Power of Cylindrical Lithium Battery Laser Welding Machine

Introduction

Lithium-ion batteries have emerged as the powerhouse for a multitude of electronic devices, fueling everything from smartphones to electric vehicles. Among the diverse array of lithium-ion batteries, the cylindrical variant stands out as a popular choice, distinguished by its unique design and performance capabilities. In this article, we delve into the realm of cylindrical lithium-ion batteries, delving into their characteristics, applications, and the advantages and disadvantages associated with this particular form factor.

You will get efficient and thoughtful service from HUIYAO.

Structure and Components of Cylindrical Lithium Batteries:

Generally, these batteries comprise an anode, cathode, separator, electrolyte, and a cylindrical metal casing. The electrode materials can vary, with commonly used options including lithium cobalt oxide (LiCoO2) for the cathode and graphite for the anode.

Advantages of Cylindrical Lithium-ion Batteries:

 - Efficient Use of Space: The cylindrical shape allows for a compact and efficient use of space, making them suitable for devices with limited room for battery placement.

 - Cost-Effective Production: Mass production of cylindrical batteries is often cost-effective, contributing to their widespread use in consumer electronics.

The Technology Behind Cylindrical Lithium Battery Laser Welding Machine

At the heart of these cutting-edge machines lies advanced laser welding technology. By harnessing the power of high-intensity laser beams, these machines can precisely fuse together the components of cylindrical lithium batteries, ensuring seamless connections and optimal performance.

Applications:

Cylindrical lithium-ion batteries find applications in a wide range of devices, including but not limited to:

 - Smartphones

 - Power tools

 - Laptops

 - Electric bicycles

 - Electric vehicles (EVs)

The Technology Behind Cylindrical Lithium Battery Laser Welding Machine

As technology advances, ongoing research aims to address the limitations of cylindrical lithium-ion batteries. Innovations in materials and manufacturing processes may contribute to enhanced performance, increased safety, and wider applications.

At the heart of these cutting-edge machines lies advanced laser welding technology. By harnessing the power of high-intensity laser beams, these machines can precisely fuse together the components of cylindrical lithium batteries, ensuring seamless connections and optimal performance.

Key Features and Benefits

Precision Welding

Cylindrical lithium battery laser welding machines boast remarkable precision, allowing for intricate welding patterns with micron-level accuracy. This level of precision ensures the integrity and longevity of the battery connections, minimizing the risk of defects or malfunctions.

Efficiency and Speed

With rapid welding speeds and efficient processing capabilities, these machines significantly reduce production time and costs. Manufacturers can streamline their operations and meet growing demands without compromising on quality or performance.

Versatility

From small-scale prototypes to large-scale production runs, cylindrical lithium battery laser welding machines offer unmatched versatility. They can accommodate various battery sizes and configurations, making them ideal for a wide range of applications across industries.

Quality Assurance

With stringent quality control measures and real-time monitoring capabilities, these machines uphold the highest standards of quality assurance. Manufacturers can rest assured knowing that each welded joint meets rigorous quality criteria, ensuring the reliability and safety of the batteries.

Applications

Electric Vehicles

The automotive industry relies heavily on cylindrical lithium batteries for electric vehicles (EVs). Cylindrical lithium battery laser welding machines play a crucial role in manufacturing high-performance battery packs for EVs, enabling sustainable transportation solutions.

Consumer Electronics

From smartphones to laptops, consumer electronics increasingly utilize cylindrical lithium batteries for their compact size and high energy density. These machines facilitate the production of reliable battery packs that power our everyday devices.

Energy Storage Systems

As renewable energy sources gain prominence, the demand for energy storage systems continues to rise. Cylindrical lithium battery laser welding machines enable the efficient assembly of battery packs for solar energy storage and grid stabilization applications.

Conclusion

Growing EV battery market demands better joining solutions: Wobble laser Welding is the best

Laser Beam Welded Joints for Lithium-Ion Batteries

The growing electrification of vehicles and tools increases the demand for low resistance contacts. Today’s batteries for electric vehicles consist of large quantities of single battery cells to reach the desired nominal voltage and energy. Each single cell needs a contacting of its cell terminals, which raises the necessity of an automated contacting process with low joint resistances to reduce the energy loss in the cell transitions. A capable joining process suitable for highly electrically conductive materials like copper or aluminium is the laser beam welding.

Related links:
How to reduce your packaging spend when prices are going up
What is the Advantage and Disadvantage of Powder Coating Reciprocator
5 Reasons Why Your Business Needs dual hydraulic cylinder？

If you want to learn more, please visit our website Laser Welder for Prismatic Rechargeable Li-ion Battery.

Over the past years, the demand for large battery packs for electric vehicles (EV) has steadily increased with the ongoing electrification of the transportation sector and a growing demand for greater ranges. State of the art EV battery packs consist of a large quantity of cells connected in series to achieve the desired voltage level and in parallel in order to enable higher charge- and discharge-currents.
For example, the EV Tesla Model S comprises of total count of over type 18,650 battery cells inside its battery pack. A single defective connection can lead to failure or a reduction in performance.
The quality of the joint has a decisive influence on the sustainability and safety of electric vehicles:  Increased resistance at a welded joint causes more heat loss at this spot and leads to an increased electrical and thermal load on the individual cells, which in turn can lead to failure or accelerated aging.

Laser beam welding is a promising technology to contact battery cells enabling automated, fast and precise production of conductive joints. In comparison to other conventional welding techniques, such as resistance spot welding, the laser beam welding has a reduced thermal energy input. Compared to ultrasonic welding, the laser beam welding technique does not induce a mechanical force. The resulting transition resistances are in the range of the basic material resistances. The overall performance of the battery pack is therefore improved by the reduction of the ohmic resistance of the joints and heat loss inside the battery cell.

High currents must flow through the welds between battery cells in order to deliver the electricity needed to power a battery electric vehicle. These welds are the bottleneck of the electric circuit. Electrical resistance causes the temperature in the welds to raise when a current is conducted. This temperature increase may be harmful to lithium-ion battery cells. Therefore, larger weld areas which are created with our wobble laser system, and thus lower resistance.  Thewelds made by wobble welding system increase the mechanical strength of the welds drastic, and reduce the temperature and thermal stress at the joints. Considering this, Wobble Laser Welding is much more suitable for battery tab joining than other types of welding.

Furthermore, laser beam welding produces a small heat-affected zone. Hence, it is crucial to understand how much heat is generated in the weld and whether the heat can damage the battery. Lithium-ion batteries must operate within a safe and reliable operating area, which is restricted by temperature and voltage windows. Exceeding the restrictions of these windows will lead to rapid attenuation of battery performance and even result in safety problems.

In the context of production, laser beam welding is well suited to be integrated into almost fully automated production lines in the manufacturing process of battery packs and EVs. 

Using Lasers for Battery Tab Welding Applications

Battery Tabs Welding with laser

From a welding perspective, the most important aspects of tab welding are the thickness and material of both the tab and the terminal. Conductivity is the name of the game, so battery tabs are generally made of aluminum or copper, sometimes plated with nickel or tin. Terminals may be cold rolled steel, aluminum, or copper, depending upon the physical size of the finished battery.

The most common battery types are cylindrical lithium ion cells around the size (18 mm x 65 mm), large prismatic cells, and lithium polymer pouch cells. Each cell type has a different set of welding requirements.

Cylindrical batteries

The key to welding the cylindrical cell type lies in the negative terminal weld, where the battery tab is welded directly to the can as opposed to the separate platform on the positive side. The weld on the negative terminal must not penetrate the can thickness which is typically around 0.3mm. The thickness of the can dictates how thick the tab can be – a rule of thumb is that the tab should be 50-60 % that of the can. Cylindrical battery can material is usually nickel-plated steel, and the tab material nickel or tin-coated copper. Nickel plating is preferred over tin because it is more stable; tin’s very low boiling point can lead to weld porosity and excessive spatter.

Large prismatic batteries

These high capacity cells need thick tabs to ensure a sufficient current carrying cross-section to deliver the pack output. However, the tab connection needs only to deal with the capacity of a single cell. Therefore, thinning or “coining” of the thick tab material to enable a lap weld or creating a through hole for a fillet weld greatly reduces the size of the weld needed. This in turn reduces heat input to the can, which is always a concern when welding thicker tabs.

For a lap weld geometry, reducing the tab thickness to a 0.25-0.5 mm thickness enables sufficient weld area for strength and capacity while keeping the temperature during the weld low enough to avoid battery damage. Material selection is generally aluminum for both terminal and tab – recommended tab materials are and .  Avoid aluminum alloy , which cracks when welded. If this material is already specified and cannot be changed, use a pre-form as a third material which will introduce a large amount of silicon into the weld, which prevents weld cracking.

Lithium polymer batteries

These pouch type cells, which are thin with a rectangular footprint, are really gaining traction for consumer electronics. The terminals on these batteries are made up of thin layers of copper and aluminum foil which are laser welded to tab of copper and aluminum respectively. This weld is traditionally made using ultrasonic technology due to the need to weld through a stack of foil, however, fiber laser welders are now being used for increased weld quality and strength.

The key to success in welding polymer batteries with a fiber laser is making sure that the foils are in close contact and you’re using a pulsed laser or even better a wobbling laser to avoid overheating.

Welding battery Tabs to battery Terminals

From a welding perspective, the important aspects of tab welding are the thickness and material of both the tab and the terminal.

Resistance welding is suited to welding nickel tab material up to 0.4 mm thickness, and nickel or steel clad copper tab material to around 0.3 mm thickness to a wide variety of terminal materials.

Laser welding is able to weld both thin and thick tab materials, with a capability of welding copper based or bi-metal tab material above and beyond 1.5 mm thickness

Although able to weld both thin and thick tab materials, laser welding is particularly well suited to addressing the needs of high power battery welding. The tab material used in the development of high power cells must be able to accommodate the associated higher capacities and power levels. In order to provide effcient energy transfer, a tab thickness of minimum 0.3 mm or greater is required, as is the use of more conductive materials. For high power lithium ion cells, the terminal material for certain battery manufacturers is different. Therefore the need for bi-metal and smart terminal design solutions is required. Defining the optimal tab material may require some development work both on the welding and material costing. In these cases, the laser is an invaluable tool that offers outstanding welding performance and flexibility.

Battery Pack Manufacturing Solutions

When planning an automated or semi automated solution based on our Wobble cube, the primary factors to consider are loading/unloading, motion and tooling that fit the planned production flow and production rate.
Loading and unloading can range from manual to conveyer or pick-and-place, motion options center around whether the laser head or the part will be moved, with options including XYZ tables and gantry’s or robotic manipulators. For tooling, the laser is non contact, so tooling of the parts can be achieved either by using a fixture that the batteries and tabs are loaded into, or using actuated tooling that is deployed prior to the welding process.
The most suitable technology and process for battery pack manufacture relates to a number of factors including the pack size, thickness and material of the tab itself, and the necessary production rate.  Laser welding processes enable high quality volume production, and, of the two joining technologies today used, spot welding and laser welding, the selection is usually made based on the specific requirements in each situation, but laser welding is taking over very fast from the spot welding, especially with the excelent wobble laser welding technology.

High efficiency lithium battery tabs laser welding machine

1. Welding of battery explosion-proof valve

The explosion-proof valve of the battery is a thin-walled valve body on the battery sealing plate. When the internal pressure of the battery exceeds the specified value, the valve body of the explosion-proof valve ruptures to prevent the battery from bursting. The safety valve has an ingenious structure, and this process requires extremely strict laser welding technology. Continuous laser welding can achieve high-speed and high-quality welding, and welding stability, welding efficiency and yield can be guaranteed.

2. Welding of battery tabs

The tabs are usually divided into three materials. The positive electrode of the battery uses aluminum material, and the negative electrode uses nickel material or copper nickel-plated material. In the manufacturing process of power batteries, one of the steps is to weld the battery tabs and poles together. In the production of the secondary battery, it needs to be welded with another aluminum safety valve. Welding must not only ensure the reliable connection between the tab and the pole, but also requires a smooth and beautiful weld.

3. Spot welding of battery poles

The materials used for the battery poles include pure aluminum tape, nickel tape, aluminum-nickel composite tape, and a small amount of copper tape. The welding of battery electrode strips generally uses pulse welding machines. Due to its good beam quality and small welding spot, Modulated CW lasers or QCW quasi-continuous lasers are suitable for high reflectivity aluminum strips, copper strips and narrow-band battery strips (polar strip width (Under 1.5mm) welding has unique advantages.

4. The power battery shell and the cover plate are sealed and welded

The shell materials of the power battery are aluminum alloy and stainless steel (stainless and acid-resistant steel). Among them, aluminum alloy is mostly used, generally aluminum alloy, and a few use pure aluminum. Stainless steel is a laser weldable material, especially 304 stainless steel, whether it is pulsed or continuous laser, it can obtain welds with good appearance and performance.

5. Power battery module and pack welding

The series and parallel connections between power batteries are generally completed by welding the connecting piece and the single battery. The positive and negative electrodes are made of different materials. Generally, there are two kinds of materials: copper and aluminum. Ultrasonic welding was usually used before, but its being replaced by laserwelding due to the regulary mechanical damage in the battery resulting from the ultrasonic vibrations. Copper and copper, aluminum and aluminum are generally used. Using laser welding. Both copper and aluminum conduct heat very quickly and have a very high reflectivity to the laser. The relatively large thickness of the connecting piece requires a higher power laser welding.