Clad Unit Terminal for Secondary Battery Welding
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Solution Overview
Problem
Existing secondary battery terminal units face reduced bonding strength due to dissimilar metal welding, particularly between electrode rivets and rivet terminals, which can lead to instability in the electrical connections.
Innovation Solution
The use of a clad unit with an outer layer of one metallic material and an inner layer of another, allowing similar metal welding to enhance bonding strength between electrode rivets and rivet terminals, and between rivet terminals and bus bars, thereby forming a stable and solid bonding structure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If dissimilar metal welding is used to bond electrode rivets and rivet terminals, then the terminal unit can be assembled, but the bonding strength is reduced and electrical connection stability deteriorates
Solution Approach 1:
The patent introduces a clad unit as an intermediary component between the electrode rivet and rivet terminal. This clad unit has a layered structure with an inner layer made of the same material as the electrode rivet and an outer layer made of the same material as the rivet terminal. This intermediary structure enables similar metal welding at both interfaces, resolving the contradiction by maintaining manufacturing feasibility while dramatically improving bonding strength and electrical connection stability.
Solution Approach 2:
The clad unit is constructed as a composite material structure with two different metallic layers. The inner layer and outer layer are made of different materials to match the electrode rivet and rivet terminal respectively, while both layers are weldable. This composite approach allows the terminal unit to achieve both ease of manufacture and high bonding strength simultaneously.
2Ease of manufacture
If dissimilar metal welding is used between rivet terminals and bus bars, then the terminal unit can be connected, but the bonding strength and weldability are reduced
Solution Approach 1:
The clad unit serves as an intermediary between the rivet terminal and bus bar connection. The outer layer of the clad unit is made of the same material as the rivet terminal, enabling reliable similar metal welding. This intermediary structure ensures stable electrical connection and high bonding strength while maintaining ease of manufacture.
3Strength
If similar metal welding is performed, then bonding strength and weldability are improved, but additional components (clad unit) are required increasing device complexity
Solution Approach 1:
The clad unit combines multiple functions into a single component: it provides material transition, enables similar metal welding at both interfaces, ensures electrical conductivity, and maintains mechanical strength. By merging these functions into one integrated component rather than using separate intermediate layers or multiple assembly steps, the patent reduces overall device complexity while achieving high bonding strength.
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 ensures a stable and solid bonding structure, preventing reductions in weldability and maintaining electrical integrity by performing similar metal welding within the terminal units.
Implementation Method 1
Bonding between the positive electrode rivet or the negative electrode rivet and a rivet terminal, and between a rivet terminal and a bus bar may be performed by using a laser welding method.
Implementation Method 2
The outer layer may be welded to the rivet terminal. The electrode rivet may be engaged with the clad unit. The electrode rivet may be welded to the inner layer of the clad unit.
Data Source
AI summary
A secondary battery and a secondary battery module, the secondary battery including an electrode assembly (60), the electrode assembly (60) including a positive electrode (61), a negative electrode (62), and a separator (63) therebetween; a case (50) for accommodating the electrode assembly (60); a cap plate (40) for sealing the case (50); and a first terminal unit including a first electrode rivet (12) electrically connected to one of the electrodes of the electrode assembly (60) and formed of a first metallic material, a rivet terminal (22) formed of a second metallic material, the second metallic material being different from the first metallic material, and a clad unit (10) between the electrode rivet (12) and the rivet terminal (22).