Researchers at the University of Texas at Austin (UT Austin) have created a new sodium-based battery material that is highly stable, can be quickly charged like traditional lithium-ion batteries, and can provide more energy than current batteries Paving the way technology.

For about ten years, scientists and engineers have been developing sodium batteries, replacing the lithium and cobalt used in current lithium-ion batteries with cheaper and more environmentally friendly sodium. Unfortunately, in early sodium batteries, components called anodes tended to grow needle-like filaments called dendrites, which could cause the battery to short-circuit, or even catch fire or explode.

In one of two recent advances in sodium batteries made by the University of Texas at Austin, this new material solves the problem of dendrites and charges as fast as lithium-ion batteries. The team published their findings in the journal Advanced Materials.

"We are basically solving two problems at the same time," said David Mitlin, a professor in the Walker Mechanical Engineering Department and Applied Research Laboratory of the Cockrell School of Engineering, who designed this new material. "Usually, the faster you charge, the more these dendrites will grow. So if you suppress dendrite growth, you can charge and discharge faster because suddenly it is safe."

Professor Graeme Henkelman of the Department of Chemistry and the Oden Institute of Computational Engineering and Science used a computer model to theoretically explain why the material has its unique properties.

"This material is also very exciting because theoretically the energy density of sodium metal anodes is the highest of all sodium anodes," Henkelman said.

The demand for stationary energy storage systems for homes and smoothing the ebb and flow of wind and solar power on the grid is on the rise. At the same time, lithium mining has been criticized for its environmental impact, including extensive use of groundwater, soil and water pollution, and carbon emissions. Lithium-ion batteries usually also use cobalt, which is expensive and is mainly mined in the Democratic Republic of Congo, which has a significant impact on human health and the environment. In contrast, sodium mining is cheaper and more environmentally friendly.

Mitlin is optimistic about the idea that this new innovation and other innovations from UT Austin, including a new solid electrolyte, can improve energy storage, which means that sodium batteries may soon be able to meet the need for fixed energy storage. Growing demand.

When charging a rechargeable battery, ions (such as lithium or sodium) move from one component called the cathode to another component called the anode. When the battery is used to generate electricity, ions move from the anode back to the cathode.

This new type of negative electrode material is called sodium antimony telluride intermetallic compound (NST-Na), which is made by rolling a thin sheet of sodium metal onto antimony telluride powder, folding it up and repeating it many times.

"Consider making a layered pastry, such as spaghetti," Mitlin said.

This process results in a very uniform distribution of sodium atoms. Compared with existing sodium metal anodes, it is less likely to form dendrites or surface corrosion. This makes the battery more stable and allows faster charging, which is comparable to the charging rate of lithium-ion batteries. It also has a higher energy capacity than existing sodium ion batteries.

Henkelman said that if the charge-carrying sodium atoms in a sodium battery bind to each other stronger than they bind to the anode, they tend to form instability, or the sodium clumps will attract more sodium atoms and eventually lead to Dendrite. He used computer simulations to reveal what happens when a single sodium atom interacts with the new composite material NST-Na.

"In our calculations, the combination of this composite material with sodium is a bit stronger than that of sodium with itself, which is the ideal situation to make the sodium atoms drop and evenly distribute on the surface and prevent the formation of these instabilities," Henkelman said.

The two lead authors of the study, Yixian Wang and Hui Dong—current and former graduate students in Mitlin’s laboratory, respectively—made the material. Colleagues at Los Alamos National Laboratory, led by John Watt, described its characteristics. The other authors of the study are Hongchang Hao, Pengcheng Liu and Naman Katyal of UT Austin.

Mitlin, Wang and Dong, together with UT Austin, applied for a patent on the manufacture, structure and function of a new type of sodium metal anode material.

-This press release was originally published on the website of the University of Texas at Austin

Tags: Battery Industry News Lithium-ion Battery Material Science Product Resources: Industry News

© 2021 Laboratory Manager. all rights reserved.