Tag Archives: Ning Chen

Rare earth elements (REE) and the Canadian Light Source

Leave a reply

Unexpectedly, this story centers on coal and in this case, coal ash. A September 12, 2024 Canadian Light Source news release (also received via email)) by Brian Owens explains how coal ash is a source for rare earth elements (RRE), Note: A link has been removed,

As the world transitions away from fossil fuels, the demand for rare earth elements (REEs) is only going to increase. These elements are vital to the production of technologies that will make the transition to green energy possible. While REEs are not technically rare, large deposits are found in only a few locations around the world – mostly in China – and they are difficult to extract.

“If we want to switch to electric vehicles by 2035 and be net-zero by 2050 we’re going to need new sources of these metals,” says Brendan Bishop, a PhD candidate studying REEs at the University of Regina.

Bishop and his colleagues have been studying one potential new source of these valuable elements: the ash that is produced as waste from coal-fired power plants. Researchers have looked into REEs in coal waste in the United States and China, but there has been little work done on ash from Canadian coal.

The team analyzed samples of ash from coal plants in Alberta and Saskatchewan to determine how much REEs the ashes contained, and how they could be extracted. While the concentration of REEs in Canadian coal ash is on par with that found in ash from other parts of the world, questions remained about whether the REEs are dispersed evenly throughout the ash particles or concentrated in certain minerals found within the ashes.

Using the powerful X-ray beamlines at the Canadian Light Source (CLS) at the University of Saskatchewan (USask), Bishop probed the ash, in search of a rare earth element called yttrium. They found it was distributed in specific mineral phases within the ash particles, most often in the form of silicates or phosphates such as xenotime which remain unchanged when the coal is burned.  The work was published in Environmental Science and Technology.

Bishop says this data can help inform development of an efficient and environmentally friendly process for recovering REEs from the ash. “This will be important when we develop a recovery process because extracting rare earth elements is technologically challenging,” he says. “In this case, since it’s in xenotime which is an ore mineral, maybe we can use an existing process and modify it for coal ash.”

The amount of REEs that could be extracted from coal ash will depend on the recovery process, says Bishop. But he thinks it could be a good short-to-medium-term source of the metals. The concentration is not particularly high, but that is offset by the fact that waste coal ash is plentiful. The concentration throughout the ash is also fairly homogenous, so no complicated grading is required as with mined ores. Once the extraction process is perfected, it will also be much faster than opening new mines, which often have gaps of up to 17 years between exploration and production.

Recovering REEs from the ash is also an important step toward a circular economy. Some ash is used in making concrete, but most just sits in landfills or tailings ponds near power plants. “It not only gets rid of an environmental liability, but it also gives us the metals we need for clean energy technologies,” says Bishop.

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

Rare Earth Element Speciation in Coal and Coal Combustion Byproducts: A XANES and EXAFS Study by Brendan A. Bishop, Karthik Ramachandran Shivakumar, Jamie Schmidt, Ning Chen, Daniel S. Alessi, Leslie J. Robbins. Environ. Sci. Technol. 2024, 58, 32, 14565–14574 Published July 30, 2024 DOI: https://doi.org/10.1021/acs.est.4c04256 Copyright © 2024 American Chemical Society

This paper is behind a paywall.

Layer of tin could prevent short-circuiting in lithium-ion batteries

Leave a reply

Lithium-ion batteries are everywhere; they can be found in cell phones, laptops, e-scooters, e-bikes, and more. There are also some well documented problems with the batteries including the danger of fire. With the proliferating use of lithium-ion batteries, it seems fires are becoming more frequent as Samantha Murphy Kelly documents in her Mach 9, 2023 article for CNN news online, Note: Links have been removed,

Lithium-ion batteries, found in many popular consumer products, are under scrutiny again following a massive fire this week in New York City thought to be caused by the battery that powered an electric scooter.

At least seven people have been injured in a five-alarm fire in the Bronx which required the attention of 200 firefighters. Officials believe the incident stemmed from a lithium-ion battery of a scooter found on the roof of an apartment building. In 2022, the the New York City Fire Department responded to more than 200 e-scooter and e-bike fires, which resulted in six fatalities.

“In all of these fires, these lithium-ion fires, it is not a slow burn; there’s not a small amount of fire, it literally explodes,” FDNY [Fire Dept. New York] Commissioner Laura Kavanagh told reporters. “It’s a tremendous volume of fire as soon as it happens, and it’s very difficult to extinguish and so it’s particularly dangerous.”

A residential fire earlier this week in Carlsbad, California, was suspected to be caused by an e-scooter lithium battery. On Tuesday [March 7, 2023], an alarming video surfaced of a Canadian homeowner running downstairs to find his electric bike battery exploding into flames. [emphasis mine] A fire at a multi-family home in Massachusetts last month is also under investigation for similar issues.

These incidents are becoming more common for a number of reasons. For starters, lithium-ion batteries are now in numerous consumer tech products,powering laptops, cameras, smartphones and more. They allow companies to squeeze hours of battery life into increasingly slim devices. But a combination of manufacturer issues, misuse and aging batteries can heighten the risk from the batteries, which use flammable materials.

“Lithium batteries are generally safe and unlikely to fail, but only so long as there are no defects and the batteries are not damaged or mistreated,” said Steve Kerber, vice president and executive director of Underwriters Laboratory’s (UL) Fire Safety Research Institute (FSRI). “The more batteries that surround us the more incidents we will see.”

In 2016, Samsung issued a global recall of the Galaxy Note 7 in 2016, citing “battery cell issues” that caused the device to catch fire and at times explode. [emphasis mine] HP and Sony later recalled lithium computer batteries for fire hazards, and about 500,000 hoverboards were recalled due to a risk of “catching fire and/or exploding,” according to the U.S. Consumer Product Safety Commission.

In 2020, the Federal Aviation Administration [emphasis mine] banned uninstalled lithium-ion metal batteries from being checked in luggage and said they must remain with a passenger in their carry-on baggage, if approved by the airline and between 101-160 watt hours. “Smoke and fire incidents involving lithium batteries can be mitigated by the cabin crew and passengers inside the aircraft cabin,” the FAA said.

Despite the concerns, lithium-ion batteries continue to be prevalent in many of today’s most popular gadgets. Some tech companies point to their abilities to charge faster, last longer and pack more power into a lighter package.

But not all lithium batteries are the same.

…

Kelly’s Mach 9, 2023 article describes the problems (e.g., a short circuit) that may cause fires and includes some recommendations for better safety and for what to do in the event of a lithium-ion battery fire.Her mention of Samsung and the fires brought back memories; it was mentioned here briefly in a December 21, 2016 post titled, “The volatile lithium-ion battery,” which mostly featured then recent research into the batteries and fires.

More recently, I’ve got an update of sorts on lithium-ion batteries and fires on airplanes, from the May/June 2024 posting of the National Business Aviation Association (NBAA) Insider,

A smoke, fire or extreme heat incident involving lithium ion batteries takes place aboard an aircraft more than once per week [emphases mine] on average in the U.S., making it imperative for operators to fully understand these dangerous events and to prepare crews with safety training.

…

At any given time, there could be more than 1,000 Li-ion powered devices on board an airliner, while an international business jet might easily be flying with a few dozen. Despite their popularity, few people realize the dangers posed by Li-ion batteries.

Hazards run the gamut, from overheating, to emitting smoke, to bursting into flames or even exploding – spewing bits of white hot gel in all directions. In fact, a Li-ion fire can begin as a seemingly harmless overheat and erupt into a serious hazard in a matter of seconds.

FAA [US Federal Aviation Administration] data shows the scope of the threat: In 2023, more than one Li-ion incident occurred aboard an aircraft each week. Specifically, the agency said there were 208 issues with lithium ion battery packs, 111 with e-cigarettes and vaping devices, 68 with cell phones and 60 with laptop computers. (The FAA doesn’t offer incident data by aircraft type.

Thankfully, the data shows the chances of encountering an unstable mobile device aboard a business aircraft are small. But so is the possibility of a passenger experiencing a heart attack – yet many business aircraft carry defibrillators.

…

The threat with lithium ion batteries is known as thermal runaway. When a Li-ion battery overheats due to some previous damage that creates a short circuit [emphasis mine], the unit continues a catastrophic internal chain reaction until it melts or catches fire.

…

Short circuits, lithium ion batteries, and the University of Alberta

A July 31, 2024 Canadian Light Source (CLS) news release (also received via email) by Greg Basky announces the University of Alberta research,

Lithium-ion batteries have a lot of advantages. They charge quickly, have a high energy density, and can be repeatedly charged and discharged.

They do have one significant shortcoming, however: they’re prone to short-circuiting.  This occurs when a connection forms between the two electrodes inside the cell. A short circuit can result in a sudden loss of voltage or the rapid discharge of high current, both causing the battery to fail. In extreme cases, a short circuit can cause a cell to overheat, start on fire, or even explode. Video: Thin layer of tin prevents short-circuiting in lithium-ion batteries

A leading cause of short circuits are rough, tree-like crystal structures called dendrites that can form on the surface of one of the electrodes. When dendrites grow all the way across the cell and make contact with the other electrode, a short circuit can occur.

Using the Canadian Light Source (CLS) at the University of Saskatchewan (USask), researchers from the University of Alberta (UAlberta) have come up with a promising approach to prevent formation of dendrites in solid-state lithium-ion batteries. They found that adding a tin-rich layer between the electrode and the electrolyte helps spread the lithium around when it’s being deposited on the battery, creating a smooth surface that suppresses the formation of dendrites. The results are published in the journal ACS Applied Materials and Interfaces [ACS is American Chemical Society]. The team also found that the cell modified with the tin-rich structure can operate at a much higher current and withstand many more charging-discharging cycles than a regular cell.

Researcher Lingzi Sang, an assistant professor in UAlberta’s Faculty of Science (Chemistry), says the CLS played a key role in the research. “The HXMA beamline enabled us to see at a material’s structural level what was happening on the surface of the lithium in an operating battery,” says Sang. “As a chemist, what I find the most intriguing is we were able to access the exact tin structure that we introduced to the interface which can suppress dendrites and fix this short-circuiting problem.” In a related paper the team published earlier this year, they showed that adding a protective layer of tin also suppressed the formation of dendrites in liquid-electrolyte-based lithium-ion batteries.

This novel approach holds considerable potential for industrial applications, according to Sand. “Our next step is to try to find a sustainable, cost-effective approach to applying the protective layer in battery production.”

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

Dual-Component Interlayer Enables Uniform Lithium Deposition and Dendrite Suppression for Solid-State Batteries by Xiang You, Ning Chen, Geng Xie, Shihong Xu, Sayed Youssef Sayed, and Lingzi Sang. ACS Appl. Mater. Interfaces 2024, 16, 27, 35761–35770 DOI: https://doi.org/10.1021/acsami.4c05227 Published June 21, 2024 Copyright © 2024 American Chemical Society

This paper is behind a paywall.

Split some water molecules and save solar and wind (energy) for a future day

Leave a reply

Professor Ted Sargent’s research team at the University of Toronto has a developed a new technique for saving the energy harvested by sun and wind farms according to a March 28, 2016 news item on Nanotechnology Now,

We can’t control when the wind blows and when the sun shines, so finding efficient ways to store energy from alternative sources remains an urgent research problem. Now, a group of researchers led by Professor Ted Sargent at the University of Toronto’s Faculty of Applied Science & Engineering may have a solution inspired by nature.

The team has designed the most efficient catalyst for storing energy in chemical form, by splitting water into hydrogen and oxygen, just like plants do during photosynthesis. Oxygen is released harmlessly into the atmosphere, and hydrogen, as H2, can be converted back into energy using hydrogen fuel cells.

Discovering a better way of storing energy from solar and wind farms is “one of the grand challenges in this field,” Ted Sargent says (photo above by Megan Rosenbloom via flickr) Courtesy: University of Toronto

Discovering a better way of storing energy from solar and wind farms is “one of the grand challenges in this field,” Ted Sargent says (photo above by Megan Rosenbloom via flickr) Courtesy: University of Toronto

A March 24, 2016 University of Toronto news release by Marit Mitchell, which originated the news item, expands on the theme,

“Today on a solar farm or a wind farm, storage is typically provided with batteries. But batteries are expensive, and can typically only store a fixed amount of energy,” says Sargent. “That’s why discovering a more efficient and highly scalable means of storing energy generated by renewables is one of the grand challenges in this field.”

You may have seen the popular high-school science demonstration where the teacher splits water into its component elements, hydrogen and oxygen, by running electricity through it. Today this requires so much electrical input that it’s impractical to store energy this way — too great proportion of the energy generated is lost in the process of storing it.

This new catalyst facilitates the oxygen-evolution portion of the chemical reaction, making the conversion from H2O into O2 and H2 more energy-efficient than ever before. The intrinsic efficiency of the new catalyst material is over three times more efficient than the best state-of-the-art catalyst.

Details are offered in the news release,

The new catalyst is made of abundant and low-cost metals tungsten, iron and cobalt, which are much less expensive than state-of-the-art catalysts based on precious metals. It showed no signs of degradation over more than 500 hours of continuous activity, unlike other efficient but short-lived catalysts. …

“With the aid of theoretical predictions, we became convinced that including tungsten could lead to a better oxygen-evolving catalyst. Unfortunately, prior work did not show how to mix tungsten homogeneously with the active metals such as iron and cobalt,” says one of the study’s lead authors, Dr. Bo Zhang … .

“We invented a new way to distribute the catalyst homogenously in a gel, and as a result built a device that works incredibly efficiently and robustly.”

This research united engineers, chemists, materials scientists, mathematicians, physicists, and computer scientists across three countries. A chief partner in this joint theoretical-experimental studies was a leading team of theorists at Stanford University and SLAC National Accelerator Laboratory under the leadership of Dr. Aleksandra Vojvodic. The international collaboration included researchers at East China University of Science & Technology, Tianjin University, Brookhaven National Laboratory, Canadian Light Source and the Beijing Synchrotron Radiation Facility.

“The team developed a new materials synthesis strategy to mix multiple metals homogeneously — thereby overcoming the propensity of multi-metal mixtures to separate into distinct phases,” said Jeffrey C. Grossman, the Morton and Claire Goulder and Family Professor in Environmental Systems at Massachusetts Institute of Technology. “This work impressively highlights the power of tightly coupled computational materials science with advanced experimental techniques, and sets a high bar for such a combined approach. It opens new avenues to speed progress in efficient materials for energy conversion and storage.”

“This work demonstrates the utility of using theory to guide the development of improved water-oxidation catalysts for further advances in the field of solar fuels,” said Gary Brudvig, a professor in the Department of Chemistry at Yale University and director of the Yale Energy Sciences Institute.

“The intensive research by the Sargent group in the University of Toronto led to the discovery of oxy-hydroxide materials that exhibit electrochemically induced oxygen evolution at the lowest overpotential and show no degradation,” said University Professor Gabor A. Somorjai of the University of California, Berkeley, a leader in this field. “The authors should be complimented on the combined experimental and theoretical studies that led to this very important finding.”

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

Homogeneously dispersed, multimetal oxygen-evolving catalysts by Bo Zhang, Xueli Zheng, Oleksandr Voznyy, Riccardo Comin, Michal Bajdich, Max García-Melchor, Lili Han, Jixian Xu, Min Liu, Lirong Zheng, F. Pelayo García de Arquer, Cao Thang Dinh, Fengjia Fan, Mingjian Yuan, Emre Yassitepe, Ning Chen, Tom Regier, Pengfei Liu, Yuhang Li, Phil De Luna, Alyf Janmohamed, Huolin L. Xin, Huagui Yang, Aleksandra Vojvodic, Edward H. Sargent. Science  24 Mar 2016: DOI: 10.1126/science.aaf1525

This paper is behind a paywall.