Gregoire's CleanTech Blog

Novel Batteries Get a Boost

General Motors has announced it will work directly with A123 Systems, a start-up based in Watertown, MA, to develop batteries that are fine-tuned for the Chevrolet Volt, an electric vehicle scheduled for production in 2010 or 2011. The new agreement between the companies is designed to speed the vehicle to market.

The co-development deal is the latest in a series of announcements by the automaker indicating it is moving forward with plans for the Volt, an extremely fuel efficient hybrid. The Volt, first announced in January, will use batteries that can be recharged from a standard electrical outlet and is expected to get 40 miles on a single charge, eliminating trips to the gas station for average daily driving. While GM has not ruled out using batteries from another supplier, the agreement is a vote of confidence that A123's technology can meet the requirements for the vehicle, says Denise Gray, GM's director of hybrid energy storage devices.

A123 uses a new lithium-ion chemistry that allows its batteries to be much lighter and more compact than the nickel metal hydride batteries in existing hybrids today, and safer than the conventional lithium ion batteries found in consumer electronics. In June GM announced that it is working with the South Korean company LG Chem, and its subsidiary Compact Power, based in Troy, MI, to make both battery packs and the individual cells inside them. They also signed an agreement with an LG Chem competitor, the Frankfurt, Germany-based Continental Automotive Systems, to develop battery packs. Continental had planned to use A123 as a subcontractor to supply the batteries for these packs. The new agreement puts A123 in direct contact with GM on the Volt project.

At the end of 2005, A123 announced its first product, a cylindrical battery for power tools. For the Volt, A123 is shifting to a much bigger and flat, rather than cylindrical, battery cell that takes up significantly less space. Hundreds of these would be combined in a large pack, with control electronics and a cooling system, to power the Volt.

A123 employees have begun testing the new cell. In one test, a prototype cell, a silvery slab about the size of three decks of cards placed side by side, was crushed from the side to demonstrate its abuse tolerance. Unlike conventional lithium-ion batteries, which use a cobalt-oxide material that can overheat and cause laptops and cell phones to burst into flame, A123's batteries use a much more stable, and potentially cheaper, iron phosphate material. The crushed test battery showed no signs of overheating.

Earlier this year GM had picked A123 Systems as a potential supplier of lithium-ion batteries for a new version of its Saturn Vue hybrid that can be recharged by plugging it in, giving it a 10 mile all-electric range. It could be on the roads as early as 2009.

But the battery requirements for the Volt are much more challenging, requiring the different cell design. Whereas in the Vue power from the battery will be supplemented with power from a gasoline engine, the Volt will rely on batteries full-time. For the first 40 miles of driving, the battery will deliver power from being plugged in overnight. After that, the battery will continue to power the vehicle as it is recharged by an on-board gasoline-powered generator.

The new batteries must pack more energy into a smaller space, the reason for the flat design. But they also need to be fine-tuned for the power demands of the Volt. To do this, engineers can subtly alter the electrode chemistry, thickness, the type of electrolyte, and other aspects of the battery cell design. The collaboration with GM will give A123 direct access to more lab space and testing equipment that could allow A123 to more quickly sort through many subtle variations on the cell design, says David Vieau, A123's CEO. "You never get enough test capacity for all of the different variations you'd like to be able to consider," says Vieau. "We hope this [agreement] will accelerate the process."

Gray says GM hopes to have the batteries in packs within the next couple of months and to have these packs in a generic vehicle platform for testing by the end of the year. The technology could be in a prototype Volt sometime next spring, she says. GM's goal of a production model by 2010 or 2011, Gray says, is an "aggressive target." But the tests they've done so far since announcing the project in January have been encouraging. "We've got no information back that says uh-oh we can't do this," Gray says.

The Volt is going to be about the size of a Chevrolet Cobalt, which currently costs between $14,000 and $20,000 depending on the configuration. Rob Peterson, a GM spokesperson, says GM won't "price themselves out of that class" of vehicles with the Volt. He adds that if GM intended the vehicle to have a hefty premium, it would have made the vehicle a Cadillac. "It was a conscious decision to make it a Chevy," he says.

The agreement with GM does not mean that A123 will be locked out of doing work with other automakers. The specific cell the two companies develop together will be co-owned--so both companies will have to negotiate for how it might be used, Gray says. That could include putting the pack in cars by other companies, Gray says, since "it's in everyone's interest to achieve economies of scale to drive down battery prices." A123 still retains control over its novel battery chemistry, however. Indeed A123 has had discussions with other automakers and its batteries are set to be used in hybrid buses starting in 2008.

Flexible batteries that never need to be recharged

Mobiles phones, remote controls, and other gadgets are generally convenient--that is, until their batteries go dead. For many consumers, having to routinely recharge or replace batteries remains the weakest link in portable electronics. To solve the problem, a group of European researchers say they've found a way to combine a thin-film organic solar cell with a new type of polymer battery, giving it the capability of recharging itself when exposed to natural or indoor light.

It's not only ultraslim, but also flexible enough to integrate with a wide range of low-wattage electronic devices, including flat but bendable objects like a smart card and, potentially, mobile phones with curves. The results of the research, part of the three-year, five-country European Polymer Solar Battery project, were recently published online in the journal Solar Energy.

"It's the first time that a device combining energy creation and storage shows [such] tremendous properties," says Gilles Dennler, a coauthor of the paper and a researcher at solar startup Konarka Technologies, based in Lowell, MA. Prior to joining Konarka, Dennler was a professor at the Linz Institute for Organic Solar Cells at Johannes Kepler University, in Austria. "The potential for this type of product is large, given [that] there is a growing demand for portable self-rechargeable power supplies."

Prototypes of the solar battery weigh as little as two grams and are less than one millimeter thick. "The device is meant to ensure that the battery is always charged with optimum voltage, independently of the light intensity seen by the solar cell," according to the paper. Dennler says that a single cell delivers about 0.6 volts. By shaping a module with strips connected in series, "one can add on voltages to fit the requirements of the device."

The organic solar cell used in the prototype is the same technology being developed by Konarka. (See "Solar-Cell Rollout.") It's based on a mix of electrically conducting polymers and fullerenes. The cells can be cut or produced in special shapes and can be printed on a roll-to-roll machine at low temperature, offering the potential of low-cost, high-volume production.

To preserve the life of the cells, which are vulnerable to photodegradation after only a few hours of air exposure, the researchers encapsulated them inside a flexible gas barrier. This extended their life for about 3,000 hours. Project coordinator Denis Fichou, head of the Laboratory of Organic Nanostructures and Semiconductors, near Paris, says that the second important achievement of the European project was the incorporation into the device of an extremely thin and highly flexible lithium-polymer battery developed by German company VARTA-Microbattery, a partner in the research consortium. VARTA's batteries can be as thin as 0.1 millimeter and recharged more than 1,000 times, and they have a relatively high energy density. Already on the market, the battery is being used in Apple's new iPod nano.

Dennler says that the maturity of the battery and the imminent commercial release of Konarka-style organic solar cells mean that the kind of solar-battery device designed in the project could be available as early as next year, although achieving higher performance would be an ongoing pursuit.

The paper's coauthor Toby Meyer, cofounder of Swiss-based Solaronix, says that the prototypes worked well enough under low-light conditions, such as indoor window light, to be considered as a power source for some mobile phones. Artificial light, on the other hand, may impose limitations. "Office light is probably too weak to generate enough power for the given solar-cell surface available on the phone," he says.

Watches, toys, RFID tags, smart cards, remote controls, and a variety of sensors are among the more likely applications, although the opportunity in the area of digital cameras, PDAs, and mobile phones will likely continue to drive research. "The feasibility of a polymer solar battery has been proven," the paper concludes.

Source : Technology Review

Plug-In Hybrids car : when A123 Systems' CEO makes his show with G. Bush

Plug-in hybrid vehicles, which can be recharged using a standard wall outlet, are becoming increasingly practical because of advances in battery technology. And now the technology is also gaining support in Washington, with the promise that it could soon receive the type of federal tax incentives that have helped fuel the sales of conventional hybrid vehicles over the past several years.

Like conventional hybrid vehicles, plug-in hybrids can run on gasoline and electricity. But plug-in hybrids have bigger battery packs that can be easily recharged. As a result, they can run longer on electric power, saving much more gas than an ordinary hybrid can. Depending on the configuration of the vehicle, people who drive less than 40 miles a day could use no gasoline at all, while the average U.S. driver could see fuel economy of 150 miles per gallon. Although the vehicles consume electricity, the power will come at a fraction of the cost of gasoline, and it promises to reduce greenhouse-gas emissions.

Although no major automaker currently sells a plug-in hybrid, a handful of companies provide aftermarket conversion kits. Indeed, at the White House last Friday, President Bush viewed one example of a Toyota Prius, a conventional hybrid car, that had been converted into a plug-in hybrid using a battery pack that fits in the car's spare-tire compartment.

President Bush called the plug-in hybrid and an all-electric-powered pickup "living proof" that his ambitious goal of reducing gasoline consumption by 20 percent in 10 years is possible. He also renewed his request for research money for alternative energies. The administration's proposed fiscal-year 2008 budget, which was released February 5, includes $41.8 million for battery- and energy-storage research and development.

Interest in plug-in cars extends to Congress. In January, a bill was proposed in the Senate that would provide an up to $4,200 tax credit to offset the expense of plug-in hybrids, which can cost about $10,000 more than a conventional hybrid.

At the White House event, David Vieau, CEO of A123 Systems, a startup based in Watertown, MA, whose batteries are used in the plug-in hybrid, proposed to President Bush that the government offer $2 to $3 billion in tax incentives over the next seven years and provide $300 to $400 million in research dollars over the next few years. Such incentives, Vieau said, could help plug-in hybrid conversions grow from a few hundred now to thousands later, starting in as soon as 12 months.

Deron Lovaas, who heads the vehicle campaign at the National Resources Defense Council, says that several such tax-incentive bills will likely be submitted this year. "There are sure to be others, because there's a lot of enthusiasm about this in D.C. right now," he says.

Lovaas says that tax credits could have a significant impact on plug-in hybrid sales. He cites the success of tax credits for conventional hybrids, whose sales have doubled every year since 2001. (See a summary of current tax credits here.)

Automakers have recently expressed increased interest in developing plug-in hybrids. Late last year, General Motors (GM) announced an upcoming plug-in version of its Saturn Vue. (See "GM's Plug-In Hybrid.") A123 Systems announced an agreement with GM to help develop a prototype battery pack for the Vue. The packs are scheduled to be ready for testing in vehicles by the end of the year. In January, GM also revealed its Volt concept car. The vehicle takes plug-in hybrids a step further by using an all-electric drive train. The battery pack can be recharged by an onboard gas-powered generator or by plugging it into the wall. (See "Powering GM's Electric Vehicles.")

A study released last week suggests that over time, plug-in hybrids could cut overall vehicle emissions of carbon dioxide in half, while saving owners about $450 a year in fuel costs. According to a press release announcing the study, which was done by the National Renewable Energy Laboratory, in Golden, CO, and the utility company Xcel Energy, based in Minneapolis, although plug-in hybrids would draw power from the electricity grid, they would not necessarily increase the need for electrical infrastructure. That's because they could be recharged at night when much of the capacity of power plants isn't being used. Another study, by the Pacific Northwest National Laboratory, also suggests that plug-in hybrids could be charged using existing power plants, at least in most of the country. (See "How Plug-In Hybrids Will Save the Grid.")

Source : Technology Review

Batteries versus ultracapacitors : just to keep in mind

 

Could Solvent-Free Manufacturing Technology Help Make Lithium Polymer Batteries a Reality?

Could Solvent-Free Manufacturing Technology Help Make Lithium Polymer Batteries a Reality?: "I had a chance to chat with Dr. Klaus Brandt, EVP of Lithium Technology Corporation (Ticker symbol LTHU.PK). LTC has been in the business of Lion battery development for over 10 years. They are focused on large energy content / high power applications, primarily using lithium polymer technologies.

The Company was formed 4 years ago through a merger of a German battery startup called and LTC. Dr. Brandt is the Executive Vice President of LTC and Managing Director of their GAIA GmbH subsidiary, joining GAIA in April, 2005. A 25 year battery industry veteran, Gaia is his 5th battery company. He previously worked for Duracell (US) and VARTA (Germany), Moli Energy & Ionity. He holds a PhD, Physics from Tech Inst of Munich.

They haven’t disclosed much on their customers, but are focused on the military markets (especially for unmanned vehicles, like UAVs, they have one announced participation with Phoenix), and in niche industrial markets like robotics. The holy grail opportunity, of course is the EV, HEV and Plug-in hybrid automotive markets, where LiOn technology has an opportunity to displace NiMh, if it can drive costs down far enough. So far LTC has been working on early demonstrator projects in this area, but doesn’t appear to have hit the big one yet.

A quote from a recent press release on some of LTC’s activities in the plug-in hybrid sector.

'LTC has powered a project in conjunction with Innosys Engineering in which a four passenger Daihatsu Cuore was converted into an electric car using the lithium-ion batteries and a three-phase asynchronous electric motor. The battery, built with cells manufactured by LTC subsidiary GAIA, has a capacity of 25 kWh and an approximate highway range of 180-200km (100-125 miles) at 90-100km/hr (56-60 mph). These results are similar to the expected performance of the recently announced Volt slated to be made available by General Motors in 2010. 'The technology is here today. LTC has it, and we've demonstrated it,' says Dr. Brandt. 'Price is the biggest factor holding back the production of these more environmentally friendly, fuel efficient vehicles. By committing to work together, the auto manufactures and battery companies can bring the cost down and make cars like the Volt an affordable reality for the consumer.' LTC's technology was recently highlighted in a video produced by Plug-In Partners, a national grass-roots initiative to demonstrate to automakers that a market for flexible-fuel PHEVs exists today. The full video discussing the economic and environmental benefits of PHEVs can be viewed on the Plug-In Partners website.

The piece featured a project in which LTC provided cells to the University of California, Davis Hybrid Electric Vehicle Group for the conversion of a Chevy Equinox to a PHEV as part of the Challenge X: Crossover to Sustainable Mobility engineering competition. The lithium-ion battery has the same capacity as the original metal hydride battery but with half the weight. The battery can be charged by either the internal combustion engine (ICE) or a standard AC household electrical socket and can drive over 40 miles on the overnight electrical charge. The converted vehicle has a fuel economy of 36 mpg in the city, and 38 mpg on the highway, as compared to the original Chevy Equinox range of 19 mpg city and 25 mpg highway.’

As a result of the merger with Gaia, Arch Hill Ventures, NV, the venture capital firm behind Gaia, now has a dominant stake in the company. I couldn’t find much information on Arch easily available, though.

The company trades over the counter in the US, and has struggled financially (revenues are around $2 mm/year), and it loses money, and the stock price for the last several years has reflected this. Of course, it doesn’t help that the company doesn’t seem to have filed a 10-K or 10-Q since May of 2006. In December the company earned a reprieve raised $3 mm in a Series C Preferred Stock at a valuation on the order of $23 mm, and converted about $2.4 mm in debt.

In Germany the company is manufacturing cylindrical cells, and packaging them into batteries, and doing some prod development, along with EU sales. In the US Dr. Bradnt says they do a limited production of flat cells, the US sales and marketing, as well engineering and assembly of batteries for American customers.

But aside from all that, I asked Dr. Brandt to give me a summary walk through of the technology, what makes it neat, and what the cost and performance advantages are.

The brief from their website:

‘LTC's unique technology allows for the production of very large cells with a high capacity and high power capability.

LTC's wholly owed affiliate GAIA Akkumulatorenwerke in Nordhausen, Germany employs a unique patented extrusion process for producing electrodes for lithium ion cells. This process is environmentally friendly (no solvent) and eliminates the need for expensive explosion proof coating and solvent recovery equipment. Using high speed winding and a unique assembly technology, large cylindrical cells are manufactured. In our Plymouth Meeting facility, we have the capability to build large footprint flat cells and stack them to form large batteries. Our proprietary technology includes critical composition, processing, and packaging aspects of the battery. Our coating, lamination and extrusion know-how enables us to achieve uniformity and consistency through a range of application techniques. Batteries for the consumer, transportation, and industrial markets require different electro-chemical systems that we believe can be easily accommodated by our extrusion process.’

According to my conversation with Dr. Brandt, LTC has two core technologies. The first is this extrusion process for a part of the cell manufacturing for either LiOn or Lithium Polymer batteries. The uniqueness is a way to avoid the use of large amounts of solvents in the process of manufacturing electrodes from electrode powders.

Normally, you make electrodes by a coating process. Taking electrode powders and mixing them in an organic solvent with has a binder and any additives dissolved in it. This results in a fairly viscous slurry with typically more than half organic solvents . Then battery manufacturers typically use a coating process (usually a printing type roller process or some sort of foil through narrow slit, controlling deposition quality mechanically) to coat the slurry onto a current collector, usually a thin metal foil, and in a post process step heat the electrode to evaporate the solvent, which by volume is often greater than the active material.
Typically the make-up of the solvents used is key intellectual property for the battery manufacturer, but most are highly volatile and toxic chemicals, and need to be recycled in some sort of a closed loop system that is generally equipment and energy intensive (read costly, and not very green).

The LTC process is different. LTC runs an extrusion process as follows – make the electrode powders into mixture of powder materials directly with a special polymer binder, which flows under some pressure and temperature, and extrude the mixture into a film sheet. The process runs in the range from 200-300F up to 350-400F, and uses off the shelf plastic extrusion equipment. As second step, LTC then laminates the film to the foil. The lamination allows good control of all kinds of properties. The whole thing is roughly similar to low temperature polymer membrane construction process.

The trick is the mix of the polymers. If mix isn’t right you can’t keep mechanical consistency or can’t control thickness of the film and uniform distribution of the components. The polymer mix also affects the binding properties.

They claim the process does not really affect the cell manufacturing or the electrolyte relative to other processes. And Dr. Brandt says it has applicability for lithium ion as well as lithium polymer.

The advantage - no solvent extraction, cleaning, and recycling process equipment, and reduced energy use. Basically a more efficient, greener, cleaner process. LTC estimates their process can reduce a cost structure on the order of 5-10% improvement over conventional technology, a big improvement in battery manufacturing techniques.

The main challenges are those similar to all lithium ion and lithium polymer battery manufacturers. In the area of automotive and HEVs, they need to address cost. Scale of production is obviously a main cost down concern for LTC at this point, but materials costs are a close second. Like all lithium polymer technologies, the materials in general are still quite high.

On the performance side, Dr. Brandt walked through another interesting technology development.

They are able to build relatively large systems at a similar power density and power rate to smaller systems compared to other manufacturers, especially useful in areas like submarine and UAV batteries.

They also get high power and excellent charge/discharge rates – on some cell types up to 80% of the energy in 2 - 3 minutes.

The trick here is LTC’s technology to manage the thermal issues in the way they make the electrical connections between electrodes and terminals in the wound cells. LTC essentially makes electrical connections at every turn of a wound cell, directly connecting each cell to the terminal, using massive (relatively) terminals. They do it with a special trick they have developed to easily allow a large number of the multiple connections.

All in all, a fascinating story. One I will have to follow closely and see how well the company pulls through its recent financial straits.

(Via Cleantech blog.)

AeroVironment IPO - Technology Developer Makes Good in Market

Aerovironment, Inc. (Nasdaq:AVAV) priced its $114 mm IPO this week, with Goldman Sachs as the lead underwriter. Shares popped up 54%.

From the prospectus 'We design, develop, produce and support a technologically-advanced portfolio of small unmanned aircraft systems that we supply primarily to organizations within the U.S. Department of Defense, and fast charge systems for electric industrial vehicle batteries that we supply to commercial customers.'

I have always liked this company. Basically it's an R&D company in power controls and aviation that has built its R&D practice into a provider of next generation solutions of UAVs to the US military.

On their small UAVs:

'Our small UAS are well positioned to support the transformational strategy of the U.S. Department of Defense, or DoD, the purpose of which is to convert the military into a smaller, more agile force that operates through a network of observation, communication and precision targeting technologies, and its efforts to prosecute the global war on terror, which have increased the need for real-time, visual information in new operational environments. . . .

We designed all of our small UAS to be man-portable, launchable by one person and operated through a hand-held control unit. Our small UAS are electrically powered, configured to carry electro-optical or infrared sensors, provide real-time situational awareness and intelligence, fly quietly at speeds reaching 50 miles per hour and travel up to 20 miles from their launch location on a modular, replaceable battery pack. These characteristics make them well suited for reconnaissance, surveillance, target acquisition and battle damage assessment operations. '

On their battery charger products:

'Our PosiCharge products and services are designed to improve productivity and safety for operators of electric industrial vehicles, such as forklifts and airport ground support equipment, by improving battery and fleet management. '

I love these products. My grandfather flew some of the predecessors to these UAVs in WWII. They were flying converted torpedo planes controlling TDR-1 radio controlled TV guided drones against Japanese installations in the South Pacific. It worked then, and the technology makes it hugely effective now for a much wider range of missions. And one of my former clients used to provide fuel cell technology to some of their earlier protoypes, so I've followed these guys for a while. This area of technology has tremendous military potential.

On the financial side, I'm a little torn.

On $140 mm in 2006 revenue, this kind of backlog is pretty impressive, and it's clear they've been able to drive growth.

'As of October 28, 2006, our funded backlog was $69.5 million and unfunded backlog was $491.5 million. '

And margins have been good for a business of this type.

But I've got a lot of heartache over a defense contractor / aviation supplier trading at a 20+ P/E (defense contracts are three quarters of revenues,, almost all of its UAVs, total US government is over 80%). Especially when selling shareholders cashed out 1/3rd of the IPO proceeds. Ouch. The post IPO pop may have taken it higher than I'd be willing to go.

But maybe for this particular firm I can get over it.

(Via Cleantech blog.)

Self-Assembling Lithium-Ion batteries

Researchers at MIT have designed a rechargeable lithium-ion battery that assembles itself out of microscopic materials. This could lead to ultrasmall power sources for sensors and micromachines the size of the head of a pin. It could also make it possible to pack battery materials in unused space inside electronic devices.

Yet-Ming Chiang, a professor of materials science at MIT, and his colleagues selected electrode and electrolyte materials that, when combined, organize themselves into the structure of a working battery. The researchers had been looking for ways to exploit short-range forces between micro- and nanoscale particles. After measuring such forces between materials using ultraprecise atomic-force microscope probes, they were able to select materials with just the right combination of attractive and repulsive forces. As a result, similar materials clustered together to form opposite electrodes, while a gap necessary for the battery to function was maintained between the electrodes. The work is the cover story in the current issue of Advanced Functional Materials.

Self-assembly is attractive because it could potentially reduce manufacturing costs and allow molecular-level control of the structure of the batteries, leading to materials and devices not easy to make using conventional manufacturing methods. Self-assembly has already been used to create a number of materials and a handful of simple devices, including half a battery. (See "Powerful Batteries That Assemble Themselves.") "Ultimately, the goal is just to chuck a bunch of stuff into a bucket and have it self-assemble into a battery," says Jeff Dahn, professor of chemistry and physics at Dalhousie University, in Canada. Chiang's work creating a prototype self-assembling battery is "really nice science," Dahn says. "Just the fact that you can do it is pretty cool."

The researchers faced a number of challenges in designing the self-assembling batteries. They are limited to materials with the electrochemical properties necessary for battery electrodes. And within each electrode, the particles need to pack together tightly, which can be accomplished if they are attracted to each other. The particles must also be attracted to materials that conduct electrons to and from the electrodes. Most important, the battery's two electrodes need to be kept separate--a challenge because they are oppositely charged and therefore tend to attract each other.

By relying on their new understanding of short-range forces, Chiang and his colleagues were able to select two electrode materials that, at very short distances on the order of a couple dozen nanometers, had surface repulsive forces greater than their attractive forces. As a result, there is always a space left between the electrodes.

The researchers used lithium cobalt oxide and microbeads of graphite for the electrodes--materials commonly used in lithium-ion batteries--pairing them with a carefully selected liquid electrolyte. The electrolyte serves as an insulator, allowing ions to shuttle between the electrodes but forcing electrons to move through an external circuit, where they can be used to power a device.

In the researchers' prototype battery, the graphite microbeads pack together to form one electrode and connect to a platinum current collector, all the while staying clear of the lithium cobalt oxide that forms the other electrode. The researchers tested the battery and showed that it could be both discharged and recharged multiple times.

The extent to which such batteries will find commercial applications is unclear. Dahn points out that in manufacturing today's batteries, the electrode materials are compressed under enormous pressures to ensure as great as possible energy storage. Such forces could not be applied to a self-assembled battery, so Dahn says it will be "very tough" to compete with conventional batteries in terms of energy capacity and maybe even in terms of cost. Dahn also notes that challenges still remain before such batteries can be commercialized. For example, it is still necessary to find a way to package the self-assembled materials to protect them once they have formed a battery.

One potential application is in very small devices. "It should be relatively easy to make a very small footprint device, rice-grain-size and smaller--the size of the head of a pin," Chiang says. He adds that self-assembly could allow more-efficient use of space than conventional batteries can. That's in part because it's possible for the electrode particles to pack into irregular shapes within a device or follow its outside contours.

As the researchers move toward such applications, which could include use in distributed sensors for the military, their next step is to replace the liquid electrolyte with a solid polymer to make the battery more rugged. The better understanding of the relevant short-range forces could also be used to select different materials for applications in transistors or certain types of solar cells.

Source : Technology Review

Eestor ambitions to repalce electro-chemical batteries in every applications

A secretive Texas startup developing what some are calling a "game changing" energy-storage technology broke its silence this week. It announced that it has reached two production milestones and is on track to ship systems this year for use in electric vehicles.

EEStor's ambitious goal, according to patent documents, is to "replace the electrochemical battery" in almost every application, from hybrid-electric and pure-electric vehicles to laptop computers to utility-scale electricity storage.

The company boldly claims that its system, a kind of battery-ultracapacitor hybrid based on barium-titanate powders, will dramatically outperform the best lithium-ion batteries on the market in terms of energy density, price, charge time, and safety. Pound for pound, it will also pack 10 times the punch of lead-acid batteries at half the cost and without the need for toxic materials or chemicals, according to the company.

The implications are enormous and, for many, unbelievable. Such a breakthrough has the potential to radically transform a transportation sector already flirting with an electric renaissance, improve the performance of intermittent energy sources such as wind and sun, and increase the efficiency and stability of power grids--all while fulfilling an oil-addicted America's quest for energy security.

The breakthrough could also pose a threat to next-generation lithium-ion makers such as Watertown, MA-based A123Systems, which is working on a plug-in hybrid storage system for General Motors, and Reno, NV-based Altair Nanotechnologies, a supplier to all-electric vehicle maker Phoenix Motorcars.

"I get a little skeptical when somebody thinks they've got a silver bullet for every application, because that's just not consistent with reality," says Andrew Burke, an expert on energy systems for transportation at University of California at Davis.

That said, Burke hopes to be proved wrong. "If [the] technology turns out to be better than I think, that doesn't make me sad: it makes me happy."

Richard Weir, EEStor's cofounder and chief executive, says he would prefer to keep a low profile and let the results of his company's innovation speak for themselves. "We're well on our way to doing everything we said," Weir told Technology Review in a rare interview. He has also worked as an electrical engineer at computing giant IBM and at Michigan-based automotive-systems leader TRW.

Much like capacitors, ultracapacitors store energy in an electrical field between two closely spaced conductors, or plates. When voltage is applied, an electric charge builds up on each plate.

Ultracapacitors have many advantages over traditional electrochemical batteries. Unlike batteries, "ultracaps" can completely absorb and release a charge at high rates and in a virtually endless cycle with little degradation.

Where they're weak, however, is with energy storage. Compared with lithium-ion batteries, high-end ultracapacitors on the market today store 25 times less energy per pound.

This is why ultracapacitors, with their ability to release quick jolts of electricity and to absorb this energy just as fast, are ideal today as a complement to batteries or fuel cells in electric-drive vehicles. The power burst that ultracaps provide can assist with stop-start acceleration, and the energy is more efficiently recaptured through regenerative braking--an area in which ultracap maker Maxwell Technologies has seen significant results.

On the other hand, EEStor's system--called an Electrical Energy Storage Unit, or EESU--is based on an ultracapacitor architecture that appears to escape the traditional limitations of such devices. The company has developed a ceramic ultracapacitor with a barium-titanate dielectric, or insulator, that can achieve an exceptionally high specific energy--that is, the amount of energy in a given unit of mass.

For example, the company's system claims a specific energy of about 280 watt hours per kilogram, compared with around 120 watt hours per kilogram for lithium-ion and 32 watt hours per kilogram for lead-acid gel batteries. This leads to new possibilities for electric vehicles and other applications, including for the military.

"It's really tuned to the electronics we attach to it," explains Weir. "We can go all the way down from pacemakers to locomotives and direct-energy weapons."

The trick is to modify the composition of the barium-titanate powders to allow for a thousandfold increase in ultracapacitor voltage--in the range of 1,200 to 3,500 volts, and possibly much higher.

EEStor claims that, using an automated production line and existing power electronics, it will initially build a 15-kilowatt-hour energy-storage system for a small electric car weighing less than 100 pounds, and with a 200-mile driving range. The vehicle, the company says, will be able to recharge in less than 10 minutes.

The company announced this week that this year it plans to begin shipping such a product to Toronto-based ZENN Motor, a maker of low-speed electric vehicles that has an exclusive license to use the EESU for small- and medium-size electric vehicles.

By some estimates, it would only require $9 worth of electricity for an EESU-powered vehicle to travel 500 miles, versus $60 worth of gasoline for a combustion-engine car.

"My understanding is that the leap from powder to product isn't the big leap," says Ian Clifford, CEO of ZENN, which is also an early investor in EEStor. "We're the first application, and that's thrilling for us. We took the initial risk because we believed in what they are doing. And energy storage is the game changer."

The key challenge, however, is to ensure that the barium-titanate powders can be made on a production line without compromising purity and stability. "Purification gives you better production stability, gives you better permittivity, and gives you the high voltages you're looking for," says Weir. "We've now got the chemicals certified and purified to the point we're looking for." (Better permittivity of the insulator improves the amount of charge that can be stored without letting the current leak across the two plates.)

EEStor announced this week that the first automated production line for its powder has performed as required and that permittivity will meet or exceed expectations. It also said that it achieved 99.9994 percent purity for its barium-nitrate powder, a crucial ingredient in the dialectric. San Antonia-based Southwest Research Institute independently confirmed the results.

In a traditional ultracap, that permittivity is given a rating of 20 to 30, while EEStor's claim is 18,500 or more--a phenomenal number by most accounts. "This is a very big step for us," says Weir. "This puts me well onto the road of meeting high-volume production."

Jim Miller, vice president of advanced transportation technologies at Maxwell Technologies and an ultracap expert who spent 18 years doing engineering work at Ford Motor, isn't so convinced.

"We're skeptical, number one, because of leakage," says Miller, explaining that high-voltage ultracaps have a tendency to self-discharge quickly. "Meaning, if you leave it parked overnight it will discharge, and you'll have to charge it back up in the morning."

He also doesn't believe that the ceramic structure--brittle by nature--will be able to handle thermal stresses that are bound to cause microfractures and, ultimately, failure. Finally, EEStor claims that its system works to specification in temperatures as low as -20 °C, revised from a previous claim of -40 °C.

"Temperature of -20 degrees C is not good enough for automotive," says Miller. "You need -40 degrees." By comparison, Altair and A123Systems claim that their lithium-ion cells can operate at -30 °C.

Burke, meanwhile, says that there's a big difference between making powder in a controlled environment and making defect-free devices in a large quantity that can survive underneath the hood of a car.

"I have no doubt you can develop that kind of [ceramic] material, and the mechanism that gives you the energy storage is clear, but the first question is whether it's truly applicable to vehicle applications," Burke says, pointing out that the technology seems more appropriate for utility-scale storage and military "ray guns," for which high voltage is an advantage.

Safety is another concern. What happens if a vehicle packed with a 3,500-volt energy system crashes?

Weir says the voltage will be stepped down with a bi-directional converter, and the whole system will be secured in a grounded metal box. It won't have a problem getting an Underwriters Laboratories safety certification, he adds. "If you drive a stake through it, we have ways of fusing this thing where all the energy is sitting there but it won't arc … It will be the safest battery the world has ever seen."

Regarding concerns about temperature, leakage, and ceramic brittleness, Weir did not reply to an e-mail asking him how EEStor overcomes such issues.

Nonetheless, the company has some solid backing. Its board has attracted Morton Topfer, former vice chairman of Dell and mentor to Michael Dell.

The company is also backed by Kleiner Perkins Caufield & Byers, a venture-capital powerhouse that has an impressive track record: it made early and highly successful bets on Google, Amazon.com, and Sun Microsystems, among others. Whether EEStor can translate that success to the energy sector remains to be seen.

"I'm surprised that Kleiner has put money into it," says Miller.

Weir maintains that his company will meet all of its claims, and then some. "We're not trying to hype this. This is the first time we've ever talked about it. And we will continue to meet all of the production requirements."

Source : Technology Review

L'ICMCB (CNRS Bordeaux) travaille sur les micro-batteries, le stockage de l'hydrogène ou les piles à combustible

L'énergie occupe une place importante à l'ICMCB. Le centre bordelais s'est d'ailleurs fait une spécialité des matériaux pour batteries, que ce soient les microbatteries en couche mince – qui n'excèdent pas 10 micromètres d'épaisseur et permettent d'alimenter des microcircuits –, ou les batteries lithium-ion – que l'on retrouve dans la plupart des ordinateurs et téléphones portables, mais aussi dans l'outillage, l'automobile, l'aviation, etc. Une compétence internationalement reconnue et donc très sollicitée : Claude Delmas rentre à peine du Japon, où il a rencontré ses collègues du centre de recherches Toyota, principal constructeur de véhicules hybrides. « Plus de puissance, plus d'énergie et une sécurité maximale de fonctionnement sont nos objectifs, souligne Laurence Croguennec, responsable du groupe Batteries. Pour cela, on joue par exemple sur la structure cristalline des composés du lithium. » Outre les batteries, les recherches sur l'énergie concernent la thermoélectricité 2, le stockage de l'hydrogène ou encore les piles à combustible – un système électrochimique qui convertit directement en énergie électrique l'énergie chimique de la réaction d'oxydation d'un combustible.

Voir l'article du Journal du CNRS

Avestor files for bankruptcy

Another Canadian energy-storage player bites the dust. Avestor, a Boucherville, Quebec-based maker of lithium-metal-polymer batteries, has let go of 260 employees and closed the doors of its manufacturing plant just outside of Montreal. The company, a joint venture between Hydro-Quebec and Kerr-McGee Corp. (now owned by Anadarko Petroleum Corp.), said it is making a bankruptcy proposal to its creditors and has appointed a trustee to oversee the process.

"Considerable sums were invested in developing a battery that could be marketed profitably to the telecommunications industry; nevertheless, the enterprise was not able to reach the break-even point," the company said in a statement. "Despite more than a year of active searching, Avestor failed to attract new industrial and financial partners to replace its current investors. Consequently, it is no longer able to continue operations."

It's not like Avestor wasn't selling product. In August the company proudly announced it had sold its 20,000th battery. At the same, CEO John Haddock was quoted as saying: "The future looks promising."

Source : Clean Break