Eric Wachsman

(Eric Wachsman will be presenting Safe, High-Energy-Density, Solid-State Li Batteries at AiMES 2018 in Cancun, Mexico on October 1, 2018.)

Behind the wheel of a ’68 Dodge Charger, Eric Wachsman discovered his passion for clean energy technology. He was a teenage boy in high school, and the open road was calling out to him.

“I just lived for cars,” says Wachsman, who serves on the ECS board of directors. “I could not wait to get my first car.”

So when he hit the road in his $1,500 hot rod, loaded with a holley double pumper carburetor, headers. “You name it.” He was thrilled. “That thing was the fastest thing around.”

However, life on the road soon came to a screeching halt.

(more…)

Focus IssueThe Journal of The Electrochemical Society Focus Issue on Lithium-Sulfur Batteries: Materials, Mechanisms, Modeling, and Applications is now complete, with 18 open access papers published in the ECS Digital Library.

“Lithium sulfur batteries are in the focus of research at many hundreds of prominent research groups throughout the world and at several industrial firms as well,” says JES Technical Editor Doron Aurbach in the issue’s preface. “These batteries are highly attractive due to their theoretical high energy density, that may be 4–5 times higher compared to that of Li-ion batteries.”

The focus issue includes invited papers and selected papers from the 2017 Li-SM3 Conference.

“The important technical challenges of Li-S batteries are dealt with in the papers of this focus issue, including development of new sulfur cathodes, protected Li anodes, new electrolyte systems including solid state electrolytes, study of degradation mechanisms, in-situ spectroscopic efforts, surface and structural aspects,” Aurbach continues. “This focus issue of JES is indeed a very suitable epilogue for a very successful and fruitful meeting on a very “hot” topic in modern electrochemistry in general and advanced batteries in particular.”

Read the full JES Focus Issues on Lithium-Sulfur Batteries: Materials, Mechanisms, Modeling, and Applications.

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.”

Electrochemistry and Data Science

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.

(more…)

Li-ion fuel cell

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.

(more…)

BatteryA team of researchers from the Joint Center for Energy Storage Research is taking a potential major step toward developing energy dense, safe solid state magnesium-ion batteries.

This research marks another step in pursing batteries that utilize solid electrolytes, which could offer significant safety benefits over conventional lithium-ion batteries.

The work was developed out of efforts to create a magnesium battery with a liquid electrolyte. While magnesium has promising properties for energy storage, the researchers had trouble finding a viable liquid electrolyte for the technology that wouldn’t corrode.

“Magnesium is such a new technology, it doesn’t have any good liquid electrolytes,” said Gerbrand Ceder, co-author of the research and member of ECS. “We thought, why not leapfrog and make a solid state electrolyte?”

(more…)

BatteryCapitalizing 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.

(more…)

BatteryA new kind of lithium sulfur battery could be more efficient, less expensive, and safer than currently available lithium batteries.

“We demonstrated this method in a coin battery,” says Donghai Wang, associate professor of mechanical engineering at Penn State. “But, I think it could eventually become big enough for cell phones, drones, and even bigger for electric vehicles.”

Lithium sulfur batteries should be a promising candidate for the next generation of rechargeable batteries, but they are not without problems. For lithium, the efficiency in which charge transfers is low, and, lithium batteries tend to grow dendrites—thin branching crystals—when charging that do not disappear when discharged.

The researchers examined a self-formed, flexible hybrid solid-electrolyte interphase layer that is deposited by both organosulfides and organopolysulfides with inorganic lithium salts. The researchers report that the organic sulfur compounds act as plasticizers in the interphase layer and improve the mechanical flexibility and toughness of the layer. The interphase layer allows the lithium to deposit without growing dendrites. The Coulombic efficiency is about 99 percent over 400 recharging discharging cycles.

(more…)

BatteryA new sodium-based battery can store the same amount of energy as a state-of-the-art lithium ion at a substantially lower cost.

As a warming world moves from fossil fuels toward renewable solar and wind energy, industrial forecasts predict an insatiable need for battery farms to store power and provide electricity.

Chemical engineer Zhenan Bao and materials scientists Yi Cui and William Chueh of Stanford University aren’t the first researchers to design a sodium ion battery. But they believe their approach has the price and performance characteristics to create a sodium ion battery that costs less than 80 percent of a lithium ion battery with the same storage capacity.

$150 a ton

“Nothing may ever surpass lithium in performance,” Bao says. “But lithium is so rare and costly that we need to develop high-performance but low-cost batteries based on abundant elements like sodium.”

With materials constituting about one-quarter of a battery’s price, the cost of lithium—about $15,000 a ton to mine and refine—looms large. Researchers say that’s why they are basing the new battery on widely available sodium-based electrode material that costs just $150 a ton.

(more…)

BatteryLithium batteries made with asphalt could charge 10 to 20 times faster than the commercial lithium-ion batteries currently available.

The researchers developed anodes comprising porous carbon made from asphalt that show exceptional stability after more than 500 charge-discharge cycles.

A high-current density of 20 milliamps per square centimeter demonstrates the material’s promise for use in rapid charge and discharge devices that require high-power density.

“The capacity of these batteries is enormous, but what is equally remarkable is that we can bring them from zero charge to full charge in five minutes, rather than the typical two hours or more needed with other batteries,” says James Tour, the chair in chemistry and a professor of computer science and of materials science and nanoengineering at Rice University.

The Tour lab previously used a derivative of asphalt—specifically, untreated gilsonite, the same type used for the battery—to capture greenhouse gases from natural gas. This time, the researchers mixed asphalt with conductive graphene nanoribbons and coated the composite with lithium metal through electrochemical deposition.

(more…)

The electric vehicle market continues to build momentum every year, with consumers around the world growing more interested. But in order for EVs to pave the way for the future of transportation, more efficient, longer-lasting batteries will need to be developed.

That’s where ECS member Jeff Dahn, leader of Tesla’s researcher partnership through his Dalhousie University research group, comes in. Recently, Dahn and his team unveiled new chemistry that could increase battery lifecycle at high voltages without significant degradation.

(more…)