How do lithium-ion batteries work and are they really dangerous?

Today, lithium-ion batteries are among the most popular choices in the construction of various devices, and you can find them in laptops, tablets, cell phones, cameras, and more. do. This category of batteries with this advanced technology is one of the most powerful rechargeable models. After the entry of this lithium-ion battery into the global market, news about the possibility of these products igniting among the people was circulating among the people, although such an event is possible, but you should know that the reports have fueled it too much and the possibility of this igniting batteries are only at the rate of two or three battery packs per million.

Despite all this, lithium-ion batteries are one of the most common and powerful products in the world, but the question that can be raised is what What makes these batteries so energetic and powerful? In this article, we will introduce you to the structure of the lithium-ion battery and reveal how it works in a simple language.

Why lithium batteries - Is ion common and popular?

Lithium-ion batteries are much lighter than other types of rechargeable batteries of the same size, because the electrodes of this category of products are made of lightweight lithium and carbon. On the other hand, lithium is a very reactive element (which means that a lot of energy is stored in its atomic bonds), for this reason, this very high energy density in lithium-ion batteries can be converted into output charge.

• Energy consumption in lithium-ion batteries: A lithium-ion battery pack only loses about 5% of its charge per month, while this amount for nickel-metal hydride batteries is about 20%.
• No memory: These batteries have no memory, meaning you don't need to fully discharge them before recharging. While in other chemical batteries, it is necessary to fully discharge the remaining charge before recharging.
• High durability: lithium-ion batteries can withstand hundreds of charge/discharge cycles do not lose their original quality.

The excellence of all the mentioned items does not mean that lithium-ion batteries are flawless.

• This category batteries expire as soon as they leave the factory, meaning they will only last two to four years from the date of manufacture, whether you use them or not!
• High temperature lithium-ion batteries they are very sensitive. Heat can cause them to degrade much faster than normal temperatures.
• Li-ion batteries can be damaged if you completely discharge them. For this reason, it is recommended not to use the phone with less than 15% battery.

Many of these features come from more curiosity and looking at the chemicals inside a lithium-ion cell. It's better understood.

A Look Inside aLithium-Ion Battery

Lithium-ion battery packs come in many different shapes and sizes. , but they all look almost the same on the inside. If you remove a lithium-ion battery from the case (which we never recommend doing), things you'll see include:

• Lithium-ion cells are the first thing you'll see. . The cells inside these batteries look like cylindrical AA batteries or can be angular, meaning they are square or rectangular.
• One or more temperature sensors to monitor the battery temperature
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• Voltage circuit and regulator circuit to maintain safety levels of voltage and current
• A notebook connector that is responsible for flowing electricity and information into and out of the battery case.
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• A voltage tap that controls the energy capacity of the cells separately in the battery case.
• A battery charge monitor, which is almost like a small computer and performs the entire charging process. It makes sure that the cells are fully charged as quickly as possible.

Inside the lithium-ion battery

If the battery as a whole gets too hot during charging or use, the battery charge status monitor , it cuts off the electricity so that everything returns to its original temperature. For example, if you leave your laptop in the car in direct sunlight, after accessing it if you try to use it, the device may not turn on until everything cools down. Remember that if the battery cells are completely discharged, the entire battery will be damaged and unusable. Also, the battery charge monitor has the ability to track the number of charge/discharge cycles and send the information to the battery charge measurement section in the laptop so that the system can give you information about the battery charge level. A very thin sheet of microscopic, plastic pores separates the positive and negative electrode plates.

Lithium-ion Cells

Like many batteries in the market, the outer body of this type of battery is also made of metal. The use of metal in the structure of this product is particularly important, because the battery is always under pressure. This metal casing has a pressure-sensitive hole that can release excess pressure and prevent danger if the battery gets too hot to risk exploding due to overpressure. Although the battery will probably be useless after such an event, so you should avoid using it again. The positive temperature coefficient (PTC) switch is also a helpful device that prevents lithium-ion batteries from overheating.

Structure of lithium-ion cells

This metal sheath has a long helix that consists of three thin sheets pressed together:

• Positive electrode
• Negative electrode
• A separator

Inside the sheath of these plates, there is an immersed organic solvent that It acts as an electrolyte. Among them, ether is also a common solvent.

The separating plate is a very thin sheet of microscopic pores and plastic, and as its name suggests, it separates the positive and negative electrode plates, while Now it allows ions to pass through. The positive electrode is made of lithium cobalt oxide or LiCoO2 and the negative electrode is made of carbon. When the battery is charged, the lithium ions move from the positive electrode to the negative electrode through the electrolyte liquid and are attached to the carbon, so this process and when the batteries are discharged, the lithium ions return from the carbon to LiCoO2.

Lithium-ion battery working process

Movement of these ions Lithium occurs at a relatively high voltage, so each cell produces about 3.7 volts of energy. As it turns out, this value is much higher than the typical 1.5V in an alkaline AA cell (1.5V pen batteries).

Why do lithium-ion batteries explode?

You've probably read reports of exploding laptops with lithium-ion batteries. As we mentioned in the introduction of this article, the probability of such an event is one in a million, so if you take proper care of your battery systems, there is probably no such risk. But these reports can be the beginning of an interesting topic! Why do lithium-ion batteries explode?

Generally, a battery explodes if it gets so hot that the electrolyte ignites. There are video clips and photos on the web that can testify to how serious the danger of battery explosions and fires can be. When such fires occur, it is more accurately caused by an internal short circuit in the battery.

As you recall from the previous section, lithium-ion cells contain a separator plate that separates the positive and negative electrodes. It keeps the negative separate. If this separator sheet is pierced and the electrodes touch each other, the battery will heat up very quickly. You can do this by putting two coins on the two ends of a regular pen battery and experience this kind of heat.

So, when the separator is damaged, the same type of short circuit that was mentioned happens inside the lithium-ion battery, and since lithium-ion batteries are very energetic, they heat up very quickly, and the heat produced in it can destroy the organic solvent. Used as an electrolyte ignite Naturally, when this happens inside one of the cells, the heat of the fire reaches the other cells and the whole package catches fire.

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• Intelligence Artificial intelligence has changed our understanding of language learning in children. are counted, paying attention to tips to make lithium-ion batteries last longer can be useful for everyone.
  • The chemistry governing lithium-ion batteries prefers partial discharge to complete discharge, so it is better to Avoid draining the battery of your phone or other devices. Because Li-ion chemistry has no "memory", you won't damage the battery as a whole with a partial discharge. But it should be noted that if the voltage of a lithium-ion cell drops below a certain limit, the entire battery may be damaged, so please use a special charger for each device only for it.
  • Life of lithium batteries- Uni's are only two to four years old, even if they're sitting on a shelf unused. So when you buy a new lithium-ion battery, you need to make sure it's really new. Because, as mentioned, the date of production of this category of goods is very important.
  • Avoid placing batteries in hot environments.
  Buy all types of phone batteries from SafirSoft.

Source: howstuffworks