Layered Copper-Aluminum Bus Bar for Stable Battery Module Welding
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Solution Overview
Problem
Existing battery modules face challenges in achieving stable and efficient electrical and mechanical connections between bus bars and cell terminals, leading to potential issues with conductivity and weld integrity.
Innovation Solution
A battery module design utilizing a first bus bar made of aluminum and a second bus bar made of copper, where the copper bus bar is stacked on the aluminum bus bar, with a specific thickness ratio and laser welding to ensure strong connections, and a fixing member to maintain contact.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a single-material bus bar (e.g., aluminum) is used to connect battery cells, then the device complexity is reduced, but the electrical conductivity and mechanical stability are insufficient
Solution Approach 1:
The patent applies composite materials by combining aluminum and copper in a layered bus bar structure. The first bus bar is made of aluminum material and the second bus bar is made of copper material, creating a composite structure that leverages the high electrical conductivity of copper and the lightweight, cost-effective properties of aluminum to achieve superior overall performance
Solution Approach 2:
The patent merges two different bus bar components (aluminum first bus bar and copper second bus bar) into a single integrated connection structure. These are connected through laser welding to form a unified bus bar assembly that connects multiple battery cells, combining the advantages of both materials in one structure
2Manufacturing precision
If laser welding is used to connect bus bars, then the manufacturing precision and connection strength are improved, but spattering and weld defects may occur
Solution Approach 1:
The patent applies parameter changes by optimizing the laser welding process parameters including laser power (3.4-4.6 kW), welding speed, and focal position. These parameter adjustments are specifically tuned for the aluminum-copper composite structure to achieve clean welds with minimal spattering while maintaining strong electrical and mechanical connections
Solution Approach 2:
The patent converts the potential harm of spattering into a benefit by using the laser welding process to create a precise, controlled melt zone that fuses the aluminum and copper materials. The controlled thermal energy that could cause spattering instead creates strong metallurgical bonds between the dissimilar metals when properly parameterized
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
Enhances electrical conductivity and mechanical stability, preventing spattering during welding and ensuring high-output and high-capacity electrical connections.
Implementation Method 1
The first bus bar and the cell terminal may be bonded to each other by laser welding
Implementation Method 2
In the connecting of the cell terminal and the first bus bar, a laser beam may be irradiated in a direction toward the first bus bar from the second bus bar
Data Source
AI summary
A battery module and a method of manufacturing the same, are capable of improving the stability of mechanical and electrical connections. The battery module includes a housing, a battery cell disposed inside the housing, a first bus bar connected to the battery cell and including a first conductive material connected to the first bus bar and a module bus bar. The second bus bar includes a second conductive material that is different than the first conductive material.