Date: 2024-08-22 hits: 153
Through statistical calculations of the number of new energy vehicles and fires in China over the past three years, it was found that the fire incidence rate of new energy vehicles has decreased from 1.85/10000 in 2021 to 0.96 per 10000 in 2023, while the fire incidence rate of fuel vehicles is around 1.5/10000. Overall, the current fire rate of new energy vehicles is even lower than that of fuel vehicles.
In Norway, the country with the highest proportion of new energy vehicle sales in the world, the fire incidence rate of gasoline and diesel vehicles is four to five times that of new energy vehicles.
What is the reason for the fire of new energy vehicles
According to investigations by relevant research institutes, in addition to traffic accidents, bottom collisions, and other situations, the most significant cause of fire related to batteries is called battery thermal runaway. The reasons for battery thermal runaway can be simply divided into charging reasons, driving reasons, etc.
What is battery thermal runaway
Thermal runaway of a battery refers to a serious safety issue where the internal temperature of the battery rises sharply due to various reasons during use or charging, and cannot be effectively controlled or cooled, ultimately leading to overheating, combustion, and even explosion of the battery,
The chemical properties of lithium are active. When lithium batteries are damaged due to their own defects, accidents, collisions, external forces, or other factors that cause the failure of heat dissipation and protection devices, or structural damage, chemical reactions will occur, and the chemical reactions will generate heat, allowing the heat to continue to accumulate. This chain reaction of 'reaction heating up again and again' ultimately leads to 'thermal runaway'.
Main cause
1. Overcharging or overdischarging: When a battery is charged to a level exceeding its design capacity, or discharged below a safe level, it can trigger internal instability and cause an increase in battery temperature. Should,
2. External short circuit: If a short circuit occurs outside the battery, the electrical energy inside the battery will be quickly released, generating a large amount of heat and causing the battery to overheat.
3. Internal short circuit: A short circuit inside a battery may be caused by defects in the manufacturing process, mechanical damage, or battery aging. A short circuit can lead to excessive current and generate a large amount of heat
4. Mechanical damage: Physical damage or compression of the battery may damage the internal separator layer, causing a short circuit between the positive and negative electrodes and leading to thermal runaway
5. High temperature environment: In high temperature environments, the internal temperature of the battery may rise, especially during charging. High temperature may accelerate the chemical reactions inside the battery, causing it to overheat
6. Thermal runaway of battery cells: When a short circuit or fault occurs inside the battery cell, a large amount of heat is quickly generated, causing thermal runaway of the battery cell and potentially leading to thermal runaway of the entire battery pack.
How can new energy vehicle owners prevent "burning"
1. Regular maintenance and inspection:
Regularly inspect the appearance and connection of the battery pack to ensure no damage, deformation, or leakage.
Use professional equipment to test battery performance, including battery capacity, internal resistance, voltage, etc., to ensure that the battery is in good condition
2. Reasonable use of vehicles:
Avoid prolonged high-speed driving or frequent emergency acceleration to reduce high current discharge of the battery.
Be cautious when using vehicles in extreme weather conditions such as high temperatures and severe cold, and minimize any adverse effects on the battery.
3. Control the usage environment:
Avoid parking the vehicle in a high-temperature, direct sunlight environment for a long time, and ensure good ventilation around the vehicle during parking and charging. In cold weather, take appropriate measures to protect the battery from the effects of low temperatures,
4. Using original accessories:
Choose and use original or certified chargers and batteries to ensure product quality and safety.
5. Understand the battery protection system:
Learn and understand the battery protection system (such as BMS) equipped on vehicles, ensure its normal operation, and regularly check its alarm and fault notification functions
6. Follow the usage rules:
Carefully read and follow the relevant regulations and precautions regarding battery use in the vehicle manual,
Follow the correct charging and discharging procedures to avoid overcharging or overdischarging.
7. Develop emergency plans:
Learn and master emergency response measures for battery thermal runaway, such as cutting off power, using fire extinguishers to extinguish fires, etc
Develop a personal emergency plan to quickly evacuate personnel, report to the police, and take initial firefighting measures in case of an emergency
