Battery Terminal Laser Welding With Helical Penetration Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The existing methods of welding battery terminals and current collectors using laser penetration from one side face the interior of the battery, leading to potential foreign matter generation and safety issues due to challenges in controlling uniformity and stability, resulting in false welding and burn-through.
Innovation Solution
A method involving laser penetration welding from the outer side of the terminal, using a helical trajectory to form a weld mark that extends from the terminal's surface to inside the current collector, with optional liquid injection holes and controlled laser parameters to ensure uniform penetration and stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If laser penetration welding is applied from the outer side of the terminal, then welding strength and safety are improved, but control difficulty increases leading to false welding and burn-through
Solution Approach 1:
The patent applies a helical trajectory for laser spot movement instead of a straight line, creating a curved welding path that improves molten pool stability and prevents burn-through while maintaining welding strength
Solution Approach 2:
The laser spot moves in a periodic helical pattern with controlled rotation, creating rhythmic heating that stabilizes the molten pool and prevents false welding while ensuring consistent penetration depth
2Reliability
If conventional welding is used from one side, then assembly is simple, but foreign matter enters the battery interior affecting safety
Solution Approach 1:
The patent welds from the outer side of the terminal rather than from the interior side, inverting the welding direction to prevent foreign matter from entering the battery interior while maintaining welding effectiveness
Solution Approach 2:
The patent transitions from linear welding to helical welding by adding a rotational dimension, creating a three-dimensional welding path that improves safety while managing process complexity
3Productivity
If laser penetration welding is used, then assembly efficiency is improved, but penetration depth uniformity becomes difficult to maintain
Solution Approach 1:
The helical trajectory distributes heating more evenly across the welding zone compared to linear motion, maintaining consistent penetration depth while preserving high assembly efficiency
Solution Approach 2:
The continuous helical motion of the laser spot ensures uninterrupted heating and welding, maintaining both high productivity and uniform penetration depth through sustained controlled action
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 enhances welding strength and reduces the risk of foreign matter generation, improving safety and assembly efficiency by ensuring consistent penetration depth and preventing liquid leakage, thereby enhancing the battery's performance and reliability.
Implementation Method 1
Irradiating a laser spot on the wall portion, and moving the laser spot along a helical trajectory, welding the wall portion and the current collector to form a weld mark
Data Source
Figure 1
Figure 2
Figure 3
AI summary
Disclosed are an assembly method for a secondary battery (1), a secondary battery (1), a battery pack (8) and an electronic device (9). The assembly method for the secondary battery (1) includes the following steps: an assembly step, assembling a current collector (30) and a terminal (40), so that a wall portion (405) of the terminal (40) abuts against the current collector (30); a welding step, irradiating a laser spot on the wall portion (405), and moving the laser spot along a helical trajectory, welding the wall portion (405) and the current collector (30) to form a weld mark (60), wherein, on a cross-section passing through a terminal axis, the weld mark (60) extends from a first end (60a) located on a surface of the wall portion (405) facing away from the current collector (30) to a second end (60b) located inside the current collector (30).