Tag Archives: Yanan Chen

‘Beleafing’ in magic; a new type of battery

A Jan. 28, 2016 news item on ScienceDaily announces the ‘beleaf’,

Scientists have a new recipe for batteries: Bake a leaf, and add sodium. They used a carbonized oak leaf, pumped full of sodium, as a demonstration battery’s negative terminal, or anode, according to a paper published yesterday in the journal ACS Applied Materials Interfaces.

Scientists baked a leaf to demonstrate a battery. Credit: Image courtesy of Maryland NanoCenter

Scientists baked a leaf to demonstrate a battery.
Credit: Image courtesy of Maryland NanoCenter

A Jan. ??, 2016 Maryland NanoCenter (University of Maryland) news release, which originated the news item, provides more information about the nature (pun intended) of the research,

“Leaves are so abundant. All we had to do was pick one up off the ground here on campus,” said Hongbian Li, a visiting professor at the University of Maryland’s department of materials science and engineering and one of the main authors of the paper. Li is a member of the faculty at the National Center for Nanoscience and Technology in Beijing, China.

Other studies have shown that melon skin, banana peels and peat moss can be used in this way, but a leaf needs less preparation.

The scientists are trying to make a battery using sodium where most rechargeable batteries sold today use lithium. Sodium would hold more charge, but can’t handle as many charge-and-discharge cycles as lithium can.

One of the roadblocks has been finding an anode material that is compatible with sodium, which is slightly larger than lithium. Some scientists have explored graphene, dotted with various materials to attract and retain the sodium, but these are time consuming and expensive to produce.  In this case, they simply heated the leaf for an hour at 1,000 degrees C (don’t try this at home) to burn off all but the underlying carbon structure.

The lower side of the maple [?] leaf is studded with pores for the leaf to absorb water. In this new design, the pores absorb the sodium electrolyte. At the top, the layers of carbon that made the leaf tough become sheets of nanostructured carbon to absorb the sodium that carries the charge.

“The natural shape of a leaf already matches a battery’s needs: a low surface area, which decreases defects; a lot of small structures packed closely together, which maximizes space; and internal structures of the right size and shape to be used with sodium electrolyte,” said Fei Shen, a visiting student in the department of materials science and engineering and the other main author of the paper.

“We have tried other natural materials, such as wood fiber, to make a battery,” said Liangbing Hu, an assistant professor of materials science and engineering. “A leaf is designed by nature to store energy for later use, and using leaves in this way could make large-scale storage environmentally friendly.”

The next step, Hu said, is “to investigate different types of leaves to find the best thickness, structure and flexibility” for electrical energy storage.  The researchers have no plans to commercialize at this time.

Here’s a link to and a citation for the paper,

Carbonized-leaf Membrane with Anisotropic Surfaces for Sodium-ion Battery by Hongbian Li, Fei Shen, Wei Luo, Jiaqi Dai, Xiaogang Han, Yanan Chen, Yonggang Yao, Hongli Zhu, Kun Fu, Emily Hitz, and Liangbing Hu. ACS Appl. Mater. Interfaces, 2016, 8 (3), pp 2204–2210 DOI: 10.1021/acsami.5b10875 Publication Date (Web): January 4, 2016

Copyright © 2016 American Chemical Society

This paper is behind a paywall.

‘Zero-dimensional’ carbon nanotubes

They never say (at least not in the news releases I read) but I get the impression that the carbon nanotube researchers are pretty competitive with the graphene researchers since graphene has largely replaced carbon nanotubes as the basis for magic materials that will transform electronics and make everything thinner, lighter, and stronger. I exaggerate the claims but not by much. At any rate, members of the carbon nanotube research community from the University of Pittsburgh have announced the smallest, thinnest carbon nanotubes yet in a Dec. 9, 2013 University of Pittsburgh news release (also on EurekAlert but dated Dec. 10, 2013),

Synthetic, man-made cells and ultrathin electronics built from a new form of “zero-dimensional” carbon nanotube may be possible through research at the University of Pittsburgh Swanson School of Engineering. The research, ““Zero-Dimensional” Single-Walled Carbon Nanotubes,” was published in the journal Angewandte Chemie.

“Since its discovery, carbon nanotubes have held the promise to revolutionize the field of electronics, material science and even medicine,” says Dr. Little [Steven R. Little, PhD, associate professor]. “Zero-dimensional carbon nanotubes present the possibility to build ultrathin, superfast electronic devices, far superior to the best existing ones and it could be possible to build strong and ultralight cars, bridges, and airplanes.”

One of the most difficult hurdles is processing the carbon nanotubes into smaller forms. However, previous research at Pitt has managed to cut the carbon nanotubes into the smallest dimensions ever to overcome this problem.

“We have confirmed that these shorter nanotubes are more dispersible and potentially easier to process for industrial as well as biomedical application, and could even constitute the building blocks for the creation of synthetic cells,” says Dr. Gottardi.

The organization of the atoms within nanotubes makes them particularly interesting materials to work with. However, they are barely soluble, making industrial processing difficult. One aspect of the team’s research will focus on creating more soluble and therefore more usable carbon nanotubes. These shorter nanotubes have the same dimensions as many proteins that compose the basic machinery of living cells, presenting the potential for cell or protein-level biomedical imaging, protein or nucleic acid vaccination carriers, drug delivery vehicles, or even components of synthetic cells.

Overall, the project is aimed at developing and working with these more dispersible carbon nanotubes with the aim of making them easier to process. The creation of the smaller nanotubes is the first step toward reaching this goal.

For the curious, here’s a link to and a citation for the paper,

“Zero-Dimensional” Single-Walled Carbon Nanotubes by Dr. Kaladhar Kamalasanan, Dr. Riccardo Gottard, Dr. Susheng Tan, Dr. Yanan Chen, Dr. Bhaskar Godugu, Dr. Sam Rothstein, Dr. Anna C. Balazs, Dr. Alexander Star, Dr. Steven R. Little. Angewandte Chemie Volume 125, Issue 43, pages 11518–11522, October 18, 2013 Article first published online: 5 SEP 2013 DOI: 10.1002/ange.201305526

Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim

This article is behind a paywall.