Battery Cell Terminal Screw Coupling Without Weld Contamination
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Solution Overview
Problem
Ultrasonic welding of a current collector and electrode terminal in battery cells creates foreign substances that can lead to defects, damage the electrode assembly, and complicate the manufacturing process.
Innovation Solution
A screw-coupling method is used to connect the electrode terminal and current collector, eliminating the need for welding and reducing the formation of foreign substances, while maintaining a stable electrical connection and improving rigidity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If ultrasonic welding is used to connect the current collector and electrode terminal, then electrical connection is achieved, but foreign substances (fumes and spatter) are generated inside the battery cell causing defects
Solution Approach 1:
The patent extracts the harmful welding process from the battery cell assembly sequence by performing the current collector to electrode terminal connection before inserting the electrode assembly into the cell case. This removes the source of foreign substances (fumes and spatter) from the sealed battery cell environment, eliminating the defect issue while maintaining electrical connection quality.
Solution Approach 2:
The patent applies preliminary action by completing the welding connection between the current collector and electrode terminal prior to assembling the electrode assembly into the cell case. This preliminary connection is made in an open environment where welding byproducts can escape, preventing contamination of the battery cell interior.
2Reliability
If ultrasonic welding is performed through the hollow portion of the electrode assembly, then the current collector and electrode terminal are electrically connected, but the electrode assembly may be damaged by welding heat
Solution Approach 1:
The patent extracts the welding operation from the post-assembly stage and performs it before the electrode assembly is inserted into the cell case. This eliminates the need to weld through the hollow portion of the electrode assembly, thereby preventing thermal damage to the electrode structure while achieving the required electrical connection.
Solution Approach 2:
The connection between current collector and electrode terminal is established preliminarily before the electrode assembly is housed in the cell case. This preliminary connection avoids exposing the electrode assembly to welding heat, preserving its structural integrity while ensuring electrical connectivity.
3Reliability
If welding is used to connect the current collector and electrode terminal, then electrical connection is achieved, but the manufacturing process becomes complicated
Solution Approach 1:
The patent performs the welding connection as a preliminary step before electrode assembly insertion, allowing the welding operation to be conducted with optimal access and positioning. This sequencing simplifies the manufacturing process by eliminating the complexity of welding through confined spaces or delicate structures, while still achieving reliable electrical connection.
Data Source
AI summary
A battery cell includes a cell case including a side wall forming an accommodation space therein and a top plate having a through-hole formed therein, an electrode terminal coupled to the through-hole and having a coupling groove formed in a bottom portion of the electrode terminal, an electrode assembly disposed in the accommodation space of the cell case, and a first current collector electrically connecting the electrode terminal and the electrode assembly. The first current collector includes a connection terminal having a protrusion screw-coupled to the coupling groove, and the coupling groove includes a second screw thread coupled to a first screw thread formed on an outer peripheral surface of the protrusion.