[YesAuto New Energy] Super broadcast, every week. With the advent of the warm spring season, the automotive circle has become lively, with new cars and new technologies being released frequently. The technical battery pack has been subjected to acupuncture experiments and realized that the ternary lithium battery pack does not catch fire after acupuncture. As soon as the technology was released, some people said it was a new hope for ternary lithium batteries, while others felt that “blade batteries should be cool”. Today, let’s not talk about it and talk about the magazine battery.
●Is the “mag battery” a gimmick bigger than reality?
What is a “mag battery”? I believe that the first time my friend hears this term will definitely have the same question as me. Is it a new type of battery? In fact, it is a new battery system safety technology released by GAC Aeon. It can be understood as putting the battery cells in a safety compartment similar to a “magazine”, which is a technology to improve the overall safety of the battery pack.
As everyone knows, the power batteries for passenger cars on the market now mainly include ternary lithium and lithium iron phosphate. According to their different characteristics, the two formed the tendency of chambers to resist courtesy. However, in terms of safety alone, the lithium iron phosphate battery is relatively safer because of its higher heat-resistant temperature. At this point, the limelight of the lithium iron phosphate battery has indeed surpassed the ternary lithium battery. Especially with the introduction of the ternary lithium battery equipped with high nickel, its instability and poor heat resistance have caused many people to equate the ternary lithium battery with unsafe.
A set of data shows the technical safety capabilities of the magazine battery. The heat-resistant temperature of the battery cell is increased by 30%, and the heat dissipation area of adjacent batteries is not prone to thermal runaway by 40%. The upper shell has a temperature resistance of more than 1400 degrees Celsius, and the timely rapid cooling and cooling efficiency is increased by 30%. The fifth-generation BMS system collects data 10 times per second in 24 hours, and can automatically start the self-rescue rapid cooling system when there is an abnormality.
From the above examples, many manufacturers have made efforts to improve the overall safety of battery packs. The most important difficulty is how to balance safety, energy density, and cost. As mentioned above, GM adds a water-cooling plate between every two battery cells, which will undoubtedly increase the overall weight of the battery pack, increase the sensor, and increase the insulation material. These will undoubtedly “invade” the volume of the battery pack, which is the same size. The capacity of the battery in the battery pack will become smaller, and the cruising range will be affected. This is the difficulty in the industry.
Although GAC Aian has not announced how to achieve enhanced safety performance, the energy density can also be improved. However, many experts in the industry believe that it is most likely to achieve this increase in energy density through the optimization of the entire package. In any case, from the results, we consumers still hope to improve safety without sacrificing battery life and increasing costs.
●Why can't I get through with the needle?
Seeing this test, we would unconsciously think of the acupuncture test of the BYD blade battery. It also gave the battery a new name and then used a needle to puncture it, but the difference is that BYD uses a single cell for the acupuncture test. , Click on the portal, you can see our detailed interpretation of the blade battery acupuncture test. The Ningde era also did acupuncture tests on battery packs, so we can’t help but ask what the needle did wrong? Why can't I get through with acupuncture?
It is also for this reason that in the new national standard test (GB 38031-2020 “Safety Requirements for Power Batteries for Electric Vehicles”, the mandatory requirements for the needle prick test of single cells have been cancelled. Instead, requirements for thermal diffusion have been put forward. The body cannot catch fire and explode within 5 minutes after the heat is out of control. It is necessary to set aside escape time for the occupants.”
Dendrite is a “side effect” of lithium-ion batteries. It can penetrate the separator between the positive and negative electrodes of the battery and cause a short circuit inside the battery. The acupuncture test can verify the thermal runaway diffusion of the cell after the internal short circuit of the cell.
So the layman looks at the excitement, the insider looks at the doorway, whether it’s a single cell or the entire battery pack, acupuncture tests never look at whether acupuncture can cause thermal runaway, because it is the degree of thermal runaway under simulated short-circuit conditions and See if the thermal runaway can be controlled so as not to spread.
●Is the blade battery cool?
As soon as the acupuncture test of the magazine battery was released, some people compared it with the BYD blade battery test. One view was that “the magazine battery has passed the test for the ternary lithium battery, and the blade battery is about to cool.” One point of view is “the safety of the single battery cells tested by the blade battery, while the magazine battery uses the entire battery pack, which is a stealth replacement of the concept.”
The magazine battery technology uses a whole set of technologies to control the heat dissipation, and the two cannot be simply compared. Using safer single cells is a way to improve safety, and improving the safety of the entire battery pack system is another way. The blade battery highlights the safety advantages of its own lithium iron phosphate, but the most important contribution is to increase the volumetric energy density of the battery pack to the same as the ternary lithium battery pack through the de-modularized layout, while the magazine battery is in Efforts to make up for the shortcomings of ternary lithium batteries, that is, poor safety, the two can be regarded as the same goal by different routes, both in order to achieve the goals of low cost, high battery life, and high safety. As for the question of who replaces whom, the two battery packs still have their own advantages and disadvantages. In the short to medium term, the “breaking head” between lithium iron phosphate and ternary lithium still cannot tell the final victory or defeat, and each will occupy The situation of one force will continue for a while.
To be honest, although the magazine battery does not bring the ternary lithium battery system and the essential technological breakthrough, it improves the safety of the entire battery pack to a higher level. In fact, no matter what the name of the battery pack is, whether it is a lithium iron phosphate battery pack or a ternary lithium battery pack, as long as everyone’s focus is on safety, manufacturers’ willingness to work hard in these invisible places is the “gospel” for consumers. . At the same time, this also shows that domestic electric vehicles have not entered the stage of “closing eyes and running wild”, and this is what the industry should be like for a healthy development.