Lithium-sulfur (Li-S) batteries, regardless of their excessive theoretical particular power, face sensible challenges together with polysulfide shuttling and low cell-level power density.
Researchers on the College of Waterloo have now proven that the light-weight superconductor MgB2 (magnesium diboride)—the typical mass/atom of which is comparable with carbon—as a metallic sulfur host fulfills each electron conduction and polysulfide immobilization properties.
In a paper within the journal Joule the groups reviews that, through the use of first-principles calculations, they discovered that borides are distinctive in that each B- and Mg-terminated surfaces bond completely with the Sx2− anions (not Li+), and therefore improve electron switch to the energetic Sx2− ions.
The surface-mediated polysulfide redox habits ends in a a lot greater change present as compared with MgO and carbon. By sandwiching MgB2 nanoparticles between graphene nanosheets to kind a high-surface-area composite construction, they demonstrated sulfur cathodes that obtain secure biking at a excessive sulfur loading of 9.three mg cm−2.
They conclude that this new avenue towards Li-S cathodes, when coupled with a protected lithium steel anode, might result in sensible implementation of batteries which might be lighter, but strong.
Quan Pang, Chun Yuen Kwok, Dipan Kundu, Xiao Liang, Linda F. Nazar (2018) “Light-weight Metallic MgB2 Mediates Polysulfide Redox and Guarantees Excessive-Power-Density Lithium-Sulfur Batteries,” Joule doi: 10.1016/j.joule.2018.09.024