When people are experiencing battery fire and explosion, LiFePO4 batteries are labeled as safe simply because the negative result is very few. LiFePO4 batteries have different chemistry, even from their own lithium family. Now, you might wonder, is there absolutely no risk of fire or explosion? Let’s find out.
Can LiFePO4 Catch Fire?
No. LiFePO4 batteries do not generally catch fire. This battery has superior chemical and thermal stability, making it safer than other batteries. That’s why the possibility of catching fire, even at a very high temperature, tends to be zero.
Lithium Iron Phosphate is in and of itself a safer cathode material compared to manganese oxide or cobalt oxide cathode. You can say a fully lithiated LiFePO4 has a similar physical state as an unlithiated LiFePO4. It shows the battery is structurally stable.
Besides, the iron phosphate oxide bond is much stronger than others, so it will maintain its physical structure even if you overcharge a LiFePO4 battery for too long. Other batteries in this situation will start producing excessive heat and eventually suffer from thermal away.
In any case of abuse or mishandling, LiFePO4 batteries will not burn, and they are also not prone to thermal runaway. They remain stable in case of mishandling during charging or discharging and short-circuit events.
Can LiFePO4 Explode?
Now you know that LiFePO4 batteries have superior cathode material and chemical stability. Let me further add that they also have a superior anode material. Altogether, they are very stable in case of any extreme incidents. So, they won’t catch fire, let alone explode.
The reason is that lithium phosphate cells are incombustible even if you abuse them during charging or discharging. They will remain stable if you overcharge them or any short circuit happens.
The chemical reaction inside LiFePO4 batteries remains highly robust during oxygen loss while charging. That’s why, unlike other batteries, LiFePO4 can reduce the exothermic reaction. It generates only 5.5% of the heat produced by lithium cobalt batteries when overcharged.
LiFePO4 batteries can tolerate much more high temperatures without decomposing. So, because of the battery chemistry and interior stability, LiFePO4 batteries do not explode or ignite unless something drastic happens.
Maximum Temperature LiFePO4 Can Withstand
One of the reasons LiFePO4 batteries are considered so safe is that they can withstand very high and very low temperatures. As a general rule, the safe usage and storage temperature of LiFePO4 battery is –20°C to 65°C.
According to a study published at IOP Conference, analysis shows that the starting temperature for thermal runaway for a 25 Ah LiFePO4 battery is 120°C at 1C. This temperature varies based on the Ah of your battery.
The highest temperature for LiFePO4 battery thermal runaway is 514°C. This shows how stable LiFePO4 batteries are. It also shows that the LiFePO4 battery can withstand high temperatures without causing fire or explosion.
The following table will show you the thermal runaway temperature for various Ah of LiFePO4 batteries.
| Ampere Hours | Temperature |
| 25 Ah | 120 °C |
| 60 Ah | 131 °C |
| 200 Ah | 116°C |
But you must be particularly serious about the temperature while storing your LiFePO4 battery. Storing the battery at below-freezing temperature will cause lithium plating, where some cells will be disconnected from others and eventually reduce your battery capacity.
It can also crack the ABS case of your LiFePO4 battery. So, even though LiFePO4 batteries have a high operating temperature range, you should always use and store your battery within this temperature.
Do LiFePO4 Batteries Get Hot?
LiFePO4 batteries have very high energy density and extended cycle life and do not generate too much heat under normal conditions. These batteries have lithium iron phosphate cathodes and graphite carbon electrodes with metallic backing anodes.
Besides, the battery chemistry is very stable as well. Again, batteries heat up during charging and discharging due to high resistance. But LiFePO4 batteries have very little internal resistance, which does not heat the LiFePO4 battery during operation.
What Causes LiFePO4 Battery Failure?
LiFePO4 batteries are safer for regular use. They won’t generally catch fire or explode. But for batteries, the possibility of short circuits from the cells and materials is inherent. In some extreme cases, this battery can catch fire.
It happens because of the material selected by the manufacturer. Sometimes, some manufacturers use somewhat inferior materials to cut costs, which in extreme cases, give up and ignite.
If your LiFePO4 battery loses too many active lithium ions during the cycle, you will get reduced capacity from your battery. External temperature can be another reason for the failure of your LiFePO4 battery.
Final Thoughts
LiFePO4 batteries are one of the safest batteries, if not the safest option available out there. That’s why they are being widely used in Electrical vehicles. But remember, no battery is absolutely safe. So, make sure you use LiFePO4 batteries at recommended settings.
References
1. F. Gao et al. (2021). Study on Temperature Change of LiFePO4/C Battery Thermal Runaway under Overcharge Condition.
2. J. D. Hyun et al. (2020). Internal Heat Self-generation in LiFePO4 Battery Module.
Eng. Matthew Joseph Nandirio is the Founder of walkingsolar.
After graduating from the University of Houston in 2002, matt started working as a Solar Electrical Engineer for several multi-national solar energy companies.
He has a wide range of experiences including solar system requirement analysis, planning, maintaining, debugging and even solar device development through research.
He now shares his 20 years of expertise through his articles on the walkingsolar website.
Further, he is also the author of two books on Solar Technology, “Solar Power for Villages” and “DIY Solar System for Dummies”.