Eco-Friendly Desalination using MOF’s could Supply the Lithium needed to Manufacture Batteries required to Mainstream EV’s


A new water purification (desalination) technology could be the key to more electric cars. How?

“Eco-Friendly Mining” of world’s the oceans for the vast amounts of lithium required for EV batteries, could “mainstream” our acceptance (affordability and accessibility) of Electric Vehicles and provide clean water – forecast to be in precious short supply in many parts of the World in the not so distant future.

energy_storage_2013-042216-_11-13-1Humanity is going to need a lot of lithium batteries if electric cars are going to take over, and that presents a problem when there’s only so much lithium available from conventional mines.

A potential solution is being researched that turns the world’s oceans into eco-friendly “Lithium supply mines.”

Scientists have outlined a desalination technique that would use metal-organic frameworks (sponge-like structures with very high surface areas) with sub-nanometer pores to catch lithium ions while purifying ocean water.

The approach mimics the tendency of cell membranes to selectively dehydrate and carry ions, leaving the lithium behind while producing water you can drink.

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While the concept of extracting lithium from our oceans certainly isn’t new, this new technology method would be much more efficient and environmentally friendly.

Instead of tearing up the landscape to find mineral deposits, battery makers would simply have to deploy enough filters.

It could even be used to make the most of water when pollution does take place — recovering lithium from the waste water at shale gas fields.

This method will require more research and development before it’s ready for real-world use.

However, the implications are already clear. If this desalination approach reaches sufficient scale, the world would have much more lithium available for electric vehicles, phones and other battery-based devices. It would also reduce the environmental impact of those devices. storedot-ev-battery-21-889x592 (1)

While some say current lithium mining practices negates some of the eco-friendliness of an EV, this “purification for Lithium” approach could let you drive relatively guilt-free

Reposted from Jonathan Fingas – Engadget

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Another step closer to wearable technology with this flexible supercapacitor from NTU Singapore: YouTube Video


 

NTU Wearable download
 Scientists have created a fabric-like supercapacitor which can be cut, folded or stretched without losing its ability to store and discharge electricity. Able to retain 98% of its power capacity even after 10,000 stretch-and-release cycles, the invention brings us a step closer to powering future wearable technology. #NTUsg

Scientists at Nanyang Technological University, Singapore (NTU Singapore) have created a customizable, fabric-like power source that can be cut, folded or stretched without losing its function.

Led by Professor Chen Xiaodong, Associate Chair (Faculty) at the School of Materials Science & Engineering, the team reported in the journal Advanced Materials (print edition 8 January) how they have created the wearable power source, a supercapacitor, which works like a fast-charging battery and can be recharged many times.

 

 

Crucially, they have made their supercapacitor customizable or “editable”, meaning its structure and shape can be changed after it is manufactured, while retaining its function as a power source. Existing stretchable supercapacitors are made into predetermined designs and structures, but the new invention can be stretched multi-directionally, and is less likely to be mismatched when it is joined up to other electrical components.

The new supercapacitor, when edited into a honeycomb-like structure, has the ability to store an electrical charge four times higher than most existing stretchable supercapacitors. In addition, when stretched to four times its original length, it maintains nearly 98 per cent of the initial ability to store electrical energy, even after 10,000 stretch-and-release cycles.

Experiments done by Prof Chen and his team also showed that when the editable supercapacitor was paired with a sensor and placed on the human elbow, it performed better than existing stretchable supercapacitors. The editable supercapacitor was able to provide a stable stream of signals even when the arm was swinging, which are then transmitted wirelessly to external devices, such as one that captures a patient’s heart rate.

The authors believe that the editable supercapacitor could be easily mass-produced as it would rely on existing manufacturing technologies. Production cost will thus be low, estimated at about SGD$0.13 (USD$0.10) to produce 1 cm2 of the material.

The team has filed a patent for the technology.

Professor Chen said, “A reliable and editable supercapacitor is important for development of the wearable electronics industry. It also opens up all sorts of possibilities in the realm of the ‘Internet-of-Things’ when wearable electronics can reliably power themselves and connect and communicate with appliances in the home and other environments.

“My own dream is to one day combine our flexible supercapacitors with wearable sensors for health and sports performance diagnostics. With the ability for wearable electronics to power themselves, you could imagine the day when we create a device that could be used to monitor a marathon runner during a race with great sensitivity, detecting signals from both under and over-exertion.”

The editable supercapacitor is made of strengthened manganese dioxide nanowire composite material. While manganese dioxide is a common material for supercapacitors, the ultralong nanowire structure, strengthened with a network of carbon nanotubes and nanocellulose fibres, allows the electrodes to withstand the associated strains during the customisation process.

The NTU team also collaborated with Dr. Loh Xian Jun, Senior Scientist and Head of the Soft Materials Department at the Institute of Materials Research and Engineering (IMRE), Agency for Science, Technology and Research (A*STAR).

Dr. Loh said, “Customisable and versatile, these interconnected, fabric-like power sources are able to offer a plug-and-play functionality while maintaining good performance. Being highly stretchable, these flexible power sources are promising next-generation ‘fabric’ energy storage devices that could be integrated into wearable electronics.”

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Watch the various customizable supercapacitors in action:

https://drive.google.com/drive/folders/16qgJpz7CKkGgVKVQeFUQxVscfZhpSAJ5

MIT: Optimizing carbon nanotube electrodes for energy storage and water desalination applications


Opt CNTs for Water Wang-Mutha-nanotubes_0Evelyn Wang (left) and Heena Mutha have developed a nondestructive method of quantifying the detailed characteristics of carbon nanotube (CNT) samples — a valuable tool for optimizing these materials for use as electrodes in a variety of practical devices. Photo: Stuart Darsch

New model measures characteristics of carbon nanotube structures for energy storage and water desalination applications.

Using electrodes made of carbon nanotubes (CNTs) can significantly improve the performance of devices ranging from capacitors and batteries to water desalination systems. But figuring out the physical characteristics of vertically aligned CNT arrays that yield the most benefit has been difficult.

Now an MIT team has developed a method that can help. By combining simple benchtop experiments with a model describing porous materials, the researchers have found they can quantify the morphology of a CNT sample, without destroying it in the process.

In a series of tests, the researchers confirmed that their adapted model can reproduce key measurements taken on CNT samples under varying conditions. They’re now using their approach to determine detailed parameters of their samples — including the spacing between the nanotubes — and to optimize the design of CNT electrodes for a device that rapidly desalinates brackish water.

A common challenge in developing energy storage devices and desalination systems is finding a way to transfer electrically charged particles onto a surface and store them there temporarily. In a capacitor, for example, ions in an electrolyte must be deposited as the device is being charged and later released when electricity is being delivered. During desalination, dissolved salt must be captured and held until the cleaned water has been withdrawn.

One way to achieve those goals is by immersing electrodes into the electrolyte or the saltwater and then imposing a voltage on the system. The electric field that’s created causes the charged particles to cling to the electrode surfaces. When the voltage is cut, the particles immediately let go.

“Whether salt or other charged particles, it’s all about adsorption and desorption,” says Heena Mutha PhD ’17, a senior member of technical staff at the Charles Stark Draper Laboratory. “So the electrodes in your device should have lots of surface area as well as open pathways that allow the electrolyte or saltwater carrying the particles to travel in and out easily.”

One way to increase the surface area is by using CNTs. In a conventional porous material, such as activated charcoal, interior pores provide extensive surface area, but they’re irregular in size and shape, so accessing them can be difficult. In contrast, a CNT “forest” is made up of aligned pillars that provide the needed surfaces and straight pathways, so the electrolyte or saltwater can easily reach them.

However, optimizing the design of CNT electrodes for use in devices has proven tricky. Experimental evidence suggests that the morphology of the material — in particular, how the CNTs are spaced out — has a direct impact on device performance. Increasing the carbon concentration when fabricating CNT electrodes produces a more tightly packed forest and more abundant surface area. But at a certain density, performance starts to decline, perhaps because the pillars are too close together for the electrolyte or saltwater to pass through easily.

Designing for device performance

OPT CNTs III graphic-1

“Much work has been devoted to determining how CNT morphology affects electrode performance in various applications,” says Evelyn Wang, the Gail E. Kendall Professor of Mechanical Engineering. “But an underlying question is, ‘How can we characterize these promising electrode materials in a quantitative way, so as to investigate the role played by such details as the nanometer-scale interspacing?'”

Inspecting a cut edge of a sample can be done using a scanning electron microscope (SEM). But quantifying features, such as spacing, is difficult, time-consuming, and not very precise. Analyzing data from gas adsorption experiments works well for some porous materials, but not for CNT forests. Moreover, such methods destroy the material being tested, so samples whose morphologies have been characterized can’t be used in tests of overall device performance.

For the past two years, Wang and Mutha have been working on a better option. “We wanted to develop a nondestructive method that combines simple electrochemical experiments with a mathematical model that would let us ‘back calculate’ the interspacing in a CNT forest,” Mutha says. “Then we could estimate the porosity of the CNT forest — without destroying it.”

Adapting the conventional model

One widely used method for studying porous electrodes is electrochemical impedance spectroscopy (EIS). It involves pulsing voltage across electrodes in an electrochemical cell at a set time interval (frequency) while monitoring “impedance,” a measure that depends on the available storage space and resistance to flow. Impedance measurements at different frequencies is called the “frequency response.”Opt CNTs II 1-newmodelmeas

The classic model describing porous media uses that frequency response to calculate how much open space there is in a porous material. “So we should be able to use [the model] to calculate the space between the carbon nanotubes in a CNT electrode,” Mutha says.

But there’s a problem: This model assumes that all pores are uniform, cylindrical voids. But that description doesn’t fit electrodes made of CNTs. Mutha modified the model to more accurately define the pores in CNT materials as the void spaces surrounding solid pillars. While others have similarly altered the classic model, Mutha took her alterations a step further. The nanotubes in a CNT material are unlikely to be packed uniformly, so she added to her equations the ability to account for variations in the spacing between the nanotubes. With this modified model, Mutha could analyze EIS data from real samples to calculate CNT spacings.

Using the model

To demonstrate her approach, Mutha first fabricated a series of laboratory samples and then measured their frequency response. In collaboration with Yuan “Jenny” Lu ’15, a materials science and engineering graduate, she deposited thin layers of aligned CNTs onto silicon wafers inside a furnace and then used water vapor to separate the CNTs from the silicon, producing free-standing forests of nanotubes. To vary the CNT spacing, she used a technique developed by MIT collaborators in the Department of Aeronautics and Astronautics, Professor Brian Wardle and postdoc associate Itai Stein PhD ’16. Using a custom plastic device, she mechanically squeezed her samples from four sides, thereby packing the nanotubes together more tightly and increasing the volume fraction — that is, the fraction of the total volume occupied by the solid CNTs.

To test the frequency response of the samples, she used a glass beaker containing three electrodes immersed in an electrolyte. One electrode is the CNT-coated sample, while the other two are used to monitor the voltage and to absorb and measure the current. Using that setup, she first measured the capacitance of each sample, meaning how much charge it could store in each square centimeter of surface area at a given constant voltage. She then ran EIS tests on the samples and analyzed results using her modified porous media model.

Results for the three volume fractions tested show the same trends. As the voltage pulses become less frequent, the curves initially rise at about a 45 degree slope. But at some point, each one shifts toward vertical, with resistance becoming constant and impedance continuing to rise.

As Mutha explains, those trends are typical of EIS analyses. “At high frequencies, the voltage changes so quickly that — because of resistance in the CNT forest — it doesn’t penetrate the depth of the entire electrode material, so the response comes only from the surface or partway in,” she says. “But eventually the frequency is low enough that there’s time between pulses for the voltage to penetrate and for the whole sample to respond.”

Resistance is no longer a noticeable factor, so the line becomes vertical, with the capacitance component causing impedance to rise as more charged particles attach to the CNTs. That switch to vertical occurs earlier with the lower-volume-fraction samples. In sparser forests, the spaces are larger, so the resistance is lower.

The most striking feature of Mutha’s results is the gradual transition from the high-frequency to the low-frequency regime. Calculations from a model based on uniform spacing — the usual assumption — show a sharp transition from partial to complete electrode response. Because Mutha’s model incorporates subtle variations in spacing, the transition is gradual rather than abrupt. Her experimental measurements and model results both exhibit that behavior, suggesting that the modified model is more accurate.

By combining their impedance spectroscopy results with their model, the MIT researchers inferred the CNT interspacing in their samples. Since the forest packing geometry is unknown, they performed the analyses based on three- and six-pillar configurations to establish upper and lower bounds. Their calculations showed that spacing can range from 100 nanometers in sparse forests to below 10 nanometers in densely packed forests.

Comparing approaches

Work in collaboration with Wardle and Stein has validated the two groups’ differing approaches to determining CNT morphology. In their studies, Wardle and Stein use an approach similar to Monte Carlo modeling, which is a statistical technique that involves simulating the behavior of an uncertain system thousands of times under varying assumptions to produce a range of plausible outcomes, some more likely than others. For this application, they assumed a random distribution of “seeds” for carbon nanotubes, simulated their growth, and then calculated characteristics, such as inter-CNT spacing with an associated variability. Along with other factors, they assigned some degree of waviness to the individual CNTs to test the impact on the calculated spacing.

To compare their approaches, the two MIT teams performed parallel analyses that determined average spacing at increasing volume fractions. The trends they exhibited matched well, with spacing decreasing as volume fraction increases. However, at a volume fraction of about 26 percent, the EIS spacing estimates suddenly go up — an outcome that Mutha believes may reflect packing irregularities caused by buckling of the CNTs as she was densifying them.

To investigate the role played by waviness, Mutha compared the variabilities in her results with those in Stein’s results from simulations assuming different degrees of waviness. At high volume fractions, the EIS variabilities were closest to those from the simulations assuming little or no waviness. But at low volume fractions, the closest match came from simulations assuming high waviness.

Based on those findings, Mutha concludes that waviness should be considered when performing EIS analyses — at least in some cases. “To accurately predict the performance of devices with sparse CNT electrodes, we may need to model the electrode as having a broad distribution of interspacings due to the waviness of the CNTs,” she says. “At higher volume fractions, waviness effects may be negligible, and the system can be modeled as simple pillars.”

The researchers’ nondestructive yet quantitative technique provides device designers with a valuable new tool for optimizing the morphology of porous electrodes for a wide range of applications. Already, Mutha and Wang have been using it to predict the performance of supercapacitors and desalination systems. Recent work has focused on designing a high-performance, portable device for the rapid desalination of brackish water. Results to date show that using their approach to optimize the design of CNT electrodes and the overall device simultaneously can as much as double the salt adsorption capacity of the system, while speeding up the rate at which clean water is produced.

This research was supported in part by the MIT Energy Initiative Seed Fund Program and by the King Fahd University of Petroleum and Minerals (KFUPM) in Dhahran, Saudi Arabia, through the Center for Clean Water and Clean Energy at MIT and KFUPM. Mutha’s work was supported by a National Science Foundation Graduate Research Fellowship and Stein’s work by the Department of Defense through the National Defense Science and Engineering Graduate Fellowship Program.

MIT: A new approach to rechargeable batteries – metal-mesh membrane could solve longstanding problems – lead to inexpensive power storage


MIT-Battery-Membranes_0A type of battery first invented nearly five decades ago could catapult to the forefront of energy storage technologies, thanks to a new finding by researchers at MIT. Illustration modified from an original image by Felice Frankel

New metal-mesh membrane could solve longstanding problems and lead to inexpensive power storage.

A type of battery first invented nearly five decades ago could catapult to the forefront of energy storage technologies, thanks to a new finding by researchers at MIT. The battery, based on electrodes made of sodium and nickel chloride and using a new type of metal mesh membrane, could be used for grid-scale installations to make intermittent power sources such as wind and solar capable of delivering reliable baseload electricity.

The findings are being reported today in the journal Nature Energy, by a team led by MIT professor Donald Sadoway, postdocs Huayi Yin and Brice Chung, and four others.

Although the basic battery chemistry the team used, based on a liquid sodium electrode material, was first described in 1968, the concept never caught on as a practical approach because of one significant drawback: It required the use of a thin membrane to separate its molten components, and the only known material with the needed properties for that membrane was a brittle and fragile ceramic. These paper-thin membranes made the batteries too easily damaged in real-world operating conditions, so apart from a few specialized industrial applications, the system has never been widely implemented.

But Sadoway and his team took a different approach, realizing that the functions of that membrane could instead be performed by a specially coated metal mesh, a much stronger and more flexible material that could stand up to the rigors of use in industrial-scale storage systems.

“I consider this a breakthrough,” Sadoway says, because for the first time in five decades, this type of battery — whose advantages include cheap, abundant raw materials, very safe operational characteristics, and an ability to go through many charge-discharge cycles without degradation — could finally become practical.

While some companies have continued to make liquid-sodium batteries for specialized uses, “the cost was kept high because of the fragility of the ceramic membranes,” says Sadoway, the John F. Elliott Professor of Materials Chemistry. “Nobody’s really been able to make that process work,” including GE, which spent nearly 10 years working on the technology before abandoning the project.

As Sadoway and his team explored various options for the different components in a molten-metal-based battery, they were surprised by the results of one of their tests using lead compounds. “We opened the cell and found droplets” inside the test chamber, which “would have to have been droplets of molten lead,” he says. But instead of acting as a membrane, as expected, the compound material “was acting as an electrode,” actively taking part in the battery’s electrochemical reaction.

“That really opened our eyes to a completely different technology,” he says. The membrane had performed its role — selectively allowing certain molecules to pass through while blocking others — in an entirely different way, using its electrical properties rather than the typical mechanical sorting based on the sizes of pores in the material.

In the end, after experimenting with various compounds, the team found that an ordinary steel mesh coated with a solution of titanium nitride could perform all the functions of the previously used ceramic membranes, but without the brittleness and fragility. The results could make possible a whole family of inexpensive and durable materials practical for large-scale rechargeable batteries.

The use of the new type of membrane can be applied to a wide variety of molten-electrode battery chemistries, he says, and opens up new avenues for battery design. “The fact that you can build a sodium-sulfur type of battery, or a sodium/nickel-chloride type of battery, without resorting to the use of fragile, brittle ceramic — that changes everything,” he says.

The work could lead to inexpensive batteries large enough to make intermittent, renewable power sources practical for grid-scale storage, and the same underlying technology could have other applications as well, such as for some kinds of metal production, Sadoway says.

Sadoway cautions that such batteries would not be suitable for some major uses, such as cars or phones. Their strong point is in large, fixed installations where cost is paramount, but size and weight are not, such as utility-scale load leveling. In those applications, inexpensive battery technology could potentially enable a much greater percentage of intermittent renewable energy sources to take the place of baseload, always-available power sources, which are now dominated by fossil fuels.

The research team included Fei Chen, a visiting scientist from Wuhan University of Technology; Nobuyuki Tanaka, a visiting scientist from the Japan Atomic Energy Agency; MIT research scientist Takanari Ouchi; and postdocs Huayi Yin, Brice Chung, and Ji Zhao. The work was supported by the French oil company Total S.A. through the MIT Energy Initiative.

NREL: New Study Indicates Shorter-Term Storage Can Reduce Variable-Generation Curtailments


Storage devices, like this one-megawatt battery at the National Wind Technology Center, can reduce variable generation curtailments. Photo by Dennis Schroeder / NREL 47219

Increasing the penetration of variable energy sources such as solar and wind energy in the grid—without introducing heavy curtailment—does not require costly, very-long-duration storage, says a new study by National Renewable Energy Laboratory researchers Paul Denholm and Trieu Mai.

Historically, energy storage has been considered too pricey an option for integrating wind and solar into the grid, and utilities have relied on less expensive options. However, declining costs indicate that energy storage solutions may play a greater role in providing grid flexibility and storing because of their ability to decrease the amounts of curtained wind and solar generation.

When wind and solar are curtailed, grid operators cannot use all of the available renewable resources (i.e., there is more wind blowing than the grid can utilize). Often, this means that the grid must rely on a fossil-fuel energy generation source, rather than a cleaner source of energy. But with storage solutions, operators can save some of that excess energy, and thereby incorporate more renewable energy into the grid.

“Interest in very-high-renewable systems warrants further exploration into storage’s role in the future grid,” says Mai.

The team’s study, “Timescales of Energy Storage Needed for Reducing Renewable Energy CurtailmentPDF,” examines the amount and configuration of energy storage required to decrease variable-generation curtailments under high-renewable scenarios. Researchers developed a case study based on the U.S. Department of Energy’s Wind Vision report, in which variable generation provides 55% of the electricity demand in the Electricity Reliability Council of Texas (ERCOT) grid system in 2050. Analysis results showed that the amount of avoided curtailment falls off rapidly with storage durations longer than 8 hours, with the first 4 hours providing the largest benefit.

Denholm and Mai developed several energy mix scenarios based on the isolated ERCOT grid system, and found that deploying wind and solar together produced much lower levels of curtailment than when deployed individually.

“Wind and photovoltaics play well together,” Denholm says. However, the mix that produces the least amount of curtailment uses about twice as much wind as solar.

Among all energy mixes analyzed, there was little incremental benefit to deploying costly, very-long-duration or seasonal storage—at penetrations of up to 55%, the greatest benefit is found with the first 4 hours of storage.

Promising New Research for High Performance Lithium Batteries – Engineering 2D Nanofluidic Channels


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Abstract: In article number 1703909, Gang Chen, Guihua Yu, and co-workers present a novel concept of 2D nanofluidic lithium-ion transport channels based on stacked Co3O4nanosheets for high-performance lithium batteries. This unique nanoarchitecture exhibits exceptional capacity and outstanding long-term cycling stability for lithium-ion storage at high-rates in both half- and full-cells.

 

Despite being a promising electrode material, bulk cobalt oxide (Co3O4) exhibits poor lithium ion storage properties. Nanostructuring, e.g. making Co3O4 into ultrathin nanosheets, shows improved performance, however, Co3O4-based nanomaterials still lack long-term stability and high rate capability due to sluggish ion transport and structure degradation.

Nanofluidic channels possess desired properties to address above issues. However, while these unique structures have been studied in hollow nanotubes and recently in restacked layered materials such as graphene, it remains challenging to construct nanofluidic channels in intrinsically non-layered materials.
Motived by the large number of non-layered materials, e.g. transition metal oxides, which hold great promise in battery applications, scientists aim to extend the concept of nanofluidic channels into these materials and improve their electrochemical properties.
Nanofluidic channels feature a unique unipolar ionic transport when properly designed and constructed. By controlling surface charge and channel spacing, enhanced and selective ion transport can be achieved in these channels by constructing them with dimensions comparable to the double Debye length and opposite surface charge with respect to the transporting ion.
In a new study published in Advanced Materials (“Engineering 2D Nanofluidic Li-Ion Transport Channels for Superior Electrochemical Energy Storage”), researchers have developed a Co3O4-based two-dimensional (2D) nano-architecture possessing nanofluidic channels with specially designed interlayer characteristics for fast lithium ion transport, leading to exceptional performance in lithium ion batteries ever reported for this material.
“Such constructed 2D nanofluidic channels in non-layered materials manifest a general structural engineering strategy for improving electrochemical properties in a vast number of different electrode materials,” Guihua Yu, a professor in Materials Science and Engineering, Mechanical Engineering, at the Texas Materials Institute, University of Texas at Austin. “The enhanced and selective ion transport demonstrated in our study is of broad interest to many applications where fast kinetics of ion transport is essential.”
Illustration of lithium ion transport in the 2D nanofluidic channels
Illustration of lithium ion transport in 2D nanofluidic channels. (Reprinted with permission by Wiley-VCH)
On the one hand, an intercalated molecule acts as interlayer pillar in the stacked oxide, constituting transport channels with proper spacing. On the other hand, negatively charged functional groups anchored on the nanosheets surface facilitate transport of positively charged lithium ions inside the channels.
“Satisfying aforementioned conditions for unipolar ionic transport, combined with other advantageous features – extra storage capacity contributed by the surface functional groups, buffered structural stress from the interlayer spacing, and shortened lithium ion diffusion distance due to the ultrathin nanosheet morphology – the resulting nanoarchitecture exhibit exceptional electrochemical performance as tested in lithium-ion batteries,” notes Yu.
In a next step, the researchers are going to extend the concept of 2D nanofluidic channels to other electrode materials with or without layering structures. With ability to further tune interlayer spacing, they expect some promising energy storage applications in beyond-lithium-ion batteries.
It might also be interesting to examine this structural engineering strategy in other applications, for example, catalysis.
Design and LIBs application of Co3O4 nanosheets with 2D nanofluidic channels
Design and LIBs application of Co3O4 nanosheets with 2D nanofluidic channels. (a) The synthetic route from Co-based layered hydroxide precursor to Co3O4 nanosheets with 2D nanofluidic channels. (b) Cycling performance of a full cell (anode: Co3O4 nanosheets /cathode: commercial LiCoO2). (Reprinted with permission by Wiley-VCH)
Constructing 2D nanofluidic channels for energy storage application is still in its infancy and the success of using non-layered materials demonstrated in this study promises a bright future in this direction with a broader material coverage.
“We are also taking this research direction even further by looking into the transport and storage properties for energy storage systems based on larger charge-carrying ions, such as Na+ and Mg2+, ” concludes Yu. “In order to realize that, an important challenge is to tune the channel spacing in a controlled manner. It is also imperative to investigate structural stability and scalability of this specially designed nanoarchitecture for its utilization in practical applications.”
@Michael Berger © Nanowerk

Berkeley Lab – DOE – Argonne – “Holy Grail” for Batteries: Solid-State Magnesium Battery a Big Step Closer


 

Berkeley Lab leads discovery of the fastest magnesium-ion solid-state conductor to date.

 

A team of Department of Energy (DOE) scientists at the Joint Center for Energy Storage Research (JCESR) has discovered the fastest magnesium-ion solid-state conductor, a major step towards making solid-state magnesium-ion batteries that are both energy dense and safe.

Argonne scientist Baris Key, shown on left at work in his nuclear magnetic resonance lab, worked with researchers at Berkeley Lab on the discovery of the fastest ever magnesium-ion solid-state conductor. (Credit: Argonne National Laboratory)

The electrolyte, which carries charge back and forth between the battery’s cathode and anode, is a liquid in all commercial batteries, which makes them potentially flammable, especially in lithium-ion batteries. A solid-state conductor, which has the potential to become an electrolyte, would be far more fire-resistant.

Researchers at DOE’s Lawrence Berkeley National Laboratory (Berkeley Lab) and Argonne National Laboratory were working on a magnesium battery, which offers higher energy density than lithium, but were stymied by the dearth of good options for a liquid electrolyte, most of which tend to be corrosive against other parts of the battery. “Magnesium is such a new technology, it doesn’t have any good liquid electrolytes,” said Gerbrand Ceder, a Berkeley Lab Senior Faculty Scientist. “We thought, why not leapfrog and make a solid-state electrolyte?”

The material they came up with, magnesium scandium selenide spinel, has magnesium mobility comparable to solid-state electrolytes for lithium batteries. Their findings were reported in Nature Communications in a paper titled, “High magnesium mobility in ternary spinel chalcogenides.”JCESR, a DOE Innovation Hub, sponsored the study, and the lead authors are Pieremanuele Canepa and Shou-Hang Bo, postdoctoral fellows at Berkeley Lab.

“With the help of a concerted effort bringing together computational materials science methodologies, synthesis, and a variety of characterization techniques, we have identified a new class of solid conductors that can transport magnesium ions at unprecedented speed,” Canepa said.

Collaboration with MIT and Argonne

The research team also included scientists at MIT, who provided computational resources, and Argonne, who provided key experimental confirmation of the magnesium scandium selenide spinel material to document its structure and function.

Co-author Baris Key, a research chemist at Argonne, conducted nuclear magnetic resonance (NMR) spectroscopy experiments. These tests were among the first steps to experimentally prove that magnesium ions could move through the material as rapidly as the theoretical studies had predicted.

“It was crucial to confirm the fast magnesium hopping experimentally. It is not often that the theory and the experiment agree closely with each other,” Key said. “The solid state NMR experiments for this chemistry were very challenging and would not be possible without dedicated resources and a funding source such as JCESR.

As we’ve shown in this study, an in-depth understanding of short- and long-range structure and ion dynamics will be the key for magnesium ion battery research.”

NMR is akin to magnetic resonance imaging (MRI), which is routinely used in medical settings, where it shows hydrogen atoms of water in human muscles, nerves, fatty tissue, and other biological substances. But researchers can also tune NMR frequency to detect other elements, including the lithium or magnesium ions that are found in battery materials.

The NMR data from the magnesium scandium selenide material, however, involved material of unknown structure with complex properties, making them challenging to interpret.

Canepa noted the challenges of testing materials that are so new. “Protocols are basically non-existent,” he said. “These findings were only possible by combining a multi-technique approach (solid-state NMR and synchrotron measurements at Argonne) in addition to conventional electrochemical characterization.”

Doing the impossible

The team plans to do further work to use the conductor in a battery. “This probably has a long way to go before you can make a battery out of it, but it’s the first demonstration you can make solid-state materials with really good magnesium mobility through it,” Ceder said. “Magnesium is thought to move slowly in most solids, so nobody thought this would be possible.”

Additionally, the research identified two related fundamental phenomena that could significantly affect the development of magnesium solid electrolytes in the near future, namely, the role of anti-site defects and the interplay of electronic and magnesium conductivity, both published recently in Chemistry of Materials.

Bo, now an assistant professor at Shanghai Jiao Tong University, said the discovery could have a dramatic effect on the energy landscape. “This work brought together a great team of scientists from various scientific disciplines, and took the first stab at the formidable challenge of building a solid-state magnesium battery,” he said. “Although currently in its infancy, this emerging technology may have a transformative impact on energy storage in the near future.”

Gopalakrishnan Sai Gautam, another co-author who was an affiliate at Berkeley Lab and is now at Princeton, said the team approach made possible by a DOE hub such as JCESR was critical. “The work shows the importance of using a variety of theoretical and experimental techniques in a highly collaborative environment to make important fundamental discoveries,” he said.

Ceder was excited at the prospects for the finding but cautioned that work remains to be done. “There are enormous efforts in industry to make a solid-state battery. It’s the holy grail because you would have the ultimate safe battery. But we still have work to do. This material shows a small amount of electron leakage, which has to be removed before it can be used in a battery.”

Funding for the project was provided by the DOE Office of Science through the Joint Center for Energy Storage Research, a Department of Energy Innovation Hub. The Advanced Photon Source, a DOE Office of Science User Facility at Argonne, added vital data to the study regarding the structure of the solid conductor.

The National Energy Research Scientific Computing Center (NERSC), a DOE Office of Science User Facility at Berkeley Lab, provided computing resources. Other co-authors on the paper are Juchaun Li of Berkeley Lab, William Richards and Yan Wang of MIT, and Tan Shi and Yaosen Tian of UC Berkeley.

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Lawrence Berkeley National Laboratory addresses the world’s most urgent scientific challenges by advancing sustainable energy, protecting human health, creating new materials, and revealing the origin and fate of the universe. Founded in 1931, Berkeley Lab’s scientific expertise has been recognized with 13 Nobel Prizes. The University of California manages Berkeley Lab for the U.S. Department of Energy’s Office of Science. For more, visit www.lbl.gov.

Argonne National Laboratory seeks solutions to pressing national problems in science and technology. The nation’s first national laboratory, Argonne conducts leading-edge basic and applied scientific research in virtually every scientific discipline. Argonne researchers work closely with researchers from hundreds of companies, universities, and federal, state, and municipal agencies to help them solve their specific problems, advance America’s scientific leadership, and prepare the nation for a better future. With employees from more than 60 nations, Argonne is managed by UChicago Argonne, LLC for the U.S. Department of Energy’s Office of Science.

DOE’s Office of Science is the single largest supporter of basic research in the physical sciences in the United States, and is working to address some of the most pressing challenges of our time. For more information, please visit science.energy.gov.

The Joint Center for Energy Storage Research (JCESR), a DOE Energy Innovation Hub, is a major partnership that integrates researchers from many disciplines to overcome critical scientific and technical barriers and create new breakthrough energy storage technology. Led by the U.S. Department of Energy’s Argonne National Laboratory, partners include national leaders in science and engineering from academia, the private sector, and national laboratories. Their combined expertise spans the full range of the technology-development pipeline from basic research to prototype development to product engineering to market delivery.

MIT: Making renewable power more viable for the grid


Making renewable power more viable for the grid

“Air-breathing” battery can store electricity for months, for about a fifth the cost of current technologies.

Wind and solar power are increasingly popular sources for renewable energy. But intermittency issues keep them from connecting widely to the U.S. grid: They require energy-storage systems that, at the cheapest, run about $100 per kilowatt hour and function only in certain locations.

Now MIT researchers have developed an “air-breathing” battery that could store electricity for very long durations for about one-fifth the cost of current technologies, with minimal location restraints and zero emissions. The battery could be used to make sporadic renewable power a more reliable source of electricity for the grid.

For its anode, the rechargeable flow battery uses cheap, abundant sulfur dissolved in water. An aerated liquid salt solution in the cathode continuously takes in and releases oxygen that balances charge as ions shuttle between the electrodes. Oxygen flowing into the cathode causes the anode to discharge electrons to an external circuit. Oxygen flowing out sends electrons back to the anode, recharging the battery.

“This battery literally inhales and exhales air, but it doesn’t exhale carbon dioxide, like humans — it exhales oxygen,” says Yet-Ming Chiang, the Kyocera Professor of Materials Science and Engineering at MIT and co-author of a paper describing the battery.

The research appears today in the journal Joule.

The battery’s total chemical cost — the combined price of the cathode, anode, and electrolyte materials — is about 1/30th the cost of competing batteries, such as lithium-ion batteries. Scaled-up systems could be used to store electricity from wind or solar power, for multiple days to entire seasons, for about $20 to $30 per kilowatt hour.

Co-authors with Chiang on the paper are: first author Zheng Li, who was a postdoc at MIT during the research and is now a professor at Virginia Tech; Fikile R. Brushett, the Raymond A. and Helen E. St. Laurent Career Development Professor of Chemical Engineering; research scientist Liang Su; graduate students Menghsuan Pan and Kai Xiang; and undergraduate students Andres Badel, Joseph M. Valle, and Stephanie L. Eiler.

Finding the right balance

Development of the battery began in 2012, when Chiang joined the Department of Energy’s Joint Center for Energy Storage Research, a five-year project that brought together about 180 researchers to collaborate on energy-saving technologies. Chiang, for his part, focused on developing an efficient battery that could reduce the cost of grid-scale energy storage.

A major issue with batteries over the past several decades, Chiang says, has been a focus on synthesizing materials that offer greater energy density but are very expensive. The most widely used materials in lithium-ion batteries for cellphones, for instance, have a cost of about $100 for each kilowatt hour of energy stored.

“This meant maybe we weren’t focusing on the right thing, with an ever-increasing chemical cost in pursuit of high energy-density,” Chiang says. He brought the issue to other MIT researchers. “We said, ‘If we want energy storage at the terawatt scale, we have to use truly abundant materials.’”

The researchers first decided the anode needed to be sulfur, a widely available byproduct of natural gas and petroleum refining that’s very energy dense, having the lowest cost per stored charge next to water and air. The challenge then was finding an inexpensive liquid cathode material that remained stable while producing a meaningful charge.

That seemed improbable — until a serendipitous discovery in the lab.

On a short list of candidates was a compound called potassium permanganate. If used as a cathode material, that compound is “reduced” — a reaction that draws ions from the anode to the cathode, discharging electricity. However, the reduction of the permanganate is normally impossible to reverse, meaning the battery wouldn’t be rechargeable.

Still, Li tried. As expected, the reversal failed. However, the battery was, in fact, recharging, due to an unexpected oxygen reaction in the cathode, which was running entirely on air. “I said, ‘Wait, you figured out a rechargeable chemistry using sulfur that does not require a cathode compound?’ That was the ah-ha moment,” Chiang says.

Using that concept, the team of researchers created a type of flow battery, where electrolytes are continuously pumped through electrodes and travel through a reaction cell to create charge or discharge.

The battery consists of a liquid anode (anolyte) of polysulfide that contains lithium or sodium ions, and a liquid cathode (catholyte) that consists of an oxygenated dissolved salt, separated by a membrane.

Upon discharging, the anolyte releases electrons into an external circuit and the lithium or sodium ions travel to the cathode.

At the same time, to maintain electroneutrality, the catholyte draws in oxygen, creating negatively charged hydroxide ions. When charging, the process is simply reversed. Oxygen is expelled from the catholyte, increasing hydrogen ions, which donate electrons back to the anolyte through the external circuit.

“What this does is create a charge balance by taking oxygen in and out of the system,” Chiang says.

Because the battery uses ultra-low-cost materials, its chemical cost is one of the lowest — if not the lowest — of any rechargeable battery to enable cost-effective long-duration discharge. Its energy density is slightly lower than today’s lithium-ion batteries.

“It’s a creative and interesting new concept that could potentially be an ultra-low-cost solution for grid storage,” says Venkat Viswanathan, an assistant professor of mechanical engineering at Carnegie Mellon University who studies energy-storage systems.

Lithium-sulfur and lithium-air batteries — where sulfur or oxygen are used in the cathode — exist today. But the key innovation of the MIT research, Viswanathan says, is combining the two concepts to create a lower-cost battery with comparable efficiency and energy density. The design could inspire new work in the field, he adds: “It’s something that immediately captures your imagination.”

Making renewables more reliable

The prototype is currently about the size of a coffee cup. But flow batteries are highly scalable, Chiang says, and cells can be combined into larger systems.

As the battery can discharge over months, the best use may be for storing electricity from notoriously unpredictable wind and solar power sources. “The intermittency for solar is daily, but for wind it’s longer-scale intermittency and not so predictable.

When it’s not so predictable you need more reserve — the capability to discharge a battery over a longer period of time — because you don’t know when the wind is going to come back next,” Chiang says. Seasonal storage is important too, he adds, especially with increasing distance north of the equator, where the amount of sunlight varies more widely from summer to winter.

Chiang says this could be the first technology to compete, in cost and energy density, with pumped hydroelectric storage systems, which provide most of the energy storage for renewables around the world but are very restricted by location.

“The energy density of a flow battery like this is more than 500 times higher than pumped hydroelectric storage. It’s also so much more compact, so that you can imagine putting it anywhere you have renewable generation,” Chiang says.

The research was supported by the Department of Energy.

Fisker Claims New Graphene Based Battery Breakthrough – 500 Mile Range and ONE Minute Charging!


When Henrik Fisker relaunched its electric car startup last year, he announced that their first car will be powered by a new graphene-based hybrid supercapacitor technology, but he later announced that they put those plans on the backburner and instead will use more traditional li-ion batteries.

Now the company is announcing a “breakthrough” in solid-state batteries to power their next-generation electric cars and they are filing for patents to protect their IP.

Get ready for some crazy claims here.

Solid-state batteries are thought to be a lot safer than common li-ion cells and could have more potential for higher energy density, but they also have limitations, like temperature ranges, electrode current density, and we have yet to see a company capable of producing it in large-scale and at an attractive price point competitive with li-ion.

Now Fisker announced that they are patenting a new solid-state electrode structure that would enable a viable battery with some unbelievable specs.

Here’s what they claim (via GreenCarCongress):

“Fisker’s solid-state batteries will feature three-dimensional electrodes with 2.5 times the energy density of lithium-ion batteries. Fisker claims that this technology will enable ranges of more than 500 miles on a single charge and charging times as low as one minute—faster than filling up a gas tank.”

Here’s a representation of the three-dimensional electrodes:

Fisker has been all over the place with its new Emotion electric car and we have highlighted that in our look at Fisker’s unbelievable claims.

But its latest solid-state project is led by Dr. Fabio Albano, VP of battery systems at Fisker and the co-founder of Sakti3, which adds credibility to the effort.

Albano commented on the announcement:

“This breakthrough marks the beginning of a new era in solid-state materials and manufacturing technologies. We are addressing all of the hurdles that solid-state batteries have encountered on the path to commercialization, such as performance in cold temperatures; the use of low cost and scalable manufacturing methods; and the ability to form bulk solid-state electrodes with significant thickness and high active material loadings. We are excited to build on this foundation and move the needle in energy storage.”

Electrek’s Take

Like any battery breakthrough announcement, it should be taken with a grain of salt. Most of those announcements never result in any kind of commercialization.

For this particular technology, Fisker says that it will be automotive production grade ready around 2023.

A lot of things can happen over the next 5 years.

In the meantime, Fisker plans to launch its Emotion electric car at CES 2018 in just 2 months. Fisker already unveiled a prototype of the new electric car and started taking pre-orders this summer.