Secondary Battery Current Collector Layout for Lower Internal Resistance
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Solution Overview
Problem
Existing secondary batteries face challenges in minimizing electrical resistance and accommodating a large electrode assembly within a compact case, while maintaining efficient current paths and structural integrity.
Innovation Solution
The design includes first and second tabs aligned in the same direction for low electrical resistance, three-dimensionally coupled current collector plates occupying a small volume, and a conductive ring plate on the case for enhanced flatness and structural support, along with a rivet terminal and case configuration that allows for efficient current flow and reduced internal resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If tabs are provided in opposite directions in conventional batteries, then structural symmetry is maintained, but electrical resistance increases and current path lengthens
Solution Approach 1:
The patent applies asymmetry by configuring all tabs (both positive and negative electrode tabs) to protrude in the same direction rather than maintaining opposite directions. This asymmetric arrangement shortens the current path length and reduces electrical resistance between tabs and current collector plates, directly resolving the technical contradiction between reliability and device complexity.
2Volume of stationary object
If current collector plates are separated in conventional designs, then electrical connection is simplified, but volume occupation increases reducing electrode assembly space
Solution Approach 1:
The patent merges the first and second current collector plates into a single integrated component with multiple connection areas. This combined structure occupies less volume than separate plates while maintaining all necessary electrical connections through its multi-functional design, resolving the contradiction between minimizing case volume occupation and managing device complexity.
Solution Approach 2:
The integrated current collector plate performs multiple functions simultaneously: it collects current from both positive and negative tabs, provides structural support, and establishes electrical connections to terminals. This multi-functionality allows a single component to replace what would traditionally require separate plates, reducing overall volume while maintaining complexity at an acceptable level.
3Reliability
If terminal flatness is not optimized, then manufacturing is simpler, but contact area and electrical connection quality deteriorate
Solution Approach 1:
The patent applies local quality by providing a specific connection area on the integrated current collector plate that is configured to contact the terminal. This localized optimized contact region ensures excellent flatness and electrical connection quality at the critical interface, while the rest of the structure maintains manufacturing simplicity, resolving the contradiction between reliability and ease of manufacture.
Data Source
Figure 1A
Figure 1B
Figure 2A
AI summary
A secondary battery (100) includes a case, an electrode assembly (120) in the case, and including first tabs (1211) protruding in a first direction, and second tabs (1221) protruding in the first direction, a first current collector plate (131) electrically connected to the first tabs, a second current collector plate (132) electrically connecting the second tabs to the case, and a rivet terminal (140) electrically connected to the first current collector plate and passing through the case.