Musk once explained his "first principles" in an interview: most of the time, we are used to thinking and guiding our lives through analogy, because others do the same, but this will only produce relatively small optimizations and iterations;First principles, on the other hand, are based on the physical framework, returning to the essence of the problem, gradually breaking down the problem, and then finding a solution from it.
Obviously, the vast majority of the work done by Xiaomi cars is "analogy", including this 800V, CTB integrated battery technology. Nevertheless, this does not prevent the Xiaomi Su7 battery pack from occupying a valuable position in the entire battery technology journey. 1. 2. CATL Kirin battery0 planIf we call the ZEEKR 009 battery system Kirin battery 10 scheme (that is, the battery cell is standing), then this battery pack of Xiaomi SU7 is a Kirin battery in the real sense of the word2The 0 solution (i.e., the cell inversion), and its mass production, marks that CATL has pushed Kirin battery technology to a new height. Kirin 1 of ZEEKR 009Although the 0 scheme realizes "thermoelectric separation", the original CTP2The whole package crossbar in 0 is removed, which further improves the integration efficiency. However, it has two obvious drawbacks: (1) the explosion venting valve of the battery cell is facing downward, although this innovation improves the thermal runaway safety of the whole package, but reduces the space utilization rate of the battery cell itself at the Z high level, which is equivalent to sacrificing the space utilization rate to achieve high safety;(2) It does not solve the problem that the upper cover needs to be bonded to the battery cell in CTB C (the existence of high and low cell connections), and cannot further promote the integration of the battery and the vehicle. 
The Kirin inverted design of Xiaomi Su7 This Kirin inverted solution of Xiaomi Su7 returns to the battery cell technology that CATL is best at, which is the upright cell (that is, a normal square cell), which ensures the quality and mass production speed of the battery cell, and at the same time, it solves the problem of thermoelectric separation at the same end of the cell explosion venting valve and the output electrode, so that the entire battery pack can really give a more efficient solution in the Z-direction space. In addition, after the battery cell is inverted, the bearing and fixing of all battery cells is a new problem, and I believe that there are corresponding solutions to solve it, which is very worthy of study. 2. The second highly referenced CTB scheme for square cellsThe integration of battery pack and vehicle, from the perspective of the current mass production technology, all the ones that are on the ground can be classified into the technical category of CTB proposed by BYD. Where:
The mass production CTB represents the product and the cell cylindrical battery, and the representative product is the 4680 structural battery of the Tesla Model YBlade cell, the representative product is BYD seal's blade CTB;Prismatic cells, although there are CTB of Leap (only remove the upper cover of the battery pack) and Xpeng G6 (the upper cover of the battery pack is integrated with the floor, and the battery cell is not integrated with the upper cover), but the above two ideas cannot reach the high integration efficiency of the battery cell vehicle like Tesla and Blade. The difficulty lies in the fact that the normal square cell pole needs to be connected by a busbar, and these high and low voltage connectors cannot bear the force of shearing and tearing up and down, so it is necessary to integrate the non-cell pole end with the upper cover. This integration difficulty of square cells has also been an important problem hindering CATL's launch of CTB CTC, although CATL proposed CTC technology very early, but the real implementation was far later than Tesla and BYD. Now, the prismatic battery cells represented by CATL are once again on the same running line as blade batteries and large cylindrical batteries in terms of technology. It provides a new CTB solution option for domestic battery companies and vehicle companies. 3. Integrate the OBC DCDC into the battery packThis is currently in personal speculation, and the actual design of the battery pack has not been seen, but from the perspective of its high-voltage chamber layout, it is the same structure as the Tesla Model 3 Y, so Xiaomi has a high probability of putting the OBC DCDC into the battery pack, which is one of the few attempts in China. 4. Difficulty in maintenance and dismantlingThis design of Xiaomi Su7 makes its battery pack the most difficult in terms of repair and disassembly, which is more difficult than Tesla 4680. The main reason is that after the cell is inverted, the cover can not be opened at the first time, and the high-voltage connection between the cells is broken, which makes the dismantling personnel unable to carry out other work after the high voltage is broken. From an aftermarket perspective, this is the worst design. With the advancement of technology, we see a lot of "technology backtracking" phenomena, and we hope to see the return of "module" technology in the future.