L822 battery.The "retreat" and "advance" of lithium battery lamination technology

　　News from China Energy Storage Network: "Recently, some soft-pack power battery companies have begun to approach our company to develop cooperative winding process solutions." A senior executive of a winding equipment company revealed to Gaogong Lithium Battery.

　　Gaogong Lithium Battery understands that in the field of power batteries, soft pack battery manufacturing is mainly based on the lamination process. However, due to the shortcomings of the lamination process in terms of efficiency and integrated automation, soft-pack power battery companies have the idea of shifting from the lamination process to the winding process.

　　The reasons are, first, that with the advantage of high energy density, the penetration rate of soft-pack batteries in the power market has increased rapidly. Data from the GGII Lithium Battery Research Institute (GGII) shows that in the first quarter of 2018, soft-pack battery shipments were approximately 1.2GWh, accounting for 14% of shipments, a significant increase from the same period last year. Lamination efficiency cannot well meet the needs of battery companies.

　　Second, judging from the reasons for choosing to switch to the winding process, whether it is semi-automatic or fully automatic winding, it can be completed quickly and with high quality, and production control is relatively simple. At the same time, subsequent slitting is convenient and the pole piece qualification rate is high.

　　Third, the winding process is cheaper than the lamination process.

　　As the application of soft-pack batteries in the power market accelerates, the solutions of the winding process in the field of soft-pack power batteries are becoming more mature. The application of the winding process in the power soft-pack market may increase in the next two years.

　　However, in the long term, batteries using the soft-pack lamination process are significantly better than the winding process in terms of safety performance, energy density, etc., and with the continuous innovation and progress of domestic lamination equipment companies, as well as the horizontal extension of large-scale lithium battery equipment companies, The lamination process will still be the mainstream trend for soft pack batteries.

　　Short-term shift in soft-pack battery technology

　　On the one hand, it is due to the surge in demand from the soft pack battery market, and battery companies are in urgent need of improving production efficiency; on the other hand, due to the need for cost control, the number of winding process routes will increase in the expansion of soft pack battery production in the next two years. .

　　According to feedback from some domestic soft pack battery companies, the current shortcomings in the application of lamination machines in China are:

　　1. Equipment efficiency is slow. At present, the efficiency of the lamination machine industry is generally 0.8 seconds/piece, which is still far behind the efficiency of imported lamination machines of 0.17 seconds/piece.

　　2. Alignment accuracy during folding process. The stacking process is very cumbersome, and the pole piece cutting qualification rate is very low. Each pole piece requires four knives. It is difficult to maintain a high degree of consistency in the quality of the pole pieces (section, burrs, etc.), and insufficient alignment accuracy will affect the battery's quality. Ultimate performance.

　　3. The level of continuous automation of the production line is low. Industry insiders said that the current integrated automation level of the production line in the middle section is still low, and the integrated automation solution is not mature enough.

　　4. The equipment is too large. Many battery manufacturers hope that the footprint of automated stacking machines will be reduced by another 20%.

　　Regarding the shift in soft pack battery technology, a power battery executive said that the lamination process and the winding process for soft pack applications have their own characteristics. The advantage of the winding process is that it is easy to make and has high efficiency, while the lamination process is very important for batteries. The performance and energy density are improved even more. At present, the company's soft-pack batteries are manufactured with both winding and lamination processes, which can be adapted to meet the requirements of different markets and customers.

　　Lamination technology is still a long-term development trend

　　As battery energy density requirements gradually increase, battery cell companies have a tendency to make batteries larger and larger. The main problems with making a single battery cell larger are safety, production efficiency, control of winding or overlapping of pole pieces and separators, Issues such as collective efficiency of production lines.

　　Industry insiders generally believe that the lamination process can better leverage the advantages of large-scale batteries, and it has advantages over winding in terms of safety, energy density, and process control. Therefore, in the field of power batteries, the lamination process is the best choice for soft-pack batteries. There is no doubt about the long-term application trend.

　　The above-mentioned power battery executives also expressed the same view: "For digital batteries, more emphasis is placed on improving efficiency than battery capacity and performance, so customers will have demand for winding processes. But for power batteries, considering the future power The core is made bigger and stronger, and the lamination process can better control the cell yield. The most important thing is to pursue high energy density, so the lamination process is the best choice in the future."

　　At the same time, companies that have long adhered to the soft packaging technology route, including Funeng Technology, Beijing Guoneng Battery, Tianjin Co., Ltd., Wanxiang A123, and Microvast Power, have stated that the company will insist on using lamination technology as the mainstay in the future.

　　In addition, under the national policy of subsidizing high-energy-density and fast-charging batteries, the lamination process has comprehensive advantages such as low internal resistance, high energy density, high high-rate discharge capacity, and resistance to deformation. Therefore, some prismatic power battery companies are also Start experimenting with the lamination process.

　　It is worth mentioning that outstanding large-scale lithium battery equipment companies in China that previously promoted winding equipment have also gradually increased their layout in lamination equipment, such as Yinghe Technology, Leading Intelligence, Xingchengjie, etc. The two-pronged approach is winding and lamination to prepare for the market.

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