Tag Archives: lithium

World’s largest battery manufacturer bets big on sodium-ion batteries

Credit: CATL.

China’s Contemporary Amperex Technology Co. (CATL) is the world’s uncontested leader in lithium-ion batteries, providing products to Tesla, Volkswagen, BMW, and just about every important name in the electric vehicle (EV) space. But despite its market position, CATL is looking towards the future. The trillion dollar company just unveiled a new sodium-ion battery that is significantly cheaper than lithium-ion power packs, which may perhaps alleviate supply chain pressure and accelerate the transition of road transportation away from dirty fossil fuel-powered cars.

Lithium, the lightest metal and the least dense solid element in the periodic table, is phenomenally good for storing energy thanks to its high electrochemical potential. The combination of high reactivity, low mass, and seamless back and forth transfer of ions and electrons between positive and negative electrodes makes lithium-ion batteries amazing for powering electric vehicles.

However, lithium comes at a high cost, both financially and for the environment. Although the cost of lithium-ion batteries has dropped by 97 percent since they were first commercially introduced in 1991, mining lithium remains expensive and as demand increases as more and more auto companies transition towards EVs, demand is expected to skyrocket. From a supply chain standpoint, lithium is also relatively rare, being mined in a handful of countries such as Australia, Chile, China, and Argentina.

In South America, demand for lithium is causing water shortage problems. More than half of the world’s supply of the light metal lies beneath the otherworldly salt flats that cover parts of Argentina, Bolivia, and Chile, aptly named the Lithium Triangle. It takes about 500,000 gallons (1.9 mil. liters) of water to extract a ton of lithium, which is quite unbearable for communities close to the mines, many of which are located in the driest places on Earth.

Sodium, on the other hand, is much cheaper, easier to extract, and about 1,000 times more abundant than lithium, writes FreeThink. What’s more, the risk of a sodium-ion battery catching fire is basically zero, unlike the batteries that currently power your phone or Tesla. They also operate at a wider temperature range, which may make them more appealing for certain applications than conventional lithium-ion products.

With its new sodium-ion battery, CATL doesn’t seek to replace its lithium-ion products but rather supplement them in order to ease the pressure on lithium demand. According to the company, its first-generation sodium-ion batteries can reach an energy density of 160 watt-hours/kilogram, which may improve to 200 Wh/kg in subsequent generations. For comparison, Tesla’s Model 3 has an energy density of 250 Wh/kg.

The lower energy density and higher mass means that a sodium-ion battery-powered EV will have a much lower range than a lithium-ion-powered one. This is why CATL decided to launch a hybrid battery that integrates both sodium-ion and lithium cells in one case.

So while sodium-ion batteries won’t completely solve our lithium shortage problems, they could dramatically influence the market by taking a massive load off the demand. Ultimately, sodium-ion batteries could play a major role in accelerating EV adoption going forward.

Calcium-based batteries could be a step closer to reality

Manufacturing calcium-based batteries could be a step closer thanks to a newly synthesized chemical discovered by researchers at the Helmholtz Institute Ulm in Germany, looking for a safer and cheaper alternative than the current lithium-based batteries.

A calcium reservoir. Credit: Wikipedia Commons

Until now, researchers working on calcium batteries have lacked a suitable electrolyte, the medium through which electrical charge flows. Batteries with anodes made of calcium — a more abundant substance — might be more sustainable and safer than batteries with lithium anodes.

Researcher Zhirong Zhao-Karger and her colleagues reacted a calcium compound with a fluorine-containing compound to create a new type of calcium salt. The resulting material conducted electricity more effectively than any calcium-based electrolyte yet reported. It also efficiently conducted ions at a higher voltage than other calcium-based electrolytes.

Lithium, now used in most electrochemical storage systems and electronic devices, is relatively expensive because of limited supplies and has technical disadvantages. The lithium-ion batteries have numerous drawbacks: they sometimes catch fire, and they depend on increasingly scarce and toxic substances such as lithium and cobalt.

To create lithium batteries, there is a need for a range of rare earth metals that require heavy mining and manufacturing that emit significant emissions. Furthermore, major components such as lithium, nickel, and cobalt exist in a finite amount that is unlikely to meet the current and future demands for battery units.

Meanwhile, calcium-ion batteries, long tipped as a viable replacement, have at least twice the number of electrons as lithium units, which means higher power density in a thinner, lighter package.

Calcium is about 2,500 times as abundant as lithium in nature, making the calcium-ion energy storage technology a promising candidate for next-generation batteries due to its high performance and low cost. However, calcium-ion batteries have been unsuccessful to attain a satisfactory performance in previous studies.

The search for alternatives to lithium batteries is mostly due to demand for extended-range electric vehicles and batteries for portable gadgets that can give a longer life span, as well as a need to reduce manufacturing costs.

Electric vehicles are set to make up more than half of global passenger car sales by 2040 and completely dominate the bus market, according to this year’s Electric Vehicle Outlook report.

Electrics will take up 57% of the global passenger car sales by 2040, with electric buses dominating their sector, holding 81% of municipal bus sales by the same date. Electric models will also make up 56% of light commercial vehicle sales.

Newly discovered star’s chemistry puzzles researchers

A team of Argentinian astronomers, peering up in the night’s sky from the Astronomical Observatory of Córdoba has found a new, young lithium-rich giant star that they designated KIC 9821622. Drawing on data obtained from the GRACES high-resolution spectograph, they were able to determine the star’s mass, radius, age, as well as determine the chemical abundances of 23 elements of the celestial body, which they will be publishing in the December issue of the Astronomy & Astrophysics journal.

This image from the New Technology Telescope at ESO’s La Silla Observatory shows Nova Centauri 2013 in July 2015 as the brightest star in the center of the picture. This was more than eighteen months after the initial explosive outburst. This nova was the first in which evidence of lithium has been found.
Image via phys

The analysis of this star was performed during an on-sky test of the GRACES system (Gemini Remote Access to CFHT ESPaDOnS Spectrograph) conducted in July of this year. The team’s report shows that KIC is an intermediate-mass giant star weighing in at about 1.64 times our Sun’s mass, located some 5,300 light years from Earth, in the Kepler Field. But what’s really caught scientist’s interest is the chemical composition of KIC 9821622; it’s very rich in lithium, and high concentration of this element is very rarely seen in stars  — it’s estimated that only 1-2 percent of all known stars boast comparable levels of this element.

Under normal conditions, lithium stands out as being the lightest metal and the least dense solid element in the periodic table. With an atomic number of just 3 protons, you’d expect this element to be very prolific in stars, as a logical progression from hydrogen (Z=1) and helium (Z=2) fusion, but it’s actually very rarely seen in stars large and hot enough to sustain fusion — lithium is actually consumed inside these stars. At the immense temperatures required for hydrogen fusion, lithium atoms collide with protons to form helium in a process known as lithium burning, and isn’t re-created afterwards. In fact, high concentrations of this element are usually a good indicator that a celestial body is substellar, such as brown dwarfs, through the Rafael Rebolo or Lithium test..

This is why scientists are quite puzzled by the find. One theory the authors propose is that the high concentration of lithium can be attributed to a fresh batch of the element that is synthesized near the luminosity bump. Another possibility they’re looking into is that KIC gained its lithium by accretion of planets or brown dwarfs, and it didn’t have time to “digest” the element yet.

However, neither theory is anything more than speculation on their part right now. While the second theory is a bit shaky — up to now, we’ve found no trace of any orbiting planet or binary star system near KIC, let alone one that could have provided the required amount of lithium — the team feels that this is where we should focus our efforts.

“Lithium enhancement in giant stars can be the result of the engulfment of a brown dwarf or planet,” the paper reads.

It’s very important that we understand how or where KIC got its lithium, the authors say — they underline the need for further research of the star, as understanding lithium abundance in stellar photospheres is an important tool in our understanding stellar evolution as a whole.

“To advance in our understanding of these rare objects, it is essential not only to continue the search of lithium rich giants, but also to derive their chemical abundances and to unambiguously establish their evolutionary status,” they write in the paper.

The authors recommend that the star be observed at longer wavelengths than those employed by the GRACE system, such as mid-infrared or submillimeter, as they believe that accretion of a planet would lead to the formation of an ejected-material shell that they could detect as infrared excess.

Aside from being lithium-rich, the scientists found that KIC 9821622 shows also a high abundance of carbon, nitrogen and oxygen. They also managed to derive the star’s precise spectroscopic fundamental parameters, including the effective temperature, surface gravity, metallicity and microturbulent velocity.

“KIC 9821622 is certainly a unique and interesting object that deserves further scrutiny to reveal the real mechanism behind the observed anomalous abundances. In this sense, high-resolution chemical analysis of more of these young giants might help to understand their origin,” the paper concludes.

Better, far more responsive touchscreen displays might be developed as a result of these findings. Photo:easy-it.ro

Adding lithium makes graphite both transparent and conductive. A great game changer for the industry

Better, far more responsive touchscreen displays might be developed as a result of these findings. Photo:easy-it.ro

Better, far more responsive touchscreen displays might be developed as a result of these findings. Photo:easy-it.ro

Materials found in nature often speak of at least one comprise. Metals for instance are highly conductive, but not transparent. Plastics on the other hand can be made to be transparent, but they’re very poor electrical conductors. This annoying tradeoff has aggravated scientists for some time in their efforts to design better solar cells or touchscreen displays, which need the best of both worlds. A team of researchers at the University of Maryland Energy Research Center and Monash University in Australia may have come across a solution after they report the development of a nearly transparent, highly conductive ultrathin graphite sheet.

Most solar cells, high end touchscreen and flexible displays – the kind that electron flexibility and transparency at the same time – employ materials such as indium tin oxide or carbon nanotubes. These haven’t turned out to be very satisfying, however. According to Jiayu Wan, a Department of Materials Science and Engineering (MSE) graduate student, ideally the industry would like a material with 90 percent transmittance and only 10 Ohms-per-square of sheet resistance. Until now, no such material has been found. With this in mind, the team may have struck gold!

It all starts with graphite, the kind you can find in any pencil lead and one of the most abundant naturally occurring form of carbon. The graphite is made ultrathin between 3 to 60 graphene layers thick, then lithium is introduced such that it becomes intercalated (embedded) between the graphene layers. Graphene is an one-atom thick sheet of carbon known for its inherent strength, transparency, and conductivity. Subsequent tests reveal the lithium molecules greately increase conductivity and visible-range transmittance.

“Lithium provides electrons to the ultrathin graphite, enhancing its conductivity,” Wan explains. “Surprisingly, unlike most other materials, the extra electrons make the graphite more transparent, due to a quantum-mechanical effect. We were able to demonstrate an ultrathin graphite sheet with 91.7 percent transmission of visible light and a sheet resistance of just 3 Ohms-per-square, the highest combined performance of sheet resistance and transmittance among all continuous thin films.”

The observed improvement is at least up to two orders of magnitude greater in both transparency and conductivity, something strikingly different than anything observed in other materials.  The unconventional modification of ultrathin graphite optoelectronic properties is explained by the suppression of interband optical transitions and a small intraband Drude conductivity near the interband edge.

This isn’t the first time intercalation has been used to improve graphite transparency, but this is the first time an increase in both transmittance and conductivity has been observed. The team also believes the measurement techniques developed over the course of the work will enhance the study of the optoelectronic properties of other nanomaterials composed of two-dimensional layers.

The paper was published in the journal Nature Communications.

The star that should not exist

If you look at this picture, you will probably see what can only be described as an unremarkable, even faint star. But this ancient star, in the constellation of Leo (The Lion), called SDSS J102915+172927 has astrophysicists scratching their heads, searching for new answers.

A team of European astronomers using ESO’s Very Large Telescope (VLT) to track down a star in the Milky Way that many thought was impossible: it is built only out of Hydrogen and Helium, with extremely low quantitites of other elements. This freakish composition puts it in the ‘forbidden zone’ of the widely accepted star formation theory, meaning that if the theory was correct, this star shouldn’t have formed.

The star has the lowest amounts of elements heavier than Helium ever to be discovered – 20.000 times lower than our Sun. It is also much smaller and older than our Sun – estimated at 13 billion years.

“A widely accepted theory predicts that stars like this, with low mass and extremely low quantities of metals, shouldn’t exist because the clouds of material from which they formed could never have condensed,” said Elisabetta Caffau (Zentrum fur Astronomie der Universität Heidelberg, Germany and Observatoire de Paris, France), lead author of the paper. “It was surprising to find, for the first time, a star in this ‘forbidden zone’, and it means we may have to revisit some of the star formation models.”

Yet here it is, looking all fine and dandy! Cosmologists believe that Hydrogen and Helium (and a little Lithium), the lightest elements, were created shortly after the Big Bang, while the others elements we see today were formed afterwards in stars. Supernova explosions spread this material across the interstellar medium, and new stars form in this enrichened environment, and therefore, the proportion of this material can give us a good dea about how old the star is.

“The star we have studied is extremely metal-poor, meaning it is very primitive. It could be one of the oldest stars ever found,” adds Lorenzo Monaco (ESO, Chile), also involved in the study.

Also, extremely surprising was the almost total absence of Lithium. Researchers believe that this star could have the same composition as the Universe in its early days; however, the star had 50 times less Lithium than you would expect in those days.

“It is a mystery how the lithium that formed just after the beginning of the Universe was destroyed in this star.” Bonifacio added.

Either way, astronomers now believe that this weird star is not the only one of its kind, so they are searching for more, using the VLT to find more examples and explain the nature of this weird star.

Great video shows alkali metal reactions with air and water

Here is the video, go watch it (it will rock your world if you don’t know your chemistry – and even if you do, it’s still great to watch). I’ll come back with a short explanation after the video.

Alkali metals are a series of metals from Mendeleev’s periodic table; you can find them right under Hydrogen, which is the first element. They include lithium, sodium, potassium, rubidium and caesium. All the metals are highly reactive under standard conditions, which is why you see all the air corrosion and the violent reactions to water. As you go down the group, the reactions become more and more violent. The typical reaction is:
Alkali metal + water → Alkali metal hydroxide + hydrogen gas