Could a new material involving a carbon nanotube and graphene hybrid put an end to the dendrite problem in lithium batteries? (Credit: Tour Group/Rice University)
The high energy capacity of lithium-ion batteries has led to them powering everything from tiny mobile devices to huge trucks. But current lithium-ion battery technology is nearing its limits and the search is on for a better lithium battery. But one thing stands in the way: dendrites. If a new technology by Rice University scientists lives up to its potential, it could solve this problem and enable lithium-metal batteries that can hold three times the energy of lithium-ion ones.
Dendrites are microscopic lithium fibers that form on the anodes during the charging process, spreading like a rash till they reach the other electrode and causing the battery to short circuit. As companies such as Samsung know only too well, this can cause the battery to catch fire or even explode.
“Lithium-ion batteries have changed the world, no doubt,” says chemist Dr. James Tour, who led the study. “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.”
For a start, it’s able to stop dendrite growth in its tracks. Key to it is a unique anode made from a material that was first created at the university five years ago. By using a covalent bond structure, it combines a two-dimensional graphene sheet and carbon nanotubes to form a seamless three-dimensional structure. As Tour explained back when the material was first unveiled:
“By growing graphene on metal (in this case copper) and then growing nanotubes from the graphene, the electrical contact between the nanotubes and the metal electrode is ohmic. That means electrons see no difference, because it’s all one seamless material.”
Close-up of the lithium metal coating the graphene-nanotube anode (Credit: Tour Group/Rice University)
Envisioned for use in energy storage and electronics applications such as supercapacitors, it wasn’t until 2014, when co-lead author Abdul-Rahman Raji was experimenting with lithium metal and the graphene-nanotube hybrid, that the researchers discovered its potential as a dendrite inhibitor.
“I reasoned that lithium metal must have plated on the electrode while analyzing results of experiments carried out to store lithium ions in the anode material combined with a lithium cobalt oxide cathode in a full cell,” says Raji. “We were excited because the voltage profile of the full cell was very flat. At that moment, we knew we had found something special.”
Closer analysis revealed no dendrites had grown when the lithium metal was deposited into a standalone hybrid anode – but would it work in a proper battery?
To test the anode, the researchers built full battery prototypes with sulfur-based cathodes that retained 80 percent capacity after more than 500 charge-discharge cycles (i.e. the rough equivalent of what a cellphone goes through in a two-year period). No signs of dendrites were observed on the anodes.
How it works
The low density and high surface area of the nanotube forest allow the lithium metal to coat the carbon hybrid material evenly when the battery is charged. And since there is plenty of space for the particles to slip in and out during the charge and discharge cycle, they end up being evenly distributed and this stops the growth of dendrites altogether.
According to the study, the anode material is capable of a lithium storage capacity of 3,351 milliamp hours per gram, which is close to pure lithium’s theoretical maximum of 3,860 milliamp hours per gram, and 10 times that of lithium-ion batteries. And since the nanotube carpet has a low density, this means it’s able to coat all the way down to substrate and maximize use of the available volume.
“Many people doing battery research only make the anode,because to do the whole package is much harder,” says Tour. “We had to develop a commensurate cathode technology based upon sulfur to accommodate these ultrahigh-capacity lithium anodes in first-generation systems. We’re producing these full batteries, cathode plus anode, on a pilot scale, and they’re being tested.”
Electrodes are critical parts of every battery architecture — charge too fast, and you can decrease the charge-discharge cycle life or damage the battery so it won’t charge anymore. Scientists have built a new design and chemistry for electrodes. Their design involves advanced, nanostructured electrodes containing molybdenum disulfide and carbon nanofibers (Advanced Energy Materials, “Pseudocapacitive charge storage in thick composite MoS2 nanocrystal-based electrodes”). These composite materials have internal atomic-scale pathways. These paths are for both fast ion and electron transport, allowing for fast charging.
Battery electrodes made of a molybdenum disulfide nanocrystal composite have internal pathways to allow lithium ions to move quickly through the electrode, speeding up the rate that the battery can charge. The key features in the structure that enable the flow of the lithium ions are the small, 20-40 nanometer, diameter of the nanocrystals (in contrast, human hairs are about 100,000 nanometers in diameter) coupled with the porosity and planar lamellar pathways shown in the electron micrograph. (Image: Sarah Tolbert, University of California, Los Angeles)
The new battery electrodes provide several benefits. The electrodes allow fast charging. They also have stable charge/discharge behavior, so the batteries last longer. These electrodes show promise for practical electrical energy storage systems.
New battery electrodes based on nanostructured molybdenum disulfide combine the ability to charge in seconds with high capacity and long cycle life. Typical lithium-ion batteries charge slowly due to slow diffusion of lithium ions within the solid electrode.
Another type of energy storage device (a.k.a., pseudocapacitors), which has similarities to the capacitors found in common electrical circuits, speeds up the charging process by using reactions at or near the electrode surface, thus avoiding slow solid-state diffusion pathways.
Nanostructured electrodes allow the creation of large surface areas so that the battery can work more like a pseudocapacitor. In this work at the University of California, Los Angeles, scientists made nanostructured electrodes from a molybdenum disulfide-carbon composite.
Many electrodes are based on metal oxides, but because sulfur more weakly interacts with lithium than oxygen, lithium atoms can move more freely in the metal sulfide than the metal oxide. The result is a battery electrode that shows high capacity and very fast charging times.
The novel electrodes deliver specific capacities of 90 mAh/g (about half that of a typical lithium-ion battery cathode) charging in less than 20 seconds, and retain over 80 percent of their original capacity after 3,000 charge/discharge cycles. Capacities of greater than 180 mAh/g (similar to cathodes in conventional lithium-ion cells) are achieved at slower charging rates.
The results have exciting implications for the development of fast-charging energy storage systems that could replace traditional lithium-ion batteries.
Source: U.S. Department of Energy, Office of Science
Researchers from UCLA and the University of Connecticut have designed a new biofriendly energy storage system called a biological supercapacitor, which operates using charged particles, or ions, from fluids in the human body. The device is harmless to the body’s biological systems, and it could lead to longer-lasting cardiac pacemakers and other implantable medical devices. The UCLA team was led by Richard Kaner, a distinguished professor of chemistry and biochemistry, and of materials science and engineering, and the Connecticut researchers were led by James Rusling, a professor of chemistry and cell biology.
A paper about their design was published this week in the journal Advanced Energy Materials. Pacemakers — which help regulate abnormal heart rhythms — and other implantable devices have saved countless lives. But they’re powered by traditional batteries that eventually run out of power and must be replaced, meaning another painful surgery and the accompanying risk of infection. In addition, batteries contain toxic materials that could endanger the patient if they leak.
The researchers propose storing energy in those devices without a battery. The supercapacitor they invented charges using electrolytes from biological fluids like blood serum and urine, and it would work with another device called an energy harvester, which converts heat and motion from the human body into electricity — in much the same way that self-winding watches are powered by the wearer’s body movements. That electricity is then captured by the supercapacitor. “Combining energy harvesters with supercapacitors can provide endless power for lifelong implantable devices that may never need to be replaced,” said Maher El-Kady, a UCLA postdoctoral researcher and a co-author of the study.
Modern pacemakers are typically about 6 to 8 millimeters thick, and about the same diameter as a 50-cent coin; about half of that space is usually occupied by the battery. The new supercapacitor is only 1 micrometer thick — much smaller than the thickness of a human hair — meaning that it could improve implantable devices’ energy efficiency. It also can maintain its performance for a long time, bend and twist inside the body without any mechanical damage, and store more charge than the energy lithium film batteries of comparable size that are currently used in pacemakers. “Unlike batteries that use chemical reactions that involve toxic chemicals and electrolytes to store energy, this new class of biosupercapacitors stores energy by utilizing readily available ions, or charged molecules, from the blood serum,” said Islam Mosa, a Connecticut graduate student and first author of the study.
The new biosupercapacitor comprises a carbon nanomaterial called graphene layered with modified human proteins as an electrode, a conductor through which electricity from the energy harvester can enter or leave. The new platform could eventually also be used to develop next-generation implantable devices to speed up bone growth, promote healing or stimulate the brain, Kaner said.
Although supercapacitors have not yet been widely used in medical devices, the study shows that they may be viable for that purpose. “In order to be effective, battery-free pacemakers must have supercapacitors that can capture, store and transport energy, and commercial supercapacitors are too slow to make it work,” El-Kady said. “Our research focused on custom-designing our supercapacitor to capture energy effectively, and finding a way to make it compatible with the human body.” Among the paper’s other authors are the University of Connecticut’s Challa Kumar, Ashis Basu and Karteek Kadimisetty. The research was supported by the National Institute of Health’s National Institute of Biomedical Imaging and Bioengineering, the NIH’s National Institute of Environmental Health Sciences, and a National Science Foundation EAGER grant. Source and top image: UCLA Engineering
“The solar energy business has been trying to overcome … challenge for years. The cost of installing solar panels has fallen dramatically but storing the energy produced for later use has been problematic.”
“In a single hour, the amount of power from the sun that strikes the Earth is more than the entire world consumes in an year.” To put that in numbers, from the US Department of EnergyEach hour 430 quintillion Joules of energy from the sun hits the Earth. That’s 430 with 18 zeroes after it! In comparison, the total amount of energy that all humans use in a year is 410 quintillion Joules. For context, the average American home used 39 billion Joules of electricity in 2013.
Clearly, we have in our sun “a source of unlimited renewable energy”. But how can we best harness this resource? How can we convert and “store” this energy resource on for sun-less days or at night time … when we also have energy needs?
Now therein lies the challenge!
Would you buy a smartphone that only worked when the sun was shining? Probably not. What it if was only half the cost of your current model: surely an upgrade would be tempting? No, thought not.
The solar energy business has been trying to overcome a similar challenge for years. The cost of installing solar panels has fallen dramatically but storing the energy produced for later use has been problematic.
Now scientists in Sweden have found a new way to store solar energy in chemical liquids. Although still in an early phase, with niche applications, the discovery has the potential to make solar power more practical and widespread.
Until now, solar energy storage has relied on batteries, which have improved in recent years. However, they are still bulky and expensive, and they degrade over time.
Trap and release solar power on demand
A research team from Chalmers University of Technology in Gothenburg made a prototype hybrid device with two parts. It’s made from silica and quartz with tiny fluid channels cut into both sections.
The top part is filled with a liquid that stores solar energy in the chemical bonds of a molecule. This method of storing solar energy remains stable for several months. The energy can be released as heat whenever it is required.
The lower section of the device uses sunlight to heat water which can be used immediately. This combination of storage and water heating means that over 80% of incoming sunlight is converted into usable energy.
Suddenly, solar power looks a lot more practical. Compared to traditional battery storage, the new system is more compact and should prove relatively inexpensive, according to the researchers. The technology is in the early stages of development and may not be ready for domestic and business use for some time.
From the lab to off-grid power stations or satellites?
The researchers wrote in the journal Energy & Environmental Science: “This energy can be transported, and delivered in very precise amounts with high reliability(…) As is the case with any new technology, initial applications will be in niches where [molecular storage] offers unique technical properties and where cost-per-joule is of lesser importance.”
The team now plans to test the real-world performance of the technology and estimate how much it will cost. Initially, the device could be used in off-grid power stations, extreme environments, and satellite thermal control systems.
Editor’s Note: As Solomon wrote in Ecclesiastes 1:9: “What has been will be again, what has been done will be done again; there is nothing new under the sun.”
Storing Solar Energy chemically and converting ‘waste heat’ has and is the subject of many research and implementation Projects around the globe. Will this method prove to be “the one?” This writer (IMHO) sees limited application, but not a broadly accepted and integrated solution.
Solar Energy to Hydrogen Fuel
So where does that leave us? We have been following the efforts of a number of Researchers/ Universities who are exploring and developing “Sunlight to Hydrogen Fuel” technologies to harness the enormous and almost inexhaustible energy source power-house … our sun! What do you think? Please leave us your Comments and we will share the results with our readers!
We have written and posted extensively about ‘Solar to Hydrogen Renewable Energy’ – here are some of our previous Posts:
Researchers at Rice University are on to a relatively simple, low-cost way to pry hydrogen loose from water, using the sun as an energy source. The new system involves channeling high-energy “hot” electrons into a useful purpose before they get a chance to cool down. If the research progresses, that’s great news for the hydrogen […]
HyperSolar has achieved a major milestone with its hybrid technology HyperSolar, a company that specializes in combining hydrogen fuel cells with solar energy, has reached a significant milestone in terms of hydrogen production. The company harnesses the power of the sun in order to generate the electrical power needed to produce hydrogen fuel. This is […]
Rice University researchers have demonstrated an efficient new way to capture the energy from sunlight and convert it into clean, renewable energy by splitting water molecules. The technology, which is described online in the American Chemical Society journal Nano Letters, relies on a configuration of light-activated gold nanoparticles that harvest sunlight and transfer solar energy […]
NREL researchers Myles Steiner (left), John Turner, Todd Deutsch and James Young stand in front of an atmospheric pressure MDCVD reactor used to grow crystalline semiconductor structures. They are co-authors of the paper “Direct Solar-to-Hydrogen Conversion via Inverted Metamorphic Multijunction Semiconductor Architectures” published in Nature Energy. Photo by Dennis Schroeder. Scientists at the U.S. […]
Photo shows a lead sulfide quantum dot solar cell. A lead sulfide quantum dot solar cell developed by researchers at NREL. Photo by Dennis Schroeder.
Scientists at the U.S. Department of Energy’s National Renewable Energy Laboratory (NREL) have developed a proof-of-principle photo-electro-chemical cell capable of capturing excess photon energy normally lost to generating heat. Using quantum […]
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As it turns out, Tesla, and its battery partner Panasonic, started production of cells for qualification at the plant in December, but today, it confirmed the start of “mass production” of the new battery cell, which will enable several of Tesla’s new products, including the Model 3.
The new cell is called ‘2170’ because it’s 21mm by 70mm. It’s thicker and taller than the previous cell that Tesla developed with Panasonic, which was in an ‘18650’ cell format.
Tesla CEO Elon Musk has been boasting about the new cell over the past few month. He said that it’s the “highest energy density cell in the world and also the cheapest”.
A battery that can be charged in seconds, has a large capacity and lasts ten to twelve years? Certainly, many have wanted such a thing. Now the FastStorageBW II project – which includes Fraunhofer – is working on making it a reality. Fraunhofer researchers are using pre-production to optimize large-scale production and ensure it follows the principles of Industrie 4.0 from the outset.
Imagine you’ve had a hectic day and then, to cap it all, you find that the battery of your electric vehicle is virtually empty. This means you’ll have to take a long break while it charges fully. It’s a completely different story with capacitors, which charge in seconds. However, they have a different drawback: they store very little energy.
In the FastStorageBW II project, funded by the Baden-Württemberg Ministry of Economic Affairs, researchers from the Fraunhofer Institute for Manufacturing Engineering and Automation IPA in Stuttgart, together with colleagues from the battery manufacturer VARTA AG and other partners, are developing a powerful hybrid storage system that combines the advantages of lithium-ion batteries and supercapacitors.
“The PowerCaps have a specific capacity as high as lead batteries, a long life of ten to twelve years, and charge in a matter of seconds like a supercapacitor,” explains Joachim Montnacher, Head of the Energy business unit at Fraunhofer IPA. What’s more, PowerCaps can operate at temperatures of up to 85 degree Celsius. They withstand a hundred times more charge cycles than conventional battery systems and retain their charge over several weeks without any significant losses due to self-discharge.
“Supercapacitors may be providing an alternative to electric-car batteries sooner than expected, according to a new research study. Currently, supercapacitors can charge and discharge rapidly over very large numbers of cycles, but their poor energy density per kilogram —- at just one twentieth of existing battery technology — means that they can’t compete with batteries in most applications. That’s about to change, say researchers from the University of Surrey and University of Bristol in conjunction with Augmented Optics.
Large-scale production with minimum risk
The Fraunhofer IPA researchers’ main concern is with manufacturing: to set up new battery production, it is essential to implement the relevant process knowledge in the best possible way.
After all, it costs millions of euros to build a complete manufacturing unit. “We make it possible for battery manufacturers to install an intermediate step – a small-scale production of sorts – between laboratory production and large-scale production,” says Montnacher. “This way, we can create ideal conditions for large-scale production, optimize processes and ensure production follows the principles of Industrie 4.0 from the outset. Because in the end, that will give companies a competitive advantage.” Another benefit is that this cuts the time it takes to ramp up production by more than 50 percent.
For this innovative small-scale production setup, researchers cleverly combine certain production sequences. However, not all systems are connected to each other – at least, as far as the hardware is concerned. More often, it is an employee that carries the batches from one machine to the next. Ultimately, it is about developing a comprehensive understanding of the process, not about producing the greatest number of products in the shortest amount of time. For example, this means clarifying questions such as if the desired quality can be reproduced. The systems are designed as flexibly as possible so that they can be used for different production variations.
Making large-scale production compatible with Industrie 4.0
As far as software is concerned, the systems are thoroughly connected. Like process clusters, they are also equipped with numerous sensors, which show the clusters what data to capture for each of the process steps. They communicate with one another and store the results in a cloud. Researchers and entrepreneurs can then use this data to quickly analyze which factors influence the quality of the product – Does it have Industrie 4.0 capability? Were the right sensors selected? Do they deliver the desired data? Where are adjustments required?
Fraunhofer IPA is also applying its expertise beyond the area of production technology: The scientists are developing business models for the marketing of battery cells, they are analyzing resource availability, and they are optimizing the subsequent recycling of PowerCaps.
A new company Tenka Energy, LLC ™ has been formed to exploit and commercialize the Next Generation Super-Capacitors and Batteries. The opportunity is based on Nanoporous-Nickel Flexible Thin-Form, Scalable Super Capacitors and Si-Nanowire Battery Technologies with Exclusive IP Licensing Rights from Rice University.
… Problem 1: Current capacitors and batteries being supplied to the relevant markets lack the sustainable power density, discharge and recharge cycle and warranty life. Combined with a weight/ size challenge and the lack of a ‘flexible form factor’, existing solutions lack the ability to scale and manufacture at Low Cost, to satisfy the identified industries’ need for solutions that provide commercial viability & performance.
Solution: For Marine & Drone Batteries – Medical Devices
High Energy Density = 2X More Time on the Water; 2X Flight Time for Drones
Simplified Manufacturing = Lower Costs
Simple Electrode Architecture = Flex Form Factor (10X Energy Density Factor)
Flexible Form = Dramatically Less Weight and Better Weight Distribution
Leaving your phone plugged in for hours could become a thing of the past, thanks to a new type of battery technology that charges in seconds and lasts for over a week.
Watch the Video
While it probably won’t be commercially available for a years, the researchers said it has the potential to be used in phones, wearables and electric vehicles.
“If they were to replace the batteries with these supercapacitors, you could charge your mobile phone in a few seconds and you wouldn’t need to charge it again for over a week,” said Nitin Choudhary, a UCF postdoctoral associate, who conducted much of the research, published in the academic journal ACS Nano.
How does it work?
Unlike conventional batteries, supercapacitors store electricity statically on their surface which means they can charge and deliver energy rapidly. But supercapacitors have a major shortcoming: they need large surface areas in order to hold lots of energy.
To overcome the problem, the researchers developed supercapacitors built with millions of nano-wires and shells made from two-dimensional materials only a few atoms thick, which allows for super-fast charging. Their prototype is only about the size of a fingernail.
“For small electronic devices, our materials are surpassing the conventional ones worldwide in terms of energy density, power density and cyclic stability,” Choudhary said.
Cyclic stability refers to how many times a battery can be charged, drained and recharged before it starts to degrade. For lithium-ion batteries, this is typically fewer than 1,500 times.
Supercapacitors with two-dimensional materials can be recharged a few thousand times. But the researchers say their prototype still works like new even after being recharged 30,000 times.
Those that use the new materials could be used in phones, tablets and other electronic devices, as well as electric vehicles. And because they’re flexible, it could mean a significant development for wearables.
Technology II: Rice University
A new company has been formed (with exclusive licensing rights) to exploit and commercialize the Next Generation Super-Capacitors and Batteries. The opportunity is based on Nanoporous-Nickel Flexible Thin-form, Scalable Super Capacitors and Si-Nanowire Battery Technologies, developed by Rice University and Dr. James M. Tour, PhD – named “One of the Fifty (50) most influential scientists in the World today” is the inventor, patent holder and early stage developer.
Identified Key Markets and Commercial Applications
Medical Devices and Wearable Electronics
Drone/Marine Batteries and Power Banks
Powered Smart Cards and Motor Cycle/ EV Batteries
Sensors & Power Units for the iOT (Internet of Things) [Flexible Form, Energy Dense]
The Coming Power Needs of the iOT
The IoT is populated with billions of tiny devices.
They need to communicate.
Their numbers growing at 20%-30%/Year.
The iOT is Hungry for POWER! All this demands supercapacitors that can pack a lot of affordable power in very small volumes …Ten times more than today’s best supercapacitors can provide.
Highly Scalable – Energy Dense – Flexible Form – Rapid Charge
Problem 1: Current capacitors and batteries being supplied to the relevant markets lack the sustainable power density, discharge and recharge cycle, warranty life combined with a ‘flexible form factor’ to scale and satisfy the identified industry need for commercial viability & performance.
Solution I: (Minimal Value Product) Tenka is currently providing full, functional Super Capacitor prototypes to an initial customer in the Digital Powered Smart Card industry and has received two (2) phased Contingent Purchase Orders during the First Year Operating Cycle for 120,000 Units and 1,200,000 Units respectively.
Solution II: For Drone/ Marine Batteries – Power Banks & Medical Devices
Double the current ‘Time Aloft’ (1 hour+)
Reduces operating costs
Marine batteries – Less weight, longer life, flex form
Provides Fast Recharging, Extended Life Warranty.
Full -battery prototypes being developed
Small batteries will be produced first for Powered Digital Smart Cards (In addition to the MVP Super Caps) solving packaging before scaling up drone battery operations. Technical risks are mainly associated with packaging and scaling.
The Operational Plan is to take full advantage of the gained ‘know how’ (Trade Secrets and Processes) of scaling and packaging solutions developed for the Powered Digital Smart Card and the iOT, to facilitate the roll-out of these additional Application Opportunities. Leveraging gained knowledge from operations is projected to significantly increase margins and profitability. We will begin where the Economies of Scale and Entry Point make sense (cents)!
“We are building and Energy Storage Company starting Small & Growing Big!”
Creating a Life-Saving, Blood-Repellent Super Material – Revolutionizing Medical Implants: Colorado State University
Goodbye Rejection – Implanted medical devices like stents, catheters, and titanium rods are essential, life-saving tools for patients around the world. Still, having a foreign object in the human body does pose its own risks – chiefly, having the body reject the object or increasing the risk of dangerous blood clots. A new collaboration between two distinct scientific disciplines is working toward making those risks a concern of the past.
Biomedical engineers and materials scientists from Colorado State University (CSU) ….
New organic-inorganic material creates more flexible, efficient technologies ~ For Solar Cells, Thermo-electric Devices and LED’s
Florida State University College of Engineering Assistant Professor Shangchao Lin has published a new paper in the journal ACS Nano that predicts how an organic-inorganic hybrid material called organometal halide perovskites could be more mechanically flexible than existing silicon and other inorganic materials used for solar cells, thermoelectric devices and light-emitting diodes.
MIT: The Internet of Things ~ A RoadMap to a Connected World And … The Super-Capacitors and Batteries Needed to Power ‘The Internet of Things”
What if every vehicle, home appliance, heating system and light switch were connected to the Internet? Today, that’s not such a stretch of the imagination.
Modern cars, for instance, already have hundreds of sensors and multiple computers connected over an internal network. And that’s just one example of the 6.4 billion connected “things” in use worldwide this year, according to research by Gartner Inc. DHL and Cisco Systems offer even higher estimates—their 2015 Trend Report sets the current number of connected devices at about 15 billion, amidst industry expectations that the tally will increase to 50 billion by 2020.
Feb 21, 2018 / Comments Off on Read Genesis Nanotech Online: Ultra-Thin Wearable Health Monitors + Rice University Expands LIG (laser induced graphene) Research + Small Auto-Drones Could be Better than Delivery Trucks + More …