Laser welding in energy storage batteries

From the energy storage battery cell manufacturing to battery PACK into groups, welding technology is a very important manufacturing production process, lithium battery conductivity, strength, air tightness, metal fatigue and corrosion resistance, is typical of the battery for welding work quality management evaluation criteria.battery pilot line Welding research methods and welding construction process selection, will have a direct impact on the cost of the battery, quality, safety issues as well as improve the consistency of the battery.

In many welding methods, laser welding has the following advantages: First, laser welding energy density, welding deformation is small, small heat-affected zone, can effectively improve the welding accuracy of the parts, the weld is smooth and free of impurities, uniformity and density, do not need additional grinding process; Second, laser welding can be accurately controlled.

Secondly, laser welding can be accurately controlled, focused spot is small, high positioning accuracy, easy to automate with a robotic arm, improve the welding efficiency, reduce man-hours, reduce costs;laser welding machine for lithium ion batteries In addition, laser welding of thin plates or fine diameter wires will not be as easy as arc welding is plagued by reflux.

Welding methods for energy storage battery mainly include wave welding, ultrasonic welding, laser welding and dissimilar metal laser welding.

1. Welding methods for energy storage batteries.

Wave appear welding: essentially a combination of ultrasonic welding and laser welding;

Ultrasonic welding: the advantage of this program is that welding is simple,ESS lithium battery machine but need to take up more space, module volume group efficiency is low;.

Laser welding: this program is currently the most widely used, but the structure is slightly different;

Dissimilar metal laser welding: this welding group efficiency is also very high, fast production speed.

2. What is laser welding?

Laser welding is the use of high energy density laser beam as a heat source, through the optical system, the laser beam will be focused on a small area, so that in a very short period of time in the welding part of the formation of a highly concentrated energy heat source area, so that the object to be welded to melt, the formation of a solid weld or weld seam.

Laser welding is a new type of welding work, currently in a high-speed economic development stage. The use of different laser welding, the heat affected zone of the workpiece is small; welding point is small, welding size precision; its welding method is a non-contact welding, without the need to add external force, the product deformation is small, high welding quality, high efficiency, easy to realize the automation control production.

The structure of the battery is usually composed of a variety of materials, such as steel, aluminum, copper, nickel and so on. These metals can be made into electrodes, wires or shells, which puts higher requirements on the welding process.

The technical advantage of laser welding lies in the wide variety of materials that can be welded and the possibility of welding between different materials.

3. Types of laser welding

Types of laser welding include laser heat conduction welding and laser deep fusion welding. The main difference between heat conduction welding and deep fusion welding is that the power density applied to the metal surface per unit of time is different, and the critical value is different for different metals.

Energy storage battery is a whole composed of battery storage equipment (from individual components to battery pack modules to battery cabinets to battery storage units to battery storage equipment), PCS and filtering links.

In the field of laser welding technology for energy storage batteries, the lasers that we use most of the time today are pulsed lasers, continuous lasers, and quasi-continuous lasers.

For these lasers, you can think of it like this: hammering a peg in with a hammer, which is a pulse; pushing a peg in by hand, which is continuous; drilling a hole, drilling for 10 seconds, taking a break for one second, and then drilling continuously for 10 seconds, and then taking a break for one second, which is called quasi-continuous.

4. Welding advantages of laser welding equipment in energy storage battery

The welding process is non-contact welding, the internal stress of the welding rod is minimized.

Welding process does not produce other welding tumor and other released substances, preventing secondary pollution;

Welding has high strength and airtightness to meet functional needs;

Laser welding can meet the welding between different materials, also can realize the thin film material, also can realize the connection technology between different materials;.

Laser welding facilitates automation integration and also enables synchronized laser welding process solutions with high efficiency and low welding internal stress according to capacity requirements;

The laser welding structure of the present invention is simple and convenient, reducing the difficulty factor of the mold structure;

The welding process can realize digital intelligent monitoring, to meet the demand for digital visualization of the welding process;

The type of welding technology process design solutions, can be effectively integrated with automated production lines, to meet the needs of mass production programs, to achieve efficient production, low consumption and other characteristics.