Cylindrical Battery Separator Layout to Prevent Collector Plate Shorts
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Solution Overview
Problem
Cylindrical secondary batteries face safety issues due to potential short circuits caused by the expansion of the negative electrode, leading to contact between the negative electrode mixture part and the positive electrode current collector plate.
Innovation Solution
The design includes a first electrode substrate tab that is bent and contacts the first electrode current collector plate, with a separator interposed between them, and a second separator that contacts the first electrode current collector plate, preventing direct contact between the positive and negative electrodes by adjusting the length and arrangement of the separators.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the negative electrode plate is allowed to expand during use, then the battery can maintain good electrical contact and performance, but the expanding negative electrode may contact the positive electrode current collector plate causing a short circuit
Solution Approach 1:
The patent introduces a separator as an intermediary component between the positive and negative electrodes. The separator extends beyond the electrode plates to contact the positive electrode current collector plate, creating a protective barrier that prevents the expanding negative electrode from directly contacting the current collector plate while still allowing ionic conduction to occur.
Solution Approach 2:
The separator is pre-positioned to extend beyond the electrode plates and contact the current collector plate before any expansion occurs. This preliminary arrangement ensures that when the negative electrode expands during battery operation, the separator is already in place to prevent contact between the negative electrode and the current collector plate.
2Reliability
If the separator is extended to contact the current collector plate, then short circuit prevention is improved, but the device structure becomes more complex
Solution Approach 1:
The separator performs multiple functions: it provides ionic conduction between electrodes during normal operation and simultaneously acts as a protective barrier that prevents short circuits by contacting the current collector plate. This multi-functionality eliminates the need for separate protective components, thereby reducing overall device complexity despite the extended separator configuration.
Data Source
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AI summary
A secondary battery includes: an electrode assembly having a first electrode plate having a first electrode substrate tab arranged in one direction, a second electrode plate having a second electrode substrate tab arranged in an opposite direction to the first electrode substrate tab, and a separator interposed between the first electrode plate and the second electrode plate, and wound into a cylindrical shape; a cylindrical can configured accommodating the electrode assembly; a first electrode current collector plate electrically connected to the first electrode substrate tab; and a second electrode current collector plate electrically connected to the second electrode substrate tab, wherein the first electrode substrate tab contacts the first electrode current collector plate, and the separator extends and contacts the first electrode current collector plate with the first electrode substrate tab interposed therebetween.