Pay attention to the long-lasting battery life of lithium batteries

Conventional lithium batteries use graphite to form the anode, which is the electrode where current enters the battery cell. Graphite has been the material of choice for this task for 30 years because it is lightweight, stable, reasonably priced, and can withstand countless battery cycles. Greer, Professor of Materials Science, Mechanics and Medical Engineering at the California Institute of Technology Ruben F. and Donna Mettler, and director of the Fletcher Jones Foundation at the Kavli Nanoscience Institute said that if only some technical challenges can be overcome, then better materials can be found. She said: Batteries that use lithium instead of graphite anodes will benefit every use of power because they can supply more power, she said. Lithium is lightweight, it does not take up much space, and its energy density is extremely high. But here is the problem with lithium metal: when the battery goes through many charge and discharge cycles, lithium naturally forms dendrites, and these crystals form a branched tree-like structure. During battery charging, dendrites grow uncontrollably in lithium metal batteries and can be used for the same purpose as thin wires. When they penetrate the system, they will short-circuit and kill the battery. Greer said that researchers have long been looking for new ways to guard against this rise. One possible way is to physically press certain objects on the lithium metal to suppress dendrites. Although a typical lithium battery has a liquid electrolyte (a substance that separates two battery electrodes and moves through lithium ions), a battery using a solid electrolyte can theoretically apply sufficient mechanical pressure to prevent dendrites. However, after studying batteries with solid electrolytes, dendrites are still growing. Greer suspects that the strength of the solid electrolyte is not strong enough to resist the growth of dendrites, because the researchers underestimated the strength of dendrites with a nanometer size. They underestimated it because macro-lithium is a relatively soft metal, comparable to lead and tin. She said that small-scale metals may be 100 times stronger than large-scale metals. Greer said: If you think of jewelry, such as gold or copper, it is very malleable. You can easily deform it with your own hands. He specializes in the mechanical properties of nanomaterials. However, when the size of the same metal is reduced, the strength can be increased by more than an order of magnitude. In 2015, Greer and her colleagues carved tiny lithium pillars and probed their elasticity, and found that they were at least an order of magnitude stronger than people thought. Greer said the experimental setup did not fully reflect the way lithium dendrites behave in real batteries. In order to simulate this more accurately, she and her collaborators, including Greer Lab alumni Michael Citrin and postdoctoral scholar Heng Yang, and FrontEdge Technology’s Simon Nieh, created a This battery is designed to process batteries that are very similar to pure lithium dendrites. Formed in the battery. The researchers found that these dendrites are 24 times stronger than bulk lithium. With this information, researchers now have a better understanding of the conditions required to make lithium anode batteries work. Greer said this represents a major research challenge because both polymers and ceramics (materials commonly used in solid electrolytes) have shortcomings. Most polymers are too soft to withstand the growth of dendrites, while ceramics tend to break under the pressure exerted by dendrites. Disclaimer: Some pictures and content of articles published on this site are from the Internet. If there is any infringement, please contact to delete. Previous: How long is the actual life of the lithium titanate battery?