Cylindrical Battery Sealing Structure to Limit Lead Rotation
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Solution Overview
Problem
Conventional cylindrical batteries face joint breakage at the positive electrode lead and sealing assembly due to excessive rotational loads from impacts, such as dropping, which compromises the integrity of the connection.
Innovation Solution
The cylindrical battery design incorporates projections on the inner surface of the sealing assembly to prevent excessive rotational movement of the positive electrode lead, ensuring the joint remains stable by limiting the angle of rotation to less than or equal to 20 degrees.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If the lead is joined to the sealing assembly without a projection, then the manufacturing process is simpler, but the joint portion is susceptible to breaking under rotational load
Solution Approach 1:
A projection is introduced as an intermediary structural element between the sealing assembly and the lead. This projection acts as a mechanical stop that prevents excessive rotation of the lead relative to the sealing assembly, thereby protecting the joint portion from breaking under rotational load while maintaining a relatively simple manufacturing process
Solution Approach 2:
The projection is pre-formed on the sealing assembly before the lead is joined to it. This preliminary structural feature is designed in advance to limit the rotation angle to 20 degrees or less, preventing the harmful rotational movement before it can cause joint breakage during subsequent handling or operation
2Ease of operation
If the lead is allowed to rotate freely, then the ease of assembly is improved, but excessive rotational load causes joint breakage
Solution Approach 1:
The projection on the sealing assembly creates a preliminary counter-action that opposes and limits rotational movement of the lead. By designing the projection to restrict rotation to 20 degrees or less, the structure preemptively counteracts the excessive rotational loads that would otherwise cause joint breakage, while still allowing sufficient assembly ease
Data Source
AI summary
This cylindrical cell comprises: an electrode body in which a positive electrode and a negative electrode are wound with a separator therebetween; a cup-shaped outer can which accommodates the electrode body; a sealing body which is affixed by crimping to the opening portion of the outer can with a gasket therebetween; and a positive electrode lead which is joined to the inner surface of the sealing body. The inner surface of the sealing body has a protrusion which faces an edge in the width direction of the positive electrode lead and prevents the positive electrode lead rotating.