Battery Electrode Pillar Welding Structure for External Joining
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Solution Overview
Problem
Existing methods for welding the electrode pillar and current collecting portion of cylindrical batteries face challenges such as high positioning accuracy requirements, low production efficiency, damage to the electrode sheet assembly, safety issues due to metal shavings, limited current-carrying capacity, and inability to detect the welding quality effectively.
Innovation Solution
A secondary battery design featuring a thinned region on the electrode pillar and a welding portion on the current collecting portion, allowing external welding, which reduces the need for precise internal positioning, prevents metal shavings, and enhances welding quality detection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If torque welding is performed through the center hole of the electrode sheet assembly, then the electrode pillar and current collecting portion can be electrically connected, but the positioning accuracy requirement becomes extremely high and production efficiency decreases
Solution Approach 1:
The patent creates a thinned region on the electrode pillar before welding, and positions the welding portion on the current collecting portion to align with this thinned region. This preliminary preparation allows the welding to be performed externally without requiring precise positioning through the small center hole, thereby improving production efficiency while maintaining electrical connection reliability
Solution Approach 2:
The patent changes the welding dimension from internal (through the center hole) to external (through the thinned region on the electrode pillar surface). This dimensional change allows welding to be performed from the outside of the battery structure, eliminating the need for high-precision positioning through the small center hole and significantly improving production efficiency
2Reliability
If torque welding is performed through the center hole, then electrical connection can be achieved, but metal shavings remain inside the battery causing safety issues
Solution Approach 1:
The patent extracts the welding process from the internal center hole location and relocates it to the external thinned region on the electrode pillar. This extraction removes the source of metal shavings generation from inside the battery, eliminating the safety hazard while maintaining the electrical connection function
Solution Approach 2:
The patent converts the thinned region, which could be seen as a structural weakness, into a beneficial feature by making it the welding location. This allows external welding that avoids generating internal metal shavings, transforming a potential disadvantage into a safety advantage
3Productivity
If the center hole is made larger to facilitate welding pin insertion, then production efficiency improves, but positioning accuracy becomes even more difficult to achieve
Solution Approach 1:
The thinned region is prepared in advance on the electrode pillar, providing a dedicated welding surface that eliminates the need for large center holes. This preliminary action allows welding to proceed with standard positioning tolerances, improving both production efficiency and maintaining manufacturing precision
4Reliability
If the electrode pillar region size is increased to improve current-carrying capacity, then electrical performance improves, but the complexity of configuration increases due to accuracy requirements
Solution Approach 1:
The thinned region and welding portion are designed with predetermined dimensions and positions that simplify the overall configuration. This preliminary design approach allows for improved current-carrying capacity through optimized welding area while reducing configuration complexity by establishing clear manufacturing guidelines
Solution Approach 2:
The patent optimizes parameters such as the thinned region thickness (T1) and welding portion thickness (T2) to achieve the desired current-carrying capacity. By carefully controlling these parameters, the patent improves electrical performance while maintaining manageable configuration complexity
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 design improves production efficiency, reduces the risk of false welding or penetration, strengthens electrical connections, and increases the current-carrying capacity while ensuring safety and consistency in manufacturing.
Implementation Method 1
another one adopts laser welding (seam welding or penetration welding)
Implementation Method 2
When performing torque welding, it is required for a welding pin to be inserted from the center hole of an electrode sheet assembly
Data Source
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AI summary
Disclosed are a secondary battery (100) and an electrical device including the secondary battery (100). The secondary battery (100) includes: a housing (110), an electrode assembly (120), an electrode pillar (130) and a current collecting portion (140). The electrode assembly (120) is disposed in the housing (110) in a sealed manner; the electrode pillar (130) penetrates through the housing (110) in a sealed and insulating manner, and is disposed with a thinned region (131) with a thickness of T1; the current collecting portion (140) is disposed in the housing (110) and electrically connected with the electrode of the electrode assembly (120); a welding portion (141) with a thickness of T2 is disposed on the current collecting portion (140) and T2 is greater than 0.3T1; the thinned region (131) is in conductive contact with the welding portion (141) and is fixed through welding.