Zinc air battery maker looks beyond lithium

Start-up ReVolt Technology is developing rechargeable zinc air batteries, a technology it says promises longer runtime for consumer electronics and plug-in vehicles.

The Switzerland-based company, which was spun out of a Norwegian research institute five years ago, anticipates commercializing a rechargeable coin-size batteries next year. But the technology has the potential to be a cheaper and more energy-dense alternative to lithium ion batteries in consumer electronics, grid storage, and transportation, according to CEO James McDougall.
Zinc air batteries, which are already used in hearing aids, create an electrical current through a chemical reaction between zinc and the oxygen in air. Researchers have pursued rechargeable zinc air batteries for many years because zinc is relatively abundant and the internal chemistry, safe.
But there remain some technical challenges. After multiple charge-discharge cycle, the anode in zinc air batteries can become damaged and stop working. McDougall said ReVolt is trying to reach between 500 and 2,000 charge cycles, depending on whether the battery is used for consumer electronics or large-scale storage.
ReVolt engineers are working on a new design in which a zinc slurry is pumped through tubes that act as an air electrode, causing the chemical reaction that produces a current, McDougall explained. He expects it will take four or five years to commercialize the technology for large-scale applications, such as grid storage. The company has raised 24 million Euros in funding, including an investment from power generator RWE of Germany, which is looking at the zinc air for storage on the electricity grid. ReVolt has applied for an ARPA-E grant aimed at breakthrough energy technologies but was not chosen in the first round of awards.
For vehicles, it makes sense to combine the relatively large energy storage of zinc air batteries with other storage technologies, McDougall said. Power-dense lithium ion batteries could be used for boosts of acceleration and ultracapacitors could capture energy from regenerative braking. "You could increase the range of next-generation of electric vehicles with hybrid storage... You could get three times the range, eliminate the safety concerns, and cut the cost of the system," he said.

Empire State Building strikes back...against pollution

What was once the world's tallest skyscraper now aims to be the greenest.

(Credit: Rocky Mountain Institute)New York's iconic Empire State Building, which played a starring role in the movie "King Kong," is set to undergo a retrofit that could cut the 102-story building's energy consumption by up to 38 percent. The energy-saving measures will initially cost approximately $20 million and will take an estimated two years to implement, according to press materials.

The program includes upgrades of the 1931 Art Deco building's 6,500 windows, radiator insulation, a new air-conditioning and heating system, air handler replacements, energy-efficient lighting, upgraded ventilation control, and an Internet-based system for tenants to monitor their energy use (that also teaches them how to conserve energy.)

"By pursuing these strategies, owners can save millions of dollars and enhance asset values while significantly reducing greenhouse gas emissions," said Raymond Quartararo, a director at Jones Lang LaSalle, a real estate consultancy that's helping manage the retrofit. "That's a win-win for owners, tenants and the global environment," he added, according to a press release.

Other organizations involved in the greening of the Empire State Building include the Rocky Mountain Institute and the Clinton Climate Initiative, which has been working with cities on projects to save energy and reducing carbon dioxide emissions in buildings.

In both the U.S. and EU, buildings--both commercial and residential--are the largest consumers of energy, accounting for 40 percent of the total energy consumption in both locations, according to sources including the Energy Information Administration. And in big cities, buildings are dominating the environmental footprint. For instance, buildings are responsible for 79 percent of all carbon emissions in New York City.

Project leaders hope the Empire State Building retrofit will result in an estimated annual energy savings of $4.4 million and could reduce carbon dioxide emissions by 105,000 metric tons over the next 15 years. That's equivalent to the annual emissions of 17,500 cars.

"If we can show that in a building like this that it makes money for the owner, and it makes money for the tenants, its pretty hard for anybody to ignore it," said James Russell, of the Clinton Climate Initiative, in anYouTube video. "It is a fantastic global flagship example for others to copy."

BART signs up for 20 years of Wi-Fi

BART, the San Francisco Bay Area's commuter railway, plans to offer Wi-Fi access on all trains and at all stations by 2011, the San Francisco Chronicle reported Saturday.

The 20-year deal, signed Friday with start-up Wi-Fi Rail, is set to bring high-speed wireless access to BART's 104 miles of track and 43 stations. The network is based on a "huge fiber-optic backbone," according to Wi-Fi Rail.

BART, short for Bay Area Rapid Transit, has been testing the service for about a year in underground sections in San Francisco and on about two miles of open track in Hayward. More than 16,000 people signed up for the pilot service, which has been free, the Chronicle said. Wi-Fi Rail plans to charge $30 per month once the service is fully installed. Other subscription plans, based on hourly, daily, or annual use, will also be available.

According to Wi-Fi Rail, tests on trains running at more than 81 mph "have consistently demonstrated upload and download speeds in excess of 15Mbps."

The company, founded in 2005, is based in the Sacramento area.

Clear Carbon-Nanotube Films

Special sheets for bendable displays and solar cells will soon hit the market.

The first electronic product using carbon nanotubes is slated to hit the market this year. Unidym, a startup based in Menlo Park, CA, plans to start selling rolls of its carbon-nanotube-coated plastic films in the second half of 2009.

The transparent, conductive films could make manufacturing LCD screens faster and cheaper. They could enhance the life of touch panels used in ATM screens and supermarket kiosks. They might also pave the way for flexible thin-film solar cells and bright, roll-up color displays. The displays could be used in cell phones, billboards, and electronic books and magazines.

In all of these applications, the nanotube sheets would replace the indium tin oxide (ITO) coatings that are currently used as transparent electrodes. ITO cracks easily and is a more expensive material. "The cost of indium has gone up by 100 times in the last 10 years," says Peter Harrop, chairman of IDTechEx, a research and consulting firm based in Cambridge, U.K.

Sean Olson, vice president of business development at Unidym, says that touch panels--which are particularly susceptible to the brittleness of ITO--will be the first market that the company will target. He says that Unidym is already working with leading touch-panel makers.

Many display manufacturers are working on products using the new films. In October, Samsung demonstrated the first prototype of a 14.3-inch color electronic paper device made with the films. Earlier last year, at the Society for Information Display symposium, Unidym demonstrated a color LCD prototype in collaboration with Silicon Display Technology, based in Seoul, Korea. Unidym is also working with Japanese chemical company Nippon Kayaku to make thin-film solar cells.

Using nanotube films instead of ITO coatings would bring multiple advantages to display manufacturers. Carbon is a cheap, abundant material. Carbon nanotubes are stronger and more flexible than ITO. Most important, the nanotube films are easier to deposit on plastic and glass substrates.

"The big benefit LCD guys are looking at is not materials cost," Olson says. "It's going from ITO, which [requires] vacuum deposition, to something that is more easily coated." That would increase the company's yields and bring down production costs.

The new film is a tangled mat of carbon nanotubes on plastic. Unidym's method to manufacture nanotubes is a key technology breakthrough. Electronic products with carbon nanotubes have been kept at bay mainly because of the difficulty in making pure batches of high-performance conducting nanotubes at reasonable cost. Batches of the material contain tubes that are both conducting and semiconducting. Nanotubes' properties also depend on other factors, such as length, diameter, and the number of walls that they have.

Unidym uses a chemical vapor deposition method to grow the material. A mixture of carbon-containing gas and a metal-catalyst-coated substrate is heated at a high temperature. The carbon atoms from the gas attach to the substrate and form nanotubes. Then the company uses purification processes, including oxidation and acid treatment, to remove unwanted nanotubes and contaminants, such as other forms of carbon.

Unidym has also patented a process to disperse the nanotubes in a liquid. It uses a roll-to-roll technique akin to printing on paper to deposit the nanotube ink on plastic. The company can print at speeds up to 50 meters a minute. Olson won't divulge any more information but says that the company has "optimized these techniques to get the best transparent, conductive film performance."

At least one other ITO replacement is already being sold. Fujitsu is using a transparent, conducting organic polymer to make touch screens. However, the polymer degrades over time when exposed to heat or light, and its conductivity is not high enough for use in LCDs or electronic-paper displays.

Other potential ITO replacements are currently being worked on in various labs. Many research groups are making advances with the carbon material graphene. University of Michigan electrical-engineering and computer-science professor L. Jay Guo has made grids of extremely thin metal wires. He says that these would be more suitable than carbon nanotubes for making electrodes on thin-film solar cells because they would enhance light absorption. "Think of it as concentrating incoming sunlight energy into a very thin layer," Guo says.

But Unidym's carbon-nanotube films could be the first viable ITO replacement for touch screens, flexible displays, and thin-film solar cells. Unidym is also developing printable thin-film transistors and fuel-cell electrodes using carbon nanotubes.

Seven things you may not know about Windows 7

While Windows 7 has gotten plenty of attention over the past two weeks, there are some features in there that haven't gotten as much attention. I wrote on Friday about a new programming interface for location-based services. Here are seven more features that caught my eye.
1. Standard approach to mobile broadbandWindows 7 treats cellular modems as a standard connection, much like a Wi-Fi network, popping them up in the same available wireless networks dialog.
Sierra Wireless has already said it will support the new approach, which should make life much easier for road warriors (myself included). One of my few gripes about the prebeta Windows 7 laptop I'm using is that it doesn't recognize my relatively new USB Sprint modem.
2. Help with public Wi-Fi spots.This was a little feature I discovered on my own. With many public Wi-Fi hot spots, once you connect to the network, you have to do something in your browser, such as agree to certain terms or enter a password. Windows 7 pops up a notification that tells you that, although you have to be connected to the network, more action may be needed and it gives you a direct link to open your browser.
3. Windows TroubleshootingSure, it would be better if your computer worked problem-free. But, acknowledging that's not the case, Microsoft has added a central place in Windows 7 to try to figure out what went wrong and why.
Among the kinds of problems that Windows Troubleshooting aims to help solve are issues with networked printers, detecting hard drive problems, and even some proactive things, like figuring out how much life a laptop battery has before it will likely need to be replaced with a new battery.
4. New sensor supportWindows 7 adds base-level support for all kinds of sensors, from GPS, to fingerprint readers, to ambient light sensors, to accelerometers. Light sensors, for example, can now be used not only to light up a keyboard, but an application could sense daylight and make type larger so that it's easier to read.
At WinHEC, Microsoft handed out 700 free sensor developer kits that included a light sensor, touch pad, and accelerometer. The kit was a big hit with the developers, prompting one of the only long lines of the show.
5. Improved battery life and playback of DVDsMicrosoft is trying to do a couple things to make the DVD-playing experience better in Windows 7.
First and foremost, it has changed things so that DVD movies just start playing, as opposed to bringing up a long list of options.
Second, the company has worked to adjust power settings while playing back movies to enable better battery life.
"I'm hopeful it will have battery life equivalent to a portable DVD player," Microsoft's Jon DeVaan said in an interview. The issue is personal, he said. If Microsoft can reach its goal, he might be able to only bring a laptop on outings. "I hope to spare my back on family trips," he said.
6. Windows Biometric FrameworkAccording to a press release from fingerprint sensor make AuthenTec, the operating system features improved biometric support that should enable a more standard way for fingerprint management applications to work with fingerprint readers in Windows 7.
"This provides ease of fingerprint sensor integration for PC manufacturers and a more consistent user experience," AuthenTec said in its release.
7. Enhancements to Windows Media CenterMicrosoft hasn't given up on its dream of having Windows gain a prominent spot in the living room and its main effort in this area--Windows Media Center--is back in Windows 7.
BetaNews has a look at some of the new features, including support for H.264 video, an on-screen keyboard, and better method of scrolling through large libraries.

Longer-Lasting Batteries for Laptops

New materials improve the reliability, safety, and storage capacity of lithium-ion batteries.

Conventional lithium-ion batteries in laptops and cell phones quickly lose their ability to store energy and can catch fire if they're overcharged or damaged. Now researchers at Argonne National Laboratory in Argonne, IL, have developed composite battery materials that can make such batteries both safer and longer lived, while increasing their capacity to store energy by 30 percent.
Last month, the researchers took a significant step toward commercializing the technology by licensing it to a major materials supply company, Toda Kogyo, based in Japan. The company has the capacity to make the materials for about 30 million laptop batteries a year, says Gary Henriksen, who manages electrochemical storage research at Argonne.
The new materials are one example of a new generation of lithium-ion electrode chemistries that address the shortcomings of conventional lithium-ion batteries. Each has its own trade-offs. For example, another material called lithium iron phosphate has better safety and durability than Argonne's materials, but it stores somewhat less energy than conventional lithium-ion batteries. Argonne's materials improve on the safety and reliability of today's laptop batteries, while also storing more energy.
The Argonne researchers have improved the performance of the positive electrodes by increasing the chemical and structural stability of the materials already used in laptop batteries. In conventional lithium-ion batteries, which have cobalt oxide electrodes, a small amount of overheating, caused by overcharging the material or by electrical shorts inside a battery, can lead to rapidly increasing temperatures inside the cell and, in some cases, combustion. That's because, as the material overheats, the cobalt oxide readily gives up oxygen, which reacts with the solvent in the battery's electrolyte and generates more heat, feeding the reactions. The Argonne researchers addressed this problem by replacing some of the cobalt oxide with manganese oxide, which is chemically more stable.
The researchers' next step was to replace some of the active metal oxide materials in the electrode with a related but electrochemically inactive material, forming a composite. This material does not store energy, because it does not release and take up lithium ions as the battery is charged and discharged. (Lithium-ion batteries create electrical current as lithium ions shuttle between positive and negative electrodes.) The inactive material makes the composite more stable than conventional electrode materials, which means it can last longer. One version of the material can last for 1,500 charges and discharges without losing much capacity, he says. That's more than double the life of conventional laptop batteries.

What's more, reducing the amount of active, energy-storing material has the counterintuitive effect of increasing the composite's storage capacity. If too much lithium is removed from conventional cobalt oxide materials, the material degrades and quickly loses its ability to fully charge and discharge. The inactive material makes it possible to use much more of the lithium without damaging the material.
The electrode material can store 45 percent to 50 percent more energy than the best electrodes in laptop batteries. In terms of an entire battery cell--given that the positive electrode represents less than half of the total weight and volume of a battery cell--the total energy storage of the battery can be improved by 20 percent to 30 percent, Henriksen says.
The researchers' next step is improving the rate at which the composite material can be charged and discharged so that it can be used in hybrid vehicles. As it's made now, the Argonne material can be completely discharged in about three hours--fast enough for laptops but far too slow for a car. Discharging rates will need to be at least three times faster, and likely more, for the technology to work in plug-in hybrids, vehicles in which the battery can be recharged from a conventional electrical outlet.

More Biofuels Woes

The projection that U.S. farmers will grow less corn this year is bad news for ethanol producers.

That strong wind you might have felt earlier this week was just more air rushing out of the biofuel bubble. Monday's statistics from the U.S. Department of Agriculture--that farmers expect to plant 8 percent fewer acres of corn in 2008, compared with 2007--is very bad news for the already struggling ethanol industry. It takes a lot of corn to make ethanol, and the feedstock is a major cost of creating the biofuel. U.S. farmers' plan to plant less corn this year means that record-high corn prices, which are already above $5 a bushel, will likely stay high. It doesn't take an economist to figure out what the grim numbers portend for ethanol manufacturers. Higher feedstock costs, at the same time that yet more ethanol production capacity is coming online, could mean another very tough year for the ethanol market.
Beyond being a pain for ethanol producers, the high corn prices will further exasperate the tensions between using the crop for fuel rather than for food. In a New York Times article, one expert issues a frightening warning:
"We're hoping for good yields," said David Orden, a senior research fellow at the International Food Policy Research Institute in Washington. "If we get bad yields and tight commodity markets are pushed even tighter, we'll get food prices skyrocketing, inflationary pressures and food riots in developing countries, and countries cutting off their exports."
No one knows, of course, whether it will be a good year or not for growing corn in the United States. If it is a bad year, look for even more criticism of ethanol biofuel and, in particular, the Renewable Fuel Standards that mandate that petroleum suppliers use nine billion gallons of ethanol this year. But even if it's a good year for growing corn, expect the poor profit margins for ethanol producers to continue and more grumbling about the economics of biofuels.