How to prolong the service life of lithium batteries, increase its safety?
lithium dendrite refers to when the lithium battery cathode and anode as growth in lithium metal surface of needles. It will cause harmful side effects, reduce the energy density, and even lead to the electrode short circuit, cause fire or explosion.
Arizona state university, a new study has found that, using three-dimensional polydimethylsiloxane ( PDMS) Layer as a battery of lithium metal anode substrate material can effectively inhibit the formation of lithium dendrite. Longer battery life and reduce safety hidden trouble. The study on March 6, in the new journal NatureEnergy on top.
the paper's lead researcher professor Jiang Hanqing said, the discovery of lithium ion battery and lithium air batteries and other metal anode cell has important significance. Because almost all used as the anode of metal will produce dendritic crystals, such as zinc, sodium and aluminium cells.
Jianghanqing said he and his team are not trying to to solve the problem from the Angle of material or electrochemical, but from the perspective of a mechanical engineer to solve the problem. He said: & other; Known research shows that under the effect of stress, the tiny tin pin, or tin whisker ( Similar to the dendritic crystal) From the surface of the tin is outstanding, therefore, by analogy, we study the reasons of the dendritic crystal growth of lithium & ndash; — Stress. ” Possibility & quot;
in the first round of study, the researchers in the bottom of the battery anode adds a layer of flexible PDMS, found that lithium dendrite growth decreased significantly. Researchers show that the accumulated stress in lithium metal electrode is released by the PDMS substrate in the form of fold deformation, the growing trend of dendrite reduce is directly related to the stress release.
“ This is the first time through the experiment proved that residual stress in the lithium dendrite formation plays a key role in the process, & throughout; Jiang Hanqing said.
in addition to the research of lithium dendrite growth mechanism, Jiang Hanqing team also further study how to use this kind of phenomenon, The stress release reduce dendrite growth) To prolong the life of lithium batteries, while maintaining high energy density.
the method is made with multiple PDMS matrix of 3 d structure. ” Contains a lot of holes of sugar as the template, the internal pore forming continuous network in PDMS into sugar, and then a thin layer of copper plating to the conduction electrons. Using metal lithium populate these pore. Jianghanqing explained: & other; As porous sponge layer, PDMS can effectively reduce stress, inhibit the growth of dendritic content. ”