[YesAuto New Energy] Super broadcast, every week. It was a relatively calm week, but on the evening of October 27, a Weimar EX5 in the Institute of Mechanics of the Chinese Academy of Sciences in Beijing suddenly caught fire. This immediately became the focus of major media reports. Today, I had to chat again. , To satisfy the curiosity of the “people who eat melons”. At the same time, we will review two things that make people happy this week. One is that NIO is developing a 150kWh battery pack, and the other is that Tesla is developing a new charging pile with a charging power of 350kW, which is the “mileage anxiety” of pure electric vehicles. To be resolved?
At around 21:00 on October 27, 2020, a Weimar EX5 caught fire in the Institute of Mechanics of the Chinese Academy of Sciences located on the West Road of Beisihuan, Haidian District, Beijing. Some netizens broke the news that the car was still accompanied by explosions and smoke at the time. Fortunately, the public security, fire protection and other departments quickly dispatched police, and the accident was dealt with in a timely manner, without causing injuries or other property losses. Subsequently, Weimar Automobile officially issued a statement stating that the accident vehicle caught fire due to impurities in the battery; on October 28, Weimar Automobile officially issued a related recall statement. In addition, we conducted an in-depth report on the incident at the first time. Interested friends can move to read: “Frequent Fire Incidents Exclusively Ask Weimar Recall Incidents” and “Where is the Problem? Interpretation of Weimar's recalled products.
Why did the Weimar EX5 catch fire this time so much attention? In addition to the fact that users have been very concerned about the safety of pure electric vehicles, another main reason is that the accident on October 27 was the fourth fire incident of the Weimar EX5 in two months. Safety issues are frequent. difficult. According to a statement issued by a battery supplier of Weimar Motors, ZTE High Energy Technology, the two Weimar EX5s that caught fire in Fujian in October were indeed supplied by ZTE High Energy Technology, but the EX5 that caught fire on October 27 in Beijing was not equipped with batteries. Cells provided by ZTE High Energy Technology,
Regardless of which supplier the Weimar EX5 that caught fire on October 27 is equipped with, let's briefly review why this EX5 caught fire. Weimar Motors mentioned in the statement that the fire of the vehicle was caused by impurities mixed into the battery during the production process, which caused abnormal lithium evolution in the power battery, which eventually led to a short circuit of the battery and thermal runaway of the power battery.
After reading the text in the above picture carefully, I believe you can understand the seriousness of impurities and lithium precipitation in the battery cell. We have done many articles on visits to power battery production lines and power battery packaging lines for a long period of time and for multiple brands. The production and packaging environment of battery cells must be dust-free, which is also to prevent impurities from being mixed in. In fact, not long ago, BMW recalled many plug-in hybrid models worldwide. The reason for the recall was that there were welding beads in the power battery unit that were not completely removed (welding metal beads or welding metal beads). Continuous deposits), which may cause a short circuit and fire in the power battery.
Impurities are mixed in the battery, which of course is directly related to the supplier, but it seems that the car companies can't clear the responsibility. If car companies can achieve more stringent quality control, can they avoid accidents as much as possible? Moreover, Weimar Motors does not only use one battery supplier, which has been questioned by many netizens; on this issue, we also asked Weimar Motors. The brand claims that it is to ensure the stability of the parts supply chain and help the development of the company. , To prevent the problem of power battery failure.
At present, many pure electric car companies have chosen to use batteries provided by suppliers, and the “power battery assembly line” of car companies is responsible for the assembly process from batteries to power battery packs. Therefore, it seems that battery suppliers and car companies are both responsible for the fire on the Weimar EX5; how to implement more stringent quality control? This should be a matter that many car companies need to reconsider, especially Weimar Motors that has just experienced a fire.
If possible, in order to avoid the poor working conditions of the power battery, we can occasionally use slow charging to charge, and at the same time avoid overcharging and overdischarging, this can also optimize the battery state to a certain extent. Of course, all that consumers do is just “treat” batteries. The root cause is that power battery suppliers and car companies must treat production and quality control more strictly.
Super broadcast comment:
The safety topic of power batteries has developed almost with the development of pure electric vehicles. From imported models to domestic models, there have been too many pure electric vehicle fire accidents in the past two years. Among them, the bottom of the battery has been bumped and caused a fire. Core problems cause spontaneous combustion. As ordinary users, we can only try to ensure that the battery is not “traumatic”, but the most fundamental thing is to require car companies and battery suppliers to provide users with protection.
Let’s talk about happiness. Recently, Wei Lai’s founder Li Bin told users that the 150kWh battery pack is currently under development, and the 100kWh battery pack will be officially delivered at the end of November. In addition, Jerome Guillen, the general manager of Tesla's automotive business, mentioned in the third quarter earnings conference call that the company is focusing on the development of charging piles with a maximum charging power of 350kW.
Pure electric vehicles are currently not popular enough. A large part of the reason is that users have “mileage anxiety”. Vehicles are tools that need to bring users freedom; while pure electric vehicles often have less cruising range than fuel vehicles, and the former is slow to replenish energy. , So for users who only have one car at home or do not have charging conditions at home, they are not suitable for buying pure electric vehicles. To solve the “mileage anxiety”, there should be three ways to solve it. One is to increase the endurance of the vehicle, the other is that the vehicle has a strong charging capacity and can accept greater charging power, and the third is to have a dense and efficient charging network.
Weilai currently has supercharged piles, ordinary household slow-charged piles, 20kW household fast-charged piles, substations and trams. Such a rich energy supplement network can indeed greatly increase the convenience of car use. If there are 100kWh batteries With the blessing of the group, are NIO owners really hopeful to get rid of “mileage anxiety”?
As for Tesla, we have previously measured the charging power of its V3 supercharger. We tested it with the Tesla Model 3 long-endurance all-wheel drive version. The V3 supercharger can reach a maximum charging power of 233kW, and the vehicle can be charged for 10 minutes. It can supplement the battery life of 208km (the battery life is EPA standard).
The maximum charging power of the Tesla V3 supercharger is 250kW. According to Jerome Guillen, the general manager of Tesla's automotive business, the company is developing a new charging station with a maximum charging power of 350kW. , Model S Plaid and Cybertruck may be adapted first. Imagine that if Model 3 with a smaller battery capacity can also be fitted with new charging piles in the future, it will be more than fragrant. By then, Tesla owners should be able to completely get rid of “mileage anxiety”?
Super broadcast comment:
NIO’s method of launching large-capacity batteries and optimizing vehicle mileage is currently the most commonly adopted method by car companies to improve the convenience of pure electric vehicles. This can indeed bring positive effects, but the negative effect may be that consumers need to bear. Higher car purchase costs too. Tesla’s approach is more sophisticated, but the technical difficulty is also higher. It is not easy for a car company to follow suit. You must know that at present, the highest charging power that our Chinese brand pure electric vehicles can accept is only a few dozen. kilowatt. If the charging efficiency is comparable to the refueling efficiency, does the vehicle range become less important? Can users also accept pure electric vehicles?