MIT News has a report on "new lithium metal batteries could make smartphones, drones, and electric cars last twice as long" - Doubling battery power of consumer electronics.

Founded in 2012 by MIT alumnus and former postdoc Qichao Hu ’07, SolidEnergy Systems has developed an “anode-free” lithium metal battery with several material advances that make it twice as energy-dense, yet just as safe and long-lasting as the lithium ion batteries used in smartphones, electric cars, wearables, drones, and other devices.

“With two-times the energy density, we can make a battery half the size, but that still lasts the same amount of time, as a lithium ion battery. Or we can make a battery the same size as a lithium ion battery, but now it will last twice as long,” says Hu, who co-invented the battery at MIT and is now CEO of SolidEnergy.

The battery essentially swaps out a common battery anode material, graphite, for very thin, high-energy lithium-metal foil, which can hold more ions — and, therefore, provide more energy capacity. Chemical modifications to the electrolyte also make the typically short-lived and volatile lithium metal batteries rechargeable and safer to use. Moreover, the batteries are made using existing lithium ion manufacturing equipment, which makes them scalable.

Jamais at Open The Future has a look at Envia's advanced lithium ion battery technology - Record Battery Energy Density in Context. More commentary can be found at REnew Economy, The Falls Church News Press and Cryptogon.

A tech company called Envia Systems has announced that it is able to produce rechargeable lithium-ion batteries (Li-ion, i.e., the standard kind of rechargeable batteries that go in everything from phones to electric cars) with a world-record energy density of 400 Watt-hours per kilogram! (Gigaom has lots of info, and useful background material.) Cool, right?

Yes? No?

Energy density is one of those really important concepts that not many people know about; it's not an exaggeration to say that a viable renewable energy future depends upon boosting energy density of batteries.

But it's hard to evaluate the importance of an announcement like this if you don't have context, so here you go:

Okay, 400 Watt-hours per kilogram (henceforth Wh/kg) means that one kilogram of battery material will be able to pump out electricity at a level of 400 Watts for one hour.

According to Envia, the best commercially-available Li-ion battery has an energy density of around 245 Wh/kg, so this new technology almost doubles that. This is good. Moreover, most Li-ion batteries operate at about 100-150 Wh/kg. The batteries in the Nissan Leaf, for example, have an energy density of about 120 Wh/kg (24 KWh/200kg). Tripling that density would, in principle, triple the range of the Leaf, taking it from around 100 miles to around 300 miles, a range close to a typical gasoline-powered car. This is very good.

But it's not revolutionary -- it's a (significant) incremental improvement.

That's because, even at 400Wh/kg, batteries still don't have an energy density anywhere close to fossil fuels.

Gasoline offers somewhere around 12,000 Wh/kg, 30x the energy density of the Envia battery technology. A Nissan Leaf with the same mass of gasoline-equivalent superbatteries would have a range of around 9,000 miles. Alternatively, to get the same 300 mile range as with the Envia batteries, the Nissan SuperLeaf would only need around 3kg of batteries.

I'm not discounting the importance of this breakthrough, not by any means, but it's important to keep this in context. There's a good reason why petroleum has such a hold on the world of transportation, and it's going to take a lot more than a tripling of battery energy density to beat it. Or, more to the point, moving beyond the gasoline automobile is going to take more than simply chipping away at energy density comparisons -- it's going to take a complete re-thinking of what we mean by transportation.

[UPDATE:]

As has been pointed out to me, in comments and in direct communication (and with varying degrees of politeness), this isn't an entirely fair comparison. It would be more accurate to compare the combination of energy density + drive efficiency.

Most standard automobiles have an average internal combustion engine efficiency of around 20% -- that is, of the energy available in the fuel, about 20% is eventually translated into motive force. So that 12,000 Wh/kg is effectively "only" 2,400 Wh/kg.

Electric motors, conversely, are extremely efficient at translating available energy into motive force; at 90%, that 400 Wh/kg Envia battery is still effectively 360 Wh/kg.

So a gasoline engine system 6.67x better than the Envia, not 30x better. The difference isn't as gobsmacking, but it's still significant, and remains a reminder of just how far battery technology has yet to evolve.

The SmartPlanet blog has a post on low cost battery technology from a company called Acquion which uses cheap and plentiful materials - Batteries Made Of Salt Water last 10x Longer.

The company claims (PDF) :

- Costs of less than US$300 per kWh (compared to lead acid batteries at US$200-400)
- A lifetime of 5000+ recharge cycles (compared to lead acid batteries at 500-1000)
- Energy density of around 25 Wh/Litre (compared to lead acid batteries with 50-80 Wh/L)

Jay Whitacre wants to change the world with batteries - and the recipe for change, he believes, is in everyday materials like salt and water.

Although he can geek out on complicated lectures on battery technology, last week at The Compass Summit in Los Angeles, Whitacre told me in much more simple terms about how his battery technology works. Using sodium ions instead of lithium, Whitacre’s batteries have been designed to store energy for the grid.

After spending two years figuring out the ideal chemistry for non-toxic batteries, Carnegie Mellon engineering professor Whitacre spun his technology into a startup company called Aquion Energy in January 2010. Pre-production of the sodium-ion batteries is expected this fall, and the production plant is on track to begin in 2013.

In September, Aquion announced a round of $30 million in funding from Foundation Capital, Kleiner Perkins Caufield & Byer, Advanced Technology Ventures, and Triple Point Capital, to build its first factory. The batteries are designed for stationary applications in residential and buildings. The plan is to start with smaller installations and move into major ones.

Aquion Energy’s technology has received some recognition: Last week, the company won a United Nations award for energy at The World Technology Summit. Even though lithium is a common technology used in iPhones or computers, it’s expensive, it needs organic solvents, and has high purity requirements. The other alternative is lead acid batteries, which are known to release toxic lead.

With that in mind, Pittsburgh-based Aquion Energy is making batteries out of non-toxic materials. The anode is made of carbon, while the cathode is made from manganese oxide. The battery is made of individual units that are put together into 8 batteries of 15V modules.

"Electrical power is the only commodity sold in the world right now without any kind of warehousing. When you plug something into the wall, you immediately pull energy from a generation asset. It’s not stored anywhere. We store data, water, and gas. We do not store electricity. Historically, it’s just been too expensive," Whitacre said.

"For the first time, renewable power sources are competitive with traditional, especially in developing countries," Whitacre said. Lead acid batteries aren’t as good as the manufacture promised. Aquion’s batteries have a much longer life. "We believe we can last 5 to 10 times longer than lead acid at the same price point," he said.

To design batteries that would be competitive, Whitacre found common, cheap materials to use: carbon, manganese, water, and different kinds of cheap plastics. For instance, one of the key ingredients is manganese, which is the cheapest metal oxide on the market. And it’s possible to reconfigure carbon, so it can be taken from corn syrup or other forms of carbon.

"We have been very conscious of manufacturing. It’s about taking cheap materials and being able to reconfigure them," Whitacre said, explaining why the company plans on using food processing, pharmaceutical processing, and other kinds of techniques that aren’t usually found in high-tech manufacturing plants.

Technology Review has an article on a possible technique for greatly improving the performance of lithium-ion batteries - Battery Storage Could Get a Huge Boost from Seaweed

Lithium-ion batteries could hold up to 10 times as much energy per cell if silicon anodes were used instead of graphite ones. But manufacturers don't use silicon because such anodes degrade quickly as the battery is charged and discharged.

Researchers at the Georgia Institute of Technology and Clemson University think they might have found the ingredient that will make silicon anodes work—a common binding agent and food additive derived from algae and used in many household products. They say this material could not only make lithium-ion batteries more efficient, but also cleaner and cheaper to manufacture.
Lithium-ion batteries store energy by accumulating ions at the anode; during use, these ions migrate, via an electrolyte, to the cathode. The anodes are typically made by mixing an electroactive graphite powder with a polymer binder—typically polyvinylidene fluoride (PVDF)—dissolved in a solvent called NMP. The resulting slurry is spread on the metal foil used to collect electrical current, and dried.

If silicon particles are used as the basis of the electroactive powder, the battery's anode can hold more ions. But silicon particles swell as the battery is charged, increasing in volume up to four times their original size. This swelling causes cracks in the PVDF binder, damaging the anode. In research published today by Science, the Georgia Tech and Clemson scientists show that when alginate is used instead of PVDF, the anode can swell and the binder won't crack. This allows researchers to create a stable silicon anode that has, so far, been demonstrated to have eight times the capacity of the best graphite-based

The polymer alginate is made from brown algae, including the type which forms forests of giant kelp. It is already widely used as a gelling agent and a food additive. Initially, the researchers thought to replace PVDF with a combination of several different materials. Then, on theoretical grounds, they realized that a polymer with just the right kind of uniform structure could do all the things the binder was supposed to do, including providing good structural support while not chemically reacting with the electrolyte.

Technology Review has a look at small scale devices harnessing ambient energy from their environment - Power-Scavenging Batteries.

MicroGen Systems, a startup based in Ithaca, New York, is developing energy-harvesting chips designed to power wireless sensors like those used to monitor tire pressure and environmental conditions. The chips convert the energy from environmental vibrations into electricity that's then used to charge a small battery. The chips could eliminate the need to replace batteries in these devices, which today requires a trip to a mechanic or, for networks of sensors that are widely distributed, a lot of legwork.

The core of MicroGen's chips is a one-centimeter-squared array of tiny silicon cantilevers that oscillate when the chip is jostled. At the base of the cantilevers is a bit of piezoelectric material: when it's strained by vibrations, it produces an electrical potential that can be used to generate electrical current. The cantilever array is mounted on top of a postage-stamp-sized, thin-film battery that stores the energy it generates. The current passes from the piezoelectric array through an electrical device that converts the current to a form compatible with the battery. When the chip is shaken by, say, the vibrations of a rotating tire, it can produce about 200 microwatts of power.

"If you can get it down to a small size, 200 microwatts is potentially quite useful," says David Culler, chair of computer science at the University of California, Berkeley, and a pioneer in developing wireless sensor networks for environmental monitoring and other applications. However, he notes, engineers are developing "zillions of harvesters" that produce energy from light, heat, radio-frequency waves, or vibration, and convert it into electrical energy that can be used right away or stored on a battery. Culler believes solar power is the technology to beat for most wireless-sensor applications.

The New York Times has an article on improving the economics of electric car battereis - A Second Life for the Electric Car Battery.

As I wrote in a recent Times article on electric car batteries, scientists are expecting big breakthroughs in battery technology over the next five years that will increase the range of electric cars while reducing their cost. But even with these advances, researchers acknowledge that any rechargeable battery will gradually lose its capacity to store energy after repeated cycles of charging and discharging.

Once storage capacity falls below a certain level, the battery can no longer provide the range that electric car owners will expect, according to Micky Bly, the executive director of global battery, electric vehicle and hybrid engineering at General Motors. For its new Chevy Volt, GM expects that level to be around 60 to 65 percent of the battery’s original capacity, he said in a telephone interview.

At the same time, with most of a battery’s useful life still intact, automakers anticipate that it could serve other, less demanding purposes than powering a few thousand pounds of car.

A number of projects and new ventures are already under way to explore second-life applications for lithium-ion batteries. G.M. has announced a cooperative agreement with ABB, an energy technology company. And Nissan has formed a joint venture called 4R Energy with the Sumitomo Corporation.

This month, researchers at the National Renewable Energy Laboratory, financed by the Department of Energy, announced their own initiative in this area, a collaboration with academic and industry partners.

From a technical perspective, a special area of focus for the laboratory’s research will be repurposing these batteries for Community Energy Storage systems on the electric utility grid, according to Jeremy Neubauer, a senior engineer in the lab’s energy storage group. If all goes as planned, in the smart grid of the future electric utilities would distribute thousands of these Community Energy Storage packs throughout the grid to help them manage power flow, especially during peak times or outages.

One pack would store 25 to 50 kilowatt hours of electricity, which could provide power for a few hours to four or five homes. Packs of this size would require stringing together two or three electric car batteries, and the compact size of these batteries lends itself to this purpose, Mr. Neubauer said. He also expects that using second-life batteries would be cheaper for the utilities than buying new ones.

But beyond the technical feasibility, what’s new about the lab’s research will be the focus on testing new financial and ownership models for the car batteries. Ahmad Pesaran, principal engineer on the lab’s study, said, “We want to prove the battery has value beyond its use in the car, and by creating business models, to realize this added value, ultimately lowering the cost of owning the car for the consumer.”

Technology Review has an article on research into improving the performance of battery cathodes and thus reducing recharge times - Batteries that Recharge in Seconds.

A new way of making battery electrodes based on nanostructured metal foams has been used to make a lithium-ion battery that can be 90 percent charged in two minutes. If the method can be commercialized, it could lead to laptops that charge in a few minutes or cell phones that charge in 30 seconds.

The methods used to make the ultrafast-charging electrodes are compatible with a range of battery chemistries; the researchers have also used them to make nickel-metal-hydride batteries, the kind commonly used in hybrid and electric vehicles.

How fast a battery can charge up and then release that power is primarily limited by the movement of electrons and ions into and out of the cathode, the electrode that is negative during recharging. Researchers have been trying to use nanostructured materials to improve the process, but there's usually a trade-off between total energy storage capacity (which determines how long a battery can run before needing a recharge) and charge rates. "People solved half the problem," says Paul Braun, professor of materials science and engineering at the University of Illinois at Urbana-Champaign.

Braun's group has made highly porous metal foams coated with a large amount of active battery materials. The metal provides high electrical conductivity, and even though it's porous, the structure holds enough active material to store a sufficient amount of energy. The pores allow for ions to move about unimpeded. ...

Jeff Dahn, professor of physics at Dalhousie University, is skeptical that these electrodes will ever end up in products. "When you look at the flow chart for making this structure, it's pretty complicated, and that is going to be expensive," he says.

Braun acknowledges: "There are lots of people coming up with elegant [electrode] structures, but manufacturing them is tricky." He says, however, that his fabrication process combines existing methods that are currently widely used to make other products, if not to make batteries, and that it shouldn't be too difficult to adapt them. The process would add extra steps to making a battery, but these steps aren't particularly expensive or complex, Braun says.

Braun's group will next test the electrode structure with a wider range of battery chemistries and work on improving batteries' other half, the anode—a trickier project.

Todd Woody at Grist has a post on a project in Texas to install a large battery for energy storage at a wind power plant - Texas to install world’s largest wind energy storage system.

They like to do things big in Texas, so it's no surprise that the Lone Star state will launch the world's largest wind battery storage project.

Duke Energy is not a Texas company, but it owns the aptly named Notrees wind farm in the Texas panhandle. The North Carolina power giant is teaming up with an Austin area startup called Xtreme Power to install a 36-megawatt battery at the 153-megawatt Notrees Windpower Project near Kermit, Texas.

That's one big battery. Such technology is likely to become crucial as wind farms become ever larger but erratic suppliers of electricity to the grid. In wind-blown West Texas, the region's massive turbine farms can generate more electricity than the grid can handle at some times while all but ceasing production at other times. That creates headaches for grid operators, and the ability to store wind energy and release it when needed would help smooth out the ebbs and flows of the electricity stream.

"This system will store excess wind energy and discharge it whenever demand for electricity is highest -- not just when wind turbine blades are turning. In addition to increasing the supply of renewable energy during periods of peak demand," Duke said in a statement.

Pacific Northwest grid operators will probably be watching the experiment closely. That region boasts abundant hydropower and huge wind farms, which has created situations when there's a surplus of both wind and water power and insufficient capacity on transmission lines to offload the electricity. Batteries would help, though it probably would take huge banks of them to have a significant impact.

The federal government is obviously interested in the technology. The Department of Energy has thrown in $22 million for the project, with Duke matching the grant with another $22 million.

Technology Review has an update on the world of batteries - A Guide to Recent Battery Advances.

Electric vehicles, hybrids, and renewable energy have at least one thing in common--if they're ever going to be more widely used, representing the majority of cars on the road or a large share of electricity supply, batteries need to get significantly better. Batteries will need to store more energy, deliver it faster and more reliably, and ultimately, cost far less. The specific ways batteries need to improve vary by the application, but in all these areas, researchers have been making significant headway.

Last week, MIT researchers led by Yang-Shao Horn , a professor of materials science and engineering and mechanical engineering, and Paula Hammond, a professor of chemical engineering, announced a new approach to high-power lithium-ion batteries, the type that's useful for hybrid vehicles or for stabilizing the electricity grid. High-power batteries accept and deliver charge rapidly. In hybrids, the goal is to supplement the gasoline engine, allowing it to run at its most efficient. The battery drives the car at low speeds for short distances and boosts acceleration, lowering demand on the engine. It also captures energy from braking that would otherwise be lost as heat. For the electricity grid, such batteries could buffer changes in supply and demand of electricity--something that's becoming more important as more variable sources of electricity are introduced, such as wind and solar power.

The MIT researchers demonstrated a new battery electrode, based on specially treated carbon nanotubes, that last for thousands of cycles without any loss in performance. Batteries made from these electrodes could deliver enough power to propel large delivery vans or garbage trucks, for example, without the batteries being too heavy to be practical. (The researchers need to increase the thickness of the electrodes for them to be practical in these applications.) Companies such as A123 Systems, based in Watertown, MA, have also developed very high-power lithium-ion batteries, and other academic groups and startups are developing carbon nanotube-based ultracapacitors, which store energy using a different mechanism than batteries that's particularly useful for high power and long life.

While the new electrodes could eventually be useful for hybrids, and for stabilizing the grid, they aren't particularly good for other applications such as all-electric vehicles. For electric vehicles, the total amount of energy that batteries store is more important than how fast that energy can be delivered, since it's the total amount that determines how far these cars can travel between charges. The MIT researchers who developed the new carbon nanotube electrodes are also developing a different type of battery to store large amounts of energy. Called a lithum-air battery, where one of a battery's two electrodes is replaced by an interface with the air, the technology has recently attracted large amounts of government funding and interest from companies such as IBM. In theory, such batteries could store three times as much energy as conventional lithium-ion batteries. But the design has a number of problems that make it hard to commercialize, among the vulnerability of its active materials to moisture (the lithium metal it uses can catch fire if it gets wet) and the batteries' tendency to stop working after being recharged just a few times.

Energy Bulletin has an article from Steve LeVine on the history of battery - The humble battery: 210 years later, the breakthrough we still await.

The battery could be a shoo-in for the most confounding of all technologies. Invented in 1799 by Alessandro Volta, it not only has yet to be perfected, but has operated all along on essentially the same chemical principles. Were that it were different: If engineers could figure out how to store sufficient electricity in a sufficiently small, light, safe container, there would be a cascading revolution -- in super-utilities, electric cars, laptops and mobile phones. With the possibility of a trillion-dollar industry at stake -- if consumers en mass decide that they want plug-in hybrids, for instance -- engineers and scientists from the Silicon Valley to Japan, China and Korea are manically working on the technological challenge.

Henry Schlesinger, a New York-based science journalist, sets out to right a gaping authorial wrong in his new book, The Battery: How Portable Power Sparked a Technological Revolution. In the introduction, Schlesinger notes rightly that an omnibus account of the this exceedingly fascinating technology -- from Volta to today -- simply doesn't exist.

It still doesn't. This is less a history of the battery than a romp through some of the biggest names in the most exciting periods of invention in the last two centuries -- Davy, Faraday, Edison and Marconi. It reads like an extended Google search of such personalities, with a special focus on electric-powered devices. Schlesinger hints as to why the book turned out this way: "If there are detours," he writes, "it is only because the facts uncovered were either too interesting or too much fun to leave out."

Point made. The missing history of the battery is still missing. Yet the result is still fun. Schlesinger's zest for those detours is infectious.

A bit of advice: Skip the first 18 pages, in which Schlesinger orphans far-afield basic science history. From there, he plunges in to his broad tale. ...

Yet we do end up understanding that batteries are important. In the last few pages, Schlesinger casts his gaze on current efforts to realize the battery's potential, hop-scotching through carbon nanotubes, genetically altered virus batteries, and bio-batteries using vodka, sugar or urine. The book ends on a hopeful note. Schlesinger writes, "Battery development is, at long last, catching up to related fields."

AFP has an article on some nanotechnology research in the UK which may lead to lighter batteries - Electric cars: put a battery in your roof.

A nanoscale material developed in Britain could one day yield wafer-thin cellphones and light-weight, long-range electric cars powered by the roof, boot and doors, researchers have reported.

For now, the new technology -- a patented mix of carbon fibre and polymer resin that can charge and release electricity just like a regular battery -- has not gone beyond a successful laboratory experiment.

But if scaled-up, it could hold several advantages over existing energy sources for hybrid and electric cars, according to the scientists at Imperial College London who developed it.

Lithium-ion batteries used in the current generation of plug-in vehicles are not only heavy, which adds to energy consumption, but also depend on dwindling supplies of the metal lithium, whose prices have risen steadily.

The new material -- while expensive to make -- is entirely synthetic, which means production would not be limited by availability of natural resources.

Another plus: conventional batteries need chemical reactions to generate juice, a process which causes them to degrade over time and gradually lose the capacity to hold a charge.

The carbon-polymer composite does not depend on chemistry, which not only means a longer life but a quicker charge as well.

Because the material is composed of elements measured in billionths of a metre, "you don't compromise the mechanical properties of the fibers," explained Emile Greenhalgh, an engineer at Imperial College and one of the inventors.

As hard a steel, it could in theory double as the body of the vehicle, cutting the weight by up to a third.

The Tesla Roadster, a luxury electric car made in the United States, for example, weighs about 1,200 kilos (2,650 pounds), more than a third of which is accounted for by batteries, which turn the scales at a hefty 450 kilos (990 pounds). The vehicle has a range of about 300 kilometers (185 miles) before a recharge is needed.

"With our material, we would ultimately lose that 450 kilos (990 pounds)," Greenhalgh said in an interview. "That car would be faster and travel further."

Technology Review has an article on the development of low-cost sodium-ion batteries - Sodium-Ion Cells for Cheap Energy Storage.

A new type of sodium-ion battery could prove cheaper than lithium-ion batteries for storing power from wind and solar farms, says Jay Whitacre, a professor of materials science and engineering at Carnegie Mellon University. Whitacre's startup, 44 Tech, based in Menlo Park, CA, will receive $5 million from the U.S. Department of Energy, as part of the 2009 Recovery Act, to develop the technology. The funding, announced last week, is part of a $620 million package for improving the electricity grid.

The startup's batteries could be not only cheaper but also longer-lasting than lithium-ion ones, Whitacre says. This would make them particularly useful for storing large amounts of electricity cheaply--something that will be essential for making renewable energy the primary source of energy in the U.S., rather than just the supplemental source it is now. Such storage will make it practical to store energy from wind turbines and solar farms for use when the wind isn't blowing and the sun isn't shining.

Whitacre's sodium-ion cells are similar in some ways to lithium-ion cells--the type used in portable electronics and in some electric vehicles. In both types of cell, ions are shuttled between the battery's positive and negative electrodes during charging and discharging, with an electrolyte serving as the medium for moving those ions. But because sodium is orders of magnitude more abundant than lithium, it is cheaper to use. To make the cells cheaper still, Whitacre plans to operate them at lower voltages, so that water-based electrolytes can be used instead of organic electrolytes. This should further decrease manufacturing costs, since water-based electrolytes are easier to work with.

AFP has a report on a new electric car battery being developed by Nissan - Nissan to double electric car power: report

Japan's Nissan Motor Co. is working on a lithium-ion battery that can power an electric vehicle for 300 kilometres (190 miles) on a single charge, the business daily Nikkei said Sunday. The distance is nearly double the 160-kilometre range of the Leaf, Nissan's first all-electric car set to go on sale in late 2010 in Japan, the United States and Europe. Nissan, Japan's third largest automaker, aims to produce electric cars incorporating the new battery by 2015, according to Nikkei.

Nissan plans to boost the capacity of the lithium-ion battery's positive electrode by adding nickel and cobalt to its main material, manganese, it said. The enhanced battery can store about twice as much electricity as batteries with positive electrodes made only from manganese. It is robust enough for practical use, able to withstand about 1,000 charge cycles, the daily said.

Technology Review has an article on "Nanowire anodes [which] could let lithium-ion batteries run twice as long" - More Energy in Batteries.

A start-up based in Menlo Park, CA, plans to sell a new type of anode for lithium-ion batteries that, the company says, will let electric vehicles travel farther and mobile devices last longer without a recharge. Amprius' lithium-ion anodes are made of silicon nanowires, which can store 10 times more charge than graphite, the material used for today's lithium-ion battery anodes. According to the company, electric vehicles that run 200 miles between charges could go 380 miles on its batteries, and laptops that have four hours of run time could last for seven hours between charges.

While other advanced battery companies are focused on power, which makes for fast charging and zippy acceleration, Amprius is trying to improve energy density, which enables longer run times. The more total energy a battery can store, the longer it can power a car or a phone between charges. As vehicle manufacturers look toward electric cars, and as mobile devices like iPhones run more energy-intensive applications, a battery's energy density, and thus the time it can go without a recharge, becomes a more pressing issue.

Technology Review has an article on new rechargeable zinc-air batteries - High-Energy Batteries Coming to Market.

A Swiss company says it has developed rechargeable zinc-air batteries that can store three times the energy of lithium ion batteries, by volume, while costing only half as much. ReVolt, of Staefa, Switzerland, plans to sell small "button cell" batteries for hearing aids starting next year and to incorporate its technology into ever larger batteries, introducing cell-phone and electric bicycle batteries in the next few years. It is also starting to develop large-format batteries for electric vehicles.

The battery design is based on technology developed at SINTEF, a research institute in Trondheim, Norway. ReVolt was founded to bring it to market and so far has raised 24 million euros in investment. James McDougall, the company's CEO, says that the technology overcomes the main problem with zinc-air rechargeable batteries--that they typically stop working after relatively few charges. If the technology can be scaled up, zinc-air batteries could make electric vehicles more practical by lowering their costs and increasing their range.

Unlike conventional batteries, which contain all the reactants needed to generate electricity, zinc-air batteries rely on oxygen from the atmosphere to generate current. In the late 1980s they were considered one of the most promising battery technologies because of their high theoretical energy-storage capacity, says Gary Henriksen, manager of the electrochemical energy storage department at Argonne National Laboratory in Illinois. The battery chemistry is also relatively safe because it doesn't require volatile materials, so zinc-air batteries are not prone to catching fire like lithium-ion batteries.

Technology Review reports that new advances may make high energy lithium-sulphur batteries practical at last - Revisiting Lithium-Sulfur Batteries.

Lithium-sulfur batteries, which can potentially store several times more energy than lithium-ion batteries, have historically been too costly, unsafe, and unreliable to make commercially. But they're getting a fresh look now, due to some recent advances. Improvements to the design of these batteries have led the chemical giant BASF of Ludwigshafen, Germany, to team up with Sion Power, a company in Tucson, AZ, that has already developed prototype lithium-sulfur battery cells.

"Compared to existing technologies used in electric vehicles, the plan is to increase driving distance at least 5 to 10 times," for a given-size battery, says Thomas Weber, CEO of a subsidiary of BASF called BASF Future Business. Other experts say that a threefold improvement is a more reasonable estimate, but that would still be an impressive jump in performance. Weber says that BASF's expertise in materials will help Sion Power further improve its technology and bring it to market faster. He declined to provide details of the arrangement, however, including how much money is involved and how the companies will share any profits.

Lithium-sulfur batteries have one electrode made of lithium and another made of sulfur that is typically paired with carbon. As with lithium-ion batteries, charging and discharging the battery involves the movement of lithium ions between the two electrodes. But the theoretical capacity of lithium-sulfur batteries is higher than that of lithium-ion batteries because of the way the ions are assimilated at the electrodes. For example, at the sulfur electrode, each sulfur atom can host two lithium ions. Typically, in lithium-ion batteries, for every host atom, only 0.5 to 0.7 lithium ions can be accommodated, says Linda Nazar, a professor of chemistry at the University of Waterloo.

Making materials that take advantage of this higher theoretical capacity has been a challenge. One big issue has been that sulfur is an insulating material, making it difficult for electrons and ions to move in and out. So while each sulfur atom may in theory be able to host two lithium ions, in fact often only those atoms of sulfur near the surface of the material accept lithium ions.

Technology Review has an article on Chrysler's choice of A123 Systems' batteries in its electric and hybrid vehicles - Why Chrysler Chose A123 Batteries.

This week, Chrysler announced that it will use batteries from A123 Systems in its planned electric vehicles and plug-in hybrids, the first of which will be available in small demonstration fleets by the end of the year. The automaker will use a modular battery system that the two companies developed together over the past three years.

Chrysler chose A123 in part because the company was looking for a supplier based in the United States, says Lou Rhodes, the vice president of advanced vehicle engineering at Chrysler. A123 is based in Watertown, MA, and is building factories in Michigan. The company's battery cells--the basic components of a battery pack--met Chrysler's performance and safety specifications, and the company was developing battery modules that could be easily adapted to fit different vehicles. This was important, Rhodes says, because the automaker plans to start selling several different electric vehicles at around the same time.

A123 and Chrysler developed battery systems that use the same battery cell--one with a flat shape known as a prismatic cell--rather than tailoring the cells' chemistries for each different vehicle. Rhodes expects that this will lead to larger volume production for the battery cell, which could drive down costs. The companies also developed battery modules--units that consist of a collection of cells with safety systems and electronic controls. The modules are designed so that the number of cells in each, as well as the voltage, can be varied according to the application. Finally, the companies developed battery packs for each vehicle. These comprise a varying number of modules arranged in different ways, depending on the configuration of the vehicle.

A123's technology also lent itself to relatively simple battery packs, Rhodes says. The cells use a lithium iron phosphate electrode that is chemically much more stable than the lithium cobalt oxide used in most laptops and in some electric vehicles. Cobalt oxide batteries have been known, in very rare cases, to catch fire in laptops. To prevent this in the much larger and potentially more dangerous battery packs in electric vehicles, companies such as Tesla Motors have designed elaborate cooling systems that carry coolant past each of the thousands of cells in the pack. Because iron phosphate cells are less prone to overheating, the coolant system can be far simpler.

Technology Review has an article on a startup that says its "solid polymer electrolytes will mean cheaper, more-reliable batteries" - Better Lithium-ion Batteries.

A new incarnation of lithium-ion batteries based on solid polymers is in the works. Berkeley, CA-based startup Seeo, Inc. says its lithium-ion cells will be safer, longer-lasting, lighter, and cheaper than current batteries. Seeo's batteries use thin films of polymer as the electrolyte and high-energy-density, light-weight electrodes. Lawrence Berkeley National Laboratory is now making and testing cells designed by the University of California, Berkeley spinoff.

Lithium-ion batteries are used in cell phones and laptops because they are smaller and lighter than other types of batteries. They are also promising for electric and hybrid vehicles. However, conventional materials and chemistries have stopped them from being used extensively in cars.

Today's lithium-ion batteries use lithium cobalt oxide electrodes and a liquid electrolyte, typically lithium salts dissolved in an organic solvent. The electrode material can release oxygen when overcharged or punctured, causing the flammable solvent to catch fire and the battery to explode. Besides, "the charged electrodes are very reactive with the liquid electrolyte, which reduces power and [cycle-life]," says Khalil Amine, manager of the advanced battery technology group at Argonne National Laboratory.

Seeo's key breakthrough is a solid polymer electrolyte. It is not flammable and hence inherently safer. In addition, the battery will retain more of its capacity over time because the polymer does not react with the charged electrode. "Lifetime data suggests that conventional lithium-ion systems lose about 40 percent capacity in 500 cycles," says Mohit Singh, the cofounder of Seeo. "We get a much better cycle life. We can go through 1,000 cycles with less than 5 percent capacity loss."

For the negative electrode, or anode, the electrolyte also works with lithium metal films, which are lighter than current anode materials. That means the battery can provide more energy for the same weight. Based on the battery's single cell, Seeo has calculated that it would have an energy density of up to 300 watt-hours per kilogram, which is 50 percent greater than lithium-ion batteries that are on the market today.

Technology Review thinks Obama's economic stimulus bill will be a boon to Green Energy and is picking battery technology as a big winner, possibly creating a new, advanced industry in the US - Stimulus Big Winner: Battery Manufacturing.

Provisions in the Congressional stimulus bill could help jump-start a new, multibillion-dollar industry in the United States for manufacturing advanced batteries for hybrids and electric vehicles and for storing energy from the electrical grid to enable the widespread use of renewable energy. The nearly $790 billion economic stimulus legislation contains tens of billions of dollars in loans, grants, and tax incentives for advanced battery research and manufacturing, as well as incentives for plug-in hybrids and improvements to the electrical grid, which could help create a market for these batteries.

Significant advances in battery materials, including the development of new lithium-ion batteries, have been made in the United States in the past few years. But advanced battery manufacturing is almost entirely overseas, particularly in Asia. As a result, advanced battery startups in the United States typically have their batteries made outside the United States. But this need not be the case, says Prabhakar Patil, the CEO of Compact Power, a subsidiary of the South Korean company LG Chem, based in Troy, MI. Battery manufacturing is largely automated, so labor costs aren't much of a concern, he says. Rather, the battery industry developed in Asia because countries there, particularly Japan, developed portable electronics and hybrid vehicles, creating a market for batteries.

Now, with the push to rely more on renewable energy and less on fossil fuels, a market for advanced batteries is starting to develop in the United States. This, combined with incentive for manufacturers in the United States, could allow an advanced battery industry to develop in this country. But many experts say that serious obstacles remain to getting the industry off the ground. Investors are reluctant to provide capital for battery plants because the markets are still relatively small. And the markets are still small in part because batteries are expensive, which is itself partly because they're currently made in low volumes.

The stimulus bill could help address both problems. It sets aside $2 billion in grants for manufacturing advanced batteries, plus tax credits to cover 30 percent of the cost of a plant (up to $2.4 billion in total credits). This is in addition to $7.5 billion in loans authorized in a previous bill for manufacturing advanced technology for vehicles, which includes batteries. Employees for these factories could be trained as part of $500 million in funding for retraining workers for green jobs. There is also $16.8 billion going to energy efficiency and renewable energy, which will likely include money for battery research to bring down costs and improve performance.

Technology Review has a post on a V2G pilot program in Newark - Recharging the Grid with Electric Cars.

A utility in Delaware has taken a step toward a future in which electric cars store renewable energy to help make its use more widespread. The city of Newark has approved a system called vehicle-to-grid (V2G), in which the battery pack in a car serves as a place to temporarily store energy from the power grid.

A big problem with renewable sources of power like solar or wind is that they only operate intermittently. For now, renewables provide such a small part of the total electricity supply that other sources can easily make up for the hours, minutes, or days when the wind isn't blowing and the sun isn't shining. But if we're ever to rely on them for a large part of our power, we'll need a cheap way to store the energy that they produce for when it's needed most.

The vehicle-to-grid concept suggests a way to store energy cheaply, since the batteries in electric cars have already been paid for. Most of the time, a car is just sitting around doing nothing. For short-term storage--needed to smooth out fluctuations in power from a wind turbine, for example--a utility could quickly charge a car (or, ideally, distribute a little charge to hundreds or thousands of cars) when the wind is blowing and then take that electricity back a few minutes later when the wind dies down. The more cars that are available, the more energy can be stored. Longer-term storage might also be possible: a car owner could charge up for a discount at night, provided she agreed to keep the car plugged in at work to supply extra power during peak power demand in the afternoon.

Of course, there would have to be some sort of agreement so that energy companies couldn't take so much that the driver ends up stranded, and they'd have to recharge a car before the evening commute. But there are even bigger challenges. There simply aren't many electric cars out there right now. Two-way hookups to the grid would also need to be installed, and the grid may have to be upgraded in other ways. And lastly, all the charging and discharging could shorten the lifetime of the battery (not to mention void the warranty from automakers).

The race is on to find the ideal battery chemistry for plug-in hybrids and all-electric vehicles, but a startup in Indiana believes that a combination of different storage technologies might be the best way to improve vehicle performance and reduce cost. The company's technology allows vehicles to run on a combination of fuel cells, ultracapacitors, and old-fashioned lead-acid batteries.

Noblesville-based Indy Power Systems has developed an energy management system for vehicles that can quickly switch between two or more energy sources, even when their voltages are different. "It's basically a switch that directs energy in any amount and any direction," says Steve Tolen, chief executive officer and founder of Indy Power, which operates out of Purdue Research Park. "The hardware handles the switching, and the software handles the timing and amounts."

Tolen says that the power electronics package--called the Multi-Flex Energy Management System--is only slightly larger than a laptop computer. He describes it as a custom, software-controlled, DC-to-DC converter that's bidirectional and variable.

"Imagine adding hot and cold water to a tub. We can add a variable amount of hot and a variable amount of cold in different volumes to match the outflow of the drain, which can also be variable," Tolen explains. "In other words, the motor can ask for different amounts of current, and we can provide that, and in different ratios from the two (or more) power sources, regardless of the voltage of the power sources."

For example, an electric vehicle could have both lead-acid and lithium-ion battery packs. Advanced lead-acid batteries may be cheaper, but they are also heavier and deteriorate more quickly if subjected to regular depletion and recharging. Lithium-ion batteries are generally more robust and lighter but are far more expensive. Combining the two means that you can use less of each. And just as important, says Tolen, the two chemistries can be balanced against each other to optimize performance. For example, the lithium-ion battery can be used to relieve stress on the lead-acid battery and extend its life, and vice versa.

Reza Iravani, a professor of electrical and computer engineering at the University of Toronto, says that Indy Power's system is part of a trend toward greater emphasis on hybrid storage. For example, he says, Researchers in Australia have designed a car-battery system that combines lead-acid technology with supercapacitors, resulting in a fourfold increase in the life of the lead-acid batteries.