Pouch Battery Tab Layout for Easier Welding and Higher Capacity
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Solution Overview
Problem
In secondary batteries with a flat-shape electrode assembly and laminated film outer housing, the positive and negative electrode tabs are difficult to position and weld due to their longitudinal extension, leading to challenges in increasing the coated area and capacity.
Innovation Solution
The battery design includes a positive electrode with a non-coated portion midway in its longitudinal direction and a negative electrode with a non-coated portion at the outermost or innermost circumferential portion, allowing the tabs to be positioned on the same side as a virtual plane passing through the electrode assembly's center, facilitating easier tab positioning and increased capacity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the positive electrode tab and negative electrode tab are extended from the center region of the flat-shape electrode assembly in the thickness direction, then the tabs can be connected to the electrode core, but it becomes difficult to position the tabs and weld them to the laminated film outer housing
Solution Approach 1:
The patent changes the tab connection position from the center region to the end region of the electrode assembly in the longitudinal direction. This dimensional repositioning allows the tabs to extend more directly toward the back surface of the laminated film outer housing, improving both positioning ease and welding reliability.
2Ease of operation
If the positive electrode tab and negative electrode tab are joined to the end of the core in the longitudinal direction, then tab positioning becomes easier, but the coated area of the electrode cannot be increased
Solution Approach 1:
The patent segments the electrode core into two functional regions: the end region where tabs are connected for easy positioning and welding, and the central region where the mixture layer is coated to maximize capacity. This segmentation allows both tab positioning ease and coated area increase to be achieved simultaneously.
3Quantity of substance
If the electrode assembly is press-molded to increase density in the thickness direction, then energy density improves, but short-circuiting risk increases
Solution Approach 1:
The patent extracts the tab connection function from the center region of the electrode assembly and relocates it to the end region. This separation allows the center region to be press-molded for high density without compromising tab positioning, while the end region provides adequate space for safe tab attachment, thereby reducing short-circuiting risk.
Data Source
AI summary
A battery with a laminate film outer package, configured by bonding film materials; and a flat electrode body contained in the laminate film outer package having a positive electrode with a positive electrode non-coated part, without a positive electrode mixture layer and an exposed positive electrode core body midway in the longitudinal direction; and a negative electrode has a negative electrode non-coated part without a negative electrode mixture layer and an exposed negative electrode core body midway in the longitudinal direction; and a positive electrode tab is bonded and electrically connected to the positive electrode non-coated part; and a negative electrode tab is bonded and electrically connected to the negative electrode non-coated part, both tabs generally pass through the center of the flat electrode body in the thickness direction, while being positioned on the same side of a virtual plane perpendicular to the thickness direction of the flat electrode body.