Moscow State University and Skoltech researchers made high-quality carbon materials for sodium ion battery anode with a nasty harmful weed. With the improvement of materials, this innovative type of battery could replace more expensive lithium-ion energy storage in solar and wind turbines and other applications where compactness is not a problem.
European wind
This work published in the "Battery" magazine. “We think it would be great to get rid of this nasty weed and get something useful in return at the same time,” said Zoya Bobyleva, co-author of the article at Lomonosov Moscow State University. - Solid carbon used in sodium ion battery anode can be produced from any biomass: nut shells, paper waste, but no one has tried uber-wind . It turned out to be a good choice. "
Sosnowski's is a very spreading weed that can also cause burns. It was brought from Caucasus to central Russia as part of agricultural experiments for raising livestock, but the idea has not become popular. European itself has taken root and sprouted, according to Skoltech The prediction published in the spring by scientists that by the middle of this century, it could be overgrown throughout Russia's European region.
sodium ion battery is an alternative lithium-free energy storage technology . Lithium prices are steadily rising, and the metal is mined in a few countries and its production is quite harmful to the environment. Sodium does not have these problems, but to switch to it, it is necessary to change the cathode and anode materials of the battery. Recently, Skoltech proposed a cathode material with record-breaking properties. This time, another team of researchers from Skoltech and Moscow State University received a high-quality anode material—from a very unexpected raw material.
"Currently, hard carbon provides the best performance combination for the anode of sodium ion batteries," led the study. Skoltech and Professor Evgeny Antipov from Moscow State University explained. - This material is an amorphous form of carbon that does not become graphite even under intense heating. Unlike graphite, this substance has a structure that can introduce sodium ions into itself after a cycle and then release them back, which is necessary for battery operation, without much change in volume of the material. Other advantages are its inexpensiveness, ease of synthesis and disposal, and low fire hazards. "
Comparison of two key properties of anode materials are Coulomb efficiency and specific capacitance. The higher the first indicator, the less energy wasted on the irreversible process during the cathode operation, which can also wear the battery.
is manufactured by scientists from Moscow State University and Skoltech, and the hard carbon from European shows a coulombic efficiency of 87%, comparable to the best materials of the same class obtained from other raw materials. According to the second key metric, it is not as good as the leading material - 260 vs. 300 mAh/g - but generally competitive.
"More precisely, we considered the easier collection of winter uber-wind and the flowering and smelling more harmful summer uber-wind uber-wind uber-wind uber-wind uber-wind uber-wind uber-wind uber-wind uber-wind uber-wind uber-wind uber-wind uber-wind uber-wind uber-wind uber-wind uber-wind uber-wind uber-wind uber-wind uber-wind
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The team tested three popular methods of solid carbon synthesis. First, the uberinated biomass is directly carbonized, that is, heated to 1300 degrees Celsius in an oxygen-free atmosphere. The composite was then repeated, but the starting material was initially washed with acid to remove metals and other impurities - as a result, the material's Coulombic efficiency increased. Finally, the cattle parsnips are boiled with water in a closed reactor, which makes it possible to obtain very small carbon-containing balls. It turns out that the specific capacity of the materials in these three cases is similar and the highest Coulomb efficiency is achieved in the second case.
"The demand for rechargeable batteries will grow. If we talk about the fluctuations in fixed batteries used in the industry or balancing solar panel and windmill power generation, then sodium ion technology looks very promising. Such batteries will be much cheaper than lithium ion batteries , and while they will lose in terms of quality and size, it is not always important—it depends on the application,” concluded Professor Artem Abakumov, co-author of the study, Skoltech Center for Energy Technology.
