With the increasing popularity of new energy vehicles in the market, their safety issues, especially the phenomenon of thermal runaway, are receiving more and more attention from the public. Thermal runaway, once it occurs, may cause fires or even explosions, posing a serious threat to personal and property safety. Therefore, it is particularly important to have a deep understanding of the triggering causes of thermal runaway and take corresponding preventive measures.
There are many causes of thermal runaway in new energy vehicles, including physical factors such as side or rear collisions, bottom impacts, and foreign object punctures, as well as environmental conditions such as high current charging, external ignition sources, vehicle immersion, and technical issues such as inconsistent power batteries, internal and external short circuits caused by vibration, and relay/fuse control failures.
1.Collision
Side and rear collisions often lead to thermal runaway of battery packs. In the stage of vehicle design and manufacturing, we should use high-strength materials to enhance the impact resistance of the body structure, in order to improve its protection ability in collisions. At the same time, in daily maintenance and upkeep, the safety performance inspection of the vehicle structure and battery system cannot be ignored, and any damaged components should be replaced in a timely manner.
2.Bottom impact
Bottom testing cannot be ignored either. Because in the actual driving process of new energy vehicles, the working conditions at the bottom of the vehicle are complex and varied. Bottom scraping, bottoming, and ball hitting/puncturing are common bottom abuse conditions, which may cause damage to the battery pack and lead to safety hazards. The bottom test includes bottom ball strike, bottom compression, and bottom puncture, which simulate different working conditions encountered at the bottom of the vehicle during driving.
After bottom ball impact testing, the structural strength and impact resistance of the battery pack have been verified. Hard shell battery packs perform outstandingly due to their metal casing’s ability to effectively absorb impact energy. The bottom compression test further verifies the stability of the battery pack under high pressure, ensuring the safety and reliability of the battery pack even in extreme situations. Although the bottom puncture test has strict conditions, it can intuitively understand the safety response of the battery when its internal structure is damaged, providing valuable feedback for battery design and production.
Strengthening the protective capability of the vehicle’s bottom structure is the key to preventing thermal runaway caused by bottom impact. In addition to using high-strength materials during the design and manufacturing phase, attention should also be paid to daily vehicle maintenance and upkeep to ensure the integrity of the bottom structure and battery system.
3.Foreign object penetration
Foreign object penetration is also a potential threat. In order to prevent external foreign objects from entering key components such as battery boxes or motor radiators, we need to improve the protective capabilities of these components. This also requires consideration of using stronger and more durable materials during the design and manufacturing stages. Meanwhile, regular inspection and maintenance of the integrity of these components are also essential.
4.Short circuit
The core task of the testing equipment during the short-circuit test is to simulate the short-circuit situation inside the battery. By accurately measuring the current and voltage changes generated by the battery in a short-circuit state, researchers can delve into key parameters such as thermal runaway characteristics and electrochemical reaction characteristics inside the battery. These experimental data and evidence not only have high reference value for the safety performance evaluation of batteries, but also provide valuable scientific basis for subsequent battery design and optimization.
5.External fire
External sources of fire are also an undeniable factor. In order to improve the fire resistance of power batteries, we need to use fire-resistant materials and effective fire isolation measures in the design and manufacturing stages. Meanwhile, users should also try to avoid parking their vehicles near flammable materials in daily use and always pay attention to fire safety.
6.Immersion
Vehicle immersion is also a common cause of thermal runaway. In order to prevent water from corroding the power battery, we need to pay attention to the implementation of waterproof measures in the vehicle design and manufacturing process. Meanwhile, users should also avoid driving through water or parking in areas that are prone to flooding during use.
7.Vibration
Inconsistencies in power batteries, internal and external short circuits caused by vibration, and technical issues such as relay/fuse control failures can also lead to thermal runaway. To address these issues, we need to adopt advanced battery management systems, high-quality wires, and connectors during the design and manufacturing stages. And high-quality relays and fuses. At the same time, users should regularly check and maintain the working status of these devices in their daily use.
DGBELL provides customers with reliable new energy vehicle testing equipment to safeguard the safety of new energy vehicles. We provide comprehensive testing equipment solutions for automobiles, automotive components, automotive batteries, and more.
