People speaks of electric car, talk very easily " lithium " color changes, tesla has produced the accident of collision spontaneous combustion many cases in the whole world, make everybody moves the Lv of safe heart be suspicious of the car to report. 2017 when, top Gear compere manage checks De Hammond to drive before Rimac Concept One is dynamoelectric super- serious traffic accident produces when running, and at that time car produced spontaneous combustion, all but of haing unconscious heart leave us and went.
But the so incidental spontaneous combustion of electric car? So terrible really?
We do not leave final conclusion first, will understand first, why lithium battery " easy " produce spontaneous combustion.
Lithium battery why spontaneous combustion? High school class hour awaits us to do the test of Guo Li Li, throw lithium in the beaker of water, lithium can produce severe reaction with water, release hydric. The metal with strong sex of lithium metal activity produces the reaction of spontaneous combustion extremely easily, we see lithium and water below (or the water in air) the equation that produces chemical reaction, he Li and oxygen produce the equation of reaction.
2↗ of Li + 2H2O = 2 LiOH + H2
4Li + O2 = 4LiO2
Lithium and water reaction generate hydrogenous lithia to mix hydric, and release much heat, reach hydric burning point when this temperature 570 Celsius when, can produce combustion or explode. If be in relatively airtight batteries group, this kind of reaction will more acuteness, can cause the chain reaction of whole batteries group especially, become ablaze conflagration finally.
What what say in front is academic qualification falls, lithium is inherent incidental spontaneous combustion, and in lithium battery, lithium ion lies stable condition. spontaneous combustion, advocate if be,be destroyed as a result of batteries.
1, metallic lethal weapon causes batteries short circuit, this very good understanding, was equivalent to metallic appliance forming loop to make batteries short receive.
2, outside force is destroyed cause diaphragmatic attaint to bring about batteries short circuit. Give out heat when dc short circuit tremendous, cause batteries to heat up out of control, the meeting when hot out of control comes in the temperature rise inside millisecond class time 300 Celsius above. Cobaltic lithium and temperature of 3 yuan hot out of control all under 300 Celsius, manganese lithium makes an appointment with 400 Celsius, tie Li is highest for 700 Celsius.
The mainest tinderbox inside lithium battery is electrolyte actually, electrolyte burning point makes an appointment with 130 Celsius. Actually each have fire retardant in domestic product, what can reduce this kind of circumstance as far as possible is exasperate, because batteries group is destroyed,the spontaneous combustion event that produces at present is for the most part, electrolyte is poured out of bring about.
because be put in such safe hidden trouble, so GB had Yan Ke's test in the light of group of electric car batteries.
Current technology basically is batteries technology gives priority to 3 yuan of lithium, GB GB/T31484, GB/T31485, GB/T31486 had moved car batteries part to have very strict test level to report, we are hep is collision, extruding, immerse, baked wheaten cake checks, these check even if undertake in the light of the situation that electric car may encounter Yan Ke checks.
We with " monomer is fought pressure " citing, above all cell line is full of, next perpendicular squash with the speed of 5mm/s at batteries plate, if voltage achieves 0V or form variable is achieved 30% or achieve 200K ox (the pressure that is equivalent to 20 tons) hind stop, observe a hour, detect whether does batteries produce spontaneous combustion. There still is most exciting puncture to experiment outside dividing take second place, the engineer is gone to with the speed of 10mm/s, 250mm/s respectively nail is knocked in batteries, I can tell you to do the meeting on fire with this true test! Then the engineer protects housing to prevent this kind of accident happening with the metal. This test cancelled temporarily in GB at present nevertheless.
The motor-car that buy electricity is added send " chassis armor "
Speak out you may very open-eyed, of electric car truckload the benzine car that security Yuan Chao is the same as price (premise is electric car platform) . Why so say? Take tesla give an example, above all electric core level has safety design, batteries is wrapped even if above what we carry undertook extruding, collision, decline test. The most important is tesla batholith undertook high strenth aggrandizement, what should answer above all is the puncture of chassis lower part, next whole batholith should undertake aggrandizement, the batteries group weight that exceeds 600kg in order to bear and answer flank and front bump, the extruding that prevents batteries bag is out of shape. We can see from the graph tesla MODEL S has apparent collision to suck can structure, at the same time aggrandizement side bridge and beam.
Summary:
Indeed, eye comes round to say electric car still exists batteries group destroys the risk that creates spontaneous combustion because of outside force, but this kind of risk is exceedingly little, theoretic the possibility that explodes with fuel car gasoline tank is adjacent. As GB standard upgrade ceaselessly, with the ceaseless innovation of technology of electric car manufacturer, the security that believes electric car is met Yuanchao fuel car.
