Naoki Ota. Photo Credit: 24M
ECS’s Detroit Section is proud to present guest speaker Naoki Ota at its September section meeting. He will speak on:
Naoki Ota
President and CTO
24M Technologies, Inc.
Cambridge, Massachusetts 02139, USA (more…)
By: Neal Dawson-Elli, Seong Beom Lee, Manan Pathak, Kishalay Mitra, and Venkat R. Subramanian
This article refers to a recently published open access paper in the Journal of The Electrochemical Society, “Data Science Approaches for Electrochemical Engineers: An Introduction through Surrogate Model Development for Lithium-Ion Batteries.”
Image via Neal Dawson-Elli
(Click to enlarge.)
Data science is often hailed as the fourth paradigm of science. As the computing power available to researchers increases, data science techniques become more and more relevant to a larger group of scientists. A quick literature search for electrochemistry and data science will reveal a startling lack of analysis done on the data science side. This paper is an attempt to help introduce the topics of data science to electrochemists, as well as to analyze the power of these methods when combined with physics-based models.
At the core of the paper is the idea that one cannot be successful treating every problem as a black box and applying liberal use of data science – in other words, despite its growing popularity, it is not a panacea. The image shows the basic workflow for using data science techniques – the creation of a dataset, splitting into training-test pairs, training a model, and then evaluating the model on some task. In this case, the training data comes from many simulations of the pseudo two-dimensional lithium-ion battery model. However, in order to get the best results, one cannot simply pair the inputs and outputs and train a machine learning model on it. The inputs, or features, must be engineered to better highlight changes in your output data, and sometimes the problem needs to be totally restructured in order to be successful.
Superior high-voltage performance of Li-ion full cell with Li-rich layered oxide cathode prepared with fluorinated polyimide (FPI) binder, compared to the cell with conventional binder PVdF. (Click to enlarge.)
Image: Seung Wan Song
In order to increase the driving range of electric vehicles, researchers across the globe are working to develop lithium-ion batteries with higher energy storage. Now, scientists at Chungnam National University and Kumoh National Institute of Technology in Korea are taking a step toward that goal with their development of the first high-voltage cathode binder for higher energy Li-ion batteries.
Today’s Li-ion batteries are limited to charge to 4.2V due to the electrochemical instability of the liquid electrolyte and cathode-electrolyte interface, and loosening of conventional binder, polyvinylidenefluoride (PVdF), particularly at elevated temperatures. The fabrication of Li-rich layered oxide cathode with a novel high-voltage binder, as the research team demonstrated, can overcome these limitations.
Charging the batteries with Li-rich layered oxide cathode (xLi2MnO3∙(1−x)LiMO2, M = Mn, Ni, Co) to higher than 4.5V produces approximately doubled capacity than those with LiCoO2 cathode, so that doubled energy density batteries can be achieved.
Capitalizing on tiny defects can improve electrodes for lithium-ion batteries, new research suggests.
In a study on lithium transport in battery cathodes, researchers found that a common cathode material for lithium-ion batteries, olivine lithium iron phosphate, releases or takes in lithium ions through a much larger surface area than previously thought.
“We know this material works very well but there’s still much debate about why,” says Ming Tang, an assistant professor of materials science and nanoengineering at Rice University. “In many aspects, this material isn’t supposed to be so good, but somehow it exceeds people’s expectations.”
Part of the reason, Tang says, comes from point defects—atoms misplaced in the crystal lattice—known as antisite defects. Such defects are impossible to completely eliminate in the fabrication process. As it turns out, he says, they make real-world electrode materials behave very differently from perfect crystals.
Just a few months ago, business magnate Elon Musk announced that he would spearhead an effort to build the world’s largest lithium-ion battery in an effort to deliver a grid-scale battery to expand South Australia’s renewable energy supply. Now, reports state that Musk is delivering on his promise, stating that the battery is already half complete.
The battery is set to sustain 100 megawatts of power and store that energy for 129 megawatt hours. That roughly translates to enough energy to power 30,000 homes. On top of this large technological order, Musk stated that if his team could not develop the battery in 100 days or less, it would be free for the Australian transmission company.
“This serves as a great example to the rest of the world of what can be done,” Musk told an audience in Australia, as reported by ABC news. “To have that [construction] done in two months; you can’t remodel your kitchen in that period of time.”
The battery is expected to cost $39 million (USD). The operational deadline, as decided by the Australian government, is December 1, 2017.
Safety concerns regarding lithium-ion batteries have been making headlines in light of smartphone fires and hoverboard explosions. In order to combat safety issues, at team of researchers from Drexel University, led by ECS member Yury Gogotsi, has developed a way to transform a battery’s electrolyte solution into a safeguard against the chemical process that leads to battery fires.
Dendrites – or battery buildups caused by the chemical reactions inside the battery – have been cited as one of the main causes of lithium-ion battery malfunction. As more dendrites compile over time, they can breach the battery’s separator, resulting in malfunction.
(MORE: Read more research by Gogotsi in the ECS Digital Library.)
As part of their solution to this problem, the research team is using nanodiamonds to curtail the electrochemical deposition that leads to the short-circuiting of lithium-ion batteries. To put it in perspective, nanodiamond particles are roughly 10,000 times smaller than the diameter of a single hair.
Researchers have found a new method for finding lithium, used in the lithium-ion batteries that power modern electronics, in supervolcanic lake deposits.
While most of the lithium used to make batteries comes from Australia and Chile, but scientists say there are large deposits in sources right here in America: supervolcanoes.
In a recently published study, scientists detail a new method for locating lithium in supervolcanic lake deposits.
The findings represent an important step toward diversifying the supply of this valuable silvery-white metal, since lithium is an energy-critical strategic resource, says study coauthor Gail Mahood, a professor of geological sciences at Stanford University’s School of Earth, Energy & Environmental Sciences.
In May 2017 during the 231st ECS Meeting, we sat down with Doron Aurbach, professor at Bar-Ilan University in Israel, to discuss his life in science, the future of batteries, and scientific legacy. The conversation was led by Rob Gerth, ECS’s director of marketing and communications.
During the 231st ECS Meeting, Aurbach received the ECS Allen J. Bard Award in Electrochemical Science for his distinguished contributions to the field. He has published more than 540 peer-reviewed papers, which have received more than 37,000 citations. Doron serves as a technical editor for the Journal of The Electrochemical Society and is an ECS fellow. His work in fundamental battery research has received recognition world-wide.
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Lithium-ion batteries power a vast majority of the world’s portable electronics, from smartphones to laptops. A standard lithium-ion batteries utilizes a liquid as the electrolyte between two electrodes. However, the liquid electrolyte has the potential to lead to safety hazards. Researchers from MIT believe that by using a solid electrolyte, lithium-ion batteries could be safer and able to store more energy. However, most research in the area of all-solid-state lithium-ion batteries has faced significant barriers.
According to the team from MIT, a reason why research into solid electrolytes has been so challenging is due to incorrect interpretation of how these batteries fail.
This from MIT:
The problem, according to this study, is that researchers have been focusing on the wrong properties in their search for a solid electrolyte material. The prevailing idea was that the material’s firmness or squishiness (a property called shear modulus) determined whether dendrites could penetrate into the electrolyte. But the new analysis showed that it’s the smoothness of the surface that matters most. Microscopic nicks and scratches on the electrolyte’s surface can provide a toehold for the metallic deposits to begin to force their way in, the researchers found.
In an effort to expand South Australia’s renewable energy supply, the state has looked to business magnate Elon Musk to build the world’s largest lithium-ion battery. The goal of the project is to deliver a grid-scale battery with the ability to stabilize intermittency issues in the area as well as reduce energy prices.
An energy grid is the central component of energy generation and usage. By changing the type of energy that powers that grid in moving from fossil fuels toward more renewable sources, the grid itself changes. Traditional electrical grids demand consistency, using fossil fuels to control production for demand. However, renewable sources such as wind and solar provide intermittency issues that traditional fossil fuels do not. Researchers must look at how we can deliver energy to the electrical grid when the sun goes down or the wind stops blowing. This is where energy storage systems, such as batteries, play a pivotal role.
In South Australia, Musk’s battery is intended to sustain 100 megawatts of power and store that energy for 129 megawatt hours. To put it in perspective, that is enough energy to power 30,000 homes and, according to Musk, will be three times as powerful as the world’s current largest lithium-ion battery.
Musk hopes to complete the project by December, stating that “It’s a fundamental efficiency improvement to the power grid, and it’s really quite necessary and quite obvious considering a renewable energy future.”
