Tab-Less Cylindrical Battery Structure for Low-Resistance Charging
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Solution Overview
Problem
Conventional cylindrical batteries face issues with current collection efficiency due to high resistance and heat generation, especially during rapid charging, which can lead to thermal runaway and reduced energy density, particularly when scaled for electric vehicles.
Innovation Solution
A cylindrical battery design with a tab-less structure where the uncoated regions of the electrodes are positioned at the top and bottom, and current collectors are welded directly to these regions to enhance current collection efficiency, and the electrical connection structure is optimized to minimize resistance and maximize energy density by using a wide area of the battery can as an electrode terminal.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional cylindrical battery structure with electrode tabs is used, then current collection is achieved, but high resistance and heat generation occur during rapid charging
Solution Approach 1:
The patent removes the traditional electrode tabs from the cylindrical battery structure. By extracting the tab component and repositioning the uncoated regions to the top and bottom ends of the electrode assembly, the design eliminates the resistance and heat generation issues associated with tab connections during rapid charging operations.
2Reliability
If electrode tabs are used for current collection, then electrical connection is achieved, but energy density is reduced due to space occupation
Solution Approach 1:
By removing the electrode tabs entirely and utilizing the top and bottom surfaces of the cylindrical battery can as current collection points, the design frees up internal space that would otherwise be occupied by tab structures and associated connection components, thereby increasing energy density.
Solution Approach 2:
The battery can structure serves dual functions: as the container for the electrode assembly and as the current collection terminal. The top and bottom surfaces of the can act as electrode terminals, eliminating the need for separate tab structures and reducing overall component count.
3Reliability
If uncoated regions are positioned at top and bottom, then current collection efficiency is improved, but manufacturing complexity increases
Solution Approach 1:
Instead of extending uncoated regions laterally as traditional tabs, the patent inverts the approach by positioning uncoated regions at the longitudinal ends (top and bottom) of the electrode assembly. This inversion simplifies the winding process and aligns with the natural orientation of cylindrical battery manufacturing.
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
The optimized design reduces internal resistance, minimizes heat generation, and increases energy density, enabling safer and more efficient operation of cylindrical batteries in electric vehicles by improving current collection and space efficiency.
Implementation Method 1
a current collector (60) coupled to the first uncoated region (11) to electrically connect the first uncoated region (11) and the electrode terminal (40)
Implementation Method 2
current collectors are welded directly to these regions to enhance current collection efficiency
Data Source
AI summary
A battery can include an electrode assembly, a battery housing, a terminal and a cap. The electrode assembly can have a first electrode, a second electrode and a separator between the first electrode and the second electrode. Each of the first electrode and the second electrode can have a first portion including an active material corresponding to the separator, and a second portion exposed beyond the separator and not coated with the active material. The battery housing can have a first end with a first opening and a second end with a second opening opposite the first end. The terminal can be electrically connected to the second portion of the first electrode and exposed out of the battery housing through the first opening of the battery housing at the first end.