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Nanostructured Paper Leads to Printable Ultracapacitors

Breakthroughs in creating printable ultracapacitors and batteries have been coming fast and furious in the last 18 months.

Perhaps the latest news on the pages of IEEE Spectrum that details how two companies are printing batteries and ultracapacitors is the most promising to date.

The spectrum article reports on a printed solid-state lithium battery developed by Planar Energy Devices that manages to replace the liquid electrolyte typically found in lithium-ion batteries with a ceramic electrolyte. The results are that it performs much better than traditional li-ion batteries, achieving 400 watt-hours of energy per kilogram and can last for tens of thousands recharge cycles.

While this is at least a factor of two better than traditional batteries, for electrical vehicles it still falls short of the 1000Wh/kg target that was suggested by Energy Secretary Steven Chu to be what is needed for a power source to replace fossil fuels in automobiles.

But if Tesla can make a buck selling sports cars with 6,831 lithium-ion batteries that weigh all together about 1500 lbs, surely a car company could do better with the lighter, cheaper to produce, greater energy density and longer life cycle of the batteries being offered by Planar.

The other company highlighted in the article is Paper Battery, which produces an ultracapacitor that uses a nanostructured paper as the separator between the electrodes in the ultraccapcitor. It looks as though initial applications will be in the areas of a medical diagnostic devices and thin film solar panels

If these two companies are any indication, we should expect things to start heating up in the printed battery and ultracapacitor space fairly soon.

Risk Assessment in Nanotechnology Is a Risky Business

In assessing the risks of nanomaterials to our environment, health and safety (EHS), regulators have faced what I consider the two main obstacles preventing them from sorting this out: how do you reevaluate risk assessment for the same material first in bulk and then in nanoscale form and how do you perform measurements when there is an acute lack of tools to test these materials in the environment and not just in some vacuum of a microscopy tool. 

It seems that regulators recognize these two main stumbling blocks as well as evidenced by a recent piece over at Nanowerk that analyzes a recent Nature Nanotechnology commentary piece (subscription required) authored by a number of international regulators that looks at the science policy considerations for responsible nanotechnology decisions.

As one might expect the government types urge industry to do more in sorting out not only the workplace risks of nanomaterials, but also the risks associated with the long-term life cycle of products that contain nanomaterials.

They can urge all they want, I suppose, but the companies making products are only going to determine whether the final product they sell to the public is dangerous.

If at some point in the future, computers make use of graphene or carbon nanotubes for their electronic components, manufacturers of that part of the computers will conduct the same life-cycle tests they did when using lead, barium and mercury in the computers.

Just so there is no mistake, I support every attempt to mitigate risks associated with any product that is sold to a generally uninformed consuming public. But I do wonder whether the turmoil over EHS concerns swirling around nanotechnology today—while we blithely go along with disposing “old-world” poisons into our environment—has more to do with highly sophisticated opposition groups digging their heels in earlier than with these other dangerous materials and less to do with the real risks of nanomaterials.

To give you a sense of where regulations can lead when led around by fear mongering I give you California. Nowhere in the US are the screeds of anti-industry taken more to heart than in California, and we already have a good indication of where those knee-jerk reactions are leading, such as California’s Office of Environmental Health Hazard Assessment (OEHHA) determination that “all nanomaterials will be considered hazardous.” 

With this kind of lazy regulating, let’s hope that John DiLoreto’s prediction is wrong that lacking national regulations statewide regulations will become the de facto law of the land.

Concept of Fuel Cells Powering Laptops Pops Up Again

Recently, I related the unceremonious disappearance of the fuel cell-powered laptop that was promised year after year at the beginning of this decade by NEC and just never materialized.

If my guess is right, I would say that NEC had little problems getting the thing to work, or else they wouldn’t have been so cavalier about announcing its introduction year after year, but they just could never sort out the market for the thing. And one look at a photo of the prototype gives you an indication of the problem.

Laptops were developed so people could travel with their computers. Traveling means going on airplanes. No one seemed to consider the problem of how you were supposed to get through airport security with a laptop computer that had a half-liter of methanol attached to it.

But this has not deterred researchers at Harvard University, who have continued perfecting a methane-powered laptop after determining the real problem with these fuel cell-powered laptops is reliability, temperature and cost. I did get a kick out of the headline for this one “Methane-powered laptops may be closer than you think.” Really? I am supposed to fall in line again on this one?

If I were the researchers, and I was really intent on seeing fuel cell-powered laptops on the market, I might contact someone at the Transportation Security Administration and ask them if the foresaw any difficulties getting through security with some methane in one’s laptop.

While you’re waiting for that answer, you could find ways of getting the things to operate at temperatures well below 500° Celsius and celebrate that you managed to develop electrodes for the fuel cells that don’t use platinum.

I welcome research in improving fuel cell technology, every breakthrough counts, but does that research need to be accompanied with application proposals that just don’t seem workable?

Nanochannels That Mimic the Channels of Transmembrane Proteins in Cells

Sometimes the aim of high technology is just to approximate what nature does. That certainly is the case with channels found in transmembrane proteins, which manage to allow the passage of ions or molecules but block larger objects. It has proven difficult to fabricate channels that duplicate the properties of these biological channels. That is until now.

Researchers at the Department of Energy’s (DOE) Lawrence Berkeley National Laboratory have developed a way to produce these channels that are only 2nm wide and do it with standard semiconductor manufacturing techniques. They also managed to ensure that the channels don’t collapse under the strong electrostatic forces of one of the semiconductor processes.

The two co-authors of the research Arun Majumdar, Director of DOE's Advanced Research Projects Agency -- Energy (ARPA-E), and Chuanhua Duan, a member of Majumdar's research group at the University of California (UC) Berkeley, initially published their work in the journal Nature Nanotechnology (subscription required) under the title "Anomalous ion transport in 2-nm hydrophilic nanochannels."

To fabricate the channels Majumdar and Duan used a technique that involved ion etching combined with an anodic bonding process. As alluded to earlier, the researchers were able to overcome the strong electrostatic forces of the anodic bonding process by using a thick oxide layer (500nm) that they deposited on the glass.

"This deposition step and the following bonding step guaranteed successful channel sealing without collapsing," says Duan.

One of the things that the researchers observed that was quite remarkable was how differently the 2nm wide channels behaved to those that were 10nm wide.

“We observed a much higher rate of proton and ionic mobility in our confined hydrated channels -- up to a fourfold increase over that in larger nanochannels (10-to-100 nm),” explains Majumdar in the Science Daily piece. “This enhanced proton transport could explain the high throughput of protons in transmembrane channels."

What I like about this story is that the early applications for this technology look to be in the area of improved batteries, especially the lithium-ion variety and fuel cells.

The researchers believe that ion transport could be improved by these 2nm channels because because of their geometrical confinements and high-surface-charge densities. In terms of batteries, by using these nanostructures as a separator between the cathode and anode in batteries they could prevent physical contact between the electrodes while allowing free ionic transport. 

"Current separators are mostly microporous layers consisting of either a polymeric membrane or non-woven fabric mat," Duan says. "An inorganic membrane embedded with an array of 2-nm hydrophilic nanochannels could be used to replace current separators and improve practical power and energy density."

 

 

The BBC Loves to Cover Nanotechnology

I have below a clip from an upcoming documentary that will air on BBC One in the UK under the title "How Science Changed Our World"  and is narrated by Professor Robert Winston, who is a Lord to you and me and has a background in fertility studies.

In the clip he visits the London Centre for Nanotechnology, which as I have said before I had the good fortune of getting a tour of myself.

The BBC seems to have taken quite an interest over the years on the prospects of nanotechnology and with varied success and failure, if you ask my opinion. The terribly pointless and exaggerated expose on grey goo within its Jan Hendrik Schön documentary back in 2005 would represent the nadir of their coverage of the subject.

I am hoping that the BBC’s affection for the subject of nanotech is accompanied with a bit more circumspection in its narration than in that instance. But I do have to wonder what Professor Mr. Winston means when he says in the clip, “That miniaturization means that chips like viruses are getting closer to us than we could have possibly imagined.” It sounds lovely but I have no idea what it might mean.

 

Is There a Future for Nano-Enabled Lithium Ion Batteries in Electric Vehicles?

We have seen recently some new breakthroughs in improving the lithium-ion (Li-ion) battery. These developments  combine the use of nanomaterials and nano-scale microscopy tools like the transmission electron microscope (TEM) to find ways of someday creating better Li-ion batteries.

Improvements to Li-ion batteries bodes well for powering small gadgets like our cell phones and MP3 players, but when it comes to powering electric cars the picture becomes a little different. By some accounts, Li-ion batteries’ energy density will only get about two times better than it is today, leaving one to ponder whether perfecting the Li-ion battery is time and money well spent in developing a way to power a vehicle that is competitive with the fossil-fuel-powered variety.

However, now it seems a lot of time and money is being invested in the hope that Li-ion battery technology will be the solution. According to Industry Week’s Nanopulse column last week, nano-enabled Li-ion batteries produced by companies like A123Systems are not only powering the electric vehicles of today but are also powering an economic recovery in the US as new plants are being built to capture back market share of Li-ion battery production from Asia.

Scott Rickert in his column provides some prices per kWh that show a dramatic drop in pricing fueled in large part by greater production than ever before. But price is really only one of the metrics that will determine whether Li-ion batteries can fuel an electric vehicle age. There is one other metric that I think supercedes all others and I like to describe it as the “will-it-work” metric.

According to that metric, barring any unforeseen development, Li-ion batteries are never going to get close to the 1000Wh/kg needed for batteries to compete with the internal combustion engine in powering vehicles. If they do improve to about twice that of where they are today, Li-ion battery will be maxed out at around 400Wh/kg.

Over at a publication called Alt Energy Stocks, they have a pretty alarming interpretation of a recent presentation given by Energy Secretary Steven Chu at the United Nations Climate Change Conference in Cancun. According to the article, penned by John Petersen, it seemed as though Secretary Chu was suggesting, at least tacitly, that “that lithium-ion batteries are a dead-end electric drive technology”. 

Petersen comes to this interpretation after hearing the following remarks that come about 25 minutes into the video above.

"And what would it take to be competitive? It will take a battery, first that can last for 15 years of deep discharges. You need about five as a minimum, but really six- or seven-times higher storage capacity and you need to bring the price down by about a factor of three. And then all of a sudden you have a comparably performing car; let's say a mid-sized car which has a comparable acceleration and a comparable range."

 ***

Now, how soon will that be? Well, we don't know, but the Department of Energy is supporting a number of very innovative approaches to batteries and its not like its 10 years off in the future, in my opinion. It might be five years off in the future. It's soon. Meanwhile the batteries, the ones we have now, will drop by a factor of two within a couple of years and they're gonna get better. But if you get to this point, then it just becomes something that's automatic and I think the public will really go for that."

While Secretary Chu is saying this, there was a slide showing what a rechargeable battery will need to be able to do to compete with fossil fuels:

"A rechargeable battery that can last for 5,000 deep discharges, 6-7 x higher storage capacity (3.6 Mj/kg = 1,000 Wh) at 3x lower price will be competitive with internal combustion engines (400 - 500 mile range)."

The Li-ion battery just does not look to be the solution to these requirements. And I am simply not swayed by the examples of the Chevy Volt  that can only manage about 40 miles before it starts using its gas tank, and it seems that estimates that the Tesla can go 200 miles without a recharge seem to be exaggerated for anyone that has watch the UK show Top Gear.

The point here is that Li-ion battery may be the solution for powering hand-held gadgets but we may need to look somewhere else if we want to get serious about replacing the internal combustion engine in our vehicles.

World's Smallest Battery with Anodes Built from a Single Nanowire

If I have a crusade on this blog, it is to see nanotechnology bring the battery up to snuff with all the high-tech gadgets they need to power.

I have covered how micrcoscopy tools are enabling us to pinpoint the reason batteries begin to fail. Recently I blogged on batteries that used nanowires to reduce their size down to that of a grain of salt.

The latest item I’ve come across in the way that nanotechnology is tackling the issue of improving the battery combines elements from the two blog entries I cited. The research claims to have produced the world’s smallest battery, which will help lead to better batteries in the future.

Researchers from Sandia National Laboratory have reported in the December 10th edition of Science of creating a battery so small that its anode consists of a single nanowire.

The lithium-based battery was created inside a transmission electron microscope (TEM) so we are not likely to see this battery powering your iPhone in the near future, but it does allow the researchers to see at an atomic scale resolution how batteries function to better understand their fundamental properties.

“What motivated our work," is that lithium ion batteries [LIB] have very important applications, but the low energy and power densities of current LIBs cannot meet the demand,” says Jianyu Huang. “To improve performance, we wanted to understand LIBs from the bottom up, and we thought in-situ TEM could bring new insights to the problem."

While nanomaterials are used in battery anodes, they are used in bulk rather than individually, a difference that Huang suggests makes it as difficult to observe their atomic structure as it would be to examine an individual tree among a forest.

The actual dimensions and parts of the battery consist “of a single tine oxide nanowire 100 nanometers in diameter and 10 micrometers long, a bulk lithium cobalt oxide cathode three millimeters long, and an ionic liquid electrolyte.”

One of the first unexpected  phenomena the researchers observed was that the oxide nanowire nearly doubles in length in during charging, significantly more than its diameter increases. While this observation runs counter to the prevailing belief that diameter rather than length increases, it also could help avoid short circuits that may shorten battery life.

This observation could be significant but perhaps more significant was that the researchers found a way to use a liquid (the electrolyte) in the vacuum of a TEM.

“The methodology that we developed should stimulate extensive real-time studies of the microscopic processes in batteries and lead to a more complete understanding of the mechanisms governing battery performance and reliability," he said. "Our experiments also lay a foundation for in-situ studies of electrochemical reactions, and will have broad impact in energy storage, corrosion, electrodeposition and general chemical synthesis research field."

Dip-Pen Lithography Applied to Graphene Devices

Whenever I consider the possibilities of dip-pen nanolithography (DPN), I always think of that Xerox commercial from the 1970s in which after toiling for incalculable hours of transcribing a text a monk presents his work to the chief monk who is impressed but asks for 500 more copies. 

Let’s face it, taking the tip of an Atomic Force Microscope (AFM) and dipping it into a sort of molecular ink and then drawing patterns on a substrate may be exact but it’s not exactly a fast process.

That understood, I was intrigued by recent work researchers at Stanford University were doing with DPN in creating graphene devices. To date, electron-beam lithography (EBL) has been used for constructing such devices.

The research, which was originally published in the journal ACS Nano, showed that an AFM could be used for creating graphene devices thereby replacing EBL techniques and eliminating some of the inherent problems of working with EBL such as exposing the graphene to electron irradiation.

"DPN has several advantages over EBL, such as no damage from electron irradiation and the ability to pattern nanostructures and image them using one system operating under ambient conditions," Maria Wang, the first author of the research, told Nanowerk. "We have demonstrated that dip-pen nanolithography can be used to create arbitrarily shaped graphene devices for nanoelectronics and identified the process steps that may affect their electrical characterization."

To address issues of scalability, which I facetiously referred to with Xerox commercial, Wang also points out that the DPN process could be done with multipen arrays, establishing a kind of parallel fabrication.

"Parallel fabrication of individual graphene devices using DPN could potentially result in higher yield and faster processing times than serial fabrication using EBL,” suggests Wang. “This increase in fabrication efficiency could potentially accelerate graphene research."

Public Engagement for National Nanotechnology Strategies Continues its Upswing

Over this past year I have become intrigued by the growing practice of the US government of opening up its strategy for nanotechnology development to public input.

In my most recent blog on this subject, the National Nanotechnology Initiative (NNI) used the month of November to collect suggestions from the public on its then current draft of its strategy.

One week now into December and I am not sure what input the NNI collected, but we do know that they have announced a new public engagement scheme this time focused on getting input on its Environmental, Health and Safety (EHS) Research Strategy.

It will be possible to contribute thoughts on the current draft of the EHS strategy from December 6th to January 6th. At least one noted expert on EHS on nanotech will be taking full advantage of this one-month window.

I think this most recent public engagement move by the NNI has changed my attitude about these initiatives from mere intrigue to begrudging respect. I mean you are not going to find a more contentious issue (and one with fewer easy solutions, if any) than determining the course of EHS research and the NNI has just said, “Let us have it.”

And have it they no doubt will. As Andrew Maynard has already pointed out in his 20/20 Science blog the NNI has already come under sharp criticism in the past for its EHS research strategy from one of its own government cousins, the National Academy of Sciences. 

Frankly, it’s pretty easy pickings to criticize the NNI, and anyone else you choose to target, for their less than coherent strategy on how to address EHS of nanomaterials.

You are essentially asking researchers—before they pick up their first microscope in anger—to develop a theoretical framework by which they can reinvent the periodic table. 

And then as soon as they pick up that microscope, they discover that they have few to no microscopy tools at their disposal to enable the research. 

But at least now we have one month of input from the public to sort this all out.

How to Make Graphene at Home for Fun

I came across the video below from the blog Frogheart and considering the recent Nobel Prize for Physics and the near daily reports on graphene within the pages of Spectrum alone, I thought it worth posting here.

The video provides a demonstration in a very rough way for how one could manage to isolate a single layer of graphite to create graphene.

The presenter, Dr. Jonathan Hare, manages to bring up the issue of the speed at which electrons travel through graphene to discuss relativistic quantum mechanics and Dirac particles and still manages to make it accessible for a general audience.

Nice piece of work and will lead me to check out the video’s producers Vega Science Trust for more material. 

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Nanoclast

IEEE Spectrum’s nanotechnology blog, featuring news and analysis about the development, applications, and future of science and technology at the nanoscale.

 
Editor
Dexter Johnson
Madrid, Spain
 
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Rachel Courtland
Associate Editor, IEEE Spectrum
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