Author ：Iflowpower – Portable Power Station Supplier
Recently, many electric cars (EV) batteries have occurred. Unlike small mobile devices used in small mobile devices such as smartphones, the battery pack of electric vehicles is composed of hundreds of battery cells, and any instability will cause major casualties and property damage. In all kinds of efforts to find out the cause of the battery, Korean researchers have developed a new analytical approach to assess the thermal stability of EV batteries.
The Korean Association of Science and Technology (Kist) announced that a research team has established a practical time analysis platform for Dr. Wynyoung, Dr. Kim, WONYOUNG, Dr.
Wang, Dr. Kim, a research team, a research team, WONYOUNG, Dr. Kim's WONYOUNG Chang, Dr.
Kim, the KIM-based Kimior Composites in the North Branch. Using the transmission electron microscope to evaluate the thermal stability of the battery positive material, through the platform, they can determine the thermal degradation mechanism according to the chemical component of high nickel positive material with electric vehicles. The positive material of the EV battery is one of the key factors that determine the battery capacity and therefore determine the mileage.
By mixing various metals (e.g., nickel, cobalt and aluminum) or nickel, manganese, and cobalt, the company and the academic researchers are trying to find suitable ingredient ratio to increase their electric vehicle drive range.
The positive electrode material contains nickel, and there is a positive correlation between nickel content and capacity. In addition, since nickel is relatively cheap, it is added to add more nickel to effectively reduce the unit cost of the EV battery. However, the fatal weakness of nickel is, because nickel is easy to react to external environments, thereby reducing the stability of the battery.
In the case where the cathode material for the third generation EV is currently being developed, the nickel content has increased to 80% or higher, and thus the deterioration of stability must be improved to ensure safety. The battery is mainly caused by a severe exothermic reaction with an electroxide cathode material and the flammable liquid electrolyte. Therefore, the Kist's research team focuses on the surface of the cathode in contact with the electrolyte, and uses a variety of transmissive electron microscopy methods (electron energy loss profiles, electron diffraction, etc.
) to carefully observe and analyze silicon-based crystal structures. Cathode and temperature rise results in component chemical changes. As a result, the reason for determining the thermal stability of the battery can determine the thermal stability of the battery based on the chemical composition of NCA (nickel, cobalt, aluminum) positive electrode material and ensuring battery safety.
The Kist Research Group survey found that the increase in nickel content increases the battery capacity than the aluminum content in the NCA positive electrode material, but significantly reduces the thermal stability in the upper limit of charging (67% of total lithium ion reactions). The analysis shows that lack of aluminum does not participate in the redox reaction, resulting in a new phase (O1 phase), which reducing thermal stability during charging. It is found that the surface of the new instability phase is the ultimate cause of the reduced thermal stability.
Dr. Wieyoungchang, WONYOUNGCHANG said: "A series of EV fires have occurred worldwide. In many cases, the source of fire is battery.
This study confirmed the importance of chemical composition design, which ensures thermal stability during development. High performance cathode material. Dr.
Seungminkim in Kist All North Society said: "Ensure that the thermal stability of the cathode material of the exothermic reaction is the key to the popularity of electric vehicles. Advanced analysis technologies developed in this study will help determine the development of trace elements and in turn lead to high-performance cathodic materials that can ensure safety. ".
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