Battery Cell Current Collector Structure for Sealed Dual-Region Tab Welding
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Solution Overview
Problem
Lithium ion batteries face significant safety hazards due to local overcurrent and polarization issues during cyclic charging and discharging, leading to lithium precipitation, which compromises their safety and reliability.
Innovation Solution
A battery cell design featuring a shell with a protruding first limit part, an end cover, and a current collector component with a body part and connecting part that includes separate welding regions, ensuring reliable electrical connection and reducing the risk of overcurrent by welding these regions to the tab of the electrode assembly, thereby enhancing the sealing and connection stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the current collector component is connected to the shell through a built-in connection position, then the connection reliability is improved, but the sealing between the end cover and the shell may be compromised
Solution Approach 1:
The current collector component is divided into a body part and a connecting part, with the connecting part extending to the first limit part on the shell. This segmentation allows the electrical connection function to be separated from the sealing function, enabling reliable electrical connection without compromising the sealing between the end cover and the shell.
Solution Approach 2:
The connecting part of the current collector component acts as an intermediary element that extends from the body part to the first limit part on the shell. This intermediary structure enables electrical connection between the electrode assembly and the shell while maintaining the sealing integrity of the battery cell.
2Reliability
If the body part includes separate welding regions, then the connection relationship between the tab and current collector component is improved, but the device complexity increases
Solution Approach 1:
The body part of the current collector component is divided into a first welding region and a second welding region, separated by the connection position. This segmentation allows independent welding operations on each region, improving the connection relationship between the tab and current collector component while maintaining manageable structural complexity through systematic design.
3Reliability
If the first welding region and second welding region are both welded to the tab, then the risk of local overcurrent is reduced, but the manufacturing process becomes more complex
Solution Approach 1:
The body part is segmented into two welding regions that can be welded to different parts of the tab, distributing the current flow path and reducing local overcurrent concentration. This segmentation addresses the safety issue while the welding process remains a standard manufacturing operation.
Solution Approach 2:
Different regions of the body part are designed with different welding characteristics - the first welding region and second welding region can be welded to different locations on the tab, creating localized current distribution that prevents overcurrent in any single area, thereby improving safety.
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 solution effectively improves the connection reliability between the current collector and the shell, reduces the risk of polarization and lithium precipitation, and enhances the overall safety and service life of the battery cell by ensuring a stable electrical connection and sealing.
Implementation Method 1
both the first welding region and the second welding region are welded to the tab
Data Source
AI summary
A battery cell includes a shell, an end cover, an electrode assembly, and a current collector component. The shell has an opening, and the inner surface of the shell is provided with a first limit part in a protruding manner. The end cover covers the opening. The electrode assembly and the end cover are respectively located on both sides of the first limit part, and the electrode assembly has a tab on the side facing the end cover. The current collector component includes a body part and a connecting part, and the connecting part is connected to the first limit part. The body part includes a first welding region and a second welding region, the first welding region is located on the periphery of the second welding region, the first welding region and the second welding region are separated by the connection position between the connecting part and the body part.