Lithium-ion technology is still the gold standard for energy storage as demonstrated by the popularity of the new Powerwall battery, Tesla Energys much-publicized foray into Li-ion energy storage for homes and businesses. However, some new technologies are sneaking up behind. In the latest development, lithium-sulfur batteries could benefit from a new designer carbon engineered by a team of researchers at Stanford University.
The new designer carbon material could have a variety of applications, but the Stanford University team has zeroed in on the energy storage potential, particularly in respect to lithium-sulfur (Li-S) batteries.
The new material is actually a synthetic form of bio-based activated carbon. For those of you new to the topic, activated carbon is a common material that shows up in water filters and deodorizers, among many other things but not energy storage devices, at least not yet.
Inexpensive forms of activated carbon are typically made from coconut shells, which involves a lot of high-temperature processing and chemical finishing. The result is a material rich in nanoscale pores, which gives it a high surface area ideal for storing electrical charges.
However, this natural form of activated carbon falls flat in terms of transporting a charge, partly because there is little connectivity between the pores.
The Designer Carbon Solution
As a workaround, the Stanford team created its own synthetic sheets of carbon from a hydrogel polymer (hydrogel is fancyspeak for a class of super-absorbing smart materials). To activate the material, they added potassium hydroxide, which also increased its surface area.
The result is a carbon material with characteristics that can be controlled in two ways: by using different polymers and organic linkers, and by changing the temperature of the fabrication process.
Source: Clean Technica
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