What circumstances will make the battery of an electric car explode?

Lithium polymer batteries are safe. Why? Mainly packaging plastic film, the battery is in a relatively high ductility, plastic film in the ninety s electronic newspaper said initial reports is Beijing XXX department invented called safety lithium polymer battery in decades past, polymer lithium battery I think a kind of safe, even if once break swells like blowing balloons than the original constitution increased more than twice as likely to also won't immediately sauce have a cushion, but more than the scope of security will burst open burning, explosive power is very small can avoid the instant it hurts, combustion is given priority to have a chance to escape, and the metal shell of lithium electricity a much higher risk, Once it expands it explodes and there's no chance of avoiding it. Remember the polymer film encapsulated lithium batteries, these batteries will be seriously affected by moisture will expand, but will not explode only about twice the size of the bulged body, there is no immediate danger of injury. These batteries are generally disposed of for safety reasons and cannot be used again.

Safety: 9.0 points

Lithium polymer battery is used for mobile power supply. As we all know, when the overcharge and short circuit of ordinary lithium ion batteries occur, the battery interior may be heated up, positive electrode material decomposition, negative electrode and electrolyte material are oxidized and other phenomena, which will lead to gas expansion and increase the pressure inside the battery. When the pressure reaches a certain degree, explosion may occur. Polymer lithium-ion batteries, which use colloidal electrolytes, do not boil and produce large amounts of gas, thus eliminating the possibility of violent explosions.

When charging, it is easy to explode. The instantaneous discharge can also cause the battery to explode. The high temperature will also cause the explosion. However, the electric car battery explosion probability is about two in ten thousand. Most of them are caused by a series of problems, such as battery fluid leakage caused by high speed, which cannot be stored without charging. Of course, there are also some bad habits caused by such as charging a line is not firmly connected, the battery short circuit and so on.

It is not possible to disconnect the connector clip while the battery is charging, because it is more open when the battery is connected in series. When you disconnect a battery clip while the other end is charging the battery a strong current will charge the battery. The correct way to disconnect the battery clip is to turn off the charger power before disconnecting the clip. When charging, firstly clamp the wiring clamp and then open the charger switch.

Addendum: I checked later, in an instant discharge can also cause battery explosion. Personally, I think you'd better go to the authority to make an appraisal to see whether there is a problem with your battery or the problem with the charger. If it's a battery problem and you have enough evidence to go after it, you'll have a better chance of winning

In the process of charging the battery of hydrogen and oxygen for failing to discharge and produce trace spark when charging you disconnect clamp, oxyhydrogen point inside the likelihood (hydrogen and oxygen mixture is flammable gas), as long as one of the lattice point of mixture was however, then the other will also broke out at the same time, so the power is enough to make the whole battery exploded

The failure of charging protection device of charger leads to excessive charging

Electric car battery is similar to cell phone battery, REDOX reaction occurs in the process of charging and discharging. The explosion or spontaneous combustion occurs mainly because the battery heats up and accumulates, and has no time to diffuse or release caused by. That is to say, a large amount of heat (reaction heat, polarization heat, joule heat, etc.) is generated in the process of charging and discharging of the battery, which leads to the rise of temperature inside the battery and the uneven temperature between single batteries, resulting in unstable battery performance.

Batteries for hybrid electric vehicles and pure electric vehicles are mainly classified as follows according to anode materials: lithium iron phosphate battery, lithium ternary battery (including NCA and NCM), lithium manganese acid pool, lithium cobalt acid pool, nickel metal hydride battery, lithium titanate pool, etc.

Among them, lithium iron phosphate battery and lithium ternary battery are the mainstream products. Their respective advantages and disadvantages are as follows. Compared with lithium iron phosphate, lithium is the safest. The cost of ternary lithium battery is more suitable for commercialization.

But this is only the property of the decision, just as the bomb itself is dangerous, but if managed and controlled, can also be safely stored. If the battery has a reasonable battery management system and a thermal management system (BMS), the battery will be controlled and can be safe, and the electric vehicle will not explode or spontaneously ignite because of the battery.

How can the battery not explode

Now we know that heat is released in the working process of the battery. If the heat generated in the charging and discharging process of the battery is not released enough, the heat will get out of control, or even spontaneously ignite or explode, which will have a significant impact on the performance and safety of the battery. Therefore, it is necessary to manage the battery temperature through the thermal management of the battery. Thermal management system is mainly a subsystem of battery management system. It can cool the battery when the battery temperature is too high or preheat the battery at low temperature to protect and give full play to the performance of the battery.

The cooling methods of batteries in thermal management system are generally as follows: forced fan cooling, phase change cooling, heat pipe cooling, thermoelectric cooling, air conditioning cooling, and cold plate cooling (the medium can be liquid or gas).

The famous tesla USES liquid cooling (50% water + 50% glycol, preventing the liquid from flowing at low temperature) to control the temperature rise. General motors Volt battery system is cooled and heated by a phase change material (PCM) method.

Volkswagen's audi a3sportbacke-tron USES a liquid cooling system with a low-temperature loop to keep the battery temperature in the optimal range and ensure that the electric drive unit can achieve the best power and endurance even in low ambient temperatures.

Only by truly mastering core technologies such as battery management system and thermal management system can natural or explosive phenomena caused by batteries of new energy vehicles be avoided. Do not blindly strive for subsidies, blindly catch up with the trend and put the cart before the horse and ignore the safety of electric vehicles and other issues.

Speaking of pure electric cars, how can we not mention tesla! On November 4, two passengers were killed when a ModelS struck a tree at high speed in Indianapolis, setting the vehicle ablaze. This is the fourth fire in netzra this year.

The battery used by tesla is a lithium cobalt 18650 battery supplied by Panasonic. The material's batteries are less safe, more likely to catch fire and more energy-dense than lithium iron phosphate batteries used in other mainstream electric cars. One of the factors behind the ModelS 'excellent range is the battery's energy density, but the risk factor has also multiplied.

In recent years, new energy vehicles have been booming. With the national subsidies and the progress of new energy technologies, the price of pure electric vehicles has been gradually reduced and entered thousands of households, providing a better choice for green travel.

A lot of friends know, gasoline belongs to flammable, explosive energy, electric car power battery is not vegetarian, temper is very hot. For example, the Samsung mobile phone "explosion gate" event which successfully topped the headlines of various media this year. It was the explosion of a mobile phone's battery when it was being recharged that reintroduced the power of lithium batteries.

Batteries used in the present, pure electric vehicles, mostly lithium-ion batteries, lithium batteries because, with other than battery, it has high voltage, high specific energy, charge and discharge, long service life, no memory effect, no pollution, quick charging, low self-discharge rate, and the advantages of the safety level of working temperature range, is widely used in electric energy.

Disadvantages: poor safety, poor high temperature resistance, poor life, poor power discharge, toxic elements (lithium ternary battery high power charge and discharge after a sharp rise in temperature, the release of oxygen after high temperature is very easy to burn).