Brief statement of the safety problems and corresponding measures of lithium ion batteries

Lithium ion battery has the advantages of high energy, long cycle times and high efficiency and is widely used in various electronic products.

For example, our common battery charger is composed of 18,650 lithium ion batteries.

The same as the laptop is composed of lithium ion batteries.

Lithium ion battery, of course, there are many other applications. Such as smart phones, mobile devices, the vast majority are using lithium ion batteries; Electric moped, the electric car industry demand for lithium ion batteries are also more and more; In the field of future energy storage, lithium ion battery will puts glorious greatly.

But in the lithium ion battery of mankind at the same time, it also has the potential danger, the frequent burning and explosion accident of the lithium ion battery brought great threat to people's life and property safety.

At 5:53 pm on May 31, 2016, a lithium battery fire and explosion accident occurred in Jiangsu Haisida Power Co., Ltd. in Qidong, Nantong, Jiangsu. The accident occurred in a three-layer lithium battery at the company’s Nanyuan West Road in Qidong City, the pool full charge state warehouse. After the fire officers and soldiers arrived, they quickly launched a rescue. During the disposal, the scene suddenly exploded. The accident caused 12 employees and 8 firefighters to be injured on the spot. Subsequently, the injured were rushed to Nantong and Qidong Hospital for treatment. However, one firefighter and one Haidida employee died after being rescued.

At present a preliminary investigation of the cause of the accident, because the battery internal short-circuit temperature quickly, at the same time affect the adjacent cells change caused by the explosion.

In addition, on January 1, 2016 Tesla charging Models in Beijing, Nanjing, Hefei fire more electric car spontaneous combustion, such as Shenzhen factory fire, a fire broke out on the highway of the lithium battery delivery truck in Hunan.

According to the Associated Press, Boeing warned passenger airlines that mass shipment of lithium-ion batteries could cause devastating fires.

The federalspecial administration said in a statement, the test indicates that transport lithium battery there is a huge risk.

Overall, according to FAA statistics, 27% of battery accidents occurred between 1991 and 2007 were lithium battery accidents, of which 68% were due to internal or external short circuits and 15% were due to charging or discharging. As a result, 7% due to unexpected start of equipment, 10% for other reasons. Lithium battery once combustion condition, only after it is depleted, combustion can be extinguished, and aircraft are equipped with HALON1301 extinguishing agent to prevent thermal runaway lithium-ion batteries has no effect at all, such a lithium battery air transport security risk is more outstanding.

Although the lithium battery is small in size, it has high energy and contains a combustible electrolyte. If this kind of energy is applied, it is efficient energy. If it is not applied well, it will generate a lot of heat to cause combustion and form a disaster. A lithium-cobalt 18650 ion battery with a capacitance of 2-3Ah has an electric energy of 25-40KJ, and the chemical reaction can produce 280KJ after combustion. That is to say, once the lithium-ion battery is out of control, the heat generated is very large, so its harmfulness is also great. You can see what happens when the lithium battery is out of control.

Researchers experiments show that due to the lithium battery internal temperature, internal thermal runaway reaction, produce the positive leak gas making lithium battery, forming a small orange flame torch; At the same time inside the battery electrolyte began to spew out and burn, quickly form a strong flame; Is desperately to produce large amounts of Mars and white after a crackling sound, release a large amount of gas and severe burns. This kind of phenomenon in a few seconds faster and explosive reaction, produce loud noises.

Lithium battery burns the highest temperature can reach 700 degrees, the degree of combustion reaction.

So we use lithium battery need to pay attention to what problem?

Don't over charge and discharge.

Over charge and discharge can cause a lot of damage to the lithium battery, also is likely to make the battery internal temperature rise, cause combustion.

The current lithium battery phone or charging treasure will automatically stop charging when the battery is full. In other words, if your lithium battery is fully charged, it will not continue to charge on the charger. And none of us can guarantee that the characteristics of the battery's charge and discharge protection circuit will never change and the quality will be foolproof, so your battery will be on the edge of danger for a long time. So try not to charge for a long time.

At the same time often run out of lithium battery power is not desirable."As far as possible put battery power run out, had better use automatic shutdown". This practice is actually only a nickel battery, the purpose is to avoid memory effects, but it is completely unsuitable on lithium batteries. If you insist on using the "first three 12-hour long charge activation" method, it will not actually work.

The best way is to charge when you use it.

Do not let the lithium battery contact with the high temperature.

The effect of temperature on battery life is actually very large, the higher the temperature, the lower the life of the lithium battery. Experiments have shown that at more than 70℃, a spontaneous exothermic reaction occurs inside the battery cell, causing the temperature to rise sharply. At more than 130℃, the lithium battery will react with the gas, causing the internal pressure to be too large to open the battery and then cause a combustion explosion.

It is hoped that lithium batteries will benefit human beings while reducing the occurrence of safety accidents, and research on advanced technologies will be further developed!

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