City Express News Yesterday, the spontaneous combustion incident of the battery car on Yuhuangshan Road in Hangzhou touched everyone's heart, and the father and daughter were seriously burned and still not out of danger of life. This accident has caused many netizens to speculate and worry, why did the electric vehicle involved suddenly spontaneously combust? The incident is so sudden, how to minimize the damage? How to self-test electric vehicles in daily life to prevent such accidents?
Experts analyze the self-ignition video of electric vehicles on Yuhuangshan Road:
The high probability is that the lithium battery explodes inside
The head of the power supply department of the R&D center of a well-known electric bicycle brand in Zhejiang said yesterday after watching the video of spontaneous combustion of electric vehicles that this situation is most likely caused by lithium batteries.
He said that at present, on the market, electric vehicle batteries are mainly lithium batteries, but there are also lead-acid batteries. Since April 2019, the country has a new national standard, and the weight of electric vehicles must not be more than 55 kg. Lead-acid batteries are relatively heavy, and it is difficult for the vehicle weight to reach within 55 kg, so most electric vehicles on the market currently use lighter lithium batteries. 48 volts, 12 amp hours (capacity) lead-acid batteries weigh about 16.4 kg, and the same standard lithium battery is only 4 kg.
Lead-acid batteries have different weights from lithium batteries and have different internal structures.
"Both kinds of batteries have cells and battery packs, but lithium batteries have electronic protection plates inside, which is because lithium batteries have a low safety factor compared to lead-acid batteries." In addition, lead-acid batteries are connected in series when they work, while lithium batteries are connected in parallel or series. The person in charge said that under the same capacity, lead-acid batteries have a lot less mileage than lithium batteries, which is also one of the reasons why there are more lithium batteries on the market.
According to family members, it cost 500 yuan to replace the battery last year.
The person in charge said that the current lead-acid battery (48 volts) is about 400 yuan, but 500 can buy lithium batteries.
"The quality of the core battery and the process technology of the battery pack are too complicated, and some manufacturers' lithium batteries reduce the quality of the cells, or the battery pack process cannot pass the requirements, but the price is relatively cheap."
The expert said that the probability of such a situation in lead-acid batteries is extremely low, or even almost impossible, because lead-acid batteries are basically less likely to spontaneously combust.
"The reason why the safety factor of lead-acid batteries is high is because the electrolyte of lead-acid batteries is dilute sulfuric acid, that is, a solution of sulfuric acid and water, which is not flammable in itself, so the probability of spontaneous combustion is very small." Of course, lead-acid batteries also have the possibility of spontaneous combustion or explosion. ”
The person in charge said that the spontaneous combustion or explosion of lead-acid batteries requires two conditions, the first is that in the case of overcharge, hydrogen and oxygen will be produced, and the second is that during the discharge process, there is an electric spark ignition. That is to say, lead-acid batteries in the case of charging, basically will not spontaneous combustion or explosion, only in the discharge that is, during the driving process, there is an electric spark or short circuit, so that the reaction with hydrogen and oxygen will spontaneously combust or explode."
However, there is an overflow valve in the lead-acid battery, when the battery is overcharged and the air pressure generated is high, the valve will automatically open to discharge the gas (hydrogen and oxygen), so the probability of spontaneous combustion or explosion during driving is small.
"And the lithium battery inside the electrolyte organic matter (lithium hexafluorophosphate), with flammability, its positive electrode is lithium ion, the negative electrode is graphite, usually, lithium ions are embedded in the positive electrode, when fully charged, if a short circuit occurs, it is easy to cause lithium precipitation, plus its chemical properties are more active, can not be in contact with oxygen in the air, a contact, it is easy to cause thermal runaway, chemical reactions are more violent (such as explosion), electric vehicles are naturally easy to burn up.
"In addition, when the lithium battery electric vehicle is in the process of driving, in the case of discharge, due to the inconsistency of the battery voltage, resulting in a single cell of the battery over-discharge, may also cause heat or explosion."
"Therefore, in the internal structure of lead-acid batteries, there is no electronic protection board, because its own safety performance is very high, and lithium-ion batteries need electronic protection boards."
In the past, spontaneous combustion of electric vehicles would smoke first, why did it suddenly burn so much this time?
The person in charge said that this depends on which component of the lithium battery spontaneously combusts, or what kind of reason is caused, like this electric bicycle fire, from the monitoring screen, it is likely that there was an explosion inside the lithium battery at that time, "The energy of the lithium battery is still very large, and the power of the explosion is no less than the impact of a small grenade."
The person in charge reminded that the use of electric bicycles on high temperature days cannot be charged for a long time at first, as long as 80% of the electricity is guaranteed.
Replace the battery must be replaced at the original store (brand store), it is best to replace the charger together, because the voltage and current requirements are different, and the mismatched charger charging case is easy to cause some battery failures.
Most importantly, be sure not to take it home to charge, once an accident occurs, the consequences at home are more serious.
Hangzhou Electric Bicycle Industry Chamber of Commerce Emergency Notice:
More than 2,000 stores immediately self-inspected and self-inspected
Lin Ping, president of the Hangzhou Electric Bicycle Industry Chamber of Commerce, just returned to Hangzhou from a business trip yesterday, and was very distressed to see the news of the electric vehicle fire, and called the reporter. Chairman Lin introduced that there are more than 2,000 electric bicycle sales stores in Hangzhou, and the Chamber of Commerce has issued an emergency notice:
All electric bicycle operators in the city:
Ask everyone to immediately self-test and self-examine the following:
One: must sell products that meet the 3C standard, and it is strictly forbidden for stores to install and modify vehicles!
Second: It is strictly forbidden to charge the electric bicycle in the unmanned state of the store.
Three: It is strictly forbidden for business owners to live in shops at night.
Four: The batteries in all car bodies must be separated.
Five: All store lithium batteries must be stored separately; at the same time matched with the necessary safety and security tools!
All merchants are requested to immediately conduct self-examination of their stores to avoid unnecessary economic losses and personal injuries!
Hangzhou Municipal Bureau of Market Supervision:
The family will be informed about the place where the spontaneous combustion electric vehicle was purchased
And whether it is a 3C certified product
There are a total of 21 electric vehicle 3C certificates in Hangzhou, and everyone can self-test
Yesterday, the reporter learned from the West Lake Scenic Area Branch of the Hangzhou Market Supervision Bureau that the relevant staff of the Market Supervision Bureau has also arrived at the scene, and will next learn from the family about the purchase location of the electric vehicle and whether it is a 3C certified product.
"Although the place of the incident is a scenic spot, the place of purchase of electric vehicles is not clear for the time being, and it needs to be understood clearly before there can be a follow-up action." The person in charge said that next, the West Lake Scenic Area will conduct a comprehensive inspection of the electric vehicle sales and maintenance business units in the jurisdiction.
From April 15, 2019, the state prohibits the production and sale of electric bicycles and other electric vehicle products that do not meet national standards. When the public buys electric bicycles, they should look for the 3C certification (CCC certificate, full name: mandatory product certification system).
3C certification is a product conformity assessment system implemented by the Chinese government in accordance with laws and regulations to protect consumers' personal safety and national security and strengthen product quality management.
Orange Persimmon Interactive reporter learned from the Hangzhou Municipal Market Supervision Bureau that at present, from the system query, there are 3 electric bicycle production enterprises in Hangzhou, 21 3C certificates, mainly concentrated in Xiaoshan District. There are about 2,400 sales and maintenance units in the city.
After the enforcement of electric vehicle 3C certification, the product safety threshold has been improved, at the same time, as a product safety standard towards the world, 3C certification plays the role of "quality passport" in international trade, and its implementation of certification and supervision in parallel ways can more effectively supervise the whole process of electric vehicle production and sales.
True 3C certification requires that in addition to the whole vehicle, there are nine major components that require 3C certification, which are: front combination lights, front turn signals, brake hoses, rear combination lights, rear license plate lights, rear mirrors, reflectors, tires, and horns.
When you buy an electric bicycle, you can pay attention to the following 5 points -
(1) 3C certification should be seen clearly
The electric bicycles sold now need to have 3C certification, so be sure to look for the 3C logo when buying.
(2) Electric vehicles 4 large pieces to pay attention to
When purchasing electric vehicles, we should also pay attention to the "4 major parts" of electric vehicles, namely motors, controllers, batteries, and chargers. As the most critical component of the electric vehicle, the quality of the four major parts directly affects the user's driving experience and safety.
(3) Brake braking is critical
As the brake device of electric vehicles, whether it is safe and secure during riding depends on it. Whether the brakes of electric vehicles are reliable or not is entirely related to the safety of cyclists' lives and property.
(4) Pro-test pro-ride on demand
Different user groups have different needs for electric vehicles, so when buying a car, if you can personally ride and experience it, it is better.
(5) After-sales warranty is very important
When buying a car, it is necessary to see whether the after-sales service is guaranteed. For example, whether there is a national unified after-sales service, whether the online and offline service system is guaranteed, and whether the "three guarantees" period is complete. Complete after-sales can make you worry a lot.
How can you intuitively and concisely judge whether the vehicle meets the new national standard?
The simplest way is to judge by checking whether the product is marked with the 3C mark; in addition, it can also be judged by checking whether it meets the requirements of the top speed of 25 kilometers per hour, the motor power of 400W, the mass of the vehicle is 55 kg, and the pedal riding function.
In addition, when purchasing, in addition to looking for 3C certified electric vehicles, electric vehicles can not be modified at will, let alone change their engines and batteries.
You can check the electric vehicle at home according to this, if the purchased electric bicycle does not meet the standard, you have the right to return or replace, and you can report to the market supervision department.
Burned Master Wei:
Delivered takeaways and worked as a security guard
Just worked a month at the new unit
Yesterday, under the complaints of many family members at the scene, I learned some of the life of the Wei family who were burned.
Around 1996, Wei Shunli and his wife Zhai Xiaojuan came to Hangzhou to work.
Over the years, Wei Shunli has worked as a security guard, delivered takeaways, and worked as a delivery man.
The family rented lotus peak road, which is two small bungalows, adding up to more than ten square meters. The monthly rent is nearly two thousand.
Crowded here, he and his wife have lived here with a pair of children for almost a decade.
A pair of children grew up slowly, and his wife and children were too busy to come, so he returned to the city.
A month ago, Wei Shunli was still working at the Jade Emperor Villa.
Zhai Xiaojuan said, "More than 4,000 a month, because two children have to be raised, he feels a lot of pressure, and then changed his current job." The salary now is a little more than in the past. ”
The new unit had only been on the job for a month, and had not yet received a salary, and Wei Shunli and his daughter had this incident.
The 14-year-old son whispered:
"I'm scared..."
Yesterday in the Zhejiang University Children's Hospital, I met Wei Jiale, the son of Wei Shunli.
14-year-old Jiale is in junior high school, with a worried look on her face and anxiety that is not commensurate with her age.
Talking about dad and mom who got burned, he talked to me a lot.
"It was hot in the summer, and when I was in the sixth grade of elementary school, my dad ran takeout every day and came home in the evening.
Every time he went out, there was a big Coke bottle filled with water, and he had to bring two or three bottles with him.
Dad was so nice and came back every night with something good to eat for me and my sister.
My sister Jackie, 8 years old, she especially loves to dance..."
Xiao Wei was very sad and couldn't say anything more.
At the end, he quietly told me, "Uncle, I'm really scared!" ”
I looked at the boy and for a moment I really didn't know how to comfort him, "You're a man..."
I met Wei Shunli's younger brother Wei Xue, who said, "My brother is also in the intensive care unit now, and he can't find a single intact skin from head to toe..."
Why is the burn so bad in such a short period of time?
Can I drink water after a large-scale burn?
How to deal with burns urgently?
"The treatment of patients with large-scale burns is a very big challenge for medical staff. Patients have to go through a 48-hour shock period, followed by infection, the condition may change rapidly, and the final result is difficult to predict. Professor Han Chunmao, director of the Burn Department of the Second Hospital of Zhejiang University, said.
Judging from the video, the battery car fire is only in a short moment, such a short period of time, why did it cause such a serious injury?
Professor Han Chunmao said that people wear less in the summer, and after encountering a fire, it is easy to cause large-scale burns. Large-scale burns are not only damaged to the surface of the skin, it can cause a chain reaction, further causing damage to various organs throughout the body.
Because after a large-scale burn of the skin, the protective barrier of the human body's skin is damaged, and while the body fluids are extravasant, the blood vessels will expand, and the blood in the blood vessels will also be extravasant at this time, causing ischemia in various organs, resulting in the failure of the organs of the whole body.
Can I give the burned person water?
Yesterday at the burn scene, the man shouted, "I want to drink water, I want to drink water..." Some passers-by shouted, "Burned, don't give water to drink..." Many netizens wondered, at this time, supplementing water should not help cool down? Can I drink water after a large-scale burn?
Professor Han Chunmao said that patients with large-scale burns really cannot drink water, in this case, they can drink a little salt water. Because people after burns, with the extravasation of body fluids at the same time, sodium salt is also lost, if you give him boiled water at this time, it can lead to a further decline in the concentration of sodium chloride in the blood, but also cause acute gastric dilation or cerebral edema, thereby aggravating the disease, and even life-threatening.
Does the material of the garment also have an impact on the severity of the skin burn?
Professor Han Chunmao said that the material of the clothes does have a certain relationship, the clothes of the chemical fiber material are more flammable in case of fire, and the cotton is relatively better, but in the fire environment, only professional fireproof material clothes can play a protective role.
How to deal with burns urgently?
Professor Han Chunmao provided the following advice on on-site first aid after flame burns:
1. Quickly get rid of the source of injury, take off the burning clothing as soon as possible, do not run, do not shout, and minimize the damage of high temperature and smoke to the respiratory tract as much as possible;
2. Cold therapy: rinse or soak in cold water, such as rinsing or showering with plenty of tap water, for 20 to 30 minutes.
3. Protection of burn wounds: Simple bandaging can be done with clean sheets of clothing, etc. The wound should not be painted with a colored drug, so as not to affect the judgment of the depth of the wound in subsequent treatment.
4. Burn patients, especially severe patients, should seek medical treatment nearby and be transferred to a hospital with a burn specialty after being evaluated by the doctor.
If it is a large-scale burn, it can not be rinsed with cold water, because the skin barrier function of the human body is destroyed after a large-scale burn, and the human body temperature will be quickly emitted, so at this time, the person should be wrapped up with a clean blanket or sheet for heat preservation, and sent to the hospital for rehydration, anti-shock and other emergency treatment as soon as possible.
All walks of life have reached out to help Xiao Jiaqi's family.
I hope this family can survive this difficult time.