Current Collecting Plate Of Cylindrical Cells Laser Welding Machine By Hanwei AMB

Current Collecting Plate of Cylindrical Cells Laser Welding Solution

The ​current collector disc​ in cylindrical batteries (e.g., 4680 specification) is a critical conductive component connecting the ​core tabs​ to the ​battery casing/cap​. It must simultaneously fulfill:

***1.​Low-resistance conduction.​

Ensure efficient current transfer from core tabs to battery terminals, minimizing electrical losses.
***2.​Structural support​.

Resist deformation during assembly (e.g., internal stress during casing insertion) and maintain ​welding zone planarity​.
***3.Thermal management​.

Reduce heat transfer to the ​separator​ during welding to prevent burn-through-induced short circuits.
***4.​Electrolyte infiltration​.

Accelerate electrolyte filling via ​through-holes​ or ​flow guide channels​, enhancing electrode wetting efficiency.

 
 

Principles, Characteristics, and Advantages of Cylindrical Current Collector Laser Welding Technology

1. Basic Principles​
Laser welding for cylindrical battery current collectors (e.g., 4680 cells) uses ​high-energy laser beams​ to melt and fuse the current collector disc with electrode tabs (foils). The core process involves:
***​Oscillating Welding Path: The laser beam moves along a preset path (e.g., sinusoidal or linear) while oscillating laterally at 120–300 Hz. This increases the welding area, reduces internal resistance, and minimizes heat concentration.
***Dynamic Power Compensation: Laser power is adjusted in real time based on distance from the central path. For example, power decreases by up to 45% (from 100% to 55%) at oscillation extremes to stabilize energy input and prevent burn-through.
***Shielding Gas Protection: Inert gases (e.g., argon) form a vortex barrier around the weld zone via tangential inlets, preventing oxidation and spatter.

​2. Key Technical Features​
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2.1 Thermal Management​
​Reduced Heat-Affected Zone (HAZ)​: Short-wavelength lasers (e.g., 450nm blue or 1,064nm infrared) minimize heat diffusion. For copper collectors (absorption rate <5% at 1,064nm), ​single-mode annular beam lasers​ achieve 65% absorption, lowering power requirements by 84% and preventing foil perforation
​Insulating Layers: Some designs integrate ​thermally conductive silicone​ beneath the collector to dissipate heat and isolate the separator

​2.2 High-Speed Welding​
***Turret Flying Welding: Rotating turrets combined with galvanometers enable dynamic "flight welding" at speeds >300mm/s. Self-developed algorithms (e.g., high-precision dynamic compensation) correct trajectory deviations during rotation, maintaining ±0.05mm accuracy at 100°/s
***Multi-Track Processing: Oscillation patterns (e.g., "sin wave") increase weld seam density without re-melting defects, cutting total welding time to 1.02s per collector

​2.3 Beam Control Innovations​
***​Single-Mode Annular Beams: These lasers feature independently adjustable ​core/ring beams​ (millisecond switching) for dual functions:

***Core beam: Deep penetration (depth-to-width ratio >1:10) for thick copper collectors.

***Ring beam: Preheating/surface treatment to reduce splatter
***​Power-Speed Synchronization: Algorithms like "4+1 motion-energy interpolation" synchronize laser power with velocity variations, especially at corners (R <5mm), eliminating voids or uneven seams

​2.4 Structural Optimization​
***​Louvered Collector Design: Collectors with ​through-holes​ allow electrode tabs to pass through and bend into an "L-shape" atop the disc. This positions the welding zone abovethe collector, reducing laser penetration depth by 60% and intercepting metal debris
***Reinforced Ribs: Radial or circular ribs resist deformation during casing insertion, maintaining weld-zone flatness