Cylindrical Battery Core Assembly for Stable Tab Ultrasonic Welding
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Solution Overview
Problem
Existing battery manufacturing methods face issues with poor welding contact and failure due to the need for supporting points and welding space when ultrasonic welding is used for connecting current collecting members and tabs in cylindrical batteries.
Innovation Solution
A manufacturing method that involves providing a jelly-roll with stacked tabs and a current collecting member, electrically connecting them, and bending the current collecting portions and tabs inward to ensure they do not extend beyond the main body's outer surface, facilitating stable ultrasonic welding without the need for additional support points.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If ultrasonic welding is used to connect current collecting member and tab, then welding connection is achieved, but supporting points and welding space are required causing poor welding contact and welding failure
Solution Approach 1:
The patent inverts the conventional welding approach by bending the current collecting member and tab inward toward the center of the battery core assembly, rather than extending outward to meet the welding head. This inversion eliminates the need for supporting points and welding space, allowing ultrasonic welding to be performed directly at the interface between the current collecting member and tab without the complexity of additional support structures.
Solution Approach 2:
The patent changes the spatial dimension of the welding interface by bending the current collecting member and tab in the radial direction toward the center. This dimensional change transforms the welding problem from a surface-level contact issue to a three-dimensional interface configuration, enabling reliable welding contact without requiring external supporting points or welding space.
2Ease of manufacture
If tabs and current collecting portions extend outward beyond outer peripheral surface, then welding access is facilitated, but manufacturing difficulty increases and safety decreases
Solution Approach 1:
The patent applies the nesting principle by bending the current collecting member and tab inward so that they are contained within the boundary defined by the outer peripheral surface of the battery core assembly. This nesting configuration ensures that no conductive elements extend beyond the safe boundary, eliminating safety hazards while maintaining welding accessibility through the inverted bending approach.
Solution Approach 2:
Instead of extending outward to facilitate welding access, the patent inverts the approach by bending the current collecting member and tab inward. This inversion demonstrates that welding accessibility can be achieved through internal geometry configuration rather than external extension, simultaneously improving ease of manufacture and ensuring safety by keeping all conductive elements within the safe boundary.
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 method enhances welding stability, reduces manufacturing difficulty, improves connection strength, and increases safety and reliability of the core assembly, while simplifying the welding process and reducing labor costs.
Implementation Method 1
when a current collecting member and a tab of a cylindrical battery are welded by using ultrasonic waves
Data Source
AI summary
Provided are a manufacturing method of a core assembly for battery, a core assembly for battery, and a battery pack including the core assembly. The method includes; providing a jelly-roll including a cylindrical main body and a tab group including tabs stacked in an axial direction of the main body and electrically connected to an axial end of the main body, each tab extending outward in a radial direction of the main body; providing a current collecting member including a current collecting portion; electrically connecting the current collecting portion to at least one of the tabs so that the current collecting portion extends outward in the radial direction; and bending the current collecting portion and at least one part of the tabs inward in the radial direction so that no current collecting portion or tab extends beyond an outer peripheral surface of the main body in the radial direction.