Wound Battery Electrode Tab Layout for Reduced Outer-Edge Breakage
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Solution Overview
Problem
The existing methods for producing wound electrode bodies in batteries result in high breakage rates of tabs on the outer periphery during the winding process, leading to reduced productivity due to warping and mechanical stress.
Innovation Solution
The solution involves a battery design where the number of tabs on the outer periphery is reduced, with a lamination structure where the ratio of tabs to electrode layers is optimized, and the tabs' alignment is improved by varying their shortest distances from the winding center, allowing for better alignment and reduced breakage during the winding process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the rotational speed of the winding core is increased to improve productivity, then the winding speed increases, but the tabs on the outer periphery break more easily due to higher mechanical stress
Solution Approach 1:
The patent applies different tab configurations to different regions of the electrode body. Specifically, the number of tabs in the first outermost periphery neighboring region (A) relative to the number of electrode layers (B) is controlled to be less than 1, and similarly for the second outermost periphery neighboring region (C/D < 1). This local differentiation reduces mechanical stress on outer peripheral tabs during high-speed winding while maintaining electrical functionality.
2Reliability
If the number of tabs on the outer periphery is increased to improve electrical connectivity, then more tabs provide better current collection, but tab breakage during winding increases
Solution Approach 1:
The patent changes the parameter of tab distribution by controlling the ratios A/B and C/D to be less than 1. This parameter optimization ensures that the number of tabs is appropriately reduced in regions prone to mechanical stress during winding, thereby reducing breakage while maintaining sufficient electrical connectivity through the remaining tabs.
3Quantity of substance
If the electrode width is increased to improve battery capacity, then more active material can be accommodated, but warping during winding increases causing tab breakage
Solution Approach 1:
The patent applies different tab configurations to different regions of the electrode body. Specifically, the number of tabs in the first outermost periphery neighboring region (A) relative to the number of electrode layers (B) is controlled to be less than 1, and similarly for the second outermost periphery neighboring region (C/D < 1). This local differentiation reduces mechanical stress on outer peripheral tabs during high-speed winding while maintaining electrical functionality.
Data Source
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AI summary
In a preferred aspect of the battery disclosed herein, a region encompassing five layers of the positive electrode (negative electrode) counting from one of outer surfaces at both ends of the lamination structure in the stacking direction is a first outermost periphery neighboring region, and a region encompassing five layers of the positive electrode (negative electrode) counting from the other outer surface is a second outermost periphery neighboring region S, and when in the first outermost periphery neighboring region, the number of the positive electrode tabs (negative electrode tabs) is A, and the number of layers of the first electrode is B, and in the second outermost periphery neighboring region, the number of the positive electrode tabs (negative electrode tabs) is C, and the number of layers of the first electrode is D, A/B and C/D are both less than 1.