Advantages and disadvantages of 18650 battery spot welder machine

18650 battery spot welder machine is one of the necessary equipment in the assembly process of lithium ion battery pack. Here we will talk about the principle, advantages and disadvantages of battery spot welding machine.

Battery Spot welding machine is part of resistance welder. Resistance welding presses the workpiece to be welded between two electrodes and passes a current. Using the resistance heat generated by the current passing through the workpiece contact surface and the adjacent area, it is locally heated to melt into a plastic state, thereby forming a metal-bonded connection method.

Spot welding is a high-speed, economical connection method. It is suitable for the manufacture of thin plate members that can be lapped, joints do not require airtightness, and the thickness is less than 3mm. The spot welding requires metal to have good plasticity. Spot welding is widely used for welding 18650 lithium-ion battery packs. It is usually welded with pure nickel sheets or nickel-plated steel, with a thickness of 0.1~0.3mm.

Advantages of 18650 battery spot welding machine:

1. The spot welding process has a short heating time and concentrated heat, so the heat affected zone is small, and the corresponding deformation and stress are also small.

2. No welding rod or welding wire is required as filler metal; no welding consumables such as oxygen, argon and acetylene are required. Therefore, the welding cost of spot welding is very low.

3. The battery spot welding machine is very simple to operate, and it is easy to achieve mechanized and automated operation. Automatic battery spot welder machines are widely used and the technology is mature.

4. High production efficiency, low noise and no harmful gas.

Disadvantages of 18650 battery spot welder:

1. There is currently no reliable non-destructive testing method. The detection and evaluation of the welding quality of the lithium battery pack is usually achieved by detecting the various parameters of the finished product.

2. It is easy to form sharp corners at the connection part of the battery cell and the nickel sheet, so that the tensile strength and fatigue resistance of the connection part will be reduced.

In order to better ensure the welding effect, bumps are usually made on the nickel sheet. It is necessary to pre-form bumps of certain shape and size on the nickel sheet. The size of the current path area during the welding process depends on the bump size, not on the electrode end size.

 

Advantages of nickel sheet with bumps:

1. The welding current is concentrated at the bumps, and a smaller current can be used to weld nickel sheets of the same thickness, or the same current can be used to weld thicker nickel sheets. The welding effect is better.

2. The positions of the bumps are accurate and the size is consistent, and the welding strength of each point will be more uniform.

3. The electrode wear is smaller than conventional spot welding, which greatly reduces the repair and maintenance costs of the electrode.

Disadvantages of nickel sheet with bumps:

1. Nickel sheet needs to increase the bumping process, the cost is higher.

2. When welding multiple welding points at a time, the requirements for the 18650 battery spot welding machine are higher, requiring higher electrode pressure and higher mechanical accuracy.