2021 power lithium battery module design trend

In the past few days, 1000 kilometers and fast charging have become controversial, but according to the current state, this kind of 100kwh-150kwh battery system will not be promoted to the market on a large scale in a short period of time. What is important in 2021 is to move from the original 148mm width cell to the 220mm width cell, and the 60-62kwh LFP battery will be used as a low-end configuration based on the 590 module design pack at home and abroad. This can be used as a PK Volkswagen 62kwh battery. Low-end solutions are worthy of our attention. 1. 62kwh LFP method LFP batteries currently form several specification systems, one is the original 173mm width system, which is mainly used in buses; and then based on 148mm batteries, this type of battery is down from the current 148mm 177Ah To form a specification of around 130Ah; and the new 157Ah battery based on the 220mm battery core is indeed very interesting as a new system method. The capacity of the corresponding high-voltage 5-series battery cell is about 242Ah. Three yuan up to achieve about 95kwh 1C is calculated according to 1/3C is about 100kwh; while LFP is calculated according to 1C to 62.7kwh, according to 1/3C is about 65kwh, currently this kind of low-end LFP battery is used, and the same Cells with size specifications are used to make larger modules to meet the Pack size models of different car companies. Table 1 Existing important specifications From the perspective of Pack, as shown in the figure below, the filling field can support up to 6 dual modules + 2 single modules, and up to 120+ cells can be integrated. Figure 1 Comparison of LFP method and ternary method. It should be noted that there are two variants, 590 double module and 590 long module. The difference between the two is mainly based on the difference in the number of cells in the module: 1) FPC Acquisition, 16 batteries use two FPCs; while 32 batteries are different, 4 FPCs are used; 2) Both modules are connected by aluminum bars, as shown in the figure below; 3) 16 batteries The side panels are eliminated, and the long modules keep the side panels connected. Figure 2 Improved 590 design (double-pin) Figure 3 Long modules based on double-row batteries, the number can reach 32 modules used in Model 3 embedded water cooling plate, in this design also adopted a model The mode of group integrated water cooling plate is shown in the figure below. This design is used in all types of batteries. Figure 4 The design of the embedded water-cooled plate designed by the large module 2. The penetration of platform-based low-end LFP After the large-scale introduction of LFP from Tesla, in fact, the introduction of LFP at EntryLevel for passenger car platforms must be a trend, nothing more than before The size of the battery provided is limited, which limits the maximum battery energy supported by the LFP. As the size of the battery system of the vehicle itself is sufficient, this energy will be further pulled up to the 65kwh direction. So judging based on the current situation: 1) The introduction of platform-based companies, LFP batteries will be gradually introduced in June 2021, this low-cost method is to deal with no subsidy, because the battery shell is relatively large, in the current method It is difficult to make the energy density meet the requirements, but the cost advantage makes this method and the subsidy-based ternary method not much different; 2) Based on the ternary method, 16 single-row and 32 double-row models can be used , Further increase the integration level. Judging from the current integration situation, under this design, CTP has no obvious advantages. I believe that the vitality of this design is relatively strong; 3) The current large module method basically uses The automation of the module line and the pack line was interrupted. The 32S module has 117V and the power is 28.4kwh. This is basically a small module. From this branch, you can derive the design summary of sealing this module into a general-purpose small Pack: The LFP method currently seen is Based on mainstream sizes. Therefore, the addition of the acupuncture experiment mentioned by BYD and the increase of the thermal diffusion time to 30 minutes, in fact, there is no difference in the current LFP method. Regarding the strict requirements of the standard, it may further accelerate the deployment of LFP.