Tab-Less Electrode Terminal Structure for Cylindrical Battery Cells
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional cylindrical battery cells face issues with high inner resistance and heat generation due to small cross-section electrode tabs, leading to inefficiencies in current collection and space usage, especially during rapid charging, which can cause thermal runaway and limit energy density.
Innovation Solution
The design features a tab-less cylindrical battery cell with a cylindrical battery can and an electrode terminal structure that includes a body portion, outer flange, inner flange, and flat portion, where the electrode terminal passes through a perforation hole in the battery can, with a gasket for sealing and insulation, and a welding pattern that increases the cross-sectional area for current flow, reducing resistance and enhancing space efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If strip-shaped electrode tabs are used to connect positive and negative electrodes, then the battery cell structure is simple and easy to manufacture, but the current collection efficiency is poor due to large resistance and heat generation from small cross-sectional area
Solution Approach 1:
The patent transitions from traditional strip-shaped electrode tabs (1D linear structure) to a three-dimensional current collecting plate with extended fingers that protrude into the battery can. This dimensional change increases the effective cross-sectional area for current flow and creates multiple current collection paths, thereby reducing resistance and improving current collection efficiency while maintaining manufacturing simplicity.
2Ease of manufacture
If traditional electrode terminal structure is used, then the battery cell assembly is straightforward, but space efficiency is poor and inner resistance is high
Solution Approach 1:
The current collecting plate is segmented into multiple fingers that extend toward the center of the battery can. This segmentation allows the current collection structure to utilize space more efficiently by distributing current collection points throughout the battery volume, reducing the distance electrons must travel, and lowering overall resistance without increasing the battery's external dimensions.
3Volume of stationary object
If small cross-section electrode tabs are used, then the battery cell structure is compact, but heat generation is excessive during rapid charging leading to thermal runaway risk
Solution Approach 1:
The patent converts the potential harm of high current density concentration at small tabs into a benefit by distributing the current across multiple extended fingers of the current collecting plate. This distribution reduces localized heat generation during rapid charging, preventing thermal runaway while maintaining the compact battery cell structure through efficient space utilization.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This configuration lowers the inner resistance of the cylindrical battery cell, increases energy density, and allows for more efficient electrical wiring, reducing the risk of thermal runaway and improving assembly and maintenance of battery packs in vehicles.
Implementation Method 1
a welding pattern that increases the cross-sectional area for current flow, reducing resistance
Implementation Method 2
with a gasket for sealing and insulation
Data Source
Figure 1
Figure 2
Figure 3
AI summary
Disclosed is a structure of an electrode terminal, and a cylindrical battery cell, a battery pack and a vehicle including the same. The structure of an electrode terminal includes a battery can configured to have one open side; an electrode terminal passing through a perforation hole formed in a bottom of the battery can; and a gasket interposed between the electrode terminal and the perforation hole. Also, the electrode terminal includes a body portion inserted into the perforation hole; an outer flange portion configured to extend along an outer surface of the bottom from a circumference of one side of the body portion exposed through the outer surface; an inner flange portion configured to extend toward an inner surface of the bottom from a circumference of the other side of the body portion exposed through the inner surface; and a flat portion provided to an inner side of the inner flange portion.