Cylindrical Battery Tab Layout for Shorter Current Paths
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Solution Overview
Problem
Existing secondary batteries face challenges in achieving low electrical resistance and efficient accommodation of large electrode assemblies within a limited space, while maintaining a short current path and ensuring flatness between terminals.
Innovation Solution
The design includes first and second tabs of an electrode assembly aligned in the same direction, connected to a first and second current collector plate that are three-dimensionally coupled and occupy a small volume, with a conductive ring plate on the second terminal to enhance electrical connectivity and accommodate a larger electrode assembly within a case.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If tabs of electrode assembly are arranged in opposite directions, then electrical connectivity is achieved, but current path length increases and electrical resistance increases
Solution Approach 1:
Instead of arranging tabs in opposite directions (conventional approach), the patent inverts this arrangement by positioning both tabs in the same direction. This inversion allows both tabs to connect to terminals on the same side of the battery, significantly shortening the current path length and reducing electrical resistance while maintaining reliable electrical connectivity.
Solution Approach 2:
The patent transitions from a two-dimensional opposite-direction tab arrangement to a three-dimensional configuration where tabs are positioned in the same direction but connected to different terminals through current collector plates. This dimensional change enables shorter current paths by utilizing the vertical space within the battery case.
2Quantity of substance
If electrode assembly size is increased, then battery capacity is improved, but available space in case is reduced
Solution Approach 1:
The patent utilizes three-dimensional space more efficiently by arranging current collector plates vertically and positioning tabs in the same direction. This allows the electrode assembly to be configured in a compact manner that maximizes battery capacity while fitting within the limited case volume, effectively using vertical space rather than only horizontal expansion.
Solution Approach 2:
The current collector plates are positioned to overlap or nest within the same region of the case, with one plate arranged above the other. This nesting arrangement allows both plates to occupy the same horizontal footprint, effectively doubling the electrical connection capability without increasing the horizontal space requirement, thus enabling larger electrode assemblies to fit within the case.
3Volume of stationary object
If current collector plates are positioned in the same region, then space utilization is improved, but electrical resistance may increase
Solution Approach 1:
The patent divides the electrical connection system into two separate current collector plates, each handling connections for one tab. By segmenting the connection paths and maintaining them separate throughout their length before termination, the patent prevents resistance increase despite the plates occupying the same horizontal region. Each plate provides a dedicated low-resistance path to its respective terminal.
Data Source
Figure 1A
Figure 1B
Figure 2A
AI summary
A secondary battery includes a case having a cylindrical shape, an electrode assembly accommodated in the case and including first tabs protruding in a first direction and second tabs protruding in the first direction, a first current collector plate accommodated in the case and connected to the first tabs, a second current collector plate configured to connect the second tabs to the case, a rivet terminal connected to the first current collector plate and passing through the case, and an insulating member in contact with a perimeter of each of the electrode assembly, the first current collector plate, and the second current collector plate.