During this time, Samsung's flagship smartphone Galaxy Note 7 has been firmly occupying the headlines, not because of its performance or design excellence (of course, Note7 performance and design is really good), but because of its In the short time after the listing, it was discovered that there was a major safety hazard in the built-in battery, and the probability of the mobile phone exploding without cause was far beyond the normal range. When the incident came out, Samsung immediately suffered a huge blow and lost countless money, and consumers of electronic products and even people from all walks of life began to talk about it, which has recently been defined by some airlines as "nonsense" of civil aviation dangerous goods. This can be seen. But then again, in daily life, the explosion of electronic products is by no means rare. Then these devices that should serve consumers suddenly become a "bomb", what is going on? Let us take a look at the interpretation of this article from a chemical perspective. They are all lithium batteries, but why are they different? Nowadays, most electronic products have entered the "lithium battery era". As a battery that has more application experience, lithium battery has the characteristics of long life, large capacity and low cost, so it is widely welcomed. It is reasonable. However, although many types of batteries can be called "lithium batteries", do you know that there is a big difference between lithium batteries and lithium batteries? In fact, lithium batteries can be roughly divided into two categories - traditional lithium-ion batteries and lithium-ion polymer batteries, which differ in many properties: Traditional lithium ion battery: A typical representative of such a battery is a 18650 lithium battery that frequently appears in various "charging power (mobile power)". The battery is named after its appearance characteristics (18 mm in diameter, 65 mm in height, cylindrical). Because of its low cost and durability, it is a "fighter" in the lithium battery market today. Conventional lithium-ion batteries, like other conventional batteries, contain an electrolyte that is responsible for transferring electrons (because the charge and discharge of the battery is essentially the process of electron-directed movement), so a certain packaging volume is required (this sometimes makes it not portable) And a hard outer casing responsible for protecting the electrolyte. Lithium ion polymer battery: At present, all portable electronic products such as mobile phones and tablets, as well as batteries used in most notebook computers, are such. Lithium-ion polymer batteries use a polymer tandem cell structure to require only a small amount of liquid electrolyte. Therefore, such batteries do not require a hard outer casing for protection, and the shape is not limited, and the packaging volume can be greatly reduced. Based on these characteristics, lithium-ion polymer batteries are heavily equipped in some electronic products that are light in weight and require thickness of equipment, and have a tendency to replace traditional lithium-ion batteries. Why is a lithium battery a "bomb"? In the Samsung Galaxy Note 7 explosion incident mentioned at the beginning of the article, Samsung subsequently confirmed that mobile phone explosion combustion is closely related to the design flaws of its lithium battery, and in recent years, electronic product explosions (such as Sony laptops in 2006) In the event of an explosion in the year, which led to Sony’s global recall of problematic products, all of them were explosions of lithium batteries. From a chemical point of view, there are many reasons for the explosion of lithium batteries, and a considerable part of them have a lot to do with the design flaws of the manufacturers. As we all know, an important cause of battery explosion is the short circuit of the battery (that is, there is no electrical appliance in the circuit where the battery is located, and the current inside the battery is too large), and the battery is short-circuited or overcharged (lithium battery explosion). Another important incentive, that is, the battery charging voltage is higher than its set upper limit, will cause a large amount of heat and gas to accumulate inside the lithium battery in a short time (the lithium battery will generate gas when it works). In this way, in order to release the pressure, the lithium battery will either activate the internal pressure release device or directly crack the outer casing, and both of these conditions will cause the internal material of the battery to directly contact the air, thereby causing combustion. In general, lithium battery explosion combustion is rarely due to external circuit failure, which means that most of the lithium battery explosion combustion events are caused by design defects inside the battery. For example, in the explosion of the Sony laptop battery described above, the electrolyte part of the problem battery was detected as a metal impurity, and the accident was caused by unexpected electrical conduction due to metal impurities, which formed an internal short circuit and induced an explosion. of. Coincidentally, the Boeing 787 aircraft lithium battery fire incident, but also with the aircraft battery in a special environment, the performance of the electrolyte dropped significantly, which induced internal short circuit. Of course, the two lithium battery explosions involved in the traditional lithium-ion battery, and the "protagonist" in this Samsung Galaxy Note 7 explosion is a lithium-ion polymer battery, then lithium ion polymerization What is special about the battery in such incidents? In fact, in general, lithium-ion polymer batteries do not have a hard outer casing, and the possibility of violent explosion combustion has been greatly reduced. Such batteries may explode in advance due to poor impact resistance of the outer casing in the event of an explosion accident. This usually manifests as a slow burning after the explosion. However, the high variability in the shape of lithium-ion polymer batteries not only gives device manufacturers more freedom in design, but also requires additional design of the battery pack. As a result, it is inevitable that the battery pack design will not be closed, which will lead to accidents. In this Samsung Galaxy Note 7 explosion, it has been initially determined that the battery pack with major defects in the production process is likely to be the culprit. How to avoid recurrence of the explosion? Although Samsung has launched a recall action for products with problematic batteries, the adverse effects of the incident, including the destruction of brand image, value, and company reputation, are bound to be irreparable, and the incident can also be included in lithium. One of the major safety incidents in the history of battery development. If this is the case, then where do we have to improve to avoid the recurrence of the accident? Today, lithium-ion polymer batteries have been widely promoted. One of the most important things that major lithium battery manufacturers have to do is to strengthen the control of battery safety. This requires strict product inspection, new product testing and yield control, as well as the importance and investment in battery design work. After all, in theory, a battery that is designed and produced to be fully qualified has a very low probability of accidents after long-term use. Even if an accident occurs, it will not damage the reputation of the manufacturer. However, if the battery has major problems in these links, then the manufacturer It can be a painful price. For consumers, choosing a reliable lithium battery and using lithium batteries properly in the right environment are the key to preventing accidents. Some consumers are tempted to be cheap for a while, and the choice of various irregular batteries has actually hidden hidden dangers for future use. Similarly, even a fully qualified lithium battery, consumers are not used in the proper environment. (such as using batteries in extreme weather, water, or high temperatures), or using improper methods to treat batteries (such as wrestling and lithium batteries) can cause accidents. Floor-Standing Transfer Box,Outdoor Floor-To-Ceiling Transfer Box,Outdoor Fiber Optic Cable Transfer Box,Specialized Fiber Optic Cable Transfer Box Shenzhen Jingtu Cabinet Network Equipment Co., LTD , https://www.jingtucabinet.com