Form-Fitting Battery Cover Plate Sealing
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Solution Overview
Problem
Conventional lithium-ion battery cells face issues with welding beads protruding beyond the housing, causing misalignment and deformation during assembly into packs, which complicates the formation of a stable cell module due to the use of cohesive welding methods.
Innovation Solution
A form-fitting connection between the covering plate and the container, combined with an elastically compressible sealing element, replaces traditional welding, ensuring a hermetic seal without deformation and misalignment, using a tapered container opening and a sealing element like Viton for enhanced sealing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If welding methods are used to connect the covering plate to the container, then hermetic sealing is achieved, but welding beads protrude causing misalignment and deformation during pack assembly
Solution Approach 1:
The invention extracts the harmful welding beads from the system by replacing the welding connection method with a form-fitting mechanical connection. The covering plate is retained in the container opening through geometric interlocking features (such as a flange on the covering plate fitting into a recess in the container wall) without using welding, thereby eliminating the source of alignment problems while maintaining hermetic sealing through dedicated sealing elements.
Solution Approach 2:
The invention segments the connection function into two separate components: (1) a form-fitting mechanical connection for structural retention and alignment, and (2) a separate hermetic sealing element for gas-tight closure. This segmentation allows each component to optimize its specific function without the compromises required when using welding for both retention and sealing.
2Reliability
If welding methods are used to connect the covering plate to the container, then hermetic sealing is achieved, but the covering plate moves or deforms under high internal pressure
Solution Approach 1:
The invention segments the connection function into two separate components: (1) a form-fitting mechanical connection for structural retention and alignment, and (2) a separate hermetic sealing element for gas-tight closure. This segmentation allows each component to optimize its specific function without the compromises required when using welding for both retention and sealing.
Solution Approach 2:
The invention employs curved or tapered geometric features in the form-fitting connection (such as a tapered recess in the container wall that receives a flange on the covering plate) to create a self-locking mechanical connection that resists outward movement under internal pressure, preventing deformation and maintaining structural integrity.
3Strength
If welding methods are used for assembly, then cohesive connection is achieved, but the process becomes complex with multiple material-processing methods
Solution Approach 1:
The invention replaces the thermal welding process with a purely mechanical form-fitting connection system. Instead of using heat and material melting to create cohesive bonds, the solution uses geometric interlocking features that provide mechanical retention, simplifying the assembly process and eliminating the need for complex welding equipment and processes.
Solution Approach 2:
The invention extracts the harmful welding beads from the system by replacing the welding connection method with a form-fitting mechanical connection. The covering plate is retained in the container opening through geometric interlocking features (such as a flange on the covering plate fitting into a recess in the container wall) without using welding, thereby eliminating the source of alignment problems while maintaining hermetic sealing through dedicated sealing elements.
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 form-fitting connection and sealing element provide a reliable, pressure-resistant seal that prevents gas or liquid leakage, ensuring smooth packing and stability of battery cells in modules, even under high internal pressures.
Implementation Method 1
An elastically compressible sealing element is arranged between a peripheral surface of the covering plate, which peripheral surface is directed towards the wall of the container, and the wall of the container
Data Source
AI summary
The invention relates to a battery cell (1), in particular a lithium ion battery cell, in which a wrapping element, two current collectors and an electrolyte are accommodated in a housing (11). The prismatically formed housing (11) comprises a container that is open towards the upper side and a cover arrangement having a cover plate (23) closing the opening (14) of said container. The cover plate (23) and a wall of the container (13) are designed in the region of the opening (14) in such a manner that the wall prevents a movement of the cover plate (23) from the opening by means of a positive connection. An elastically compressible sealing element (31) is provided between the wall and a wall surface of an outer edge (27) of the cover plate directed towards said wall, in order to seal the cover plate (23) hermetically against the container (13). On the basis of the positive connection between the cover plate (23) and the edge of the container (13) a sealing effect can hereby likewise increase while the inner pressure in the housing (11) increases. The invention relates to a battery cell (1), in which it can be prevented that the cover plate (23) must be welded to the container (13).