Lithium batteries not guilty? Samsung Note 7 Fire Explosion What Causes

Samsung Electronics has announced a permanent shutdown of its Galaxy Note7 phone, but there has been another battery burning problem with the replacement, which has led many media to question that Note7's problem may have surpassed lithium batteries.

Samsung Electronics has assembled hundreds of engineers to study the Note7 battery problem, but has been unable to recreate the combustion process, according to media reports. Note7's problem is not a battery failure, according to leading battery experts.

Samsung Electronics has shut down its Note7 phones worldwide and is organizing a full-scale product recovery, making it the most short-lived high-end phone in Samsung's history.

The next question is to study where Note7 went wrong.

In the beginning, some people thought that Samsung's subsidiary Samsung SDI (Samsung SDI) was the culprit. The batteries it produced were not safe. Samsung later switched to ATL batteries in China. When Samsung sent the safe Note7 to loyal users, it caught fire again. The new Note7 device not only has the risk of overheating, but also does not have any warning when overheating. South Korean media reported that the cell phone fire seems to be caused by the design.

Lithium batteries not guilty? What was the cause of Samsung note 7's fire explosion?

South Korean SBS TV station observed the batteries of Samsung SDI and China ATL with a microscope. It was found that the isolation plate of Samsung battery is too close to the edge of the battery block, and the battery will be compressed under pressure, resulting in a short circuit of positive and negative poles. In September, Samsung reported that this was the cause of the battery fire.

Why is the new phone still on fire? It may be due to the Galaxy Note 7 design. Samsung was proud of Note7's symmetrical design. The glass covers the front and back panels of the phone. Although it looks beautiful, it may put too much pressure on the internal battery.

A generation of Note phones launched in 2011 was only 5.3 inches. The Note7 was narrower and installed a 7000 series of aluminum alloys. The aluminum alloy was 1.3 times harder than the aluminum alloy used in Galaxy S7Edge. As a result, the highly sealed Note7 was under great pressure. Together with the Galaxy Note 7's seal level, which meets the IP68 standard and can be waterproof, this standard makes the phone more stressful.

What was the reason for the explosion at Samsung Note 7?

Although in theory design may be the real cause of the cell phone fire, it still needs Samsung to confirm whether it is. The Galaxy S7Edge is equipped with 3,600 mA batteries and the phone is only 7.7 mm thick. Galaxy Note 7 is equipped with a 3500 mA battery. The frame is 7.9 mm thick. Although thicker, it is narrower than the previous version. Samsung needs to make room to install S-Pen stylus and other components. Because of this, the space left for the battery is very small. Once the battery becomes hot, the situation becomes dangerous because heat dissipation is difficult.

It was also reported that a source had a conversation with a senior executive of Samsung, who suggested that the problem might be due to Samsung engineers modifying the processor in order to speed up charging. In other words, the fire may not be a battery problem or a design problem, but an underlying technical problem.

"If the charge is too fast, it could lead to battery instability," the source said. Just as the engine explodes too fast. We have to give up. "

Knowledge link:

To be precise, the so-called "explosion" is actually a fire, and lithium batteries spontaneously ignite and catch fire. So what caused the lithium battery to catch fire?

Too fast to charge.

The main composition of lithium-ion batteries is the use of lithium alloy metal oxides as positive electrode materials, graphite as negative electrode materials, and the use of non-aqueous electrolyte solutions to achieve chemical reactions and provide power batteries. When charging, lithium ions are located at the positive pole and move to the negative pole when discharging. The principle is very simple.

The problem is that the rate of movement of lithium ions is limited, and if it is exceeded, it will become unstable, such as short circuits. Although companies including Qualcomm and others are actively promoting fast charging technology, the charging speed needs to meet the limit of lithium ions and create a stable environment through some technologies to prevent short-circuit phenomena.

If this link is not handled properly, the short circuit will heat the electrolyte solution and the battery will catch fire.

Electrolytes are critical.

Improving the properties of the electrolyte solution is of positive significance for improving the stability of lithium batteries. For example, some chemists are developing non-flammable electrolytes. Even if lithium ions are overheated and short-circuited, they will not cause the spontaneous combustion of mobile phones. There are also more effective alternative materials under development.

For now, mobile phone manufacturers in the development of new fast-charging technology, we need to consider the first security, not a quick success. When users use a mobile phone, they must try to avoid external force collisions and use it at high temperatures. When they feel that the mobile phone is not normal, it is best to shut down and suspend use.

The page contains the contents of the machine translation.