The United States proposes a new method for solving lithium ion batteries

Autor: Iflowpower - Dodavatel přenosných elektráren

Guide: A research team in the National Renewable Energy Laboratory (NREL) proposed a new method to solve the problem of lithium-ion battery. The key to the answer may be in the temperature sensitive current collector. What happens when a nail is on a lithium-ion battery battery? The researchers who observed this process claim that they have developed a polymer-based approach that can counter-related fire hazards in the lithium-ion battery.

From the National Renewable Energy Laboratory (NREL), NASA, the University of NASA, the United Kingdom of Didcot, London, National Physics Laboratory, and France's European Synchronous Accelerator, Nail into the cylindrical "18650 battery" commonly used in automotive applications (18x65mm). Researchers try to reproduce the mechanical stress that electric vehicles (EV) batteries must bear in collision. The nail will touch the short circuit inside the battery, resulting in a temperature rise.

In more detail, when the nail penetrating the battery, what happened inside, the researcher uses a high-speed X-ray camera to capture this event at a speed of 2000 frames per second. NREL's staff scientist DonalFinegan said: "When the battery really fails, its fault speed is very fast, so it can be intact from completely intact in a few seconds to swallow and completely destroyed. Very fast, it is very difficult to understand what happened within two seconds.

But it is very important to understand what happened, because the management of these two seconds is an important factor in improving battery safety. "If you don't control, the thermal out-of-control battery temperature rise has been proven to exceed 800 degrees Celsius. The battery cell contains aluminum and copper collectors, and the research team uses aluminum-coated polymers to play the same use, and observed that their current collectors contracted at high temperatures, immediately arrest current flow.

The short circuit heat causes the polymer to form a physical barrier between the nails and the negative electrode, and the short circuit is stopped. During the experiment, all batteries without polymer dischargers, if the nails are done, will knock out. In contrast, there is no such behavior that is equipped with a polymer.

Finegan said: "The condition of the catastrophic failure of the battery is very rare, but when this situation occurs, it may cause great damage. Not only is the safety and health of relevant personnel, not only the same for a company. "Considering the company that is integrated battery unit, NREL pointed out its battery fault database, with hundreds of lithium-ion battery abuse tests hundreds of radiation video and temperature data points.

Finegan said: "Small manufacturers don't always have time and resources to test batteries in such a strict way in the past five to six years. "Russia's researchers have recently born to use polymers to prevent the battery from getting angry. Oleglevin and colleagues developed a polymer, St.

Petersburg University, developed a polymer, and the electrical conductivity of this polymer changes as calorie or voltage changes. The team called this method as "chemical introduction". According to the microsolytic team, this polymer of Russian scientists is only suitable for lithium iron phosphate (LFP) batteries because different cathode components work at different voltages.

About the LFP battery is 3.2V. The working voltage of the nickel manganese cobalt (NMC) cathode of the competitor is between 3.

7V to 4.2V, depending on the type of NMC battery.