Battery Module Bus Bar Laser Welding for Short Circuit Prevention
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Solution Overview
Problem
Existing secondary battery modules face challenges in preventing short circuits and efficiently connecting unit batteries in series due to varying terminal distances and structural differences, which affects the reliability and efficiency of the battery module.
Innovation Solution
The use of laser or ultrasonic welding to precisely join terminal bus bars with clip-type configurations that can be easily controlled and adjusted in height, allowing for flexible connection structures and varying thicknesses to accommodate different terminal spacings, thereby preventing short circuits and ensuring reliable series connections.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If nuts are screwed onto terminals to fix bus bars, then the connection structure is simple and easy to manufacture, but the connection reliability is reduced due to potential loose connections and short circuits
Solution Approach 1:
The patent replaces the mechanical nut-bolt fastening system with a laser welding system. The bus bar includes contact portions that directly contact the terminals, and laser welding is used to create permanent, reliable connections without requiring additional fasteners. This substitution eliminates the risks of loose connections while maintaining manufacturing efficiency through automated laser welding processes.
Solution Approach 2:
The patent changes the connection method from mechanical (nut-bolt) to thermal (laser welding). The laser welding process uses concentrated thermal energy to melt and fuse the bus bar contact portions with the terminals, creating strong, reliable connections. This parameter change from mechanical fastening to thermal joining resolves the contradiction between connection reliability and manufacturing complexity.
2Adaptability or versatility
If fixed-height bus bars are used, then the manufacturing precision is improved, but the adaptability to varying terminal distances is reduced
Solution Approach 1:
The patent makes the bus bar height adjustable rather than fixed. The support portions can be positioned at different heights to accommodate varying terminal distances between unit batteries. This dynamic adjustment capability allows the same bus bar structure to adapt to different spacing configurations while maintaining precise contact through laser welding, thus resolving the contradiction between adaptability and manufacturing precision.
Solution Approach 2:
The patent changes the height parameter of the bus bar from fixed to variable. The support portions can be adjusted to different heights, and the connecting portions can be bent to different angles, allowing the bus bar to adapt to various terminal distances. This parameter flexibility enables the system to maintain manufacturing precision while achieving adaptability to different spacing configurations.
3Adaptability or versatility
If thick connecting portions are used to accommodate distance variations, then the adaptability is improved, but the device complexity and material usage increase
Solution Approach 1:
The patent divides the bus bar into distinct functional segments: contact portions for electrical connection, support portions for positioning, and connecting portions for structural linkage. This segmentation allows each part to be optimized independently - the connecting portions can be made thinner since their only function is structural linkage, while the contact portions are optimized for electrical connection. The segmented design reduces overall material usage and complexity while maintaining adaptability through the adjustable support portions.
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 solution effectively prevents short circuits and ensures reliable connections between unit batteries, maintaining high current collection efficiency and low contact resistance regardless of terminal spacing variations, enhancing the overall performance and stability of the secondary battery module.
Implementation Method 1
the terminals of the unit batteries are precisely joined to bus bars by laser or ultrasonic welding to prevent short circuits between the terminals
Implementation Method 2
the terminals of the unit batteries are precisely joined to bus bars by laser or ultrasonic welding to prevent short circuits between the terminals
Data Source
AI summary
A secondary battery module including a plurality of unit batteries, each including a first terminal and a second terminal, and a plurality of bus bars, each electrically connecting the first terminal of one of the unit batteries to the second terminal of an adjacent unit battery, wherein the first terminal and second terminal each include a first contact surface and a second contact surface opposite to the first contact surface, the bus bars include a first coupling portion in contact with the first contact surface and the second contact surface of the first terminal of one of the unit batteries, a second coupling portion in contact with the first contact surface and the second contact surface of the second terminal of an adjacent unit battery and a connecting portion connecting the first and second coupling portions.