1. Overview of Battery Coating Machine

(1) What is a battery coating machine

The battery coating machine, also known as the lithium battery coating machine, is a kind of mechanical equipment specifically used for the production of lithium-ion battery electrode sheets. It evenly coats the slurry on substrates such as aluminum foil or copper foil through a specific coating process. After drying and curing treatment, it is made into positive and negative electrode sheets. The coating process is a core link in the production of lithium batteries, and its quality is directly related to the consistency, safety and life cycle of the batteries.

(2) Working principle

The working principle of the battery coating machine is based on the precise control of the flow rate, speed and thickness of the coating solution to achieve stable and uniform electrode coating. Specifically, the slurry is evenly coated on the moving substrate through a pumping system or a scraper device. After the coating, the electrode sheet undergoes drying and curing treatment to remove the solvent in the slurry and ensure that the active material adheres firmly to the substrate. This equipment can automatically complete the coating process of electrode materials, significantly improving production efficiency and reducing production costs.

2. The function of the battery coating machine

（1） Precise coating: Control the coating thickness (error ±1%-2%) and uniformity to ensure electrode consistency and avoid local overcharging and overdischarging.

（2）Performance optimization: Enhance energy density (through high loading), extend cycle life (reduce material shedding), and lower short-circuit risk (eliminate coating defects).

（3）Production adaptability: Supports roll-to-roll automated production, with a coating speed of up to tens of meters per minute, suitable for various scenarios such as power batteries (thick-layer coating) and consumer batteries (thin-layer high-precision coating).

（4）Cost reduction and efficiency improvement: Reduce slurry waste through high-precision processes, lower pollution and costs by integrating solvent recovery systems, and promote technological iteration by being compatible with new materials (such as silicon-based anodes and solid electrolytes).

3. Main types of battery coating machines

(1)Transfer coating machine

The transfer coater drives the slurry by the rotation of the coating roller. The amount of slurry transfer is adjusted through the gap of the comma scraper, and the slurry is transferred to the substrate by the rotation of the back roller and the coating roller. This coating method has low requirements for the viscosity of the slurry and is easy to adjust the coating parameters. However, it has problems such as the slurry being completely exposed to the air and the material at the scraper opening easily absorbing and caking to form particles, which makes it impossible to guarantee the consistency of the coating.

(2) Extrusion coating machine

As a precise wet coating technology, the extrusion coating machine uses a specially designed extrusion die head to extrude the slurry along the slit and coat it onto the moving foil. The uniformity and thickness are adjusted through the cavity structure of the extrusion die head and the width of the slit. It has the advantages of fast coating speed, high precision, uniform wet thickness, etc. The coating system is closed, which can prevent contaminants from entering during the coating process. The slurry utilization rate is high, the slurry properties can be maintained stable, multi-layer coating can be carried out simultaneously, and it can adapt to different slurry viscosities and solid content ranges. Compared with the transfer coating process, it has stronger adaptability.

4. Key points for selecting a battery coating machine

(1)Coating accuracy and uniformity

Coating accuracy and uniformity are the key factors affecting battery performance. High-precision coating machines can achieve consistent and uniform electrode coating, ensuring the stability and reliability of product quality. When choosing a coating machine, it is necessary to pay attention to whether it is equipped with an automatic thickness adjustment system, which can adjust the coating thickness in real time according to the requirements of the battery electrode sheet to ensure the consistency of the thickness.

(2) Equipment stability and reliability

The stability and reliability of the equipment are crucial for reducing poor coating. Coating machines that operate smoothly and have a low failure rate should be selected to ensure the continuity and stability of the production process. At the same time, attention should be paid to the maintenance and calibration of the equipment. Regular maintenance and calibration work should be carried out to ensure the long-term stable operation of the equipment.

(3) Production efficiency and capacity

With the continuous expansion of the lithium battery market, the requirements for production efficiency and capacity are also getting higher and higher. When choosing a coating machine, it is necessary to consider whether its production speed and capacity can meet the production requirements. The extrusion coating machine, due to its advantages such as fast coating speed, high precision and uniform wet thickness, can better meet the production demands of high capacity and high efficiency.

5. Application of Battery Coating Machines in Lithium Battery Production

Battery coating machines play an important role in the production of lithium batteries. It can control the thickness and uniformity of electrode coating, thereby optimizing the electrode structure and enhancing the energy density and cycle performance of the battery. By precisely controlling the flow rate, speed and thickness of the coating solution, the coating machine can achieve consistent and uniform electrode coating, ensuring the stability and reliability of product quality. At the same time, it has the ability to operate at high speed and continuously, which can meet the demands of large-scale production of lithium batteries and promote the rapid development of the lithium battery industry.

Battery coating machines, as key equipment in lithium battery production, play a decisive role in battery performance. When choosing a battery coating machine, factors such as coating accuracy and uniformity, equipment stability and reliability, production efficiency and capacity, equipment cost and return on investment, as well as after-sales service and technical support should be comprehensively considered. Different types of coating machines have their own advantages and disadvantages. Manufacturers should choose the most suitable coating machine for themselves based on their production needs and actual situations.