Rapid development and frequent accidents sound the alarm for global electric vehicle safety

In recent years, as new and old car companies have spared no effort to accelerate the electrification process, electric vehicles have developed rapidly, but with it comes frequent safety issues. Previously, electric vehicles of many car companies have caught fire one after another, and the investigation results of many incidents all involved battery safety issues. From this point of view, the frequent occurrence of electric vehicle accidents should sound the alarm for the entire industry chain.

Recently, two consecutive electric vehicle fires occurred in South Korea while they were charging, and both vehicles were Hyundai Motor's pure electric vehicles KONA.

In the early morning of the 4th of this month, a KONA that was charging in the underground parking lot of a residential building in Daegu, South Korea suddenly caught fire and the vehicle was severely burned. Fortunately, the accident did not cause casualties. Just a week before, the same vehicle caught fire while charging in Jeju Island. In fact, as Hyundai Motor's flagship electric vehicle, KONA has had a total of 13 fire accidents at home and abroad since it was launched in April 2018.

The Ministry of Land, Infrastructure and Transport of South Korea is currently investigating the cause of the two fire accidents. According to the investigation of the National Institute of Science Investigation of South Korea into several KONA electric vehicle fire accidents last year, it was initially believed that the fire might have been caused by internal problems in the power battery components.

As the world's leading electric car manufacturer, Tesla's models are sold all over the world. After setting up a factory in China, its market competitiveness has greatly increased due to a significant reduction in costs, making Tesla the undisputed "leader" in the current domestic pure electric car market. However, this does not mean that Tesla's models will be safer.

According to Tesla's official report, between 2012 and 2019, Tesla models had an average of one fire accident for every 280 million kilometers of mileage.

Last April, a Tesla electric car caught fire in an underground garage in a residential area in Shanghai. Video surveillance showed that white smoke suddenly came out of the chassis of the car at the time of the accident. In just a few seconds, the white smoke became larger and larger, and then it exploded and a flame rose up. The fire was fierce. The accident also caused two cars parked next to the vehicle to be burned to varying degrees, but fortunately there were no casualties. In response, Tesla said that the spontaneous combustion accident was caused by a single battery module failure located at the front of the vehicle.

From the above cases, we can see that there are various reasons for safety accidents of new energy vehicles, but batteries are an important cause of safety accidents of electric vehicles.

Experts said that when an electric vehicle's battery is short-circuited, punctured, overcharged, or impacted, the electrolyte inside the battery will quickly accumulate heat energy. When the temperature inside the battery core rises to a certain level, such as 110°C, it reaches the starting point of thermal runaway or explosion. What follows may be a series of chain reactions, resulting in the continuous accumulation of heat energy and temperature, which may cause fires and other safety accidents.

In recent years, the production and sales of new energy vehicles have continued to rise, proving that their market recognition continues to increase. Because of this, eliminating consumers' safety concerns about electric vehicles is an urgent task to be solved, especially the battery problem, which is the main cause of many vehicle fire accidents. Therefore, the safety of electric vehicles, especially the safety of batteries, should be given high attention by the entire industry.

For decades, the development of electric vehicle batteries has been constrained by factors such as long time and huge investment costs. The battery industry currently has two mainstream routes: lithium iron phosphate and ternary lithium. For consumers, the core needs are driving range and fast charging speed, which requires the battery energy density to continue to increase. However, as the energy density increases, the safety risk will also increase. How to meet consumer expectations while ensuring safety is a difficult issue.

At present, major international automakers are stepping up their research and development of electric vehicle batteries. According to Reuters, Tesla is discussing with Canadian mining company Giga Metals how to develop a large mine, which will enable Tesla to obtain enough low-carbon nickel to meet the growing demand for electric vehicle batteries. At the same time, Tesla's Canadian battery research team led by Jeff Dahn proposed in a paper how to use electrolyte solutions to solve the failure problem of anode-free batteries. The paper is titled "Diagnosing and Correcting Failure Problems of Anode-Free Batteries through Electrolyte and Morphological Analysis." The battery team said that some anode-free batteries can store more energy per unit volume than traditional lithium-ion batteries. In addition, anode-free batteries are lighter than traditional batteries.

According to foreign media reports, the German Federal Research Ministry has invested 3 million euros in the EPIC project to improve the electrode drying process of lithium-ion batteries. The project aims to reduce the cost of producing dry electrodes by at least 20%. Scientists in the EPIC project plan to speed up the electrode drying process by at least 50% while maintaining the quality and long-term stability of the electrode.

Porsche recently launched its latest mobile charging solution: a mobile charging truck equipped with a giant 2.1-megawatt-hour battery system that can charge 10 electric vehicles at the same time. Porsche said the truck's giant battery is charged with renewable energy.

It can be seen that major new energy vehicle companies should first increase scientific and technological support, continue to carry out basic research on power battery safety, and develop the best system solutions to ensure power battery safety. Secondly, safety standards should be continuously improved, and the safety requirements for power batteries and complete vehicles should be increasingly stringent. At the same time, countries should conduct special investigations on new energy vehicle fire accidents and conduct research on information sharing mechanisms to further improve defect determination technology and capabilities. In addition, government supervision should be continuously strengthened, and various systems such as recalls and three guarantees for new energy vehicles should be further improved.