Battery Cell End Cover Support for Weld Seam Tear Resistance
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Solution Overview
Problem
Lithium ion batteries face issues with reduced service life and safety due to deformation and tearing at the heat-affected zone near the welding seam, caused by vibration, which affects the sealing performance and leads to potential leakage and safety hazards.
Innovation Solution
A battery cell design featuring an end cover with a support body that abuts the inner case surface, providing reverse support and buffering against deformation and external stress, combined with an integrated structure and hot-melt colloid for enhanced sealing and structural integrity, reducing the tearing force and improving safety.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the case end cover is fixedly connected to the battery case by laser welding, then the sealing performance is improved, but the heat-affected zone near the welding seam is susceptible to tearing due to vibration, reducing service life and safety
Solution Approach 1:
The support body is pre-installed on the bottom surface of the end cover body before welding. This preliminary action provides structural reinforcement to the heat-affected zone before any deformation or vibration occurs, preventing tearing by distributing stress away from the vulnerable welded area.
Solution Approach 2:
The support body acts as an intermediary element between the end cover body and the battery case. It mediates the stress and vibration forces, preventing them from directly affecting the heat-affected zone of the laser welding seam, thus protecting the welded joint from tearing while maintaining sealing performance.
2Stability of the object's composition
If the end cover body is welded and fixed to the case, then the structural integrity is improved, but the deformation of the heat-affected zone reduces the flatness of side walls and compromises safety
Solution Approach 1:
The support body is pre-installed on the bottom surface of the end cover body before welding. This preliminary action provides structural reinforcement to the heat-affected zone before any deformation or vibration occurs, preventing tearing by distributing stress away from the vulnerable welded area.
Solution Approach 2:
The support body provides a counteracting force against the deformation tendencies of the heat-affected zone. By being disposed along the edge of the end cover body in the circumferential direction, it creates a balancing effect that maintains the flatness of the case side walls despite thermal and mechanical stresses during and after welding.
3Area of stationary object
If the support body is disposed along the edge of the end cover body in the circumferential direction, then the support area is increased, but the device complexity increases
Solution Approach 1:
The support body and end cover body are integrated into a single component, eliminating the need for separate assembly steps. This merging increases the support area along the circumferential edge while avoiding the complexity of assembling multiple separate parts, as the support structure is formed as an integral part of the end cover during 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 design effectively prolongs the service life and enhances safety by counteracting deformation, reducing the tearing force at the heat-affected zone, and ensuring better sealing performance, thus preventing liquid leakage and water seepage.
Implementation Method 1
the support body is used for abutting against the inner side surface of the case... the support body also plays a role in buffering the external stress and the impact of an interior electrode assembly
Implementation Method 2
the end cover body is used for being welded and fixed to the case... the case end cover is fixedly connected to the battery case by means of laser welding
Implementation Method 3
combined with an integrated structure and hot-melt colloid for enhanced sealing... ensuring better sealing performance, thus preventing liquid leakage and water seepage
Data Source
AI summary
A battery cell includes a case having an opening and an end cover configured to cover the opening. The end cover comprises an end cover body and a support body. The end cover body is configured to be welded and fixed to the case. The support body is disposed on a bottom surface of the end cover body and is disposed along an edge of the end cover body in a circumferential direction. The support body is configured to abut against an inner side surface of the case.