The “fire” of the tram has a pool of the original, recently come to TSLA, Wei Si, Roewe and BYD, etc., is shaking the entire new energy automotive industry..
Behind this trigger the user’s accident on the new energy vehicle trust crisis, not only the surface is so simple, and the more critical “guided fire” is a strategy choice for car companies on dynamic lithium battery technology.. We will analyze the deep reasons behind the accident with TSLA.
. 60S Quickly understand the core argument: 1. The important issue of the TSLA spontaneous combustion accident lies in the choice of the battery.
. Tsla selected three-dimensional ion battery, energy density, advanced technology, but safe dispute. 2, Shanghai garage spontaneous incident is a minority of TSLA fate, not only because TSLA has the highest number of accumulated quantities in the pure electric car EV field, more importantly, TSLA radical strategy.
3, although Mask once said that the solid-state battery “has a certain foreground”, but the distance technology is still time, it is not enough to “change the strategy of TSLA”. TSLA Fire Event Review Tsla’s fire in Shanghai garage, it is difficult to think about “fire”. Because the speciality of the fire is “three in one”: the car is in a static non-driving state + non-charging state + battery spontaneous combustion, plus video surveillance is open, and the way is also ignited to Audi and other small friends next to it.
. Keeping a free ES8, which is less than 24 hours, Xi’an Wei to authorize the service center, also burn (official explanation that the chassis impact caused the battery pack extrusion deformation), which is equivalent to adding firewood. Although TSLA has repeatedly emphasized that they have obtained the “Double Five Star” safety rating, while enjoying the spotlight, TSLA and Masque should also endure their mistakes to observe their mistakes.
. After all, new energy cars is still new things, consumers have lack of clear cognition of battery characteristics, fire causes and consequences, and more worry. From 2012, TSLA began to deliver a large scale, but the vehicle spontaneously, but it is more precisely that the battery is angry.
It is no longer a new thing, and the light is not reported to the TSLA battery. Nearly 50. The above incident list excluded the self-ignition caused by the speed or alcohol, which is a fascinating thing that is the owner of TSLA, and has not caused a major death accident.
Otherwise, it is also a big news.. However, this article wants to explore more than just this matter itself.
. The Shanghai garage spontaneous combustion event is a slight shadow of TSLA destiny, although it seems to be occasional, but from Murphy Law, it is possible to happen, regardless of this possibility, it will eventually happen. Of course, everyone knows that there are two prerequisites for the establishment of Murphy Law: 1, greater than zero probability; 2, time is long enough.
TSLA is not only available in pure electric sectors, but also the selection strategy of battery technology methods is also very radical.. Is the radical battery technical strategy be deserved? The mainstream method of electric vehicle battery is now divided into two major camps, distinguishing between battery positive material: One is a lithium phosphate ion battery – limited energy density, relatively high, but has lower price, longer cycle service life and resistance High temperature and more secure; the other is a three-dimensional lithium-ion battery with high energy density and advanced technology, but safety is not as stable.
. If the lithium iron phosphate ion battery is like a prostitute, the ternary lithium-ion battery is like a babes: the energy storage energy of the lithium iron phosphate ion battery is only 150Wh / kg, and the 18650 three-dimensional lithium ion battery storage density of TSLA has reached 250Wh. / kg, the latest 21700 battery exceeds 300Wh / kg, the two are twice.
Since the energy density of the lithium phosphate ion battery is not high, the development of lithium iron phosphate ion battery is constrained. Prior to 2016, the lithium iron ion battery was rapidly expanded as an important power lithium battery positive material, yield and yield, but after 2016, the three-dimensional ion battery replaced the lithium iron ion battery became a power lithium battery positive material. Important development direction.
To put it bluntly, the lithium iron phosphate ion battery is not too high, and the three-yuan lithium-ion battery is popular.. TSLA is not only the earliest “hot girl” company, but also “wearing the most daring hot girl”.
Why do you say this? The three-dimensional lithium ion battery method is also divided into two major schools.. The first is the commonly used nickel-wateng manganese (NCM): Different from the three contents, the NCM material can be divided into NCM111, NCM523, NCM622, NCM811, etc.
, wherein the rear number represents the ratio of the three, and the tall nickel can bring The higher energy density, the more unstable. Another big genre is the Nickel-cobalt aluminum (NCA) selected by TSLA, and the common ratio is 8: 1.5: 0.
5, which has already spelled the high-level 811 in the NCM system.. Deep review: Is it reliable when the fire is frequent? The battery material itself is not stable enough, and the TSLA uses a large-capacity long-lived method.
The battery pack of a car integrates 7000-9000 yuan 18650 or 21700 model cell. , Each set of cells have 2 positive and negative electric shock, and the electric shock of the connecting battery is more than 14,000 to 18,000, which can be seen that the monitoring difficulty is large..
According to public data, the NCA ternary lithium-ion battery thermal out-of-control temperature in TSLA does not exceed 200 degrees, and then the ternary material is reached a certain temperature, it will decompose the extremely lively primary ecological oxygen, even if there is no external oxygen. In the case of the supply, the battery is also equipped with three elements, which is also the reason why the TSLA is quickly spread and difficult to extinguish..
Although TSLA is radical in NCA selection strategy, it is safe to ensure that the overall battery method is safe, and it is necessary to consider the battery management system BMS (BatteryManagementsystem), how to prevent accidents caused by battery cells and even combustion? Two points need to focus on the battery management system design: 1, to isolate the battery cell that generates heat. When the thermal out of control occurs, if the battery or module group can be separated, the loss can be effectively reduced to prevent spontaneous combustion..
The design method includes surface connection bus structure optimization heat dissipation, lower surface flow channel heat dissipation design, heat insulation treatment of the battery connection spacer, and low temperature heating algorithm for the battery pack side arrangement semiconductor heating sheet. This series of design guarantees that the entire battery pack has a uniform thermal state, which reduces the risk of thermal out-of control..
2, the precise estimate of the battery status helps monitor the charge and discharge state of the battery in real time, preventing heat loss caused by over charge. Through the combination of state estimation and short-circuit model in the battery, it can effectively identify whether there is a short circuit, and in turn, the system will warn. To be honest, TSLA has done a lot of efforts in the above aspects (with more than 200 related patents), whether the entire battery system is more likely to spontaneously ignite than the oil car? The response of Mask is: “There are more than a million fuel-fuel-burning events and thousands of people die, but as long as a TSLA spares and no one is injured, it will become headlines.
. Why do you want to double standard? Tsla and most electric cars are the same, the possibility of spontaneous combustion is 500% lower than the fuel truck, why no one mentioned? “Masque responded to the TSLA accident on social media to zoom in, this is the fact. TSLA has been playing the role of “small steel gun” in the automotive industry – has a skill, but the overall quality needs to be improved.
. Masque style radical, dare to try new techniques. At the same time, there is also passive reasons, in the super centuries accumulated automotive industry, TSLA, which is delivered in 2012, does not have enough cards, whether it is a technical accumulation or capital accumulation, can only explore a new technology in various fields The best route, running quickly, unlike other car giants have more test error costs.
Overall, the probability of new energy vehicles is probably low than the oil truck in the oil car, but the fire accidents of the two-year three will also show that new energy automotive technology is still flawed and battery safety needs to be strengthened.. Although the pressure of the endless mileage anxiety, the vehicle enterprise cannot use the energy density as the first indicator, but to continue to improve the safety design and test verification of the battery, management system.
. How to choose the future battery technology route? Tsla is currently 300 pieces of patents in the battery field, but important in the field of battery systems, battery packs and charging. In terms of small patents, there is no patent, and the material is gamble, and there is no too much energy and resources to invest in other directions, such as the possible solid-state battery and fuel power battery in the future.
. Mask once said that the solid-state battery “has a certain foreground”, but the technology matures is still time, it is not enough to “change the strategy of TSLA”. However, in a longer-term perspective, the power lithium battery plays a decisive use in the performance of the vehicle.
Under the current ternary lithium ion battery system, the combination of high nickel-based three-dimensional electrode, silicone carbon negative electrode and electrolyte will be 3 – 5 years to achieve performance limits (energy density limit 350Wh / kg), still unable to completely meet the requirements of power lithium battery on safety, energy density and cost. Solid State Battery is more secure in addition to energy density (expected 500WH / kg)..
The full solid-state lithium-ion battery is based on solid material non-volatile, no corrosion, no volatilization, no leakage problem, so more advantages in preventing heat loss. Toyota has had a large number of patents (252 pieces, accounting for 13%, the world) in the Solid State Battery, and plans to invest $ 13 billion in R & D funds to the battery in the field 2030, in 2022, in 20022, an electric car type with full solid state 2025 realization. At the same time, my country’s leading company’s leading company – BYD and CATL are also layout in Solid State Battery.
. BYD has determined that the solid-state battery is in the development direction, and it has begun to use a small-scale trial; in August 2017 applied for a full solid-state lithium-ion battery positive material invention patent, in the next 10 years, the fastest 5 years for the type of product. CATL has designed a polymer battery cell having a capacity of 325mAh.
Therefore, the automotive companies in the industry are fascinating with TSLA to focus on the three-yuan lithium-ion battery route, 3-5 years to achieve the performance limit, or follow the Toyota key research new battery materials – solid state batteries, even more aggressive Fuel power battery? This is not just a problem, but also the problem of survival. .