Researchers Develop Method to Mitigate Formation of Dendrites in Rechargeable Batteries

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Researchers developed a method to mitigate formation of dendrites in lithium metal batteries, according to a study conducted on April 9, 2018.

An international team of researchers is working on developing lithium metal batteries that have more capacity when compared to the lithium ion batteries. A method was developed by the team, which will reduce the formation of dendrites in lithium metal batteries.

In a lithium ion battery, the anode, which is the current-generating side, is made of a material such as graphite and lithium ions are bound to it. These lithium ions then flow to the cathode or current-collecting side. However, in a lithium metal battery, lithium metal is used to make anode and electricity is generated when electrons flow from the anode to the cathode. Since lithium is electrically positive metal and has very high capacity, rechargeable batteries made of lithium metal is very promising. Bingqing Wei, a professor of mechanical engineering at the University of Delaware said, “Theoretically, lithium metal is one of the best choices for batteries, but it is hard to handle in practice.”

The formation of dendrites in lithium batteries have made them very inefficient and unstable, and has also affected their performance. Dendrites look like tiny stalagmites made of lithium deposits. When a battery is being used, lithium ions are collected on the anode and over time, this deposition becomes non-uniform and leads to the formation of dendrites. Further, this can cause the battery to short circuit.

Researchers found that a porous material can inhibit the growth of these dendrites and for this, they made use of mathematical modeling. When compared to the dendrites that were formed in systems that did not have a porous material, the dendrites formed here were 75 percent shorter. Furthermore, a membrane made of tiny wires of porous silicon nitride was fabricated by the team. This membrane was further integrated into lithium metal cells in a battery, ran it for 3,000 hours and not dendrites were formed.

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