Semi-Automatic Square Winding Machine for Soft pack lithium battery production

Semi-automatic square winding machine is a kind of equipment that can be applied to square battery winding process. The equipment is designed to load the diaphragm coil, load the electrode piece, manually place the piece, automatically pull the diaphragm, insert the needle and wind. The winding needle adopts a trapezoidal plug-in combination design, which can adjust the width of the wound battery cell within a certain range.

Main features

> Plug-in trapezoidal winding needle, one side automatically retracts, the other side can be pulled out, and the winding speed can be set;

> Design of winding cell size compatibility, length within 30-100mm can be achieved by adjusting the fixture, and the winding needle can be adjusted within 10mm of width change, and the winding needle must be replaced if it exceeds;

> PLC control, touch screen operation, all parameters can be set, and the fully automatic cycle stepping function is designed, which can be retracted step by step;

> Optional automatic tape machine to assist in tape application;

> Single plate structure, which can be applied to square lithium-ion battery winding process;

> Isolation film coil feeding, passive tension control, adjustable tension;

> Sheet electrode piece feeding, guide plate correction, manual feeding of winding needle, vacuum-assisted sheet suction during winding process.

Purchase information

If you are interested in our winding machine, please contact us for more information.

• Tel：138 3857 9492

• Email：carol@cysitech.com

• Contact：Carol Xu

• Wechat：15290599353

• WhatsApp/Skype: 13838579492

Technical parameters

Case: Application of semi-automatic square battery winding machine in the production of electric vehicle power batteries

Background and demand

A battery manufacturing company focuses on the production of power battery packs for electric vehicles (EVs). With the rapid growth of the electric vehicle market, the company's order volume has increased significantly, and the existing production capacity can no longer meet the demand. In order to improve production efficiency and product consistency, while reducing the error rate of manual operation, the company decided to introduce a semi-automatic square battery winding machine.

The company mainly produces square batteries with a specification of 32700 (32mm wide and 70mm long), which are used in power battery packs for electric vehicles. To ensure the stability and efficiency of the battery, the accuracy of the winding process is crucial, so it is necessary to introduce semi-automatic equipment to ensure higher consistency and efficiency.

Equipment selection

The semi-automatic square battery winding machine selected by the company has the following features:

Semi-automatic operation: The operator only needs to place the electrode material and the diaphragm material on the winding machine, and the winding machine will automatically control the winding speed, tension and material ratio to reduce the impact of manual operation on product consistency.

Precise tension control: The equipment uses an advanced tension control system to ensure uniform tension of each layer of electrode material and diaphragm material, avoiding problems such as uneven winding or bubbles.

Multifunctional adaptability: It supports winding of different battery specifications (such as 32700, 33120, etc.), and is suitable for a variety of electrode materials (such as lithium nickel cobalt manganese oxide, lithium iron phosphate, etc.).

Automatic cutting function: After winding, the equipment automatically cuts excess electrode materials and diaphragms to ensure the flatness of both ends of the battery core and avoid material waste.

Process flow

1. Raw material preparation

Preparation of positive and negative electrode materials: The company selected lithium nickel cobalt manganese oxide (NCM) as the positive electrode material and graphite as the negative electrode material. The positive and negative electrode materials are first coated on aluminum foil and copper foil through a coating process, and then dried and cut to prepare the electrode sheets required for winding.

Preparation of diaphragm materials: The diaphragm uses polyolefin materials (such as PE or PP), which have good ionic conductivity and mechanical strength. The diaphragm needs to be cut to a suitable size during the production process to meet the winding requirements of square batteries.

2. Semi-automatic winding process

Loading materials: The operator places the cut positive and negative electrode sheets and diaphragm materials in turn to the feed end of the winder. The positive and negative electrode materials need to be placed in the order of the battery design to ensure that the diaphragm between the positive and negative electrodes is properly separated.

Automatic winding: After the winder is started, the equipment automatically winds according to the preset parameters. The machine automatically adjusts the winding tension, winding speed and material stacking method to ensure that each layer of electrode and diaphragm material is wound consistently to avoid bubbles, wrinkles or interlayer misalignment.

Tension control: Through the tension control system of the equipment, each layer of electrode material and diaphragm material will be tightened and wound together evenly to ensure the stability of the core.

Winding speed adjustment: According to the characteristics of the material, the winder automatically adjusts the winding speed to ensure the stability of the core quality. Too fast speed may cause the material to break or uneven winding, while too slow speed will reduce production efficiency.

3. Processing after winding

Automatic cutting: After winding, the winder automatically cuts off excess electrode material and diaphragm. The ends of the cut battery core are neat, which is convenient for subsequent assembly and packaging.

Quality inspection: After winding is completed, the operator checks each battery core to ensure the consistency of the winding process. If any defects (such as bubbles, wrinkles, etc.) are found, they will be repaired immediately.

Battery core testing: After the battery core is completed, basic electrical performance tests such as internal resistance and voltage will be carried out to ensure that the battery core meets the design requirements.

4. Subsequent processing and packaging

The battery core after the test will be further packaged and installed in the battery shell for final charging, discharging and safety performance tests. Ensure the safety and stability of the battery in electric vehicles.

Challenges and solutions

Uneven winding problem: In the initial testing, it was found that the electrode material in the winding process sometimes appeared uneven, affecting the battery performance. The company solved this problem by adjusting the tension system of the winder and optimizing the material ratio.

Bubble problem: Because the material of the battery core is thin and very sensitive, bubbles are prone to appear during the winding process. To solve this problem, the operator optimized the tension of the diaphragm and the laying method of the electrode material during the winding process, and added more stringent quality inspection links.

Experimental results and achievements

Production efficiency improvement: After the introduction of the semi-automatic square battery winding machine, the production efficiency has been significantly improved. Compared with the traditional manual winding, the production speed has increased by about 40%, and the hourly production volume has been significantly improved.

Battery performance consistency improvement: Due to the introduction of the automatic control system, the winding accuracy of the battery core has been greatly improved, the internal resistance and capacity stability of the battery have been enhanced, and the overall performance of the battery pack has been more consistent.

Labor cost reduction: Through the semi-automatic operation of the equipment, the manual participation links are reduced, the dependence on highly skilled workers is reduced, the occurrence of human errors is reduced, and the production cost is optimized.

Summary

The company has successfully improved the production efficiency and quality consistency of electric vehicle power batteries by introducing a semi-automatic square battery winding machine. In battery production, automated winding can significantly reduce manual operation errors, improve battery consistency and stability, and thus ensure the performance and safety of electric vehicle power battery packs. In addition, as the production volume grows, the company plans to further improve the level of automation to meet higher production needs and technical requirements.