Endurance, charging, and safety can be called the "impossible triangle" of battery technology. Battery technology is one of the biggest obstacles to BEVs. In the face of this dilemma, solid-state battery technology is like a master key hanging in the future. Everyone is waiting for it to open the next era of new energy vehicles. But even if solid-state batteries promise a perfect technological future, what about the cost and yield problems? Or rather, instead of dwelling on an unknown technology, it is better to focus on the present. Perhaps, our demand for new energy vehicles only needs to be based on the existing mature technology.
Large capacity + supercharge, which point of lithium phosphate is not as good as ternary lithium?
The ternary lithium battery, which once relied on long battery life and fast charging, was counterattacked by the lithium phosphate Jedi with safety as a breakthrough. Even CATL, the most loyal technical supporter of high-nickel ternary lithium, has also begun to develop lithium iron phosphate batteries. The most representative work is the Shenxing battery released in the second half of last year. With a charging speed of 4C level, the full-blooded version of the 800V platform can also be easily adapted. Intuitively speaking, that is, 10 minutes of charging, you can get a range of 400km. The cruising range of a single charge can also touch the 700km mark. Even a behemoth like ZEEKR 001, and on the basis of satisfying the performance of dual-motor four-wheel drive, with the blessing of the Shenxing battery, the CLTC range is also 675km.
It can be said that the Shenxing battery of the CATL era has basically caught up with the performance of ordinary ternary lithium batteries in terms of battery life and charging speed. However, compared with the Kirin battery, which can easily achieve a range of more than 1,000 kilometers, the performance of the Shenxing battery seems to have room for upgrading. However, it can already meet the needs of 800V lithium iron phosphate, is there still the potential to be tapped in technology?
As one of the representative works of CATL and even high-end ternary lithium battery technology. Kirin batteries do not rely on large-scale innovation in cell technology, but through the art of "packaging", they can accommodate more cells per unit volume. At the same time, the passive safety capability of the battery pack will be strengthened in physical form, so as to further improve the range and safety capability of electric vehicles. The core of the whole set of technologies is simply the third-generation moduleless technology CTP 3.0.
Since it is its own technology, it is obvious that Shenxing battery can also learn from this. In fact, at the Beijing Auto Show, CATL brought the upgraded Shenxing PLUS battery. After about 8 months, CATL has strengthened the application of CTP 3.0 technology on the basis of Shenxing battery. As long as the packing technique is good enough, the same suitcase can always pack a few more clothes than others. On the basis of lithium iron phosphate cells, the energy density of the battery system can even reach 205Wh/kg. Although the energy density of Kirin battery 255Wh/kg is still slightly inferior, it is combined with the energy density of Shenxing battery and the loading performance. Electric vehicles equipped with Shenxing PLUS batteries have the possibility of achieving a range of more than 1,000. While achieving this goal may require far more than 100 kWh of battery capacity, the depth of module-free applications makes it possible.
Of course, these aren't exactly upgrades that come with packaging technology. After all, the Shenxing PLUS battery, in addition to the increased capacity, its peak charging speed can also reach 700kW. In other words, even under daily working conditions, it can be charged for 10 minutes and has a range of about 600km. The increase in charging speed is inevitably related to the cathode material. In fact, the first generation of Shenxing battery has been upgraded to the positive electrode, negative electrode, electrolyte, separator and other parts. Otherwise, it is impossible for lithium iron phosphate batteries to meet the needs of 800V high-voltage platforms.
If we say that the nano-scale cathode material of Shenxing battery is to break up the positive lithium ions, so that it can be more flexibly de-embedded from the positive electrode to the negative electrode. Then the Shenxing PLUS battery further optimizes the arrangement of the cathode material, so that the cathode can be pressed more solidly. It is worth mentioning that neither version of the Shenxing battery discusses the topic of adding manganese to the cathode material. Although lithium manganese iron phosphate can also enhance the endurance performance, the overly stable cathode structure and the low conductivity efficiency of its own contradiction with the development trend of high-voltage platforms. Compared with the lithium manganese iron phosphate scheme that solves the energy density first and then solves the high pressure problem. The development direction of Shenxing PLUS battery is closer to solving the problem of high-voltage efficiency first, and then optimizing the single-time battery life performance through moduleless batteries.
The second echelon follows up, and no one cares about solid-state batteries?
From blade batteries, to Shenxing PLUS. What remains unchanged for lithium iron phosphate batteries is the safety brought by its own stable cathode structure and the advantages of low cost. What has changed is the grouping and encapsulation process, such as the lamination process of blade batteries, the module-less battery technology of Shenxing PLUS, and so on. and the upgrading of electrolyte, separator and anode including cathode material. Although the technical solutions vary, the goal is to increase the capacity of lithium iron phosphate batteries and the charging speed. And this technological trend is also being followed up by the second echelon behind leading players such as CATL and BYD.
For example, last year, Ruipu Lanjun's installed capacity of lithium iron phosphate has reached the sixth in the industry. As a "novice player" established for about 7 years, Ruipu Lanjun also brought its own Wending 2.0 series battery at the Beijing Auto Show. To say that the technical direction of the top battery is lithium iron phosphate at the beginning, I am afraid it is not true. Its technical scheme to accelerate the cathode detachment and enhance the cathode embedding ability is a set of solutions that can be compatible with ternary lithium cathode and lithium phosphate cathode. The chemistry of this part has not been found to be more precise, but the electrolyte part of the top battery is obviously very interesting.
Judging from the technical profile, the battery may have applied semi-solid electrolyte technology. But it needs to be emphasized here again, whether it is Ruipu Lanjun's top battery, or the CATL condensed matter battery we talked about before. The direction of the so-called semi-solid electrolyte and gel electrolyte is not a technical category at all with the solid-state battery we often say. To put it simply, one is the application of an electrolyte in a semi-solid form. The solid-state battery is only one of the results of the technical molding, and the electrolyte part is completely solid-state. The former is a technical means, and the latter is a technical result.
Back to the lithium iron phosphate battery, the late-developed Ruipu Lanjun Wending battery also worked the battery module of the physical part. Shorter tabs for lower internal resistance. This is similar to the previous speculation about the new blade battery, when BYD's patented technology also involved how to reduce internal resistance and optimize the battery packaging space by changing the design of the battery tabs. From the perspective of the top battery 2.0, the optimization including the tab part has increased the space utilization rate by more than 7%.
In terms of specific data, the top battery 2.0 can step on the threshold of 4C charging speed when using lithium iron phosphate cathode, and the energy density can reach the level of 150Wh/kg. Judging from several key data, its performance may be at the same level as CATL's Shenxing battery. Of course, product strength is only a temporary manifestation of the technical direction. Importantly, lithium iron phosphate batteries are generally realizing their potential for long battery life and ultra-fast charging. The realization of this potential is only a test of technology, and its manufacturing cost can still be controlled at a low level. And the solid-state battery, which has not yet realized its talent for mass production, is enough to turn away many consumers, at least initially, in terms of cost.