Ultrasonic Welding Flat Battery Cells Horizontal Tab Connection
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Solution Overview
Problem
Current methods for connecting flat-type cells in series for high-voltage batteries face challenges with ultrasonic welding, including difficult automation and mechanical bonding issues that affect reliability and maintainability.
Innovation Solution
The use of specifically shaped electrode tabs and insulating sheets allows for ultrasonic welding of flat-type cells in a laminated state without mechanical bonding, enabling easy automation and improved reliability and maintainability by dispersing welding positions across multiple directions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If ultrasonic welding is performed by moving cells to create insertion space for the welding head, then welding can be performed, but the operation becomes troublesome and automation becomes difficult
Solution Approach 1:
The patent changes the welding approach from vertical welding (requiring head insertion space) to horizontal welding along the lamination direction. By welding electrode tabs at the side surfaces of laminated cells in the horizontal direction, the welding head no longer needs to insert vertically between cells, eliminating the need to move cells and enabling straightforward automation.
Solution Approach 2:
The patent performs welding operations in a predetermined sequence along the lamination direction before final assembly. By welding electrode tabs of adjacent cells horizontally in advance, the structure is prepared for subsequent stacking without requiring complex repositioning operations during assembly.
2Ease of manufacture
If mechanical bonding with bolts, nuts and washers is used, then connection is achieved, but contact resistance variation and loosening due to vibration occur
Solution Approach 1:
The patent replaces mechanical bonding (bolts, nuts, washers) with ultrasonic welding technology. This substitution eliminates contact resistance variation and vibration-induced loosening by creating a direct metallurgical bond between electrode tabs, while still maintaining ease of manufacture through automated welding processes.
Solution Approach 2:
The patent merges the electrode tabs of adjacent cells directly through ultrasonic welding, eliminating the need for separate mechanical fastening components. This direct merging of conductive parts ensures consistent electrical contact and structural integrity without additional parts that could loosen.
3Productivity
If electrode tabs are welded in the laminated state of all combined batteries, then connection efficiency is improved, but the welding head cannot access all tabs simultaneously
Solution Approach 1:
The patent transitions from vertical welding access (requiring cell displacement) to horizontal welding access along the lamination direction. This dimensional change allows the welding head to access electrode tabs of laminated cells from the side, enabling welding in the laminated state without increasing device complexity.
Solution Approach 2:
The patent segments the welding operation into multiple horizontal welding stations or sequential welding steps along the lamination direction. Instead of attempting to weld all tabs simultaneously with a single vertical head, the process divides welding into manageable segments that can be performed sequentially on adjacent cell pairs.
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
This approach facilitates efficient and reliable connection of flat-type cells in series, enhancing operational ease and endurance while preventing contact resistance variations and loosening due to vibration.
Implementation Method 1
welding the plus and the minus electrode tabs themselves to compose a set, by using an ultrasonic welding machine
Data Source
AI summary
A combined battery (100) comprising a plurality of flat-type cells (10A to 10F) by laminating thereof so that polarity of electrode tabs (11A to 11F and 12A to 12F) is alternately set, wherein welding parts to connect in series the flat cells themselves, to compose a set when all the flat-type cells (10A to 10F) are laminated, are separated at a plurality of positions of the combined battery, and the flat-type cells having such a structure that all the flat-type cells are electrically connected in series by welding each of the welding parts.