What is the process in the manufacturing of lithium battery pack?-xmacey.com

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What is the process in the manufacturing of lithium battery pack?

August 02 , 2023

What is the process in the manufacturing of lithium battery pack?

1. Paste barley paper on the positive electrode of the battery cell

Lithium batteries have high energy density and are widely used, but the production cost of lithium batteries is not low, so improving the yield rate of products is an effective means to reduce the production cost of batteries. In the production process of lithium batteries, multiple processes can be added to improve the yield of products. Among them, insulating paper is pasted on the electrodes between the positive and negative electrodes of the lithium battery, which can effectively reduce the welding head when the electrodes are welded to the battery tabs. The internal short circuit of the battery caused by wrong welding together.

There are two main ways to stick barley paper:

Method 1: Manual stickers

Method 2: Fully automatic sticking barley paper machine: Manually put the battery cells into the upper hopper - the wave wheel turns the battery out - the belt moves the battery cells - the cylinder pushes out the battery cells to form a team - the battery is positioned and pressed - stepping the battery Drive the whole roll of highland barley paper to move—stick the highland barley paper on the cylinder—waste recycling—finished batteries to the feeding chute—manual boxing (operating parameters can be set freely according to the actual requirements of customers).

2. Cell sorting and grouping

The sorting of batteries is to pursue the consistency of batteries (capacity, voltage, internal resistance), and the consistency difference of batteries, just like mixing old and new batteries. Batteries with large differences, in addition to dragging down normal batteries, are also the weak points of the entire battery pack. Overcharge, overdischarge, and heat all start from them.

Battery automatic sorting machine: put the battery into the silo—the test wheel runs to the test position—test the cylinder action—the test needle presses the battery—the tester reads the data—transmits to the computer—computer Carry out gear matching—the batteries are transferred to the sorting belt——the sorting belt runs to the designated gear——the gear cylinder acts to push out the batteries.

3. Battery pack welding

Method 1: Manual welding

Gantry spot welding machine: power on - check whether the WELED switch is on - place the product to be welded on the table - step on the pedal - press down the welding head - complete spot welding - return the welding head

Method 2: Fully automatic spot welding machine:

Double-sided automatic spot welding machine: the battery cell/bracket/battery nickel sheet is loaded into the jig - place the jig to the sensing position - the equipment is automatically spot-welded and sent to the pick-up position (choose the discharge method: forward, out, Forward and backward) - remove the battery pack from the jig - proceed to the next production cycle

Single-sided automatic spot welding machine: battery cells/brackets/battery nickel sheets are loaded into jigs—place the jigs to the sensing position on the left platform——the equipment is automatically spot welded and sent to the pick-up position—manually flip the jigs— Place the jig to the sensing position on the right platform—the equipment is automatically spot-welded and sent to the pick-up position—take out the battery pack from the jig—start the next production cycle (when the left platform is working, there is a platform to put the product in, wait for the left After the welding of the platform is completed, it will automatically transfer to the right platform for welding. When welding the right platform, the left platform can replace the product, wait for the right platform to be welded, it will automatically transfer to the left platform for welding, and cycle in turn).

battery spot welding machine

4. Welding of battery pack protection board

Method 1: Manual welding

Method 2: Fully automatic single-sided protective plate spot welding machine: place the welded battery pack in the protective plate fixture - place the protective plate on the battery pack - close the fixture - put the installed BMS fixture into the BMS point On the welding machine platform - start welding the protective plate.

5. Semi-finished product insulation

Necessary fixation and insulation should be carried out on the voltage acquisition line, wires, and positive and negative output lines. The auxiliary materials are usually high-temperature adhesive tape, highland barley paper, epoxy board, cable ties, etc. Safety awareness is required, and do not superimpose pressure on the battery pack voltage acquisition line or output wire, which may easily lead to extrusion damage and short circuit.

6. Semi-finished product test

After the battery pack is added with BMS, a semi-finished product test can be carried out. The routine tests include: simple charge and discharge test, the whole group internal resistance test, the whole group capacity test, the whole group overcharge test, the whole group over discharge test, short circuit test, overcurrent test. If there are special requirements, high temperature and low temperature tests, acupuncture tests, drop tests, salt spray tests, etc. are required. Special lithium battery pack tests are destructive and random inspection is recommended.

It is necessary to pay attention to the bearing capacity of the battery pack, such as whether the BMS can withstand high voltage during the overcharge test of the entire group; whether the BMS can withstand instantaneous high voltage and high current during the short circuit test; whether the BMS can withstand pulse current during the overcurrent test, etc.

7. Lithium battery pack packaging

This step also needs to look at the design. But before packaging, the signal acquisition line and the insulation of the positive and negative poles of the battery pack must be done.

PVC-packed battery pack, overheated shrink machine. Ultrasound-sealed battery pack, put on the ultrasound machine. Battery pack with metal case, case assembled. During this process, care should be taken to handle the battery pack with care, avoiding collisions, extrusion, etc. Wires should be well insulated to avoid short circuits.

8. Whole group aging test

The battery pack life cycle tester is a charge/discharge cycle aging test for battery packs with analog motor to calculate the capacity and the number of charge/discharge or working life of the battery pack. The test items include: battery charge protection voltage, discharge protection voltage, capacity, etc.

Battery pack life cycle tester

Acey new energy is a professional supplier specialized in Lithium Battery Pack Assembly Machine, such as battery capacity grading machine, battery insalution paper sticking machine, battery sorting machine, BMS tester, battery spot welding machine, laser welding machine, ultrasonic aluminum wire bonding machine, battery comprehensive tester, battery pack charge and discharge aging tester, etc and we provide one-stop solution for cylindrical battery pack assembly line. If any interested, please feel free to contact us.

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