Lithium iron phosphate batteries will catch fire due to a short circuit. Lithium iron phosphate batteries will not explode or catch fire under normal circumstances. Lithium iron phosphate batteries are relatively safe during normal use, but there is no guarantee that they may be dangerous in certain extreme circumstances. This has a lot to do with each company's material selection, ratio, process and subsequent use.
Lithium iron phosphate batteries will not explode or catch fire under normal circumstances. Lithium iron phosphate batteries are relatively safe during normal use, but there is no guarantee that they may be dangerous in certain extreme circumstances. This has a lot to do with each company's material selection, ratio, process and subsequent use.
Although the phosphate materiallithium iron has the highest thermal stability and structural stability among all current cathode materials in terms of thermodynamics, and has also been verified in the detection of actual safety performance, but from the material and in terms of the possibility and the likelihood of a short circuit inside the battery, this can be the most dangerous.
First of all, from the perspective of material preparation, the solid-phase sintering reaction of lithium iron phosphate is a complex multi-phase reaction, including solid-phase phosphate, l iron oxide and lithium salt, plus a carbon precursor and reducing gas phase. In order to ensure that the iron element in lithium iron phosphate is divalent positive, the sintering reaction should be carried out in a reducing atmosphere. In the process of reduction of ferric ions to positive divalent iron ions in a strong atmospherereductively, there will be some positive. divalent iron ions. Possibility of further reduction of iron ions to trace amounts of elemental iron.
Elemental iron can cause micro-short circuits in batteries and is the most taboo substance in batteries. This is one of the main reasons why Japan does not use lithium iron phosphate in lithium-ion batteries. Additionally, an important characteristic of solid phase reactions is the slowness and incompleteness of the reaction, which allows for the existence of trace amounts of Fe2O3 in lithium iron phosphate. The Argonne Laboratory in the United States attributes the poor high-temperature cyclability of lithium iron phosphate. lithium iron phosphate to Fe2O3 Dissolution during charge and discharge cycles and precipitation of elemental iron on the negative electrode. In addition, in order to improve the performance of iron phosphate andlithium, its particles must be nanometric in size. A notable feature of nanomaterials is their low structural and thermal stability, as well as high chemical activity, which to a certain extent also increase the probability of dissolution of iron in lithium iron phosphate, especially under conditions of cycling and storage at high temperatures. The test results also indicate that the presence of an iron element was detected on the negative electrode by chemical decomposition or energy spectrum decomposition.
In terms of lithium iron phosphate battery preparation, due to the smaller nanoscale particles of lithium iron phosphate, the specific surface area is higher, and due to the carbon coating process, activated carbon with a high specific surface area is very effective in air. Gases such as moisture have strong adsorption properties, whichresults in poor electrode production performance and poor adhesion of the binder to its nanoparticles. Whether during the battery preparation process or during the battery's charge-discharge and storage cycle, nanoparticles can easily detach from the electrodes, causing internal micro-short circuits in the battery.
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The explosion of electric vehicles is a ternary lithium battery. Lithium battery explosions are caused by thermal runaway or damage to the separator. Thermal runaway is easy to understand, it is overheating. If the lithium battery overheats, it will catch fire and explode.
Basically, there is a separator inside the lithium battery. If the separator is damaged, the positive and negative electrodesatives will immediately come into contact, causing a short circuit. If the battery is short-circuited, it will explode instantly. Of course, when using lithium batteries, be careful not to puncture the battery. This is fundamentally very dangerous behavior.
When charging, be careful not to overcharge, and the voltage and current should not exceed the limits. If the voltage and current exceed the limit, the temperature of the lithium battery will also be too high, which can easily cause the lithium battery to explode and fire.
Lithium batteries commonly used in pure electric vehicles
There are two types of lithium batteries commonly used in pure electric vehicles, one is lithium iron phosphate battery and the other is It is ternary lithium battery. Ternary lithium batteries have a high energy densitye and light weight, but their safety factor is poor.
Lithium iron phosphate batteries have a very good safety factor, but their energy density is low. Lithium iron phosphate batteries will only burn at 800 degrees Celsius, while ternary lithium batteries will start burning at 200 degrees Celsius.