Secondary Battery Sub-Tab Design for Welding Quality
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing secondary battery manufacturing techniques face challenges in ensuring battery capacity and improving welding quality of current collectors, leading to internal space loss and reduced efficiency.
Innovation Solution
The secondary battery design incorporates sub-tabs integrally formed with current collectors, which are bent approximately 90 degrees to be coupled with electrode tabs, reducing internal space loss and enhancing battery capacity by minimizing the width of the sub-tab's bent region and using side insulation members to prevent short circuits.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If conventional current collector designs are used without bent sub-tabs, then the manufacturing process is simpler, but internal space is wasted and battery capacity is reduced
Solution Approach 1:
The current collector design extends from a single-plane structure to a multi-dimensional configuration by adding bent sub-tabs that fold at approximately 90-degree angles. This dimensional transformation allows the current collector to utilize vertical and lateral spaces within the battery case, converting wasted internal volume into functional space for electrode assemblies, thereby increasing battery capacity without proportionally increasing device footprint.
Solution Approach 2:
The current collector is segmented into multiple functional regions: a main body portion and multiple bent sub-tabs. This segmentation allows different portions to serve distinct purposes - the main body provides structural support and primary electrical connection, while the bent sub-tabs extend electrical connectivity to remote electrode tabs and define precise positioning. The segmentation enables more efficient space utilization within the battery case.
2Reliability
If sub-tabs are not integrally formed with current collectors, then manufacturing is easier, but welding quality and electrical connection reliability deteriorate
Solution Approach 1:
The sub-tabs are integrally formed with the current collector as a single monolithic component, merging what could have been separate parts into one unified structure. This integration eliminates the need for welding or other joining processes between the sub-tabs and current collector, ensuring perfect electrical continuity and mechanical strength. The integral construction guarantees reliable electrical connection while the entire assembly can be manufactured in one step using techniques like stamping or extrusion.
3Productivity
If bent sub-tabs are not used to couple electrode tabs, then internal space is maximized, but electrical connection and current collection efficiency are reduced
Solution Approach 1:
The bent sub-tabs function as flexible conductive elements that can be shaped into angular configurations. These thin, adaptable metal structures efficiently bridge the gap between the current collector and electrode tabs, providing optimal electrical connection pathways. The flexible geometry allows the sub-tabs to conform to the spatial arrangement of components, maximizing electrical connectivity while occupying minimal volume within the battery case.
Data Source
Figure 1
Figure 2
Figure 3
AI summary
Provided are a secondary battery and an assembling method thereof, which can ensure a battery capacity and improve welding quality of a current collector. The secondary battery includes an electrode assembly including first and second electrode tabs, a case accommodating the electrode assembly and having an opening, a cap plate coupled to the case at the opening of the case, a first current collector electrically connected to the first electrode tab of the electrode assembly, a second current collector electrically connected to the second electrode tab of the electrode assembly, and a sub-tab coupled to the first electrode tab or the second electrode tab of the electrode assembly. The sub-tab is bent along a boundary between the sub-tab and the first or second current collector and contacts an outer periphery of the first or second current collector. The sub-tab is integrally formed with the first or second current collector.