Battery Current Collector Structure for Larger Tab Welding Area
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Solution Overview
Problem
The existing current collector structures in lithium-ion batteries have complex forming processes with arc-shaped, flanging, and multiple protrusions and groove structures, resulting in a small welding area prone to poor welding issues.
Innovation Solution
A simplified current collector structure with a large welding area is proposed, where the entire surface of the current collector body is used for welding with the positive tabs of the winding core, incorporating center and peripheral underflow holes, and employing laser screw or spot welding techniques to increase the contact area and stability of the welds.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If complex forming processes with arc-shaped, flanging, and multiple protrusions and groove structures are used, then the current collector structure can be formed, but the welding area becomes small and poor welding problems occur
Solution Approach 1:
The invention removes the complex protrusions and groove structures from the current collector surface, extracting only the essential flat surface structure needed for welding. This simplifies the forming process while maximizing the welding area by eliminating unnecessary geometric features that reduced the effective welding surface.
Solution Approach 2:
The invention merges the current collector body into a unified flat surface structure, combining what were previously separate features (protrusions, grooves, flanges) into a single continuous welding surface. This integration eliminates the fragmentation caused by multiple structural elements and creates a large, uniform welding area.
2Device complexity
If multiple protrusions and groove structures are added to the current collector, then structural features are provided, but the welding area is reduced and welding stability deteriorates
Solution Approach 1:
The invention applies local quality by providing structural features (such as reinforcement ribs or specific surface treatments) only in areas where they are truly needed for mechanical strength, while maintaining a large flat welding surface in the areas critical for welding. This selective application of structural complexity preserves welding stability while providing necessary structural support.
Solution Approach 2:
The invention segments the structural support function from the welding surface function, placing reinforcement elements underneath or around the periphery of the welding area rather than interrupting the welding surface itself. This segmentation allows the welding surface to remain large and continuous while still providing structural integrity through separately positioned support features.
3Ease of manufacture
If the current collector has a small welding area, then the forming process is simplified, but poor welding problems occur and welding stability is poor
Solution Approach 1:
The invention makes the flat current collector surface universally applicable for welding by creating a large, uniform surface that can accommodate various welding configurations and positions. This universal welding surface design simplifies the forming process while ensuring reliable welding by providing a consistent, defect-free surface that works for all welding operations without requiring additional structural modifications.
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
The increased welding surface and contact area improve the current-carrying capacity and rate performance of the battery, reduce heat generation, and enhance welding stability, thereby minimizing the occurrence of poor welding.
Implementation Method 1
a welding surface of the current collector body is welded by laser screw welding or laser spot welding to form one or more of laser screw welds or one or more of laser spot welds
Data Source
AI summary
Proposed in the present disclosure is a current collector structure, including a positive current collector, in which the positive current collector includes a current collector body and a current collector leading-out tab connected to each other; in which the current collector body is provided with a center underflow hole through the current collector body in a thickness direction thereof, and an entire surface of a surface of the current collector body in the thickness direction is a welding surface configured to weld with a positive tab of a winding core. Proposed in the present disclosure is also a battery pack including the aforementioned current collector structure.