Cylindrical Battery Cell Cap Welding with a Thickened Collector
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Solution Overview
Problem
The existing cylindrical battery cell welding process faces challenges with a low process window and high defect rate due to the difficulty in welding the cap to the current collecting component using laser penetration welding.
Innovation Solution
The solution involves a cylindrical battery cell design where a thickened portion is added to the current collecting component, increasing its thickness at the welding point with the cap, thereby reducing the risk of false welding or penetration during laser penetration welding.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If laser penetration welding is performed to connect the cap and the current collecting component, then welding connection is achieved, but the process window is low and defect rate is high due to thickness mismatch
Solution Approach 1:
The current collecting component is designed with a thickened portion at the welding location, creating local thickness variation. This allows the welding area to have sufficient thickness for reliable laser penetration welding while the rest of the component maintains its original thin profile, thus improving welding quality without unnecessarily increasing overall material usage.
Solution Approach 2:
The thickness parameter of the current collecting component is locally modified by adding the thickened portion. This parameter change at the welding interface enables better process window and reduced defect rate by ensuring adequate material thickness for laser penetration, directly addressing the welding difficulty caused by the original thickness mismatch between the cap and current collecting component.
2Strength
If the cap thickness is greater than the current collecting component thickness, then the cap provides sufficient structural strength, but welding penetration or false welding occurs due to thickness mismatch
Solution Approach 1:
Instead of uniformly increasing the thickness of the current collecting component throughout, a thickened portion is added only at the welding location. This local quality enhancement provides sufficient material for precise laser penetration welding while maintaining the overall thin profile of the current collecting component, thus improving welding precision without compromising the structural strength provided by the cap's original thickness.
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
This design enhances the welding quality by reducing the difficulty of welding and the defect rate, while also minimizing thermal impact on the electrode assembly and improving adhesion between the cap and the current collecting component.
Implementation Method 1
the thickened portion may also effectively reduce the heat generated during the welding process of the current collecting component and the cap to be transmitted to the electrode assembly
Implementation Method 2
when laser penetration welding is performed to connect the cap and the current collecting component
Implementation Method 3
welding penetration or false welding are likely to occur
Data Source
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AI summary
A cylindrical battery cell (100) including a housing (110), an electrode assembly (120) disposed in the housing (110), a cap (140) and a current collecting component (130) is provided. The housing (110) includes an end wall (111) and a side wall (112). An opening (113) is formed on one side of the side wall (112) facing away from the end wall (111). A first tab (121) is provided on one side of the electrode assembly (120) facing the opening (113). The cap (140) is disposed on a side where the opening (113) located and is welded to the side wall (112). The current collecting component (130) is disposed on one side of the electrode assembly (120) facing the opening (113) and is welded to the first tab (121). The current collecting component (130) includes a current collecting body (133) and a thickened portion (131) welded to the cap (140).