 1:
The connection portion incorporates a second region with deliberately reduced strength compared to the first region. This local quality variation ensures that the connection portion maintains high sealing strength in the first region while providing a controlled weak point in the second region for pressure release.
Solution Approach 2:
The design converts the potentially harmful effect of internal pressure accumulation during thermal runaway into a beneficial controlled release mechanism. The second region with lower strength acts as a predetermined failure point that safely releases pressure, transforming a dangerous situation into a controlled safety feature.
3Reliability
If the connection portion has a weak point for pressure relief, then the battery cell safety is improved during thermal runaway, but the sealing effect may be compromised
Solution Approach 1:
The connection portion is designed with spatially differentiated properties: the first region maintains high strength for sealing, while the second region has lower strength for pressure relief. This local quality approach ensures that the weak point for pressure relief does not compromise the overall sealing effect.
Solution Approach 2:
The connection portion is divided into functional segments where the first region provides sealing strength and the second region provides pressure relief capability. This segmentation allows each region to optimize its specific function without interfering with the other.
Data Source
AI summary
A battery cell, a battery and an electric device are provided. The battery cell includes a casing, which is provided with an opening; an electrode assembly, which is accommodated inside the casing; and a cover body, which closes the opening and forms a sealing structure with the casing. One of the casing and the cover body is provided with a first flange portion; the first flange portion is connected to the other one of the casing and the cover body by means of a connection portion; the connection portion includes a first region and a second region; and the strength of the second region is lower than the strength of the first region.