How to extend the life and safety of lithium-ion batteries

A few days ago, a new study by Arizona State University found that the use of a three-dimensional polydimethylsiloxane (PDMS) layer as the base material of the lithium metal anode in the battery can effectively inhibit the formation of lithium dendrites, thereby greatly Extend battery life and reduce potential safety hazards. The research was published in the latest outstanding journal Nature Energy on March 6. The lead researcher of the paper, Professor Hanqing Jiang, said that this discovery has significance for both lithium-ion batteries and lithium-air batteries, and also has great significance for other metal anode batteries. Because almost all metals used as battery anodes will appear dendrites, such as zinc, sodium and aluminum batteries. Jiang Hanqing said that he and the research team did not solve this problem from the perspective of materials or electrochemistry, but from the perspective of mechanical engineers to find a solution. He said that known studies have shown that tiny tin needles or tin whiskers (similar to dendrites) will protrude from the surface of tin metal under stress applications. Therefore, by analogy, we have studied stress as the reason for the growth of lithium dendrites. possibility. The compressive stress formed in the process of electroplating the lithium layer makes the copper layer on the PDMS substrate wrinkle deformation; (b) the wrinkle deformation of the PDMS substrate releases the stress in the lithium layer, thereby inhibiting the formation of dendrites; (c) there is no flexible PDMS The substrate is used for stress release, and dendrites are formed on the surface of lithium metal. In the first round of research, the researchers added a layer of flexible PDMS to the bottom of the anode of the battery and found that the growth of lithium dendrites was significantly reduced. The researcher's analysis shows that the stress accumulated in the metal lithium electrode is released by the PDMS substrate in the form of wrinkle deformation, and this tendency of dendrites reduction is directly related to this stress release. This is the first time it has been experimentally proved that residual stress plays a key role in the formation of lithium dendrites, Jiang Hanqing said. In addition to studying the growth mechanism of lithium dendrites, Jiang Hanqing's team further studied how to use this phenomenon (stress release to reduce dendritic growth) to extend the life of lithium metal batteries while maintaining high energy density. The method proposed by the researchers is to make the PDMS matrix into a three-dimensional structure with many surfaces. Using a sugar cube with a large number of small pores as a template, PDMS enters the pores inside the sugar cube to form a continuous network substrate, and then a thin copper layer is plated to conduct electrons. Finally, lithium metal is used to fill these pores. As a porous sponge layer, PDMS can effectively reduce stress and inhibit dendrite growth. Statement: Some pictures and content of articles published on this site are from the Internet. If there is any infringement, please contact to delete the previous one: About the explosion of lithium-ion batteries Detailed