Sealed Battery Can Structure for Controlled Sidewall Deformation
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Solution Overview
Problem
Conventional sealed batteries with bottomed cylindrical exterior housing cans suffer from irregular deformation of the side surface portion when subjected to a load in the height direction, leading to damage of the electrode assembly.
Innovation Solution
The exterior housing can is designed with a thin thickness portion along the circumferential direction, recessing the inner surface of the side surface portion, to preferentially deform and reduce irregular deformation, thereby minimizing damage to the electrode assembly.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a notched portion is formed on the can bottom side to enable electrode assembly discharge, then short circuit prevention is improved, but irregular deformation of the side surface portion occurs causing electrode assembly damage
Solution Approach 1:
The patent applies local quality by forming a thin thickness portion at a specific location on the can body (at a height of 1/4 to 3/4 from the bottom in the circumferential direction) rather than uniformly thinning the entire can. This localized thinning creates a controlled weak point that preferentially deforms under load, preventing irregular deformation of the side surface portion while maintaining the notched portion's short circuit prevention function.
2Stability of the object's composition
If the exterior housing can is made thinner to reduce deformation, then resistance to irregular deformation is improved, but structural strength is reduced
Solution Approach 1:
Instead of uniformly thinning the can which would compromise overall structural strength, the patent creates a localized thin thickness portion only in the circumferential direction at a specific height range. This allows the can to resist irregular deformation through controlled local flexibility while maintaining sufficient structural strength in other areas.
Solution Approach 2:
The can's thickness is segmented into different regions: a thin thickness portion in the circumferential direction at mid-height for deformation control, and thicker regions at the top and bottom for structural strength. This segmentation allows different parts of the can to serve different functions - flexibility where needed and strength where required.
Data Source
AI summary
A sealed battery according to one example of an embodiment comprises: an electrode body in which a positive electrode and a negative electrode are laminated with a separator therebetween; a bottomed cylindrical external can which has a bottom surface part and a side surface part and which accommodates the electrode body; and a sealing body which closes an opening of the external can. The external can has a thin portion that is formed along the circumferential direction such that an inner surface of the side surface part is recessed. The lower end of the thin portion is positioned between the bottom surface part and the lower end of the positive electrode in the height direction of the external can.