The stability of the U.S. Tesla Model X deflagration after a traffic accident has been questioned

In California, USA, a Tesla Model X caused a deflagration after a traffic accident. The owner of the car died of serious injuries after being taken to the hospital. Some insiders told reporters that Tesla's good-looking data on performance and mileage can be said to be achieved under the premise of radical technology. He said that during the use of Tesla's 18650 battery, as long as there is a slight inconsistency in the battery array, a circulating current will be formed inside the battery pack, which will cause self-discharge and greatly increase the loss of the battery. He also said that because the manufacturing process is not yet fully mature, the yield rate of the 21700 battery of Panasonic and Samsung SDI will be lower than that of the 18650 battery, and the Model 3 may have insufficient output due to battery module assembly problems, which may be related to this. Tesla's fatal accident. Tesla first crashed into the barrier in the middle of the highway, and then crashed into the second lane on the far left. After being hit by a Mazda in that lane, it ended up on the far left. Driving in the lane collided with an Audi, and a total of three cars were involved. According to the local traffic police patrol, the Model X involved caught fire soon before being hit by the other two cars. According to the reporter's understanding, the ModelX was severely damaged after the incident, the front of the car was completely destroyed, and the wreckage was burned only to the frame. As a large number of batteries in the car were exposed after the accident, road workers could not immediately clean up the wreckage on the road. The Center for Health Protection summoned engineers from Tesla to evaluate the batteries. According to data, Tesla is currently the only automobile company that uses 18650 lithium cobalt oxide batteries. The above-mentioned battery has a diameter of 18mm and a length of 65mm, and is often used as a battery cell in a notebook computer. As the lithium-ion battery is approaching the power threshold at this stage, Tesla has always adopted the approach of placing thousands of batteries in a battery array under the vehicle as the power for its electric vehicles. However, such a design makes the battery array more likely to be impacted when the vehicle is in a collision, which in turn causes the cells or modules to be easily displaced, causing the wires for parallel and series connection to fall off and short-circuit to cause fire. In addition, in order to reduce weight and cost, the 18650 battery arrays of ModelS and ModelX also eliminated the outermost insulating layer. Although the company claims that it has excellent battery management system and battery pack technology, and timely temperature monitoring system technology, the natural defects of the 18650 battery arrays that are frequently reported by accidents are still difficult to overcome. In this regard, Tesla proposed that a large amount of water should be used to extinguish the fire after the battery is on fire. After the battery is completely cooled, a thermal imaging camera is still required to monitor the battery's condition. The stability of lithium cobalt oxide batteries has been questioned. In fact, as early as April last year, a Model X caught fire and exploded after a collision in Guangzhou, and the vehicle was seriously damaged. At that time, the car owner questioned the quality of the Tesla ModelX vehicle itself; at the beginning of this year, another Tesla spontaneously ignited due to the battery. So, why does the battery technology, which is Tesla's core competitiveness, have repeated accidents? An industry insider told reporters that the good data on Tesla's performance and mileage can be said to be obtained under the premise of radical technology. He said that although the initial consistency of Tesla's 18650 battery is stable, the battery array will inevitably have inconsistent battery attenuation during use. As long as there is a slight inconsistency, a circulating current will be formed inside the battery pack, causing self-discharge, and greatly increasing battery loss. Speaking of Model3, he said that the current yield rate of 18650 batteries of Panasonic and Samsung SDI is generally above 98%, but after switching to 21700 (the battery array used in Model3), the yield rate will be affected because the manufacturing process is not yet fully mature. The recent exposure of Model 3 production is insufficient or related to this. Previously, Tesla said that an important processing limitation for Model 3 is battery module assembly. Musk said that there are four 'regions' in Model 3's battery module processing, and one of these 'regions' has a particularly serious problem. According to reports, a Tesla employee who had worked in a super factory broke the news that as of mid-December last year, part of the processing of Model 3 batteries was still done manually.