New semiconductor technology reduces the risk of fires in lithium batteries for vehicles

Despite the rapid development of electric vehicles, the safety of lithium-ion batteries is still worrying.
Its dendrites have multiple branches, which can cause electric vehicle batteries to catch fire
.
According to recent news on the official website of the American Chemical Society publications, Korean researchers have used semiconductor technology to improve the safety of lithium-ion batteries

When a lithium-ion battery is charged, lithium ions are transported to the anode and deposited on the surface in the form of lithium metal, forming a tree-like structure
.
These lithium dendrites cause uncontrollable volume fluctuations and cause a reaction between the solid electrode and the liquid electrolyte, which can cause a fire

In order to prevent the formation of dendrites, the research team exposed fullerene (a highly electronic conductive semiconductor material) to plasma, resulting in the formation of a semiconductor passivation carbonaceous layer between the lithium electrode and the electrolyte
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The semiconductor passivation carbonaceous layer allows lithium ions to pass through, and at the same time blocks electrons due to the generation of a Schottky barrier, and prevents electrons and ions from interacting on the surface and inside of the electrode, thereby preventing the formation of lithium crystals and the growth of dendrites

The stability of an electrode with a semiconductor passivation carbonization layer was tested in an extreme electrochemical environment using a lithium symmetrical battery.
The typical lithium electrode remained stable during up to 20 charge/discharge cycles; while the newly developed electrode was stable The performance is significantly enhanced, and the growth of lithium dendrites is inhibited in up to 1200 charge and discharge cycles
.
In addition, in addition to the electrodes that have been developed, the use of lithium cobalt oxide as a positive electrode maintains approximately 81% of the initial battery capacity after 500 cycles, which is approximately 60% higher than traditional lithium electrodes

Li Zhongji said: "Effectively inhibiting the growth of dendrites on the lithium electrode helps to improve the safety of the battery
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The technology proposed in this study to develop a highly safe lithium metal electrode is for the development of the next generation that does not pose a risk of fire.

The next goal of the research team is to improve the commercial feasibility of this technology.