Rechargeable Lithium Metal Battery

Rice University scientists have created a rechargeable lithium metal battery with three times the capacity of commercial lithium-ion batteries by resolving something that has long stumped researchers: the dendrite problem.

The Rice battery stores lithium in a unique anode, a seamless hybrid of graphene and carbon nanotubes. The material first created at Rice in 2012 is essentially a three-dimensional carbon surface that provides abundant area for lithium to inhabit. Lithium metal coats the hybrid graphene and carbon nanotube anode in a battery created at Rice University. The lithium metal coats the three-dimensional structure of the anode and avoids forming dendrites.

The anode itself approaches the theoretical maximum for storage of lithium metal while resisting the formation of damaging dendrites or “mossy” deposits.

Dendrites have bedeviled attempts to replace lithium-ion with advanced lithium metal batteries that last longer and charge faster. Dendrites are lithium deposits that grow into the battery’s electrolyte. If they bridge the anode and cathode and create a short circuit, the battery may fail, catch fire or even explode.

Rice researchers led by chemist James Tour found that when the new batteries are charged, lithium metal evenly coats the highly conductive carbon hybrid in which nanotubes are covalently bonded to the graphene surface. As reported in the American Chemical Society journal ACS Nano, the hybrid replaces graphite anodes in common lithium-ion batteries that trade capacity for safety.

Lithium-ion batteries have changed the world, no doubt,” Tour said, “but they’re about as good as they’re going to get. Your cellphone’s battery won’t last any longer until new technology comes along.

He said the new anode’s nanotube forest, with its low density and high surface area, has plenty of space for lithium particles to slip in and out as the battery charges and discharges. The lithium is evenly distributed, spreading out the current carried by ions in the electrolyte and suppressing the growth of dendrites.

Source: http://news.rice.edu

Bubbles And The Future Of Electric Cars

With about three times the energy capacity by weight of today’s lithium-ion batteries, lithium-air batteries could one day enable electric cars to drive farther on a single charge. But the technology has several holdups, including losing energy as it stores and releases its charge. If researchers could better understand the basic reactions that occur as the battery charges and discharges electricity, the battery’s performance could be improved. One reaction that hasn’t been fully explained is how oxygen blows bubbles inside a lithium-air battery when it discharges. The bubbles expand the battery and create wear and tear that can cause it to fail.

A paper in Nature Nanotechnology provides the first step-by-step explanation of how lithium-air batteries form bubbles. The research was aided by a first-of-a-kind video that shows bubbles inflating and later deflating inside a nanobattery. Researchers had previously only seen the bubbles, but not how they were created.

If we fully understand the bubble formation process, we could build better lithium-air batteries that create fewer bubbles,” noted the paper’s corresponding author, Chongmin Wang, of the Department of Energy’s Pacific Northwest National Laboratory (PNNL). “The result could be more compact and stable batteries that hold onto their charge longer.”

Wang works out of EMSL, the Environmental Molecular Sciences Laboratory, a DOE Office of Science user facility located at PNNL. His co-authors include other PNNL staff and a researcher from Tianjin Polytechnic University in China.

The team’s unique video may be a silent black-and-white film, but it provides plenty of action. Popping out from the battery’s flat surface is a grey bubble that grows bigger and bigger. Later, the bubble deflates, the top turning inside of itself until only a scrunched-up shell is left behind.

The popcorn-worthy flick was captured with an in-situ environmental transmission electron microscope at EMSL. Wang and his colleagues built their tiny battery inside the microscope’s column. This enabled them to watch as the battery charged and discharged inside.

Video evidence led the team to propose that as the battery discharges, a sphere of lithium superoxide jets out from the battery’s positive electrode and becomes coated with lithium oxide. The sphere’s superoxide interior then goes through a chemical reaction that forms lithium peroxide and oxygen. Oxygen gas is released and inflates the bubble. When the battery charges, lithium peroxide decomposes, and leaves the former bubble to look like a deflated balloon.

Source: http://www.pnnl.gov/

 

Efficient, Fast, Large-scale 3-D Manufacturing

Washington State University (WSU) researchers have developed a unique, 3-D manufacturing method that for the first time rapidly creates and precisely controls a material’s architecture from the nanoscale to centimeters – with results that closely mimic the intricate architecture of natural materials like wood and bone.

3D manufacturing Hex-Scaffold-web-

This is a groundbreaking advance in the 3-D architecturing of materials at nano- to macroscales with applications in batteries, lightweight ultrastrong materials, catalytic converters, supercapacitors and biological scaffolds,” said Rahul Panat, associate professor in the School of Mechanical and Materials Engineering, who led the research. “This technique can fill a lot of critical gaps for the realization of these technologies.”

The WSU research team used a 3-D printing method to create foglike microdroplets that contain nanoparticles of silver and to deposit them at specific locations. As the liquid in the fog evaporated, the nanoparticles remained, creating delicate structures. The tiny structures, which look similar to Tinkertoy constructions, are porous, have an extremely large surface area and are very strong.

The researchers would like to use such nanoscale and porous metal structures for a number of industrial applications; for instance, the team is developing finely detailed, porous anodes and cathodes for batteries rather than the solid structures that are now used. This advance could transform the industry by significantly increasing battery speed and capacity and allowing the use of new and higher energy materials.

They report on their work in the journal  Science Advances  and have filed for a patent.

Source: https://news.wsu.edu/

How To Fast Manufacture NanoRobots

A team of researchers led by Biomedical Engineering Professor Sam Sia at Columbia Engineering has developed a way to manufacture microscale machines from biomaterials that can safely be implanted in the body. Working with hydrogels, which are biocompatible materials that engineers have been studying for decades, Sia has invented a new technique that stacks the soft material in layers to make devices that have three-dimensional, freely moving parts. The study, published online January 4, 2017, in Science Robotics, demonstrates a fast manufacturing method Sia calls “implantable microelectromechanical systems” (iMEMS).

By exploiting the unique mechanical properties of hydrogels, the researchers developed a “locking mechanism” for precise actuation and movement of freely moving parts, which can function as valves, manifolds, rotors, pumps, and drug delivery systems. They were able to tune the biomaterials within a wide range of mechanical and diffusive properties and to control them after implantation without a sustained power supply, such as a toxic battery. They then tested the payload delivery in a bone cancer model and found that the triggering of releases of doxorubicin from the device over 10 days showed high treatment efficacy and low toxicity, at 1/10th of the standard systemic chemotherapy dose.

implantable nanorobot

Overall, our iMEMS platform enables development of biocompatible implantable microdevices with a wide range of intricate moving components that can be wirelessly controlled on demand and solves issues of device powering and biocompatibility,” says Sia, also a member of the Data Science Institute. “We’re really excited about this because we’ve been able to connect the world of biomaterials with that of complex, elaborate medical devices.  Our platform has a large number of potential applications, including the drug delivery system demonstrated in our paper which is linked to providing tailored drug doses for precision medicine.”

Source: http://engineering.columbia.edu/

The Rise Of The Hydrogen Electric Car

Right now, if you want an alternative-fuel vehicle, you have to pick from offerings that either require gasoline or an electrical outlet. The gas-electric hybrid and the battery-powered car — your Toyota Priuses, Chevy Volts, and Teslas — are staples in this space. There are drawbacks for drivers of both types. You still have to buy gas for your hybrid and you have to plug in your Tesla — sometimes under less than favorable conditions — lest you be stranded someplace far away from a suitable plug. Beyond that, automakers have been out to find the next viable energy source. Plug-in vehicles are more or less proven to be the answer, but Toyota and a handful of other carmakers are investigating hydrogen.

toyota-mirai

That’s where the Toyota Mirai comes in. The Mirai‘s interior center stack has all the technology you would expect from a car that retails for $57,500, including navigation, Bluetooth, and USB connectivity. It’s all accessible by touch screens and robust digital displays.
A fill-up on hydrogen costs just about as much as regular gasoline in San Francisco. The Mirai gets an estimated 67 MPGe (67 Miles per gallon gasoline equivalent = 28,5 kilometers per liter)), according to Toyota.
It’s an ambitious project for Toyota because the fueling infrastructure for this car is minimal. There are only 33 public hydrogen-filling stations in the US, according to the US Department of Energy. Twenty-six of those stations are in California, and there’s one each in Connecticut, Massachusetts, and South Carolina.

If you include public and private hydrogen stations, then the total climbs to 58 — nationwide. Compare that to the more than 15,100 public electric-charging stations and the 168,000 retail gas stations in the US, and you can see the obvious drawback of hydrogen-powered cars. Despite this, the Mirai is an interesting project, and you must keep in mind that Japan at the Government level seems to bet on a massively hydrogen powered economy in the near future (fuel, heating, replacement of nuclear energy, trains, electric vehicles, etc…).

Source: http://www.businessinsider.com

Solar Powered House: Tiles Instead Of Panels

Tesla founder and CEO Elon Musk wasn’t kidding when he said that the new Tesla solar roof product was better looking than an ordinary roof: the roofing replacement with solar energy gathering powers does indeed look great. It’s a far cry from the obvious and somewhat weird aftermarket panels you see applied to roofs after the fact today.

tesla-solar-tiles

The solar roofing comes in four distinct styles that Tesla presented at the event, including “Textured Glass Tile,” “Slate Glass Tile,” “Tuscan Glass Tile, and “Smooth Glass Tile.” Each of these achieves a different aesthetic look, but all resembled fairly closely a current roofing material style. Each is also transparent to solar, but appears opaque when viewed from an angle.

The current versions of the tiles actually have a two percent loss on efficiency, so 98 percent of what you’d normally get from a traditional solar panel, according to Elon Musk. But the company is working with 3M on improved coatings that have the potential to possibly go above normal efficiency, since it could trap the light within, leading to it bouncing around and resulting in less energy loss overall before it’s fully diffused.

Of course, there’s the matter of price: Tesla’s roof cost less than the full cost of a roof and electricity will be competitive or better than the cost of a traditional roof combined with the cost of electricity from the grid, Musk said. Tesla declined to provide specific pricing at the moment, since it will depend on a number of factor including installation specifics on a per home basis.

Standard roofing materials do not provide fiscal benefit back to the homeowner post-installation, besides improving the cost of the home. Tesla’s product does that, by generating enough energy to fully power a household, with the power designed to be stored in the new Powerwall 2.0 battery units so that homeowners can keep a reserve in case of excess need.

The solar roof product should start to see installations by summer next year, and Tesla plans to start with one or two of its four tile options, then gradually expand the options over time. As they’re made from quartz glass, they should last way longer than an asphalt tile — at least two or three times the longevity, though Musk later said “they should last longer than the house”.

Source: https://techcrunch.com/

Friendly Alternative To Li-Ion Battery

An unexpected discovery has led to a rechargeable battery that’s as inexpensive as conventional car batteries, but has a much higher energy density. The new battery could become a cost-effective, environmentally friendly alternative for storing renewable energy and supporting the power grid.

A team based at the Department of Energy’s Pacific Northwest National Laboratory (PNNL) identified this energy storage gem after realizing the new battery works in a different way than they had assumed. The journal Nature Energy published a paper today that describes the battery.

PNNL batteryPNNL’s improved aqueous zinc-manganese oxide battery offers a cost-effective, environmentally friendly alternative for storing renewable energy and supporting the power grid.

“The idea of a rechargeable zinc-manganese battery isn’t new; researchers have been studying them as an inexpensive, safe alternative to lithium-ion batteries since the late 1990s,” said PNNL Laboratory Fellow Jun Liu, the paper’s corresponding author. “But these batteries usually stop working after just a few charges. Our research suggests these failures could have occurred because we failed to control chemical equilibrium in rechargeable zinc-manganese energy storage systems.”

After years of focusing on rechargeable lithium-ion batteries, researchers are used to thinking about the back-and-forth shuttle of lithium ions. Lithium-ion batteries store and release energy through a process called intercalation, which involves lithium ions entering and exiting microscopic spaces in between the atoms of a battery’s two electrodes.

This concept is so engrained in energy storage research that when PNNL scientists, collaborating with the University of Washington, started considering a low-cost, safe alternative to lithium-ion batteries − a rechargeable zinc-manganese oxide battery − they assumed zinc would similarly move in and out of that battery’s electrodes. After a battery of tests, the team was surprised to realize their device was undergoing an entirely different process. Instead of simply moving the zinc ions around, their zinc-manganese oxide battery was undergoing a reversible chemical reaction that converted its active materials into entirely new ones.

Source: http://www.pnnl.gov/

Battery That Could Be Recharged 200,000 Times

Scientists have long sought to use nanowires in batteries. Thousands of times thinner than a human hair, they’re highly conductive and feature a large surface area for the storage and transfer of electrons. However, these filaments are extremely fragile and don’t hold up well to repeated discharging and recharging, or cycling. In a typical lithium-ion battery, they expand and grow brittle, which leads to cracking.

Researchers fron the University of California Irvine (UCI) have solved this problem by coating a gold nanowire in a manganese dioxide shell and encasing the assembly in an electrolyte made of a Plexiglas-like gel. The combination is reliable and resistant to failure.

Mya Le Thai

The study leader, UCI doctoral candidate Mya Le Thai, cycled the testing electrode up to 200,000 times over three months without detecting any loss of capacity or power and without fracturing any nanowires. The findings were published today in the American Chemical Society’s Energy Letters. Hard work combined with serendipity paid off in this case, according to senior author Reginald Penner.

Mya was playing around, and she coated this whole thing with a very thin gel layer and started to cycle it,” said Penner, chair of UCI’s chemistry department. “She discovered that just by using this gel, she could cycle it hundreds of thousands of times without losing any capacity”.

That was crazy,” he added, “because these things typically die in dramatic fashion after 5,000 or 6,000 or 7,000 cycles at most.

Source: https://news.uci.edu/

Solar Hubs Provide Clean Water, Electricity & Internet to 3000 people

The Italian company Watly aims to deliver a hat trick of very needful things to the developing world, in the form of both a standalone unit and as a network of units. The team of this ambitious company describes their creation as the “biggest solar-powered computer in the world,” which combines solar photovoltaics (PV) and battery storage for powering the unit (and for charging external devices), with a water filtration system and an internet connectivity and telecommunications hub. The Watly system, which has been in the works for the last few years, and has now attracted the attention of The Discovery Channel, was run as a pilot program at a village in Ghana, where the 2.0 version of the device was successfully deployed to deliver clean drinking water to residents.

watly solar hub

The next step, however, is to build out the Watly 3.0 system, which is the full-sized version of the device, measuring some 40 meters long, and which is expected to be able to provide as much as 5000 liters of water per day, every day, for at least 15 years, along with producing solar electricity and charging services to as many as 3000 people. According to the company, one unit could offset the emissions equivalent of 2500 barrels of oil over the course of those 15 years, along with providing clean water and an off-grid power source. To get to that next step, Watly has turned to – wait for it – crowdfunding with an Indiegogo campaign that seeks to raise money for the installation of the 3.0 version as a pilot program in Africa (location TBD).

Along with the solar power and drinking water, Watly aims to provide an internet/telecom hub for local residents, with an onboard system for connecting to 3G/4G, radio link data systems, and/or satellites, as well as to communicate with other Watly units to act as a node in an “EnergyNet.”

Watly is a powerful communication device that can collect and send any kind of data (videos, images, audios, texts, ratios, etc.) to the Internet as well as to any other compatible communication device. A single Watly is a standing alone machine, but two or more Watlys become a network where each node is auto-powered, self-sustained and multi-functional.

Source: https://watly.co/

Nanotechnology Improves Next Generation Of Batteries

In the global race to create more efficient and long-lasting batteries, some are betting on nanotechnology — the use of minuscule parts — as the most likely to yield a breakthrough. Improving batteries’ performance is key to the development and success of many much-hyped technologies, from solar and wind energy to electric cars. They need to hold more energy, last longer, be cheaper and safer. Research into how to achieve that has followed several avenues, from using different materials than the existing lithium-ion batteries to changing the internal structure of batteries using nanoparticles — parts so small they are invisible to the naked eye. Nanotechnology can increase the size and surface of batteries electrodes, the rods inside the batteries that absorb the energy. It does so by effectively making the electrodes sponge-like, so that they can absorb more energy during charging and ultimately increasing the energy storage capacity. Prague-based company HE3DA in Czech Republic has developed such a technology by using the nanotechnology to move from the current flat electrodes to make them three dimensional. With prototypes undergoing successful testing, it hopes to have the battery on the market at the end of this year.

Tesla Model 3

In the future, this will be the mainstream,” said Jan Prochazka, the president. He said it would be targeted at high-intensity industries like automobiles and the energy sector, rather than mobile phones, because that is where it can make the biggest difference through its use of his bigger electrodes.

In combination with an internal cooling system the batteries, which are being tested now, should be safe from overheating or exploding, a major concern with existing technologies. Researchers at the University of Michigan and MIT have likewise focused on nanotechnology to improve the existing lithium-ion technology. Others have sought to use different materials. One of the most promising is lithium oxygen, which theoretically could store five to 10 times the energy of a lithium ion battery, but there have been a number of technical problems that made it inefficient. Batteries based on sodium-ion, aluminium-air and aluminium-graphite are also being explored. There’s even research on a battery powered by urine.

Source: http://www.he3da.cz/
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http://bigstory.ap.org/

Electric Cars That Eat CO2

An interdisciplinary team of scientists has worked out a way to make electric vehicles that only are not only carbon neutral but carbon negative, capable of actually reducing the amount of atmospheric carbon dioxide as they operate.

They have done so by demonstrating how the graphite electrodes used in the lithium-ion batteries that power electric automobiles can be replaced with carbon material recovered from the atmosphere. The unusual pairing of carbon dioxide conversion and advanced battery technology is the result of a collaboration between the laboratory of Assistant Professor of Mechanical Engineering Cary Pint at Vanderbilt University and Professor of Chemistry Stuart Licht at George Washington University. The team adapted a solar-powered process that converts carbon dioxide into carbon so that it produces carbon nanotubes and demonstrated that the nanotubes can be incorporated into both lithium-ion batteries like those used in electric vehicles and electronic devices and low-cost sodium-ion batteries under development for large-scale applications, such as the electric grid.

Tesla Model 3

This approach not only produces better batteries but it also establishes a value for carbon dioxide recovered from the atmosphere that is associated with the end-user battery cost unlike most efforts to reuse CO2 that are aimed at low-valued fuels, like methanol, that cannot justify the cost required to produce them,” said Pint. “Our climate-change solution is two fold: (1) to transform the greenhouse gas carbon dioxide into valuable products and (2) to provide greenhouse gas emission-free alternatives to today’s industrial and transportation fossil fuel processes,” adds Licht. “In addition to better batteries other applications for the carbon nanotubes include carbon composites for strong, lightweight construction materials, sports equipment and car, truck and airplane bodies.

The project builds upon a solar thermal electrochemical process (STEP) that can create carbon nanofibers from ambient carbon dioxide developed by the Licht group and described in the journal Nano Letters last August. STEP uses solar energy to provide both the electrical and thermal energy necessary to break down carbon dioxide into carbon and oxygen and to produce carbon nanotubes that are stable, flexible, conductive and stronger than steel.

The recipe for converting carbon dioxide gas into batteries is described in the paper titled “Carbon Nanotubes Produced from Ambient Carbon Dioxide for Environmentally Sustainable Lithium-Ion and Sodium-Ion Battery Anodes” published online on Mar. 2 by the journal ACS Central Science.

Source: http://news.vanderbilt.edu/

How To Charge A Phone Battery In 30 Seconds

If you add quantum dotsnanocrystals 10,000 times smaller than the width of a human hair – to a smartphone battery it will charge in 30 seconds, but the effect only lasts for a few recharge cycles.

However, a group of researchers at Vanderbilt University report in  of the journal ACS Nano that they have found a way to overcome this problem: Making the quantum dots out of iron pyrite, commonly known as fool’s gold, can produce batteries that charge quickly and work for dozens of cycles.

The research team headed by Assistant Professor of Mechanical Engineering Cary Pint and led by graduate student Anna Douglas became interested in iron pyrite because it is one of the most abundant materials in the earth’s surface. It is produced in raw form as a byproduct of coal production and is so cheap that it is used in lithium batteries that are bought in the store and thrown away after a single use.

Despite all their promise, researchers have had trouble getting nanoparticles to improve battery performance.

nanocrystals

Researchers have demonstrated that nanoscale materials can significantly improve batteries, but there is a limit,” Pint said. “When the particles get very small, generally meaning below 10 nanometers (40 to 50 atoms wide), the nanoparticles begin to chemically react with the electrolytes and so can only charge and discharge a few times. So this size regime is forbidden In commercial lithium-ion batteries.”

Source: http://news.vanderbilt.edu/