The reasons are as follows: First, with the advantage of high energy density, the penetration rate of soft-pack batteries in the power market has risen rapidly. Second, from the reasons for choosing the winding process, whether it is semi-automatic or fully automatic winding, it can be completed quickly and with high quality, and the production control is relatively simple. At the same time, the subsequent slitting is convenient, and the pole piece qualification rate is high.
The third is that the winding process has a lower cost than the lamination process.
With the acceleration of the application of soft pack batteries in the power market, the winding process in the field of soft pack power lithium-ion batteries has become more mature, and the application of the winding process in the power soft pack market may increase in the next two years.
However, in the long run, the battery of the soft pack lamination process is significantly better than the winding process in terms of safety performance and energy density, and with the continuous innovation and progress of domestic lamination equipment companies, and the horizontal extension of large lithium battery equipment companies, The lamination process will still be the mainstream trend of soft pack batteries.
Short-term turnaround of soft-pack battery technology
On the one hand, it comes from the surge in demand on the soft-pack battery market, and battery companies urgently need to improve production efficiency; on the other hand, because of the need for cost control, the choice of winding process routes in the expansion of soft-pack batteries in the next two years will increase. .
According to feedback from some soft-pack battery companies, the current shortcomings in the application of the stacker are:
1. Equipment efficiency is slow. At present, the efficiency of the stacker industry is generally at an efficiency of 0.8 seconds/piece, which is far behind the efficiency of 0.17 seconds/piece for the imported stacker.
2. Alignment accuracy during folding. The lamination process is very cumbersome, and the pass rate of pole piece slitting is very low. Each pole piece needs four cuts. It is difficult to maintain high consistency in the quality of the pole piece (section, burr, etc.), and insufficient alignment accuracy will affect the battery's performance. Final performance.
3. The continuous automation of the production line is low. According to industry insiders, at present, the degree of integrated automation in the mid-stage production line is still low, and the integrated automation method is not mature enough.
4. The equipment is too large. Many battery manufacturers expect the area of automated stacking machines to be reduced by another 20%.
Regarding the transition of the soft-pack battery technology, a senior power lithium-ion battery executive stated that the soft-pack application lamination process and the winding process have their own characteristics. The advantage of the winding process is that it is easy to make and efficient, while the lamination process The improvement of battery performance and energy density is even better. At present, the company's soft-pack batteries are manufactured with winding technology and lamination technology, which can respond to and meet the requirements of different markets and customers.
Lamination process is still a long-term development trend
With the gradual increase in battery energy density requirements, battery cell companies have a trend to make batteries bigger and bigger. The most important problems in the larger single battery cell are safety, production efficiency, control of winding or stacking of pole pieces and diaphragms, Issues such as the collective efficiency of the production line.
The industry generally believes that the lamination process can better utilize the advantages of large batteries, and it has advantages over winding in safety, energy density, and process control. Therefore, in the field of power lithium-ion batteries, the lamination process is soft. There is no doubt about the application trend of long-term development of pack batteries.
The above-mentioned power lithium-ion battery executives also expressed the same view: “For digital batteries, more emphasis is placed on the improvement of efficiency than battery capacity and performance. Therefore, customers will have requirements for winding technology. But for power lithium-ion batteries , Considering that the battery cell will be bigger and stronger in the future, while 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."