[Fact Check] Is Chinese-Made More Dangerous? ... Battery Information Disclosure Is a Double-Edged Sword

Battery Type More Important Than Domestic vs. Chinese Origin
Specific Battery Information Beyond Manufacturer Must Be Provided
Information Disclosure Expected to Promote Safe Battery Development
Sprinkler Operation More Influential Than Large-Scale Damage

On the morning of the 8th, police, fire department, the National Forensic Service, and representatives from Mercedes-Benz conducted a second joint inspection of the electric vehicle that caught fire on August 1st in the underground parking lot of an apartment complex in Cheongna, at an industrial site in Seo-gu, Incheon. 2024.8.8 [Image source=Yonhap News]

The government has recommended the disclosure of battery information for all electric vehicles sold domestically, and almost all automakers have posted battery information on their official websites. As of the 14th, nine complete car brands including Hyundai Motor Company, Kia, KG Mobility, BMW, Mercedes-Benz, Volkswagen, Audi, Volvo, and Stellantis have disclosed battery information. Tesla and GM have not yet made their information public.

Among the 78 electric vehicle models currently sold domestically that have disclosed information, 25 models are equipped with Chinese-made batteries, accounting for 32% of the total. The rest use domestic batteries from LG Energy Solution, SK On, Samsung SDI, and others.

Following a large-scale property damage caused by an electric vehicle fire in an underground parking lot of an apartment complex in Cheongna, Incheon on the 1st, concerns about electric vehicles have spread, leading to calls for battery information disclosure. In particular, it was confirmed that the Mercedes-Benz EQE350+ vehicle involved in the fire was equipped with a Chinese Parasys battery, contrary to initial reports, which strengthened these demands.

However, many point out that the current level of disclosure makes it difficult to verify battery safety. Being Chinese-made does not necessarily mean a higher risk of fire. We have outlined key points consumers should know regarding electric vehicle battery fires.

1. Does disclosing battery information help prevent electric vehicle fires?

-Disclosing battery information can help guarantee consumers' right to choose and alleviate vague anxieties, but it is not directly related to preventing electric vehicle fires. However, since consumers are likely to check whether an electric vehicle contains a 'safe battery' when purchasing in the future, it may encourage automakers and battery companies to pay more attention to battery safety.

2. Are Chinese-made batteries more vulnerable to fires?

-It cannot be concluded that Chinese-made batteries are more vulnerable to fires. The Mercedes-Benz vehicle involved in the recent fire was equipped with a battery from China's Parasys company, which ranks within the top 10 globally but is relatively unknown to domestic consumers. The vehicle reportedly used Parasys's NCM811 battery. Nickel-Cobalt-Manganese (NCM) ternary battery technology is considered to lag behind Korea's technology. On the other hand, Lithium Iron Phosphate (LFP) battery technology, which is regarded as more stable than ternary batteries, is actually more advanced in China. Therefore, Chinese-made batteries are not inherently safer or less safe than Korean-made ones; the type of battery used in the electric vehicle is more important.

3. Why are ternary batteries more vulnerable to fires?

-Ternary batteries refer to Nickel-Cobalt-Manganese (NCM) and Nickel-Cobalt-Aluminum (NCA) batteries. All ternary batteries use nickel as a key cathode material. The higher the nickel content, the more lithium ions can be stored, increasing energy density. Higher energy density increases the overall battery capacity and driving range. However, nickel is a material with poor thermal stability, making it more prone to heat generation and thus more vulnerable to battery fires. This is especially true for so-called high-nickel batteries, which contain over 80% nickel.

4. Then, are LFP batteries better?

-LFP batteries use iron phosphate as the cathode material. They are inexpensive and have a stable crystal structure, which reduces the risk of fire. However, they store fewer lithium ions, resulting in lower energy density and smaller battery capacity. This is why LFP batteries are commonly used in mid- to low-priced electric vehicles. Most high-performance, expensive electric vehicles use ternary batteries.

5. Are there batteries that are both high-performance and safe?

-Battery manufacturers are developing technologies to compensate for the drawbacks of ternary and LFP batteries. Domestic battery companies are developing high-voltage mid-nickel batteries that reduce nickel content to enhance safety while achieving high energy density. Chinese companies are using Cell-to-Pack (CTP) technology to increase the energy density of LFP batteries at the pack level. Therefore, disclosing only the battery manufacturer makes it difficult for consumers to assess battery safety. Just as internal combustion engine vehicles emphasize specific engine performance when launching new models, electric vehicles also need to provide key battery performance, technical characteristics, and safety features.

6. What battery technologies help prevent fires?

-Batteries used in vehicles are divided into cell, module, and pack units. Battery cells are first modularized, modules are assembled into packs, and then installed in the vehicle body. Battery manufacturers use advanced inspection equipment during cell manufacturing to filter out defective batteries. Inside battery cells, features such as CID (Current Interrupt Device), which cuts off current when internal pressure rises, and vent functions that release gas are added. The Battery Management System (BMS) in electric vehicles manages hundreds or thousands of battery cells to ensure even charging and discharging, as overloading a specific cell can lead to fire. Sensors inside the battery monitor overcurrent and undercurrent. These functions can detect abnormal signs in advance to prevent fire accidents.

7. When will fire-resistant solid-state batteries be available?

-Samsung SDI domestically and Toyota internationally are accelerating the development of solid-state batteries. Solid-state batteries replace the liquid electrolyte with a solid one among the four main components of a battery (cathode, anode, separator, electrolyte). This significantly reduces fire risk but is technically challenging, so it will take time before electric vehicles equipped with solid-state batteries are released. Manufacturers aim for commercialization around 2027. Even after commercialization, due to high costs, solid-state batteries are expected to be applied only to ultra-high-end electric vehicles initially. For the next several years, lithium-ion batteries will remain the mainstream for electric vehicles.

8. Are electric vehicle fires more dangerous than internal combustion engine vehicle fires?

-Lithium-ion batteries commonly used in electric vehicles contain large amounts of flammable materials. Battery cells are closely packed, which can lead to rapid thermal runaway. Electric vehicle fires also have characteristics of metal fires, which are difficult to extinguish. However, the large-scale damage in the Cheongna apartment fire was more due to the sprinkler system not functioning properly than the electric vehicle fire itself. Sprinklers reduce surrounding temperatures, preventing extensive damage. In May, an electric vehicle fire occurred in an underground parking lot in Gunsan, but the sprinkler system operated, preventing greater damage. Conversely, in July 2020, a fire in an underground parking lot in Yongin caused extensive damage to hundreds of internal combustion engine vehicles due to sprinkler failure.

9. Will battery information disclosure provide a windfall for K-batteries?

-Not necessarily. The confirmation that the Mercedes-Benz vehicle involved in the accident was equipped with a Chinese battery is expected to increase domestic preference for Korean-made batteries. However, if fires occur in electric vehicles equipped with domestic batteries in the future, it could backfire. The domestic electric vehicle market is small, and since Korean battery companies mainly target markets in the U.S. and Europe, the impact of this accident may be limited. While research and development by automakers and battery manufacturers have focused on improving energy density, it is now necessary to balance battery capacity and safety.