This article comes from Nano Letters and will be of interest to who wish to stabilize their grids.
A search for the next great high-energy, rechargeable battery technology has been on for a while. Recently, scientists report they have overcome key obstacles toward making lithium-sulfur (Li-S) batteries, which have potential to outperform today’s lithium-ion technology. This study appears in the ACS journal Nano Letters.
To better confine the sulfur/polysulfides in the electrode of lithium–sulfur (Li/S) batteries and improve the cycling stability, we developed a double-layered core–shell structure of polymer-coated carbon–sulfur. Carbon–sulfur was first prepared through the impregnation of sulfur into hollow carbon spheres under heat treatment, followed by a coating polymerization to give a double-layered core–shell structure. From the study of scanning transmission electron microscopy images, we demonstrated that the sulfur successfully penetrated through the porous carbon shell and aggregated along the inner wall of the carbon shell, which, for the first time, provided visible and convincing evidence that sulfur preferred diffusing into the hollow carbon rather than aggregating in/on the porous wall of the carbon.
Xingcheng Xiao, Weidong Zhou, Mei Cai and colleagues point out that the capabilities of lithium-ion batteries, which power many of our consumer electronics, as well as electric vehicles, have largely plateaued. Scientists have been pursuing a number of new battery technologies to topple today’s standard. One heavy focus has been on a key battery component that is currently made out of a metal oxide. Some researchers have been trying to replace the metal oxide with cheaper and lighter sulfur, to make Li-S batteries. In theory, this could allow batteries to pack five to eight times the energy of existing technology. One of the main problems with this approach, however, is that Li-S compounds escape from where they’re supposed to be, which causes the battery to lose charge quickly. The team set out to find a way to contain the errant compounds.
To solve the problem, the researchers made tiny, hollow shells out of carbon, which is conductive. They then coated them with a polymer to help confine the Li-S compounds inside. When tested, the structures kept up a high-energy storage capacity (630 mAh/g versus less than 200 mAh/g of lithium-ion batteries) over 600 cycles of fast charging and discharging. “These results provide promising insights and novel concepts for future sulfur-based batteries,” the researchers conclude.
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