Electricity Storage Module Connection Member Segmentation
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Solution Overview
Problem
Existing electricity storage modules face challenges in connecting lead terminals made of different metal materials, particularly aluminum and copper, due to the risk of forming brittle alloy phases during laser welding, which limits their application in narrow stacking intervals and increases the overall size.
Innovation Solution
The solution involves a connection member with intersecting terminal and member joining portions, where the first metal portion matches the cathode lead terminal material and the second metal portion matches the anode lead terminal material, preventing overlap and allowing for secure welding without forming brittle regions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a clad material with parallel arrangement of first and second metal materials is used as busbar, then different metal materials can be connected, but an overlapping region with different metals creates brittle alloy phases during laser welding
Solution Approach 1:
The connection member is divided into separate first and second metal portions that are joined at a member joining portion, with terminal joining portions extending in intersecting directions. This segmentation prevents the formation of a continuous overlapping region with different metals, eliminating brittle alloy phase formation during laser welding while maintaining the ability to connect different metal materials.
Solution Approach 2:
The terminal joining portions are arranged in intersecting directions (orthogonal arrangement) rather than parallel overlap. This spatial reconfiguration in multiple dimensions allows different metal materials to be connected without creating a problematic overlapping region, resolving the contradiction between adaptability and reliability.
2Ease of manufacture
If ultrasonic welding is used to join lead terminals of adjacent electricity storage elements, then joining is achieved, but a gap for welding jig insertion is required which limits the number of layers and increases overall size
Solution Approach 1:
The connection member acts as an intermediary component that joins lead terminals from multiple electricity storage elements. By using this intermediate connection structure, the patent enables welding of closely stacked elements without requiring large gaps for welding jig insertion, thus reducing overall size while maintaining ease of manufacture.
3Productivity
If laser welding is applied to join different metal materials directly, then joining speed is high, but brittle alloy phases form making it difficult to apply to narrow stacking intervals
Solution Approach 1:
The connection member segments the different metal materials into separate first and second metal portions that are joined at a member joining portion. This segmentation allows laser welding to be applied to like-material joints (avoiding brittle alloy formation) while maintaining high joining speed, making the process suitable for narrow stacking intervals.
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 configuration enables the secure electrical connection of lead terminals with different metal materials in a limited space, reducing the risk of corrosion and facilitating easier assembly by avoiding metal overlaps during welding.
Implementation Method 1
a clad material obtained by pressure welding a first metal material composed of a metal material of the same type as that of the cathode terminal, and a second metal material composed of a metal material of the same type as that of the anode terminal
Implementation Method 2
If the overlapping region with different types of metals and the electrode terminals are laser welded, there is a risk that an alloy phase will be formed
Data Source
AI summary
An electricity storage module includes: an electricity storage element group formed by stacking multiple electricity storage elements each having lead terminals of a cathode and an anode; and a connection member that is joined to the lead terminals. A cathode lead terminal and an anode lead terminal are composed of different metal materials, and the connection member is formed by joining a first metal portion that is connected to the cathode lead terminal and is composed of the same metal material as the cathode lead terminal, and a second metal portion that is connected to the anode lead terminal and is composed of the same metal material as the anode lead terminal. The first metal portion and the second metal portion each have a terminal joining portion joined with a lead terminal and a member joining portion at which the first metal portion and the second metal portion are joined.