Secondary Battery Pillar Welding Structure for Shaving-Free Joining
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Solution Overview
Problem
Existing methods for welding the electrode pillar and current collecting portion of secondary batteries face challenges such as low production efficiency, high positioning accuracy requirements, damage to the electrode sheet assembly, safety issues due to metal shavings, limited current-carrying capacity, and difficulty in detecting the welding quality.
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 by controlling the thicknesses of these regions.
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 production efficiency is low and the electrode sheet assembly is often damaged due to high positioning accuracy requirements
Solution Approach 1:
The invention divides the welding process into two separate stages: first welding the electrode pillar to the current collecting portion through the center hole, then removing the center hole and welding the current collecting portion to the housing. This segmentation allows each welding operation to be optimized independently, improving both reliability and productivity.
Solution Approach 2:
The center hole is removed after the first welding operation but before the second welding operation. This preliminary action of removing the center hole enables the second welding to be performed with better access and positioning, improving welding quality and efficiency without compromising the already-established electrical connection.
2Reliability
If torque welding is performed through the center hole, then electrical connection is achieved, but metal shavings remain inside the secondary battery causing safety issues
Solution Approach 1:
The center hole is extracted (removed) after the first welding operation. This removal eliminates the confined space where metal shavings would accumulate during welding, allowing shavings to be easily removed and preventing them from remaining inside the battery, thus resolving the safety issue while maintaining electrical connection reliability.
3Ease of manufacture
If seam welding method is used among laser welding methods, then welding can be performed, but the size of electrode pillar region is small limiting strength and current-carrying capacity
Solution Approach 1:
The invention transitions from two-dimensional seam welding on the surface to three-dimensional penetration welding through the electrode pillar. By welding through the entire thickness of the electrode pillar, the connection strength and current-carrying capacity are significantly enhanced compared to surface-level seam welding.
4Reliability
If the pillar integrated on the current collecting portion passes through the through hole of the electrode pillar, then connection is achieved, but the required accuracy is influenced by electrode assembly entering housing causing difficulties in configuration
Solution Approach 1:
The configuration process is segmented into distinct steps: first inserting the electrode assembly, then removing the center hole, and finally performing the second welding. This segmentation simplifies each individual step and reduces the overall configuration complexity compared to attempting to complete all operations in one complex sequence.
5Reliability
If torque welding is performed, then electrical connection is achieved, but there is no effective way to separate and suck out metal shavings generated during welding
Solution Approach 1:
The center hole is removed preliminarily before the second welding operation. This creates an open pathway that enables metal shavings to be easily separated and removed from the welding area, preventing accumulation and safety issues while maintaining reliable electrical connection.
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 safety risks, enhances the electrical connection strength and current-carrying capacity, and facilitates detection and identification of the welding process, ensuring consistent manufacturing and reliable electrical energy supply.
Implementation Method 1
the welding method is laser welding or resistance welding
Implementation Method 2
the welding method is laser welding or resistance welding
Data Source
AI summary
Disclosed are a secondary battery and an electrical device including the secondary battery to solve the problem of welding between the electrode pillar and the current collecting portion of the existing secondary battery. The secondary battery includes: a housing, an electrode assembly, an electrode pillar and a current collecting portion. The electrode assembly is disposed in the housing in a sealed manner; the electrode pillar penetrates through the housing in a sealed and insulating manner, and is disposed with a thinned region with a thickness of T1; the current collecting portion is disposed in the housing and electrically connected with the electrode of the electrode assembly; a welding portion with a thickness of T2 is disposed on the current collecting portion and T2 is greater than 0.3T1; the thinned region is in conductive contact with the welding portion and is fixed through welding.