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Creators of the lithium ion battery awarded 2019 Nobel Prize in Chemistry

Creators of the lithium-ion battery awarded the 2019 Nobel Prize in Chemistry

The 2019 Nobel Prize in Chemistry has been awarded to John B. Goodenough, M. Stanley Whittingham, Akira Yoshino by the Royal Swedish Academy for developing lithium-ion batteries. 

The Nobel committee has stressed the importance of this technology which has given us the freedom to use and enjoy portable devices such as laptops, mobile phones to even electric cars and spacecraft. The lithium-ion batteries can be easily recharged by plugging them into the mains power supply. 

To perfect such technology, there were many challenges. Lithium can release electrons easily, thus making it suitable to store and conduct electricity. However, since it is quite reactive, it has to be adjusted for making it functional inside a battery. 

A battery comprises the cathode(positive side) and anode(negative side). Dr. Whittingham was working on energy technologies that are free from fossil fuel in the 1970s, which is when he discovered a method to make cathode for a lithium battery made from titanium disulfide. It was good however the anode was made from metallic lithium making it quite explosive to work with. Dr. Goodenough improved on this in 1980, using cobalt oxide to prepare the cathode. This increased battery voltage. 

The anode in previous batteries was made from lithium metals making it not so safe to work with as it was highly reactive. Dr. Yoshino focused on this problem as he created an anode from petroleum coke where the carbon layers allowed the lithium ions to be present between them. Ions moved across batteries as electrons moved in the circuits thereby powering the devices. This whole process is reversible hence this can be repeated many times. So the battery can be charged as many times as possible before it started deteriorating. The first lithium-ion battery that was commercially viable was created by Yoshino in 1985.  

Dr. Goodenough is now the oldest person to win a Nobel Prize at 97 years of age as he surpassed Dr. Arthur Ashkin who won the Nobel Prize for Physics last year. Yoshino mentioned during the announcement of the award that the prime motivation for continuing the research was simply their curiosity. 

Only five women have been awarded the Nobel Prize in Chemistry out of 203 Chemistry Nobel Laureates since 1901. 89 of these recipients were awarded for carrying out work in the United States while only 60 were actually born. 

Check out the Nobel Prize winners from the field of Medicine and their discovery.

Performing Chemistry in Floating Droplets

Performing Chemistry in Floating Droplets

Could chemists be ready to ditch the venerable test tube, the very symbol of chemistry in the minds of many people? Maybe not quite yet, but Caltech’s Jack Beauchamp is working on it.

Beauchamp is doing work in what he calls “lab-in-a-drop” chemistry, in which chemical reactions are performed within a drop of liquid suspended in midair through acoustic levitation.

Acoustic levitation works by creating areas of high and low pressure in the air through the use of ultrasonic transducers. These transducers act like tiny but powerful speakers that operate at a frequency above what human ears can hear. The sonic energy emitted by these transducers is focused in such a way that the high- and low-pressure zones they create form “traps” that can hold small objects in place in the air. An object placed in one of the low-pressure zones is held there by the high-pressure zones that surround it. An acoustic levitator of this sort can be constructed for about $75 from off-the-shelf parts using 3D-printing techniques.

An animated gif showing a hand place a pellet in the levitator. Graphics showing high- and low-pressure zones are superimposed.

Credit: Caltech

In a new paper, Beauchamp and his colleagues describe the use of the technique to study how a skin-cancer drug works at a chemical level. The research, he says, represents the first successful use of acoustic levitation as a “wall-less” reactor in a detailed study of chemical reactions.

In the work, Beauchamp and his team coated a droplet of water with lipids, biomolecules that make up cell membranes. They then applied an anti-cancer drug to the droplet and used a mass spectrometer to “sniff” the chemical signature given off by the droplet as the drug reacted with the lipid when illuminated with a red laser pointer.

In the experiment, the researchers added a small amount of one of two lipids, cardiolipin and POPG (1-palmitoyl-2-oleoyl-sn-glycero-3-phospho-(1′-rac-glycerol)), to each drop of water. The lipids migrated to the surface of the droplet, where they organized to form a thin film that is similar in composition to the cell membrane of a living cell.

With the membrane established, a chemical called temoporfin was added to the droplet. Temoporfin, a ring-like molecule, is excited by red light. In this state, the temoporfin transfers energy to molecular oxygen, forming an excited electronic state that easily oxidizes molecules it comes into contact with, including those that make up cell membranes. This makes temoporfin useful as a treatment for some skin cancers. A doctor could apply the drug to a cancerous lesion and then illuminate it with red light, which easily shines through tissues. As the compound is illuminated and excited, it oxidizes vital cellular materials, including lipids, proteins, and nucleic acids, triggering cell death.

It was this cancer-killing process that Beauchamp wanted to study. “When you’re doing this chemistry, you’d like to be able to carry out these reactions under conditions where you don’t have any contact of the liquid with surfaces,” he says. “We achieve this goal by performing chemistry in a levitated droplet.”

The acoustic levitator allowed Beauchamp and his team to suspend in midair a 1 millimeter droplet of water containing a mixture of the lipid and temoporfin. The droplet was then illuminated by red laser light, exciting the temoporfin and causing it to oxidize the molecules of the membrane layer.

As this oxidation was occurring, a pair of high-voltage electrodes placed near the droplet pulled minute amounts of material off the droplet and into the sensor of a mass spectrometer, which provided readings that allowed researchers to deduce the molecular structures of compounds within the drop. By continually monitoring these readings, the researchers were able to see how the compounds on the surface became progressively more oxidized. By looking at these reaction products, Beauchamp says the research team could determine how the oxidation processes work.

“As far as I know, we’re the only people doing serious chemistry this way, examining the kinetics and mechanism of the reactions involved” Beauchamp says.

Acoustic levitation could find use in other fields as well, he says. As an example, he cites the research of Caltech’s Joe Parker, an assistant professor of biology and biological engineering who studies the symbiotic relationship between certain species of ants and beetles. Beauchamp says it would be possible to levitate an ant and a beetle in close proximity to one another and then use the apparatus to analyze the pheromones they emit.

The technique could have other applications as well. In collaborative studies with Caltech’s John Seinfeld, Louis E. Nohl Professor of Chemical Engineering, Beauchamp previously revealed details of the complex environmental chemistry that leads to the formation of organic aerosols in the atmosphere in studies using droplets hanging on the end of a capillary. With the new levitation methodology, that capillary would no longer be required.

The paper describing Beauchamp’s research, titled “Mass Spectrometric Study of Acoustically Levitated Droplets Illuminates Molecular-Level Mechanism of Photodynamic Therapy for Cancer Involving Lipid Oxidation,” appears in the April 23 issue of Angewandte Chemie, the flagship journal of the German Chemical Society. Beauchamp’s co-authors include Chaonan Mu, Jie Wang, and Xingxing Zhang of Nankai University, and Kevin J. Barraza, a postdoctoral scholar in chemistry at Caltech.

Materials provided by the California Institute of Technology

schematic model of boron

Combination of experiments and calculations allows examination of boron’s complicated dance

In a study that combines experimental work and theoretical calculations made possible by supercomputers, scientists have determined the nuclear geometry of two isotopes of boron. The result could help open a path to precise calculations of the structure of other nuclei that scientists could experimentally validate.

Researchers at the U.S. Department of Energy’s (DOE) Argonne National Laboratory, in collaboration with scientists in Germany and Poland, determined the difference in a quantity known as the nuclear charge radius between boron-10 and boron-11. The nuclear charge radius indicates the size of an atomic nucleus — which often has relatively indistinct edges.

This is one of the most complicated atomic nuclei for which it is possible to arrive at these precise measurements experimentally and derive them theoretically.” — Argonne nuclear physicist Peter Mueller

Nuclear charge radii are difficult to compute with high precision for atoms much larger than boron because of the sheer number of neutrons and protons whose properties and interactions must be derived from quantum mechanics.

The nuclear theory builds from quantum chromodynamics (QCD), a set of physical rules that apply to quarks and gluons that compose the protons and neutrons within the nucleus. But trying to solve the nuclear dynamics using QCD alone would be an almost impossible task due to its complexity, and researchers have to rely on at least some simplifying assumptions.

Because boron is relatively light — with only five protons and a handful of neutrons — the team was able to successfully model the two boron isotopes on the Mira supercomputer and study them experimentally using laser spectroscopy. Mira is part of the Argonne Leadership Computing Facility (ALCF), a DOE Office of Science User Facility.

This is one of the most complicated atomic nuclei for which it is possible to arrive at these precise measurements experimentally and derive them theoretically,” said Argonne nuclear physicist Peter Mueller, who helped lead the study.

Looking at how the nuclear configurations of boron-11 (11B) and boron-10 (10B) differed involved making determinations at extraordinarily small length scales: less than a femtometer — one-quadrillionth of a meter. In a counterintuitive finding, the researchers determined that the 11nucleons in boron-11 actually occupy a smaller volume than the 10 nucleons in boron-10.

To look experimentally at the boron isotopes, scientists at the University of Darmstadt performed laser spectroscopy on samples of the isotopes, which fluoresce at different frequencies. While most of the difference in the fluorescence patterns is caused by the difference in the mass between the isotopes, there is a component in the measurement that reflects the size of the nucleus, explained Argonne physicist Robert Wiringa.

To separate these components, collaborators from the University of Warsaw and Adam Mickiewicz University in Poznan carried out state-of-the-art atomic theory calculations that precisely describe the complicated dance of the five electrons around the nucleus in the boron atom.

Earlier electron scattering experiments couldn’t really say for sure which was bigger,” Wiringa said. ​By using this laser spectroscopy technique, we’re able to see for certain how the extra neutron binds boron-11 more closely.”

The good agreement between experiment and theory for the dimensions of the nucleus allows researchers to determine other properties of an isotope, such as its beta decay rate, with higher confidence. ​The ability to perform calculations and do experiments go hand-in-hand to validate and reinforce our findings,” Mueller said.

The next stage of the research will likely involve the study of boron-8, which is unstable and only has a half-life of about a second before it decays. Because there are fewer neutrons in the nucleus, it is much less tightly bound than its stable neighbors and is believed to have an extended charge radius, Mueller said. ​There is a prediction, but only experiment will tell us how well it actually models this loosely bound system,” he explained.

An article based on the research, ​Nuclear Charge Radii of 10,11B,” appears in the May 10 issue of Physical Review Letters. In addition to Argonne’s Alessandro Lovato, researchers from two German and two Polish universities also collaborated.

Materials provided by Argonne National Laboratory