In the field of lithium battery manufacturing, coating process technology is crucial, directly affecting the performance, safety and service life of the battery. With the rapid development of the new energy industry, lithium battery coating process technology continues to innovate, and companies have made efforts to introduce their own unique process technologies to seize the opportunity in the market competition.

At present, the main methods of coating the pole pieces of lithium-ion batteries are comma roller transfer coating and slit extrusion coating. Comma roller transfer coating measures the slurry on the coating roller by adjusting the gap between the coating roller and the comma scraper, and then transfers the slurry to the foil through the gap between the back roller and the coating roller. This process is relatively simple to operate, but there are certain limitations in the coating accuracy, which is suitable for production scenarios where the accuracy requirements are relatively low. For example, in some low-end lithium battery production, comma roller transfer coating is still widely used due to its low equipment cost and flexible process adjustment.

Slit extrusion coating is a high-precision pre-metering coating method. It feeds Newtonian or non-Newtonian fluid slurry to the slit die through a metering pump, and uniformly coats the surface of the substrate. This process can precisely control the coating thickness, especially for the manufacture of high-end products with strict battery performance requirements. There are many factors that determine the coating quality, including the gap between the coating head and the baseband, flow rate, substrate speed, coating head structure, and fluid characteristics. As the coating speed increases, in order to ensure the coating quality, a vacuum chamber mechanism is often used for high-speed coating (usually the coating speed is ≥ 30m/min). In the production of high-end electric vehicle lithium batteries, the slit extrusion coating process has become the mainstream choice because it can ensure the uniformity and stability of the pole coating.

Lankwitzer has an excellent performance in lithium battery coating process technology. The UV insulating battery coating (EvoProtect 455 UV) developed by it adopts a special process, which has significant advantages in curing. The coating can achieve ultra-fast curing in less than 5 seconds through ultraviolet irradiation, which greatly improves production efficiency. At the same time, it supports automated production, which can effectively ensure the consistency and stability of product quality, setting an industry benchmark in the lithium battery cell insulation coating process.

From the perspective of material application, different lithium battery coating processes have different requirements for slurry characteristics. Lithium battery slurries are generally composed of active substances, conductive agents, binders, and solvents, and belong to solid-liquid two-phase fluids. In production, the quality control points of the slurry cover viscosity, solid content, density, fineness, and pH value. Like slit extrusion coating, due to the high requirements for coating accuracy, the uniform consistency of the slurry and the stability of fluid characteristics are more stringent. In the development of paint formulations, Lankwitzer fully considers the slurry characteristics and process suitability, and continuously optimizes the product, so that its paint can be better combined with various coating processes to improve the overall coating effect.

In addition, some companies are exploring the preparation process of dry pole pieces. If combined with solid-state battery technology, it is expected to meet the needs of new lithium batteries in the future. This technology has the advantages of environmental protection, safety, low equipment cost, and the preparation of thick pole pieces. Although it has not yet been widely applied, it has become a research and development hotspot in the industry, indicating the future development direction of lithium battery coating process technology. In the field of lithium battery coating process technology, each process technology has its own advantages and disadvantages under different application scenarios. Through continuous technological innovation, companies continue to optimize the process, improve product quality and production efficiency, and promote the development of the lithium battery industry towards higher performance, safer and more reliable direction.