Secondary Battery Electrode Assembly Without Separate Negative Tabs
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Solution Overview
Problem
Conventional secondary batteries face challenges in reducing internal resistance and improving current collection efficiency, particularly in designs that require separate electrode tabs, which can lead to increased costs and reliability issues due to tab-related cracks or deformations.
Innovation Solution
The design incorporates a negative electrode extension uncoated portion that is folded or protrudes to be electrically connected to the case, eliminating the need for a separate negative electrode tab, and can also include similar protrusions on the positive electrode, with specific dimensions and configurations to enhance contact and reduce internal resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If separate electrode tabs are used for current collection, then electrical connection is achieved, but internal resistance increases and reliability decreases due to tab-related cracks or deformations
Solution Approach 1:
The patent merges the electrode tab function with the electrode plate itself by extending the uncoated portion of the negative electrode plate to form a integrated current collection structure, eliminating separate tabs and reducing potential failure points from tab-related cracks or deformations
Solution Approach 2:
The uncoated portion of the negative electrode plate serves multiple functions: it acts as both the active electrode material carrier and the current collection terminal, replacing the traditional separate tab component and simplifying the overall battery structure
2Reliability
If separate electrode tabs are used for current collection, then electrical connection is achieved, but internal resistance increases
Solution Approach 1:
By combining the current collection function directly into the electrode plate structure, the patent reduces the number of interface connections, thereby reducing contact resistance and overall internal resistance of the battery
Solution Approach 2:
The patent extracts the current collection function from the separate tab component and integrates it into the electrode plate, eliminating the additional resistance introduced by tab connections and welds
3Reliability
If the negative electrode uncoated portion is folded to extend downward, then contact with the lower plate is improved, but manufacturing complexity increases
Solution Approach 1:
The uncoated portion is pre-formed with a folded configuration during electrode plate manufacturing, ensuring proper contact geometry is established before battery assembly, which simplifies the overall manufacturing process despite the complex final shape
Data Source
Figure 1
Figure 2a~2b
Figure 2c~3
AI summary
A secondary battery (10) including an electrode assembly (100, 100A, 100B, 100C) including a positive electrode plate (110) having a positive electrode uncoated portion (114, 115), a negative electrode plate (120, 220, 320, 420) having a negative electrode uncoated portion (124, 125, 224, 225, 324, 325, 424, 425), and a separator (130) between the positive electrode plate (110) and the negative electrode plate (120, 220, 320, 420), a case (200) including a side plate (210) with a cylindrical body, the case (200) accommodating the electrode assembly (100, 100A, 100B, 100C) and a lower plate (215), the lower plate (215) sealing a lower portion of the side plate (210), and a cap assembly (300) coupled to an upper portion of the case (200) and electrically connected to the positive electrode plate (110), the negative electrode uncoated portion (124, 125, 224, 225, 324, 325, 424, 425) including a negative electrode extension uncoated portion (126, 226, 326, 426) of which one end portion is folded, extends downward from the electrode assembly (100, 100A, 100B, 100C), and is connected to the lower plate (215) of the case (200).