High performance solid-state sodium-ion battery

High performance solid-state sodium-ion battery

Solid-state sodium-ion batteries are more secure than traditional lithium-ion batteries, which pose a threat to fire and explosions, but their performance is very weak to offset the benefits of safety. 

Researchers reported on Friday to develop an organic cathode that dramatically improves both stability and energy density.

Better performance reported in the magazine Joule is related to two major findings:

Resistance interface between electrolyte and cathode, which can usually be reversed during cycling, expanding cycle life, and

The flexibility of organic cathode allowed it to maintain intimate contact with the concrete electrolyte, even expanded the cathode and contracted during cycling.

Yan Yao and Associate Professor of Electrical and Computer Engineering of Yan Yao University, a related author of the paper, said that organic cathode - known as PTO, pyrene-4,5,9,10 - for introns - providing unique benefits Does the previous inorganic cathode But he said that underlying principles are equally important.

"We found for the first time that the resistive interface that is formed between the cathode and electrolyte can be reversed," said Tao.

It can contribute to stability and long life cycle." Yao UH also has a major investigator for the Texas Center for Superconductivity. His research group focuses on green and durable organic matter for energy production and storage.

Yanliang "Leonard" Liang, a research assistant professor in the ULA Department of Electrical and Computer Engineering, said that the interface is the resuscitation key, allowing solid-state batteries to reach high energy density without sacrificing cycle life. 

Generally, the ability to store the energy of a solid-state battery is stopped when the resistive cathode; Electrolyte interface forms; He said that due to resistance the energy density is high during cycling, he said.

Lithium-ion batteries with their liquid electrolytes are able to store relatively high amounts of energy and are usually used to deliver the means of modern life to the hearing devices from cell phones. 

But the risk of fire and explosion has increased interest in other types of batteries, and a solid-state sodium-ion battery promotes increased security on low cost.

Xiaowei Chi, a post-doctoral researcher in Yao's group, said that one important challenge was to find a solid electrolyte which is conductive in the form of liquid electrolytes used in lithium-ion batteries.

 Now when there are adequate conductive concrete electrolytes available, the remaining challenge is solid interfaces.

One issue raised by a solid electrolyte: Electrolyte struggles to maintain intimate contact with a conventional rigid cathode because later the battery spreads and contracts during cycling. Fang Hao, a Ph.D. student working in the Yao group, said that biological cathode is more viable and in this way cycling is able to stay in touch, to stay in touch with the interface. 

Researchers said that the contact remained stable through at least 200 cycles.

"If you have a reliable connection between electrodes and electrolyte, then you will have a great chance to build high-performance solid-state batteries," said Hao.

In addition to Yao, authors include co-first authors Hao and Chi, Liang, Ye Zhang and Hui Dong, all of UH; Rong Xu and Kejie Zhao of Purdue University; and Hua Guo, Tanguy Terlier and Jun Lou of Rice University. 

The majority of this work was funded by the U.S. Department of Energy's Advanced Research Projects Agency-Energy (ARPA-E).