Monday, April 17, 2017

"long" battery without fear of explosions, fires and degradation of materials

Scientists have figured out how to change the crystal structure of the cathode in lithium-ion batteries to significantly improve the efficiency and extend the life without compromising security. The study is published in the prestigious journal Nature Materials .

Lithium-ion batteries are commonly used as the primary source of energy in modern portable equipment - laptops, tablets, mobile phones and cameras. Lithium is the charge carrier when the battery is charged, lithium ions leave the crystal lattice of a mixed oxide of a transition metal, capable of changing its degree of oxidation. In modern batteries typically used, cobalt oxide and layered lithium.
 

The crystal structure of the layered cathode material LiCoO 2

Two basic characteristics of a lithium-ion battery
- the number of charging cycles and the capacity (amount of lithium leaving the crystal lattice during the charge and returning back at discharge). The problem is that all of the lithium never leaves the cathode structure (not more than 60%). Otherwise, increasing the likelihood of an explosion and a fire. Are finite and the number of recharge cycles (the energy contained in the charged batteries decreases with time).

Scientists have found a solution to these problems. They suggested that other crystalline structure of the cathode material. Classical lithium-ion battery has a layered "structure" in which the lithium layers are interleaved with layers of oxygen and a transition metal. At that time, when Li is leaving his position, his place is taken by transition metal ions. Therefore, to come back, he could not - his place is already taken. As a result, the battery capacity decreases.

New battery structure suggests a shift layers relative to each other, so that the battery gets skeleton structure and is much more stable: almost no energy is lost. This makes it possible to extract from it all the lithium when charging. It is not the risk of fire occurs.


 The crystal structure of the layered cathode material LiCoO 2

"Previously it was thought that the capacity of the lithium ion battery is determined by the change in the degree of oxidation of the transition metal included in its composition. In one of our previous work, we showed that oxygen can also contribute to the battery capacity, it increases it due to the fact that its degree of oxidation is also changing. In our new study, we have demonstrated a way to use this capacity to the full, without fear of explosions, fires and degradation of materials, " -  commented Professor Skolkovo Tech Center for electrochemical energy storage Artem Abakumov.

As long as the "concept" of the sample, researchers used a lithium compound with an oxide of iridium. But this option is expensive, so its mass production is inefficient. A further objective of specialists - find better and more cheap metals.

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Milan Techglyphs
Milan Techglyphs

Author & Editor

Milan Antony is the founder of TGS.He is a Technology Enthusiast with a keen eye on the Cyberspace and other tech related developments.