In the case that new energy vehicles have a penetration rate of nearly 4 percent, how to solve safety anxiety, endurance anxiety and (charge and discharge) performance anxiety in order to further popularize new energy vehicles have become the three major contradictions on the table. In fact, behind them, there is another anxiety that car companies can't say most of the time, that is, cost anxiety. But for users, it is also in vain to create consumer goods that meet their needs, but cannot meet the needs of their wallets. Therefore, when ZEEKR released the "Golden Brick Battery" this time, it did not avoid all the above four anxieties. Next, let's disassemble how the new battery faces these four problems from a technical point of view.
First of all, to solve a "talent" problem, if safety is the highest priority, then lithium iron phosphate batteries can naturally stand out. Its olivine structure has an inherently high stability compared to the layered structure of ternary lithium. Behind this feature, lithium iron phosphate also has a significantly better cost control than ternary lithium batteries. Therefore, only on the talent side, choosing lithium iron phosphate as the battery cathode can already well control the two anxieties of safety and cost. But is that enough?There are not too many lithium iron phosphate batteries on the market, if you want to get out of the circle, what real ability does the golden brick battery of ZEEKR have?
In fact, battery technology is not so high, whether it is to improve safety or performance, it can be summed up in two directions. The first is the chemical route, that is, the optimization of the core components of the battery, such as the positive and negative electrodes, electrolytes, and separators. The second is the physical route, that is, the ability to optimize the packaging process and move around in the limited battery pack space. To put it more directly, the chemical route is to help all the batteries to be a "good guy", while the physical route is to assume that there may be "bad guys" in the battery pack.
The understanding of the safety of ZEEKR's gold brick battery is more biased towards the so-called "physical route". In fact, a little clue can be found from the form, and the gold brick battery cell presents a long and thin visual effect. This is mainly because the lamination process is gradually widely used in lithium iron phosphate batteries. The advantages of its capacity and performance are not listed for the time being. In terms of temperature management, due to the disadvantages of the winding process in terms of cell isolation and cell internal resistance, the battery cells are more likely to heat up, and the local part of the battery pack is prone to high temperature phenomena that are not easy to eliminate. As a result, the lamination process began to be more optimistic, especially in the lithium iron phosphate battery solutions of various companies (in fact, this is also a "physical solution"). However, the lamination process has higher requirements for production process and efficiency, especially in terms of consistency, which is the "natural enemy" of lithium iron phosphate batteries. Therefore, this series of restrictions may also give birth to ZEEKR's self-developed and self-produced gold brick batteries.
On the basis of self-development, ZEEKR has room to make more big moves. For example, the most representative "gold brick" shape. Of course, this is not deliberately for the appearance of "gold bricks", but an insulating film that can withstand 4000V DC high voltage. The cover of the battery pack can withstand a high temperature of 1000 meters for more than 30 minutes to prevent external fire from spreading to the battery cells. Inside the battery, the thermal insulation layer between the cells is assisted by heat-absorbing materials. Then, with water circulation cooling and pressure relief channels, etc., the most extreme considerations of the battery cell after the temperature runaway are done. Of course, before that, security measures such as cloud monitoring, security alerts, and emergency power outages are also provided. In summary, ZEEKR gold brick battery has made great efforts in temperature control and battery strength. This is also one of the fundamental reasons why the gold brick battery can pass the pinprick test while being squeezed.
After making sufficient preparations for safety, we will start talking about the capacity and performance of ZEEKR gold brick batteries. Let's start with the lamination process that I haven't talked about before, which makes the energy density of the single cell significantly improved. But for BRICS batteries, what is more important is that their layout is more flexible. Because of this, through a series of flashing and moving, the utilization rate of the battery pack space of the gold brick battery has reached an exaggerated 837%。If a battery pack of the same size can be crammed into more cells, the overall battery capacity will of course go up. The logic of this design is actually the modularization of power batteries that we often mentioned before. It's just that the ZEEKR gold brick battery is playing bigger this time. In addition to the sufficiently optimized layout concept, the main reason for this is to use more high-quality parts and less space in the parts including the aforementioned barrier materials, cover plates and other parts. As well as no worries in temperature control, heat dissipation, etc.
When you see this, you will find that we have been talking about the topic of "physical level" throughout the ZEEKR gold brick battery. In fact, the BRICS battery also has a "chemical level" effort, but the direction of the effort is exactly the opposite of what we talked about earlier, because it is mainly to enhance the performance. Previously, we have also analyzed the technical routes of many lithium iron phosphate batteries, and a key word "manganese" has been mentioned many times. The more representative one is the lithium manganese iron phosphate scheme. The addition of manganese can increase the energy density of the battery cell while maintaining safety. However, the disadvantage is that the conductivity of manganese is extremely poor, and with lithium phosphate, it is obviously not comparable to ternary lithium in terms of performance. The improved scheme is mainly based on the lithium manganese iron phosphate cathode material, plus suitable metal elements to enhance the conductivity. However, how to choose metal elements, as well as proportions, processes and other issues, also exist objectively.
Going back to the ZEEKR gold brick battery, we can first determine a few priorities. For example, the pursuit of performance of ZEEKR's models, as well as the technical scheme that needs to roll 800V overcharging in this round, are destined to the performance of the battery cannot be ignored. As for the capacity part, ZEEKR has solved the problem of energy density of the battery pack through the methods we talked about earlier. So we can come to a conclusion that ZEEKR does not have a large demand for whether to add manganese to battery cells. On the contrary, there are higher requirements for continuing to increase the performance of lithium iron phosphate batteries.
How to improve the performance of power batteries?To put it simply, it is to speed up the running speed of lithium ions between the positive and negative electrodes. In fact, today's graphite anode is basically in a surplus state in terms of embedding, so everyone in the past focused on the cathode material. However, due to the overly stable structural characteristics of lithium iron phosphate cathode, the efficiency of lithium ions during deintercalation is low. To this end, the method of ZEEKR gold brick battery is to further "break" the cathode particles, and cooperate with a special conductive agent to increase the reactivity and the efficiency of lithium ions being released. In addition, the electrolyte and anode materials are adjusted to accelerate the transmission of lithium ions and shorten and open up the embedding channel. However, in terms of separators, ZEEKR still has an insurance, a three-layer composite porous membrane to ensure the stability of the lithium-ion transmission process. Especially in the case of adaptive overcharging, it effectively limits the possibility of being punctured by the negative dendrite. Finally, with the design of multi-tab and bipolar column diversion of the packaging part, the overall charging and discharging performance of the battery pack is further improved.
Write at the end:The advantages of lithium iron phosphate are clear, such as cost, safety, and so on. This is also a prerequisite for lithium iron phosphate batteries to stand out. But the problem is also very clear, capacity and performance cannot go up. It's really piled up, and the security advantage is easy to spit out. In terms of safety, the ZEEKR gold brick battery chooses "keep the frame", in terms of capacity, "simplify decoration", and in terms of performance, "lay high speed". Finally, on the lithium iron phosphate battery with controllable cost, it is adapted to the 800V high-voltage platform, with a maximum charging power of 500kW and a range of more than 500km in 15 minutes. At the same time, it is adapted to ZEEKR 007 to meet 2The performance of breaking 100 in 84 seconds.