In recent months, the new leader of China's automobile industry, Wei Lai, has suddenly "fired". In just more than two months, there were many hidden safety hazard accidents in Weilai Automobile, most of which were auto spontaneous combustion. First, in late April, a Weilai electric vehicle under repair in Xi'an spontaneously ignited; then, in mid-May, a Weilai ES8 being charged in Shanghai spontaneously ignited;
The "sources" of the above-mentioned spontaneous combustion of electric vehicles are all power batteries. At present, most of the power batteries of electric vehicles are lithium batteries, which is a type of chemical battery. If the positive and negative electrodes of a lithium battery are short-circuited, it will generate heat, which will cause the battery to swell to a certain extent, which will cause the electrolyte to leak, and it will easily contact with oxygen in the air and cause a fire and explosion. The above is a theoretical analysis of the causes of spontaneous combustion of electric vehicles. From a "macro" point of view, what are the causes of spontaneous combustion of electric vehicles?
First, the quality of the power battery is not up to standard
General power battery manufacturers will consider the safety of their use when designing and manufacturing batteries. Usually, a separator with many pores is added to the battery. A good quality separator can effectively shield positive and negative ions from meeting when the internal temperature of the battery is too high to prevent short circuits. On the contrary, the power batteries produced by some manufacturers may not meet the standards due to the poor quality of the separator, which poses a great safety hazard.
Second, the "fire prevention" measures of new energy vehicle companies are not in place
After selecting a power battery supplier, experienced new energy vehicle companies will do a series of "fire prevention measures". For example, Tesla is equipped with a temperature control device at the positive electrode of the battery cell, so that the resistance increases with the increase of the internal temperature of the battery cell, so that the current can be effectively limited to prevent overheating.