Samsung Galaxy Note 7 mobile phone explosion to let the trend of the new product to lead the trend stranded, but also to a battery called ATL battery manufacturers are more familiar with the consumer.
However, for consumers, this event is a greater role in awakening people on the long-term problems of electronic product safety, so that more and more people began to pay attention to the safety of consumer electronics products.
Samsung uses a general-purpose lithium-ion battery as a mobile phone power source, and later the official accident investigation statement also admitted that the battery caused internal defects caused by heat and explosion.
Another lithium-ion battery commercial activist Tesla seems to have no battery safety problems in the troubled.
According to the public news, Tesla model S power is located at the bottom of the vehicle, using Panasonic lithium-ion battery, the entire battery pack contains 8000 battery cells, in series and parallel connection.
From the choice of power supply materials, Tesla's battery is no special place, as a traditional automotive manufacturer of innovation, the core technology is in the new energy automotive circuit design and multiple security protection.
Lithium-ion batteries are rapidly commercialized due to a series of advantages such as high energy density. However, in the process of charging and discharging of lithium-ion batteries, the redox reaction of the positive electrode is very severe. Therefore, the charging conditions have been strictly limited.
In actual use, lithium-ion batteries are actually batteries together with a set of security circuits and a variety of safety devices packaged together, these safety design can protect the battery in the overcharging, over-discharge and short-circuit automatically cut off the power.
Even when the battery internal pressure is too high will trigger the exhaust device decompression, the temperature is too high will trigger the thermal protection device.
Lithium-ion batteries currently used in mobile phones and computers typically rely on liquids as electrolytes, which consist of organic solvents and dissolved salts.
The liquid electrolyte allows the charged ions to be effectively moved between the electrodes separated by the semipermeable membrane, thereby generating a current.
But the fluid electrolyte is easy to lead to the crystallization of lithium: This dendritic crystal lithium fiber, is the occurrence of battery short circuit and charging the battery when the rapid rise in temperature one of the culprits.
One way to solve this problem is to make a fuss about the electrolyte used in the battery.
Recently, Cyrus Rustomji, a postdoctoral fellow at the University of California, San Diego, and his colleagues tried to use liquefied fluoride gas as an electrolyte.
The test battery showed that the charging time was still at the same level as that of the new product after 400 complete charge and discharge cycles. Microscopic results showed that there was no dendritic crystal in the gas battery, and the study was published in the "Science" on.
If the standard lithium-ion battery is pierced and the semipermeable membrane of the separation electrode is pierced, this will cause contact and short-circuiting of the electrode, followed by a severe reaction of the lithium electrode in the presence of the electrolyte, which may cause a fire, Oxygen entering from outside will intensify burning.
However, fluoromethane is liquefied only under pressure, so if the new cell is pierced and the pressure is released, the fluoromethane liquid will return to the gas state at atmospheric pressure and the gas will escape thereafter, explains the subject author, Rustomji.
Therefore, 'no electrolyte will cause the impact of ion movement', so it will not cause heat and fire, he said.
According to Rustomji, unlike the standard lithium-ion battery, the battery is currently performing at temperatures as low as minus 60 degrees Celsius, which is an effective complement to the power supply environment for high-altitude unmanned aerial vehicles and long-range spacecraft.
Because the sensitivity of the gas to expand its volume when the temperature rises is much stronger than that of the liquid, Donald Sadoway, a professor of chemical chemistry at MIT, added that researchers need to ensure that overheating does not cause rapid expansion of the liquefied gas of the battery and the risk The
