The iteration of plug-in hybrid vehicles began in 2010, and has experienced 2-3 generations of models at home and abroad, but there is a certain bottleneck in the development of PEV batteries.
With the platformization and generalization of PHEV models, the battery system adopts a universal battery module design, and the next direction is: the battery system is increasingly similar to pure electric, arranged at the bottom of the vehicle; under such arrangement requirements, the PHEV battery module also requires the module size to be reduced and flattened, and the combination is more flexible.
In 2022, with the launch of many domestic DHT plug-in models in this field, observing the development of PHEV batteries has become an interesting topic.
In this regard — how to use 8, 10, 18, 22 and even higher 40kwh of iron lithium batteries - the current practice of two iron lithium companies, Fordy and Honeycomb, may be a mainstream direction.
Remarks: Around the high-nickel ternary development of PHEV cells, there are not too many companies paying attention to development now
▲Figure 1 The direction of PHEV batteries in the "Energy-saving and New Energy Vehicle Technology Roadmap Version 2.0" also deviates
Part 1 Fordy battery
BYD began to use soft-pack lithium iron phosphate battery module (referred to as small blade) on its own DMI model, which is essentially a secondary sealing technology, the battery cell is packaged with a soft package (aluminum-plastic film), and the blade battery is packaged with a duralumin shell.
Figure 2 Planning of Fordy Battery on PHEV Battery
In this sense, it is also possible to achieve the above different sizes of different capacities (26Ah, 40Ah, 42Ah, 47.7Ah, 65.2Ah and 85.2Ah) different sizes. From the current logic, the biggest feature of the soft package is that the size can be cut, and the soft package battery core is rolled up through the internal bracket, and then used internally through the fixed way.
▲Figure 3 The small blade battery adopts 8-shell batteries
As shown in Figures 4 and 5 below, this interface connects the voltage of each battery cell and then connects it to the CMU through a unified connector.
Figure 4 Top design of the small blade battery
▲Figure 5 The small blade module uses FPC to bridge the sampling line internally
Part 2 Hive Energy L400
At this Hive Battery Day, the L400 product debuted, and also used lithium iron phosphate on the PHEV like Fordy, launching a PHEV product that can cover a long range of 150-200km, with a cell energy density of 170Wh/kg
-180Wh/kg, mass production will be completed by the end of 2022. This is also from the cost point of view, will be significantly lower than ternary lithium, while the volume utilization rate increased by 40%.
My understanding is that this is also a model of borrowing small blades (which can be made into soft packs or directly made into square shells) to do CTP.
Figure 6 The battery of the hybrid L400 of the hive
Doing so in conjunction with the Great Wall's previous DHT planning can actually replace the battery position of the HEV and push the PHEV into a series.
Note: The previous 43kwh of the extended range EREV was still done with a three-yuan BEV battery, and once the iron lithium was imported to do it, the cost was still optimized a lot under the premise that the power was unchanged
Figure 7 The battery of the DHT platform of the Great Wall
I feel that 2021 has changed a lot, in the design before the Great Wall and the Hive, it was all done around VDA, and under the rapid change of a year's time, the entire technical route was completely reversed.
▲Figure 8 The previous 45kwh battery cell has been replaced
Summary: I have worked with labor before a called "PHEV battery system integration technology", and now look at the battery cells around the VDA and the overall technical direction, all subverted in the PHEV, this also represents the domestic PHEV battery idea also has one more direction - around the high volume utilization rate, in the energy density is not demanding PHEV in the greater use.