In recent years, consumers have increasingly recognized new energy vehicles, but some people still have concerns about the safety of new energy vehicles, especially electric vehicle power batteries, even the safest lithium iron phosphate batteries. Many consumers may ask, how high is lifepo4 battery safety? Will it explode?
1. Is the lithium iron phosphate battery itself safe?
Whether the lithium iron phosphate battery (that is lifepo4 battery) will explode or not depends on whether the daily battery usage scenario has the conditions for explosion. An explosion requires the presence of sufficient oxygen, the concentration of combustibles up to the standard, an ignition source and a limited space at the same time.
As far as the lithium iron phosphate battery itself is concerned, it benefits from the properties of the battery material itself. Only when the battery temperature is at a high temperature of 500 - 600 ° C, its internal chemical components begin to decompose.
Compared with the high-nickel material of the ternary lithium battery, which begins to decompose and release oxygen at around 200°C, the lithium iron phosphate battery is much safer, so lifepo4 battery safety is higher. This is because the P-O bond in the lithium iron phosphate battery crystal is stable, and it will not form a strong oxidizing substance even at high temperature.
Under the limited oxygen supply of the battery compartment, it cannot generate high temperature instantly by itself, and it is difficult to meet the explosion conditions. Lithium iron phosphate battery itself has good safety.
2. What are the lifepo4 battery safety designs of battery system?
The lifepo4 battery safety is only passive safety, in order to reduce battery accidents and improve vehicle safety. Engineers will also add an additional safety barrier when designing the battery management system, also called active safety.
When the battery system is designed, a temperature sensor will be laid on the surface of the battery to detect the working temperature of the battery. At the same time, it will also detect the current of the battery system and battery cells and car battery voltage, and transmit the data to the vehicle processor in real time.
Once the characteristics of the early stage of battery thermal runaway, such as abnormal temperature and zero battery cell voltage, will immediately cut off the working circuit and display the fault on the control screen to remind the owner to deal with it, so as to improve lifepo4 battery safety.
If the battery breaks through the first line of defense set by lifepo4 battery safety and "thermal runaway" occurs, lifepo4 battery safety will have further explosion-proof measures. For example, Great Wall's "Dayu Battery", after the battery thermal runaway occurs, the double-layer composite material between the cells can effectively isolate the heat source, inhibit the expansion of the cells, and prevent internal heat from spreading.
The high-temperature, high-pressure gas flow generated during this process will be distributed through the commutation channel to avoid re-ignition. In the event of a serious vehicle accident or extreme "thermal runaway", the explosion cannot be avoided.
The battery is also equipped with a fire extinguishing and oxygen barrier mechanism at the explosion discharge outlet to quickly suppress the flame and prevent secondary combustion while directional explosion discharge.
3. What happened to the lithium iron phosphate battery explosion?
Although the lifepo4 battery safety is very high, related explosive news can still be found on the Internet. For example, in 2021, the explosion investigation of the Beijing energy storage power station was determined to be caused by a short circuit of the lithium iron phosphate battery.
However, a detailed study reported that the lithium iron phosphate battery in the battery room of the South Building had an internal short circuit fault, which caused the battery to run out of control and catch fire and produce flammable and explosive gases. In the final analysis, the safety monitoring system was not considered comprehensive and failed to detect combustible gases in time.
The explosion was not caused by the lithium iron phosphate battery itself, but because the four conditions of sufficient oxygen, standard combustible concentration, fire source and limited space were met to induce the explosion. In daily new energy vehicle accidents, you can see that fires and combustion are reported instead of explosions. This is because the two conditions of meeting the standard combustible concentration and limited space are generally difficult to meet.
4. Precautions for using lithium iron phosphate battery
Charging: The lithium iron phosphate battery should be charged with a special charger, and the charging voltage should not exceed the specified maximum charging voltage, so as not to damage lifepo4 battery safety.
Charging temperature: The charging temperature of the lithium iron phosphate battery should generally be controlled between 0°C and 45°C. If it exceeds this range, it will have a great impact on the lifepo4 battery safety.
Operating environment: The ambient temperature of the lithium iron phosphate battery should be controlled between -20°C and 60°C. Exceeding this range will have a great impact on battery performance and lifepo4 battery safety.
Discharge: Lithium iron phosphate battery should try to avoid low voltage discharge, so as not to affect the life of the battery.
Storage: Lithium iron phosphate batteries should be stored in an environment of -20°C-30°C for a long time to avoid lifepo4 battery safety to the battery due to overdischarge.
Maintenance: Lithium iron phosphate batteries need regular maintenance to ensure the normal use of the battery.
5. Precautions for lifepo4 battery safety
Lithium iron phosphate batteries should not be placed in the fire source to avoid fire.
The lithium iron phosphate battery cannot be disassembled, so as not to cause the battery cell to burn and explode due to misuse.
Lithium iron phosphate batteries should be kept away from flammables and oxidants to improve lifepo4 battery safety to avoid fire.
When using lithium iron phosphate batteries, care should be taken to avoid dripping and polluting the environment, and pollutants should be cleaned up in time.
The battery pack voltage of the lithium iron phosphate battery should not exceed the specified maximum voltage, so as not to damage the battery pack.
Lithium iron phosphate batteries should be placed in a dry and ventilated environment to avoid overheating and short circuits.
During the use of lithium iron phosphate batteries, attention should be paid to regularly checking the voltage and temperature of the battery pack, and replacing the battery pack regularly to avoid failure.
Lithium iron phosphate battery has the advantages of high energy density, high safety, long life, low cost and environmental friendliness, and is currently the most advanced lithium-ion battery technology. However, you also need to pay attention to the above precautions and lifepo4 battery safety precautions during use to avoid battery damage, fire and other dangerous situations.
No matter when lifepo4 battery safety always ranks first, although the lithium iron phosphate battery itself and its application have multiple safety guarantees, explosion is already an ultra-low probability event.
Battery companies such as the top 10 lithium battery companies in the world are advised to pay more attention to the relevant knowledge of lifepo4 battery safety to prolong the service life of the battery. Consumers who are still on the sidelines for new energy vehicles can boldly choose models with lithium iron phosphate batteries.