Create automotive-grade products CATL/pioneer intelligent winding technology innovation

　　There is a serious shortage of supply of automotive-grade power batteries that meet the needs of OEMs. One of the important factors is that there are too many power batteries of different models and specifications, especially square and cylindrical power batteries.

　　At the "Li Yuanheng·2019 Senior Engineer Lithium Battery & Electric Vehicle Annual Conference" held from December 16 to 18, nearly 20 battery and equipment companies conducted in-depth discussions on how to build car-grade batteries.

　　Among them, battery companies believe that the entire industry needs to reach a consensus to make car-grade products. Only under the premise of ensuring safety can we move from the ppm level to the tens of millions level. Regarding the hard indicators of automotive-grade batteries, the first is safety. Controlling and eliminating workshop dust is the key to producing automotive-grade batteries.

　　Equipment companies believe that if battery companies want to make car-grade products, they must upgrade the core technology and performance of the equipment. Therefore, equipment companies must continue to carry out product iteration and innovation.

　　Regarding how to upgrade lithium battery equipment, we can start with the square and cylindrical power battery structures. As shown in Figure 1, it is made by winding the positive electrode sheet, negative electrode sheet and separator at a certain speed through the winding needle on the winding machine.

　　During the winding preparation process of the battery core, the winding needle of the winding machine is often fixed in size, and the winding diameter cannot be adjusted. The operation is complicated and debugging is difficult, and rapid changes in the winding diameter of the winding needle cannot be achieved.

　　At the same time, as the battery replacement rate increases and cost-effectiveness requirements become increasingly stringent, power battery companies are in urgent need of improving production efficiency. Therefore, it is crucial to have a flexible winding production line with quick changeover.

　　For power battery winding machines, when switching production of different types of batteries, it is often necessary to remove the winding needle and replace the winding needle with different winding diameters. During the disassembly process, a large amount of manpower and material resources are wasted, and production is delayed and production efficiency is affected.

　　The reason is that when the winding needle is disassembled, the winding linear speed, tension fluctuation, alignment accuracy of the diaphragm and pole piece, etc. will change and need to be re-adjusted. In addition, it also delays production efficiency and battery quality consistency.

　　For cylindrical and square batteries, the winding methods are similar, and the main differences are the needle size and speed.

　　The winding difficulty lies in how to change the winding needle, tension fluctuation and diaphragm pole piece alignment accuracy control. The development trend of winding equipment is higher efficiency, stronger battery model compatibility, faster model change, and higher level of intelligence.

　　Regarding the company’s technological innovation in needle rolls, Gaogong Lithium Battery’s patent search found that representative companies include CATL and Pioneer Intelligence.

　　CATL: Detachable rolling needle

　　The patented detachable winding needle invented by CATL can switch the winding needle to the corresponding rolling diameter according to the corresponding battery model. Specifically, by adjusting the adjustment block in the outer needle assembly, the exposed length of the connecting piece on the fixed seat is changed, and then the roll diameter size is adjusted.

　　In addition, Ningde Times has a receiving groove and a positioning pin hole on the surface of the outer needle assembly to facilitate quick disassembly and precise positioning of the rolling needle assembly.

　　The patent benefits of CATL mainly fall into two aspects. On the one hand, it greatly reduces the frequency of needle replacement and disassembly and assembly, saving the time of needle change. On the other hand, it reduces the production cost of needle change and improves the utilization rate of automated production lines. More importantly, while increasing the winding speed, good control of the winding tension can also be achieved.

　　(1 first outer needle assembly 2 second outer needle assembly 3 first inner needle block 4 second inner needle block 5 first pole piece 6 second pole piece 7 diaphragm H pin hole S receiving space 13 first connector 11 a fixed base)

　　Leading Intelligence: Sleeve Type Rolling Needle

　　The patented sleeve-type winding needle invented by Leading Intelligence focuses on solving the problem that when the winding core is removed from the winding needle mechanism, the inner winding material is easily taken away or wrinkled.

　　The patented feature of this sleeve-type rolling needle is that the rolling needle is designed in a semi-circular arc thin-wall shape. The sleeve assembly of the needle rolling mechanism is provided with an extrusion component. Under the required working conditions, the rolling needle is squeezed, thereby reducing the cylinder diameter of the needle rolling mechanism, thereby changing the rolling diameter size.

　　As shown in Figures 5-7, the structural feature of the sleeve-type rolling needle is that a dividing groove 310 is designed between the rolling needle 300 and the rolling needle 400. On the one hand, a receiving space is reserved for the winding material, and on the other hand, a deformation space can be reserved for the first rolling needle 300 and the second rolling needle 400 .

　　Pioneer Intelligent's patented sleeve-type winding needle can change the diameter of the winding needle to ensure the integrity of the inner layer of the winding material during peeling. At the same time, it improves battery production efficiency, saves material resources, and does not affect the tension, alignment, accuracy, etc. of the separator and pole pieces.

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