Tag Archives: cobalt

The million-mile battery promised by Tesla is here

Elon Musk promised a battery that could take an e-vehicle a million miles and last for years at a time. Jeff Dahn, one of the pioneers of the modern lithium-ion batteries, has now delivered on that promise.

Image credits Paul Brennan.

In a new paper, Dahn announced that the company will soon be in possession of a battery that would make its robot taxis and long-haul electric trucks viable. Dahn is a Professor in the Department of Physics & Atmospheric Science and the Department of Chemistry at Dalhousie University, as well as a research partner of Tesla.

Charge for days

“Cells of this type should be able to power an electric vehicle for over one million miles and last at least two decades in grid energy storage” Dahn says.

Dahn’s research group is recognized as one of the most renowned and prestigious worldwide in the field of electrochemistry. Their new paper details the new power cell they created and a benchmark of its capabilities for further research.

The power cell is constructed using a nickel-rich NCM (nickel-cobalt-manganese) alloy for its cathode. The team explains that the alloy they used, known as NCM 523 (50% Nickel, 20% Cobalt, 30% Manganese), is stable and an excellent reference and starting point for further developments. Other elements that the team tested include graphite anodes, and different mixes of solvents, additives, and salt for the electrolyte solutions

All in all, the cells have a specific capacity (the ratio of energy storage ability to weight) 20% higher than that of the cathodes used in Li-ion batteries that power today’s mobile electronic devices. What’s more, the findings can be turned into useable batteries right away.

“However, since the goal of the study was to provide a reliable benchmark and reference for Li-ion battery technology, the specific energy density of the batteries described is not the highest compared to what can be really reached by advanced Li-ion batteries,” says Doron Aurbach the batteries and energy storage technical editor for the journal that published the study.

“Based on the study, Li-ion batteries will soon be developed that make driving over 500 kilometers (over 300 miles) from charge to charge possible.”

The paper “A Wide Range of Testing Results on an Excellent Lithium-Ion Cell Chemistry to be used as Benchmarks for New Battery Technologies” has been published in the Journal of The Electrochemical Society.

City smoke.

Prolonged exposure to Los Angeles Bay air induces dangerous mutations in the brains of rats

Mice trials suggest that city air may be even worse for your health than previously thought.

City smoke.

Image credits Johannes Plenio.

Prolonged exposure to fine particulate matter sourced air in the Los Angeles bay area does not do the brains of mice a lot of good. According to a new study published by researchers from the Cedars-Sinai Medical Center, a non-profit hospital in Los Angeles, it triggered inflammation and the appearance of cancer-associated genes in the animal’s neurons.

Brain trouble

The fact that air pollution is linked to a wide range of diseases isn’t exactly news by now — quite on the contrary. The adverse effects air pollution has on health have been widely documented and reported on. However, one new (and not exactly encouraging) discovery the team made is that certain materials in coarse air pollution — particularly nickel — may have a role promoting genetic changes that underpin the development of diseases such as cancer.

“This study, which looked at novel data gathered in the Los Angeles area, has significant implications for the assessment of air quality in the region, particularly as people are exposed to air pollution here for decades,” said lead author Julia Ljubimova, director of the Nanomedicine Research Center at Cedars-Sinai.

The team worked with one hundred mice — separated in groups of 6 to 10 animals. Each group was exposed to coarse (PM2.5–10: 2.5–10 µm in diameter), fine (PM<2.5: <2.5 µm), or ultrafine particles (UFPM: <0.15 µm) sourced from ambiental air in Riverside, California. Each type of particulate matter was analyzed using atomic emission spectroscopy, so the team had an idea of how much nickel, cobalt, and zinc they contained.

PM exposure lasted for 5 hours daily, 4 days per week for either two weeks (short exposure), one to three months (intermediate), or 12 months (long). One cohort of rats served as control and was kept in the same exposure chambers, for the same duration as the rats in the other groups, but was exposed to filtered air.

Afterward, the team analyzed the brains of each group to see how much of each metal had accumulated and whether this build-up had any effect on the organs’ health.

Metal build-up

They report that all three metals accumulated following intermediate-or-longer exposure. RNA sequencing revealed that intermediate exposure to PM2.5–10, which also correlated to nickel accumulation in the brain, triggered the expression of EGR2 — the early growth response gene 2 which regulates inflammatory processes — and of RAC1 — a gene that has the potential to cause cancer. The team believes the observed effects are a cumulative effect of exposure to the metals and certain toxins present in the air recovered from the Los Angeles Basin.

Furthermore, they report that coarse particulate matter from air pollution entered the body via two mechanisms. Trace metals and other pollutants could pass into the bloodstream from air inhaled through the lungs, later making their way to the brain. Alternatively, some of them could pass directly through mucosa in the nose, from where they had a much more direct pathway to the brain.

The study’s main limitations are that it only involved animal models — so the observed effects may carry over identically to humans — and that it only used a local ‘blend’ of pollutants — so the results may not be universally valid. Ljubimova notes that while the results may be unique to the Los Angeles Basin area, they do reinforce previous findings regarding the health consequences of exposure to air pollution in major cities.

Considering that most of humanity today lives with “unsafe” levels of air pollution, the findings are even more troubling.

“Our modern society is becoming increasingly urbanized and exposed to air pollution,” she says. “This trend underscores the need for additional research on the biology of air-pollution-induced organ damage, along with a concerted effort aimed at reducing ambient air pollution levels.”

The paper “Coarse particulate matter (PM2.5–10) in Los Angeles Basin air induces expression of inflammation and cancer biomarkers in rat brains” has been published in the journal Scientific Reports.

New crystal might allow us to breathe Underwater

Researchers from Denmark have synthesized crystalline materials that can bind and store oxygen in high concentrations, releasing them when needed. A single crystal about the size of a sponge can suck all the oxygen from a room.

Professor Christine McKenzie (center in photo) and postdoc Jonas Sundberg. Credit: Image courtesy of University of Southern Denmark

Naturally, there are many potential applications for this type of technology. The most obvious one would be breathing underwater or in outer space. We do fine with the approximately 21 percent of oxygen in the air, but when you want to breathe in unnatural environments (like those mentioned above) you want oxygen in higher concentrations to fill your tanks – and this is exactly where this type of technology would come in handy.

“This could be valuable for lung patients who today must carry heavy oxygen tanks with them,” said professor Christine McKenzie of the University of Southern Denmark, in a statement. “But also divers may one day be able to leave the oxygen tanks at home and instead get oxygen from this material as it “filters” and concentrates oxygen from surrounding air or water. A few grains contain enough oxygen for one breath, and as the material can absorb oxygen from the water around the diver and supply the diver with it, the diver will not need to bring more than these few grains.”

The material they created is crystalline and it has two main characteristics: it can absorb vast quantities of oxygens and release it whenever necessary.

“An important aspect of this new material is that it does not react irreversibly with oxygen — even though it absorbs oxygen in a so-called selective chemisorptive process. The material is both a sensor, and a container for oxygen — we can use it to bind, store and transport oxygen — like a solid artificial hemoglobin,” says Christine McKenzie.

To make things even better, the material can do this several times without actually losing its ability to absorb oxygen – which means that it could not only be used reliably to breathe underwater, but it could also be used in artificial photosynthesis:

“We see release of oxygen when we heat up the material, and we have also seen it when we apply vacuum. We are now wondering if light can also be used as a trigger for the material to release oxygen — this has prospects in the growing field of artificial photosynthesis,” says Christine McKenzie.

The exact chemical make-up of the crystal haven’t been released yet (or at least I couldn’t find it), but the key element is cobalt.

“Cobalt gives the new material precisely the molecular and electronic structure that enables it to absorb oxygen from its surroundings. This mechanism is well known from all breathing creatures on earth: Humans and many other species use iron, while other animals, like crabs and spiders, use copper. Small amounts of metals are essential for the absorption of oxygen, so actually it is not entirely surprising to see this effect in our new material,” explains Christine McKenzie.

Depending on the atmospheric conditions (oxygen content, humidity etc) it can take anywhere between a few minutes and more than a day. Furthermore, different versions of the substance can bind oxygen at different speeds.

Other potential uses are in medicine:

“This could be valuable for lung patients who today must carry heavy oxygen tanks with them. But also divers may one day be able to leave the oxygen tanks at home and instead get oxygen from this material as it “filters” and concentrates oxygen from surrounding air or water. A few grains contain enough oxygen for one breath, and as the material can absorb oxygen from the water around the diver and supply the diver with it, the diver will not need to bring more than these few grains.”

Journal Reference: Jonas Sundberg, Lisa J. Cameron, Peter D. Southon, Cameron J. Kepert, Christine J. McKenzie. Oxygen chemisorption/desorption in a reversible single-crystal-to-single-crystal transformation. Chemical Science, 2014; 5 (10): 4017 DOI: 10.1039/C4SC01636J

Purpurin, left, extracted from madder root, center, is chemically lithiated, right, for use as an organic cathode in batteries. (c) Ajayan Group/Rice University

‘Green’ batteries made from a red dye plant as an alternative to toxic batteries

Purpurin, left, extracted from madder root, center, is chemically lithiated, right, for use as an organic cathode in batteries. (c) Ajayan Group/Rice University

Purpurin, left, extracted from madder root, center, is chemically lithiated, right, for use as an organic cathode in batteries. (c) Ajayan Group/Rice University

Researchers at Rice University and City College of New York have devised rechargeable lithium-ion batteries using a substance extracted from the madder plant as a cathode. The plant has been used since ancient times as a dye, and only recently have researchers learned about its fantastic capabilities it poses as an alternative green battery.

The madder plant or  Rubia tinctorum is a potent source of purpurin, an organic dye that also works as a reliable cathode  for lithium-ion batteries. The organic compound’s alternative use as a prime ingredient for green batteries was found after the researchers extensively searched for organic molecules for their ability to electrochemically interact with lithium and found purpurin most amenable to binding lithium ions.

Currently most of the world’s lithium-ion batteries, used to charge just about any mobile device from your smartphone to an electric car, employ cobalt as the cathode, which is a toxic element in excess. Currently 30% of the world’s production of cobalt is directed to lithium-ion production and is extremely expensive to extract and chemically manufacture it into a cathode since it requires a high temperature environment, at a huge energy expense. This is why they’re also very expensive to recycle. In 2010 alone, almost 10 billion lithium-ion batteries had to be recycled, which uses a lot of energy. Furthermore 72 kilograms of carbon dioxide are pumped into the atmosphere for every kilowatt-hour of energy in a lithium-ion battery.

“Green batteries are the need of the hour, yet this topic hasn’t really been addressed properly,” said  lead author Arava Leela Mohana Reddy. “This is an area that needs immediate attention and sustained thrust, but you cannot discover sustainable technology overnight. The current focus of the research community is still on conventional batteries, meeting challenges like improving capacity. While those issues are important, so are issues like sustainability and recyclability.”

Less expensive, easier-to-recycle alternative to cobalt oxide cathode

The researchers added 20 percent carbon to purpurin for conductivity half-battery cell with a capacity of 90 milliamp hours per gram after 50 charge/discharge cycles. The whole process was undertaken at room temperature, so the high energy consumption need to heat cobalt is now saved.

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“It’s a new mechanism we are proposing with this paper, and the chemistry is really simple,” Reddy said.

Purpurin doesn’t necessary have to come solely from madder, however. Agricultural waste may be a source of purpurin, as may other suitable molecules, which makes the process even more economical, though some of you might have found the prospect of growing millions of climbing plants amusing. The idea isn’t half bad, though, as millions of madder plants would soak up important amounts of carbon from the atmosphere.

“We’re interested in developing value-added chemicals, products and materials from renewable feedstocks as a sustainable technology platform,” said co-lead author George John, a professor of chemistry at the City College of New York-CUNY and an expert on bio-based materials and green chemistry. “The point has been to understand the chemistry between lithium ions and the organic molecules. Now that we have that proper understanding, we can tap other molecules and improve capacity.”

For the anode, the other electrode in a lithium-ion battery, the same team of scientists experienced interesting results with a combination of silicon and a porous nickel current collector. The next obvious step towards building a completely green battery is to find a suitable organic molecule for the anode. “What we’ve come up with should lead to much more discussion in the scientific community about green batteries,” Reddy said.

The findings were reported in Nature’s online, open-access journal Scientific Reports.

source: Rice University