Once the lithium battery itself is manufactured, it still needs to be tested before it can be used. The use of shrapnel microneedle modules can effectively improve the testing efficiency of mobile phone lithium batteries. During current transmission, it can pass a large number of tests. 50A current and can also handle small steps. With stable connection function and long service life, it is a reliable battery test module.
Common causes of lithium battery fire are:
Insufficient capacity of the negative electrode
When the capacity of the negative electrode is insufficient or does not have capacity, charge Some or all of the generated lithium cannot be inserted into the graphite interlayer structure of the negative electrode and will precipitate on the surface of the negative electrode, forming "dendrites" protruding during the next charge,this protruding part is larger. likely to form lithium precipitation. After dozens or even hundreds of charge and discharge cycles, the “dendrites” will grow and eventually pierce the barrier paper, causing an internal short circuit. The battery core discharges quickly, generating a lot of heat, burning the diaphragm and forming a larger short circuit, which will cause the electrolyte to decompose into gas, and the negative carbon and paper in the diaphragm will burn, resulting in excessive internal wear. Pressure. When the battery core casing cannot be exposed to this pressure, the cell will burst.
Moisture content is too high
Moisture can react with the electrolyte in the battery core to produce gas. During charging, it can react with the generated lithium to generate lithium oxide, which will cause a reaction. cause damagebattery core oration. Loss of capacity can easily overload the battery core and generate gas. The water decomposition voltage is low, and it is easy to decompose and generate gas during charging. When this series of gases generated increases the internal pressure. of the battery core, when the outer casing of the battery core is unacceptable, the battery core will explode.
Internal short circuit
Due to an internal short circuit, the battery core discharges with a large current, generates a lot of heat, burns the diaphragm and forms a larger short circuit. phenomenon, so that the battery core produces high temperature, causing the electrolyte to decompose into gas, resulting in excessive internal pressure. When the outer shell of the battery core cannot withstand this pressure, the battery core will explode.
Overload
WhenIf the battery is overcharged, excessive release of lithium from the positive electrode will cause the structure of the positive electrode to change. If too much lithium is released, this will happen. It will easily be impossible to insert it into the negative electrode, and it will also easily cause the battery to overcharge. Lithium will precipitate on the surface of the negative electrode, and when the voltage reaches more than 4.5V, the electrolyte will decompose and produce a large amount. quantity of gas. All of the above can cause explosions.
External short circuit
An external short circuit may be caused by incorrect operation or misuse. Due to external short circuit, the battery discharge current is very large, which will cause the battery core to fail. High temperature will cause shrinkage or complete damage to the diaphragm inside the core of thebattery, causing an internal short circuit and therefore an explosion.
How to extinguish fires in lithium batteries
The reasons are probably as follows:
The battery is overcharged, the charging time is too long, and the battery never dies after charging. Disconnect the battery and leave the charger connected to the battery.
Excessive use of the battery, heavy charging for a long time, excessive discharge of the battery, the battery will heat up and there is a risk of explosion due to overheating.
The battery circuit is shorted.
I hope this can help you
When lithium iron phosphateWhich components are usually damaged first when the positive and negative terminals of the battery are short-circuited?
The method of extinguishing a lithium battery fire is as follows:
1. UtUse a fire extinguisher to put out the flames. Usually after that the fire is extinguished and the battery continues to smoke. Most fire extinguishers can achieve this effect.
2. Since lithium batteries will reignite if not cooled, it is very important to use plenty of water to cool the batteries. (Note) Continue watering.
3. It is best to move the burning battery outside and then call the fire department to deal with it.
4. Smoking is harmful to the body. Do not breathe smoke.
?Causes of lithium battery fires:
1. Insufficient capacity of the negative electrode of the lithium-ion battery
When the negative electrode of the positive electrode of the lithium-ion battery. When the site capacity is insufficient, the lithium atoms that appear during charging cannot be inserted into the graphite interlayer structure of the electricnegative electrode and will precipitate on the surface of the negative electrode to form crystals. Long-term crystal formation in lithium-ion batteries can lead to short circuits. At this time, the cells discharge rapidly, generating a large amount of heat and burning the separators. High temperature will cause the electrolyte to decompose into gas. When the pressure is too high, the battery core will explode.
2. The moisture content is too high
During charging, water may react with lithium to generate lithium oxide, which will cause the battery to lose capacity and be easily overcharged. Battery. Gas is generated. The decomposition voltage of water is low. It is easy to decompose to generate gas during charging. When this series of gases generated increases the internal pressure of the battery core, when the battery core shell cannot resist. that,the battery core will explode.
3. Internal short circuit
The internal short circuit of the cell causes a large current discharge, a large amount of heat, burns the diaphragm and causes a larger short circuit, which causes the decomposition of the electrolyte into gas, if the internal pressure is too high, the battery core will explode.
4. Overcharging of lithium-ion batteries
When the battery cell is overcharged, excessive release of lithium from the positive electrode will cause the structure of the positive electrode to change, and also a large amount of released lithium will easily make it impossible to insert. In the negative electrode, it is also easy to cause lithium precipitation on the surface of the negative electrode. In addition, when the voltage reaches more than 4.5V, the electrolyte will decompose to produce a large amount of lithium. quantity of gas. Everything thati above may cause an explosion.
5. External short circuit
External short circuit can be caused by poor connection of the positive and negative poles. Due to the external short circuit, the battery discharge current is very high. large, which will cause the battery core to heat up, and the high temperature will cause the diaphragm inside the battery cell to shrink or completely damage, causing an internal short circuit and thus explosion.
When the positive and negative poles of a lithium iron phosphate battery are short-circuited, which components are usually damaged first? Dear Hello, when are the positive and negative poles of a lithium iron phosphate battery? are shorted, the separator is usually the first to be damaged. Reasons for short circuit of lithium iron phosphate battery: Short circuit of lithium iron phosphate battery means that the electroPositive and negative of the battery are directly connected with wires to form one. abnormal path, which will cause serious damage to the battery and cause burns, which may cause fire, or the battery container may be damaged due to excessive pressure and explosion. Lithium iron phosphate batteryThe short circuit caused the positive and negative poles of the battery to come into contact.