To refresh, silicon’s advantage is a high capacity for energy storage comes from taking on a much larger charge than today’s electrodes. Silicon’s disadvantage is that it swells up when charged, expanding up to 3 times its discharged size. The expansion and contraction over charge and discharge cycles quickly destroys the silicon structure that makes an electrode.

The PNNL study examines a new type of silicon-carbon nanocomposite electrode revealing details of how they function and how repeated use could wear them down.  The study also provides clues to why this material performs better than silicon alone.

Right off the silicon-carbon electrode equipped battery has an electrical capacity five times higher than conventional lithium battery electrodes.  There’s a strong motive in place for more research because silicon-carbon nanocomposite electrodes could lead to longer-lasting, cheaper rechargeable batteries for electric vehicles.  A five-fold increase changes the economics for consumers in a major way.

Wang explains the PNNL role, “The electrodes expand as they get charged, and that shortens the lifespan of the battery. We want to learn how to improve their lifespan, because silicon-carbon nanofiber electrodes have great potential for rechargeable batteries.”

Silicon Carbon Electrode for Lithium Ion Battery

Wang led a multi-institution effort to test the nano-sized electrodes consisting of carbon nanofibers coated with silicon. The carbon’s high conductivity, which lets electricity flow, nicely complements silicon’s high capacity, which stores it.  Researchers at Department of Energy’s Oak Ridge National Laboratory and Applied Sciences Inc. and General Motors Global R&D Center created the silicon-carbon nanofibers and forwarded the electrodes to the team at PNNL to probe their behavior while functioning.

Then the PNNL team tested how much lithium the electrodes could hold and how long they lasted using a small testing battery called a half-cell. At 100 charge-discharge cycles, the electrodes still maintained a very good capacity of about 1000 milliAmp-hours per gram of material. That’s 5 to 10 times the capacity of conventional electrodes in lithium ion batteries.  So far so good.

The team knew the expansion and contraction of the silicon could be a problem for the battery’s longevity, since stretching tends to wear things out.  (Like kinking a wire quickly back and forth till it separates – note smaller wires take longer to break than large ones – so stay with this.)

To see how well the electrodes weather the repeated stretching, Wang popped a specially designed, tiny battery into a transmission electron microscope, which can view objects nanometers wide.  They zoomed in on the tiny battery’s electrode allowing the team to study the electrode in use, and they took images and video while the tiny battery was being charged and discharged.  There are images and videos on the study’s Supporting Information page – so click here!

Previous work has shown charging causes lithium ions to flow into the silicon.  The PLLN team’s study showed lithium ions flowed into the silicon layer along the length of the carbon nanofiber at a rate of about 130 nanometers per second. This is about 60 times faster than silicon alone, suggesting that the underlying carbon improves silicon’s charging speed.  There’s a bonus worth more examination.

The team expected the silicon layer to swell up about 300 percent as the lithium entered.  But the combination of the carbon support and the silicon’s unstructured quality allowed it to swell evenly.  That compares favorably to silicon alone, which swells unevenly, causing imperfections.

Beyond the swelling up, lithium is known to cause other changes to the silicon. The combination of lithium and silicon initially form an unstructured, glassy layer. Then, when the lithium to silicon ratio hits 15 to 4, the glassy layer quickly crystallizes, as seen in previous researcher’s work.

The team examined the crystallization process in the microscope to better understand it. In the microscope video, they could see the crystallization advance as the lithium filled in the silicon and reached the 15:4 ratio.

Here’s the breakthrough – the team found that this crystallization is different from the classic way that many substances crystallize, which builds from a starting point. Rather, the lithium and silicon layer snapped into a crystal all at once when the ratio hit precisely 15 to 4. Computational analyses of this crystallization verified its snappy nature, a type of crystallization known as congruent phase transition.

And the crystallization isn’t permanent. Upon discharging, the team found that the crystal layer became glassy again, as the concentration of lithium dropped on its way out of the silicon.

That’s the key to the huge capacity.

On the longevity front the team charged and discharged the tiny battery 4 times. Comparing the same region of the electrode between the first and fourth charging, the team saw the surface become rough, similar to a road with potholes.

Wang has an explanation about the changes being likely due to lithium ions leaving a bit of damage in their wake upon discharging, “We can see the electrode’s surface go from smooth to rough as we charge and discharge it. We think as it cycles, small defects occur, and the defects accumulate.”

The fact that the silicon layer is very thin makes it more durable than thicker silicon. In thick silicon, the holes that lithium ions leave behind can come together to form large cavities. “In the current design, because the silicon is so thin, you don’t get bigger cavities, just like little gas bubbles in shallow water come up to the surface. If the water is deep, the bubbles come together and form bigger bubbles,” is Wang’s metaphor.

For the future work the team expects to explore the thickness of the silicon layer and how well it bonds with the underlying carbon to optimize the performance and lifetime of the electrodes.

Lots of possibility here.  Great work and a great start.  And a big thanks to the American Chemical Society for making the images and videos available.  Seeing an electrode in action is quite a treat as well as highly instructional.

So far this is the best solution seen to getting the silicon advantage into the lithium ion battery chemistry.  Silicon has tempted and bedeviled for years.  The potential using the preliminary numbers are tremendous bait – a 5 to 10 fold increase in capacity could double range for 40% of the mass.  Plus those flow rates suggest very quick charges and discharges offering simpler engineering, better performance and fast recharge.  This is a technology to watch very carefully.

The world record looks secure for now, the battery prototype has third party tests confirming the energy density at the 400 watt hours per kilogram.  In comparison, one of the currently manufactured at scale batteries is made by Panasonic rates at 245 Wh/Kg.  That’s a battery model a person can buy.

Across from the new density rating are the projected costs.  Envia’s Sujeet Kumar, Co-founder, President & CTO explains the demonstration prototype packaged as a 40 Ah pouch cell, in a new system could lower Li-ion cell costs to $180/kWh with further reductions to come.

A lot of people from the mainstream media to bloggers run numbers projecting a deep cut in electric vehicle prices.  It’s not been easy to notice or find the specific number of charging cycles being talked about.  There is graphic suggesting that by 300 cycles the battery is still at 91% capacity.  This isn’t thousands of cycles, but hundreds. Lets all calm down.  Envia still has work to do.

What has Envia way out in front are the electrodes.  Envia calls the cathodes “high capacity Manganese rich” (HCMR), which is a lithium-rich layered-layered Li2MnO3·LiMO2 composite. The HCMR composite cathode material offers twice the specific capacity and lower cost compared to more conventional cathode materials.

Envia Coated Cathode. Click Image for more info.

Envia’s Kumar explains by engineering the cathode composition, structure, dopants, morphology and nano-coating, they’re able to precisely control and tune the specific capacity, cycle life, calendar life, rate capability and physical properties of the material to match any application.  This suggests there can be trade offs among the specifications to get to specific applications.  Retuned for cycles over 1000 the capacity is between 220 and 295 Wh/kg.

On the anode side Envia engineered at nano size with Si-C anodes at a resulting high capacity at 1530 mAh/g reversible capacity, a good rate capability running 95.5% capacity retention and good cycling performance  – 90% capacity retention after 50 cycles in a half cell.  On the anode side there doesn’t seem to be any easy quotes to reassure the careful observer.  Again, this cycling performance isn’t a setup for mass marketing.

Envia Silicon Based Anode. Click image for more info.

The company says it can see light now at the end of the tunnel for its working prototype based on lithium-ion chemistry and also said it will prove other scientists wrong who have said lithium-ion chemistry is limited in how inexpensive and energy dense it could be made to be.

Add to the electrodes technology the electrolyte is a proprietary compound.  It’s very interesting to look at the effect of the nail gun test.  Punch a nail through a conventional battery and the results are quite flammable spreading collateral damage, a nightmare potential in a serious collision or impact.  The Envia website shows a proprietary pouch with a nail driven through that has, well, a hole in it – lacking the flame burned ripped apart imagery.  Of course this is a proprietary test, but its quite an attractive property for a lithium-ion battery.

Envia Nail Penetration Test Result. Click image for the largest view.

Congratulations are in order for getting to a rechargeable silicon anode based lithium-ion battery.  This is no small feat.  It seems the Envia team thinks it can drive to better results in the next few years.  Keep in mind the requirements for cell phones and other small rechargeables, laptops and other mid-sized devices and electric vehicles have very different specifications and consumer expectations.  Envia could get to some markets sooner than others.

But for electric vehicles a rebattery job at 1,000 cycles isn’t going to cut it or even come close.  Your humble writer has looked at numerous studies over the years and today, subject to revision, is thinking electric vehicle batteries have to get to 300 Wh/kg charged over 3000 cycles at better than 90% capacity for under $130.

Lets say Envia gets to 400 W/kg and recharges 3000 times at $125. Then you will have a revolution.

Meanwhile – lets all stay calm.  So, go get ‘em Envia!

To start, a flow battery or accurately a Redox Flow Battery (RFB) is a type of rechargeable electrochemical system that relies on the redox states of various chemicals for the purpose of storing energy.  The electroactive components, anolyte and catholyte, are liquids held in tanks.  Charging and discharging of these batteries happens through a redox process in the cell.  RFBs are attractive because in addition to the rapid charge/discharge ability is they can scale way up.

Process Graph of Metal Based Ionic Liquids used in a Flow Battery. Click image for the largest view.

To increase the energy stored in this type of system requires simply to only increase the size of the anolyte and catholyte tanks.  Likewise, increasing the power output of the flow battery only necessitates the addition of more cells.

So far the problems have been charge cycle efficiencies, low energy densities, raw material costs, cross contamination of the anolyte and catholyte, plus corrosiveness and safety issues all have contributed to an unacceptably high cost per kWh.

The Sandia research published in Dalton Transactions, might lead to devices that can help economically and reliably incorporate large-scale intermittent renewable energy sources, like solar and wind, into the nation’s electric grid.

Anthony Medina, director of Sandia’s Energetic Components Realization program opens the discussion, “The U.S. and the world need significant breakthroughs in battery technology for renewable energy sources to replace today’s carbon-based energy systems. MetILs are a new, promising battery chemistry that might provide the next generation of stationary storage battery technology, replacing lead-acid and lithium-ion batteries and providing significantly higher energy storage density for these applications.”  The electrical grid was designed for steady power sources, making fluctuating electricity from intermittent renewable energy difficult to accommodate.  Battery based energy storage techniques can help even out the flow from fluctuating sources.

Sandia’s Travis Anderson is leading a team developing the next generation of flow batteries.  In a flow battery a pump moves a solution of free-floating charged metal ions, dissolved in an electrolyte substance, with free-floating ions that conducts electricity, from an external tank through an electrochemical cell to convert the chemical energy into electricity. Flow batteries are rapidly charged and discharged by changing the charge state of the electrolyte.  The electroactive material can be easily re-used many times. Anderson said flow batteries can sustain more than 14,000 cycles in the lab, equivalent to more than 20 years of energy storage.  Sounds great.

But flow battery grid storage systems are roughly the size of a house and can cost more than equivalent lithium-ion batteries. So the Sandia group goal is to make flow batteries smaller and cheaper, while increasing the amount of energy stored for a given volume, or energy density.  So far some flow batteries are out there, mostly using zinc bromine and vanadium redox, but they are moderately toxic and vanadium has big price fluctuations, plus they are vulnerable to the temperature.  The Sandia group’s leaders hope to build a battery without water and solve these issues.

The Sandia team is multidisciplinary experts including electrochemist David Ingersoll, organic chemist Chad Staiger and chemical technologists Harry Pratt and Jonathan Leonard. What they’ve designed is a new family of electrochemically reversible, metal-based ionic liquids, or MetILs, which are based on inexpensive, non-toxic materials that are readily available within the U.S., such as iron, copper and manganese. They have a home run on new flow battery cathode materials.

Sandias Ionic Liquid Metal Salt Electrolyte Samples. MetILs are, from left to right: copper-based compound, cobalt-based compound, manganese-based compound, iron-based compound, nickel-based compound, and vanadium-based compound. Click the link above to the Sandia press release for more info and larger views.

Anderson takes up the explanation, “Instead of dissolving the salt into a solvent, our salt is a solvent. We’re able to get a much higher concentration of the active metal because we’re not limited by saturation. It’s actually in the formula. So we can cost-effectively triple our energy density, which drastically reduces the necessary size of the battery, just by the nature of the material.”

Here’s the payoff – The electrochemical efficiency, or ability to reverse charge, in MetILs is far greater than anything else published to date. The team has prepared nearly 200 combinations of cations, anions and ligands, and of those, five outperform the electrochemical efficiency of ferrocene, which has long been considered the efficiency gold standard.

The team has worked up the early solutions.  Usually when mixing up positively and negatively charged molecules, the molecules will start clumping together, eventually causing the solution to turn gummy and clog up the battery membrane and electrode surfaces. The team solved that challenge by developing asymmetric cations, or positively charged ions, that resemble a soccer ball. In this analogy, the black pentagons represent negatively charged areas and the white hexagons represent positively charged regions. Such an arrangement lowers the melting point by preventing the ionic liquid constituents from bonding and becoming a solid, while the partial charge still allows electrons to flow freely through the cell to generate a current.  It’s sort of “pre clumped” and works better for it – just don’t let it completely discharge.

Imre Gyuk, energy storage systems program manager at the Department of Energy’s Office of Electricity Delivery and Energy Reliability said, “The MetILs approach represents an ingenious, out-of-the-box solution to the cathode/electrolyte paradigm. Because it is based on readily available, inexpensive precursors, it may well lead to innovative, cost-effective storage systems with major impacts on the entire U.S. grid.”

Next up for the Sandia team is to find similar materials for the flow battery anodes.  The team is encouraged by their progress so far.

Anderson said, “There are three things you’re juggling at the same time, and they aren’t always related: viscosity, electrical conductivity and the fundamental electrochemical efficiency. The excitement of having all three things go right at the same time, it’s like finding the treasure, but without the map. We’re creating that map, and we’re very excited by the possibilities.”

Lets see . . . low or non-toxic, 14,000 cycles, temperature tolerance, highest density so far, capacity by tank size . . .  is anyone else thinking miniaturization?

Advanced batteries are the major barrier to electrification of a significant share of transport and for better, lighter and cheaper electronics.

The research group’s technique is described in the journal Nature Materials.  As well as a look inside without destruction the technique may also improve battery performance and safety by offering diagnostics of battery internal operations.  Therein lies the breakthrough.

MRI Image From Inside a Battery. Click image for more info.

The MRI has been extremely successful in the medical field for visualizing disorders and assessing the body’s response to therapy.  But an MRI isn’t usually used in the presence of a lot of metal, a primary component in many batteries’ shells, as part of the anode and cathode and in many cases the electrolyte.  The problem is metallic surfaces and dense concentrations conduct electricity that effectively block the radio frequency fields that are used in a MRI to see beneath surfaces or inside the human body.  With the radio waves shielded or absorbed and converted to electrical current – there isn’t anything to see.

The research group has cleverly turned this limitation into a virtue. Because radio frequency fields do not penetrate metals, one can actually perform very sensitive measurements on the surfaces of the conductors.  Using popular lithium-ion batteries, for example, the team was able to directly visualize the build-up of lithium metal deposits on the electrodes after charging the battery. Those deposits can also detach from the electrode surface, eventually leading to overheating, battery failure, and, in some cases – to a fire or an explosion.

This breakthrough is sure to speed development up because the ability to visualize small changes on the surface of the batteries’ electrodes, which would allow in principle, for testing of many different battery designs and materials while operating under normal conditions.

The breakthrough comes from a collaboration between Clare Grey, associate director of the Northeastern Center for Chemical Energy Storage and a professor at Cambridge and Stony Brook universities, and Alexej Jerschow, a professor in the Department of Chemistry at New York University who heads a multi-disciplinary MRI research laboratory.  The group isn’t saying whose brainstorm found the virtue in the limitation, but that’s OK.

Jerschow illustrates the import by explaining, “New electrode and electrolyte materials are constantly being developed, and this non-invasive MRI technology could provide insights into the microscopic processes inside batteries, which hold the key to eventually making batteries lighter, safer, and more versatile. Both electrolyte and electrode surfaces can be visualized with this technique, thus providing a comprehensive picture of the batteries’ performance-limiting processes.”

Grey points out why the technique offers such an advantage, “MRI is exciting because we are able to identify where the chemical species inside the battery are located without having to take the battery apart, a procedure which to some degree defeats the purpose. The work clearly shows how we can use the method to identify where lithium deposits form on metal electrodes.” Grey adds, “The resolution is not yet where we want it to be and we would like to extend the method to much larger batteries, but the information that we were able to get from these measurements is unprecedented.”

It’s a start that works.  Other team members include S. Chandrashekar, a postdoctoral fellow at both Stony Brook and New York Universities; Nicole Trease, a postdoctoral fellow at Stony Brook University; and Hee Jung Chang, a Stony Brook University graduate student.

Looking ahead the group offers that the method could lead to the study of irregularities and cracks on conducting surfaces in the materials sciences field. In addition, they add, the methods developed here could be highly valuable in the quest for enhanced battery performance and in the evaluation of other electrochemical devices, such as fuel cells.

They might want to consider more thoroughly the impact the technique might have on catalysts – but that field will surely find them quite soon.

Chandrashekar sums up briefly, “We still have some way to go to make the images resolve better and make imaging time shorter. However, we feel that with this work, we have made the field wide open for interesting applications.”

Battery development has been racing ahead for a decade when many used to believe little progress could be made.  Now we have a technology that puts the activity inside a battery in view. Should Chandrashekar’s prognosis come to pass soon and at high resolution and high speed “shutter speed” so to speak, development for batteries should gather much more momentum and achieve results faster and at lower cost.

But that’s just one field.  The fuel cell field and other catalyst processes can use a boost of high-speed development diagnostics, too.

This is great news.  Congratulations are in order.  We’d sure like to know though, who was the person or who were the folks who had the brainstorm?  That would be a double up on the congratulations.

This week the UWO scientists report that using nitrogen-doped graphene nanosheets (N-GNSs) as cathode materials significantly increases the performance of a non-aqueous lithium-oxygen battery by about 33% more than the high-performance pristine graphene nanosheets announced in August.

The paper has been published in the journal Electrochemistry Communications.

The research team led by Professor Xueliang (Andy) Sun found that their nitrogen-doped graphene nanosheet cathode materials delivered a discharge capacity of up to 11,660 mAh g^-1 compared to the pristine graphene nanosheet capacity of up to 8,706 mAh g^-1.

Nitrogen Doped Graphene NanoSheet Diagram from researchers at University of Western Ontario .

The team had been following recent studies where nitrogen doping was applied to carbon powder and nanotubes.  Those research efforts showed higher discharge capacities.  The UWO team then set out to try nitrogen doping on carbon nanosheets by testing for electrocatalytic activity of N-GNSs for oxygen reduction in the non-aqueous electrolyte.  The nitrogen doping for oxygen reduction result is 2.5 times that of the pristine graphene nanosheet. The team is attributing the excellent electrochemical performance of N-GNSs to the defects and functional groups as active sites introduced by the nitrogen doping.

The team is pointing out the finding not only shows that N-GNSs are promising electrode materials, but also gives a rational direction to modify other carbon materials for application in lithium-oxygen batteries.

The hard numbers reported in the study show the initial discharge capacity of the GNS electrode was 8,530 mAh g^-1 at a current density of 75 mA g^-1, while the N-GNS electrode delivered 11,660 mAh g^-1 for N-GNSs an increase about 37% higher.

Keep in mind these are lab research batteries and other questions are coming up.  Another worthwhile consideration is as the current densities increased, the discharge capacities of both samples decreased.  At a current density doubled to 150 mA g^-1 discharge capacities were 5,333 mAh g^-1 for GNS and 6,640 mAh g^-1 for N-GNS.  At 300 mA g^-1 capacities went to 3,090 mAh g^-1 for GNS and 3,960 mAh g^-1 N-GNS.  These results are pretty much linear with no big surprises.

Nitrogen isn’t especially expensive, but graphene nano sheets aren’t a common item yet.  In fact graphite is usually mined rather than made from petroleum.  Thus for now the new cathodes are anything but cheap.  But mass markets and scaling up have amazing effects on pricing product components.

Meanwhile . . . down in the U.S. the IBM effort has been working on air batteries too.  One or the other of these or perhaps others are going to find a practical and affordable way to store very high capacities of electricity one day. Things have come a long way from carbon dry cells and lead acid.

Maybe the Canadians up at Western can provoke a bit of news out of IBM.  Air battery news isn’t coming at raging speed, but the bits we’re getting are encouraging.

An EMB (a technical description of a flywheel) stores energy through spinning a composite flywheel with an electric motor that’s built in, driving the rotating mass to speed making the system into a battery. Then use the electricity by using the motor as a generator that slows the flywheel down.  EMBs aren’t quite dead, the once widely admired Beacon Power flywheel builder that’s in bankruptcy has found a buyer that may put the intellectual property back to work and return a chunk of a federal loan to the taxpayers.

Mr. Peart’s idea is quite futuristic. Aside from the problems of either lifting the whole thing into orbit or building a manufacturing system in orbit, the concept does overcome the twin drags on rotating masses, the friction of air and bearings blocking gravity’s effect.  Peart is suggesting the flywheel spin at speeds in excess of 60,000 RPM. The flywheels would float (through the use of magnets) in a frictionless vacuum chamber, removing almost all friction and drag.  That would enable the storage of energy for years on end.

Peart's Orbital ElectroMechanicalBattery Layout. Click image for the largest view.

Peart’s satellite would collect energy through an incorporated solar array.  Once the energy is stored the system would seem conventional with other ideas – the energy can be transferred through the use of a microwave antenna and then converted back into electricity through a rectenna (receiving antenna), located down on Earth. The antenna could be repositioned so to allow energy transfer to multiple reactenna locations on Earth, from a single position in orbit.

Peart's Solar Energy Collector and Storage Satellite. Click image for the largest view.

The idea has some thought in it; the satellite would incorporate a system of easy access doors to allow the servicing or removal of worn batteries. The batteries would be oriented on a circular plate that rotates allowing the removal of a set of batteries in a series. The batteries would be mounted with alternating clockwise and counter-clockwise rotations to balance out the gyroscopic effects.  That way two in pairs would speed up twisting opposite to each other leaving the satellite undisturbed.

Peart's Orbital Power Station EMB Service Door. Click image for the largest view.

The proposal has ten series mounted vertically in a column, and six columns are mounted in each individual satellite making a total of 360 batteries mounted in each satellite. The satellite images shown here are small-scale examples, full power satellites would contain several thousand batteries. Each battery would have capacity ratings about 25kWh.

An orbital power station offers the cleanest renewable energy storage and production so far imagined.  Such power station satellites would provide energy on a constant basis, and could answer demand at peak power consumption times with the stored energy.  Peart also points out orbital power stations can also be used as a practical means to sell power services worldwide.

The problem is going to be the capital investment.  Lifting simply a very large solar array is going to challenge the economics.  Adding in batteries at current orbital lift prices doesn’t seem practical for now.

Yet the concept has great stimulating value.  The Republican primary race has one candidate that sees the future of mankind returning to the solar system, which is for now a government sized job and one best done by the free people of earth instead of despots.

Almost everyone it seems has forgotten the root of the information age is the American effort to put a man on the moon. Without the research and development during the 1960s searching for small, lightweight and energy efficient devices, primarily integrated circuits, the information age we now know would not exist as we know it.  Societies have myopic views of the past; it will always be a challenge to avoid a myopic view of the future.

Peart’s concept has value, a measure of thought that can solve problems, worthy of note and keeping saved for those in the future who can build off planet.  Peart’s idea is part of that vision thing that is so painfully lacking in American political and economic discourse.

It’s a pity that virtually all political energy is devoted to cutting up the proceeds of the past, dividing up the production of the present and promising the potential of the future – without investing in the ideas that make future filled with possibilities, challenges and opportunity.  We’re missing that vision thing.

The assertion now is IBM believes it has solved a fundamental problem that may lead to the creation of a rechargeable battery with a 500-mile (800-kilometre) range – letting EVs potentially compete with most petroleum fueled engines.  That would solve the major concern with owning an electric vehicle (EV), the range anxiety – a driver’s estimation that the battery charge will not get the vehicle to the destination on the charge.

As the technology sits today the best offerings of EVs use lithium-ion batteries, which still occupying a large volume and rarely provide 100 miles (160 kilometers) of driving before they’re discharged.

IBM is well into their Battery 500 Lithium/Air Battery project.  The original idea is to come up with and electrical storage solution as good as gasoline, runs out 500 miles and is fully electric with size weight and pricing comparable to a gasoline internal combustion drive.

A lithium-air cell has more potential because it has theoretical energy densities more than 1000 times greater than conventional lithium-ion battery chemistry, setting up an energy density comparable to gasoline.  Lithium-air cells use carbon, instead of metal oxides for the positive electrode, which is lighter and reacts with oxygen from the air around it to produce an electrical current.

The problem has been chemical instabilities limiting the recharging cycles, making lithium-air impractical for use in cars.

Wilcke said, “We now have one which looks very promising.”  No disclosure is being made about what material it is but he says that several research prototypes have already been demonstrated.

To get to this point Wilcke studied the underlying electrochemistry of lithium-air cells using a form of mass spectrometry. What he learned was that oxygen is reacting not just with the carbon electrode, as it was known to, but also with the electrolytic solvent – the conducting solution that carries the lithium ions between the positive and negative electrodes.  When the electrolyte reacts with the oxygen as the battery is used it will eventually be depleted.

Wilcke teamed up with colleague Alessandro Curioni at IBM’s Zurich research labs in Switzerland.  Curioni explains they used a Blue Gene supercomputer to run extremely detailed models of the reactions to look for alternative electrolytes. This included a form of atomistic modeling right down to the quantum mechanics of the components.

The pair’s work is part of the Battery 500 project, where IBM is leading a coalition involving four US national laboratories and commercial partners, with the hope to have a full-scale prototype ready by 2013, with commercial batteries to follow by around 2020.

Graham-Rowe found Phil Bartlett, head of electrochemistry at the University of Southampton, UK for his counter point who offers, “Lithium in water spontaneously catches fire.”

But if the IBM lead consortium has come up with an anode and cathode that works with the oxygen in an electrolyte that doesn’t react with the oxygen they would have solved a major obstacle with lithium-air batteries.  Keeping the H2O molecules out would be a much less challenging matter.

So we’re bursting with questions!  Have the Battery 500 folks got both of the electrode materials sorted out and a selection of electrolytes?  Is the oxygen transport inbound handling the nitrogen, water vapor and trace gasses or are the barriers at the electrodes and electrolytes?  Perhaps both methods are under study?  The questions just take off from there.

This is good news and congratulations are in order for the Battery 500 team people and Mr. Graham-Rowe for finding the news and getting it out.

With no great surprise, price sensitivity about buying a plug in type of vehicle remains a significant issue.  Survey participants’ willingness to pay for a vehicle purchase is much lower than the prices currently planned by automakers.  That’s a certain klaxon kind of wake up call.  Electric vehicles would sell well and range is not the first concern, it’s the battery cost.

All is not lost, survey respondents indicated strong fundamental interest in PEVs, with 40% of participants stating that they would be “extremely” or “very” interested in a plug-in hybrid or all-electric vehicle with a range of 40 to 100 miles and an electricity cost equivalent of $0.75 per gallon.  That price metric on energy is a strong indicator of the sensitivity of gasoline prices.

The Pike research isn’t some slap happy poll, the Pike Research price sensitivity analysis, utilizes the Van Westendorp Price Sensitivity Meter methodology, a widely-used market technique for determining consumer price preferences, introduced in 1976 by Dutch economist Peter van Westendorp.  The Westendrop methodology indicates that for a traditional gasoline internal combustion engine vehicle that would ordinarily cost $20,000, the optimal price point for consumers of a comparable PEV would be $23,750, a significant price premium of 18.75%, meaning about a sixth more cash would come to the table.

That premium isn’t enough to buy today’s battery sets.  The gap between actual pricing and consumer willingness to pay will be a problem for creating demand for PEVs.

There is still more education to do.  A 500-gallon year gasoline buyer might have a better idea of value comparing an annual $1,750 fuel bill vs. a $375 charging bill. It would be better to compare $145.83 for gasoline each month vs. $31.25 to charge up, freeing $114.58 back to disposable income.  $110 will usually buy more than a $3,750 upgrade.

The inside of the survey offers some curious details.  Of the 1,051 respondents interviewed, 4% currently own or lease a hybrid, a figure higher than the current overall hybrid market share in the US.  81% of respondents stated that improved fuel efficiency would be an important factor when purchasing their next vehicle.

Pike noted that consumers under age 30 are somewhat more likely to demonstrate interest in PEVs, as are people with higher levels of education.  But the level of interest in PEVs is not dramatically different between demographic segments such as age, gender, income, and level of education.  That observation leads Pike to conclude that PEVs should have solid mass-market appeal.

Now for the shock. When asked which vehicle brands they would consider for an EV, respondents were most likely to choose Toyota (51%) and Ford (46%), two automakers that did not have PEVs on the market at the time of the survey. Chevrolet (42%) and Nissan (33%), the two manufacturers that launched models in North America in 2010, ranked fourth and fifth, respectively.  Its not looking like advertising is getting the job done.

In the broader view when asked to choose between five different plugin hybrid EV and straight plug in EV range/price options, respondents did not state a clear preference for any one configuration. Of the choices offered, the electric-only model with a 100-mile range had the greatest number of respondents showing interest with 24%.  Another 25% of respondents stated that they would not purchase any of the options provided.

Still with those 25 % not making a choice, 80% indicated that they would be “extremely” or “very” interested in upgrading to a residential “fast-charging” EV charging unit that would utilize the same amount of electricity but reduce charging times from 8 to 12 hours to 2 to 4 hours.  It looks like people have thought this out.

Again the money comes up.  The results also indicate that pricing is once again an issue with fast-charging equipment. Pike’s analysis suggests that the first generation of residential fast-charging equipment will cost between $500 and $800, but only 28% of panelists stated that they would be willing to pay $500 or more for this capability. The average price consumers were willing to pay was $408.  $400 should buy an impressive battery charger, and people know it.  Fast charge doesn’t look like an exploitable idea, it better be standard equipment.

Here’s a sound bit of insight to wind up.  Those respondents likely to get in the market expressed strong interest in workplace, private, and public charging stations. The most popular choices for charging stations were the workplace (74%) and roadside charging stations (82%).

Pike does a great job of looking into things.  While the pricing points for Pike studies are astronomical for regular folks, the press releases and interview tidbits are well worth the attention.

Electric vehicles have a good foundation for massive growth.  A lot could be done to nurse them along, but in the end, it’s the price that will matter.  That $3,750 noted might be a goal for a 400-mile range battery set.  Get to anywhere close and your batteries could not be built fast enough.

That’s the gauntlet, who will get to pick it up first?

Stanford researchers have developed part of a new dream battery with a new electrode that employs crystalline nanoparticles of a copper compound.  During the laboratory tests, the electrode survived 40,000 cycles of charging and discharging, after which it could still be charged to more than 80 percent of its original charge capacity.  That’s over a 100 years of daily charges.

The Stanford researchers use nanoparticles of a copper compound in developing a high-power battery electrode that is so inexpensive to make, so efficient and so durable that it could be used to build batteries big enough for economical large-scale energy storage on the electrical grid.

Copper Crystal Electrode Graphic. Click image for more info.

Colin Wessells, a graduate student in materials science and engineering who is the lead author of a paper describing the research, published this week in Nature Communications said, “At a rate of several cycles per day, this electrode would have a good 30 years of useful life on the electrical grid.”

Yi Cui, an associate professor of materials science and engineering, who is Wessell’s adviser and a coauthor of the paper adds, “That is a breakthrough performance — a battery that will keep running for tens of thousands of cycles and never fail.”

That’s a pair of pretty cheery guys with a big claim in hand.

It’s because the electrode’s durability derives from the atomic structure of the crystalline copper hexacyanoferrate used to make it. The crystals have an open framework that allows ions — electrically charged particles whose movements en masse either charge or discharge a battery — to easily go in and out without damaging the electrode. Most batteries fail because of accumulated damage to an electrode’s crystal structure.

Now add because the ions can move so freely, the electrode’s cycle of charging and discharging is extremely fast, which is important because the power you get out of a battery is proportional to how fast you can discharge the electrode.

Fast and very very long lifetime at low cost.

To maximize the benefit of the open structure, the Stanford scientists needed to use the right size ions. Too big and the ions would tend to get stuck and could damage the crystal structure when they moved in and out of the electrode. Too small and they might end up sticking to one side of the open spaces between atoms, instead of easily passing through. The right-sized ion turned out to be hydrated potassium, a much better fit compared with other hydrated ions such as sodium and lithium.

Wessells explains, “We decided we needed to develop a ‘new chemistry’ if we were going to make low-cost batteries and battery electrodes for the power grid.”  So they chose to use a water-based electrolyte, which Wessells described as “basically free compared to the cost of an organic electrolyte” such as is used in lithium ion batteries. They made the battery’s electrical materials from readily available precursors such as iron, copper, carbon and nitrogen — all of which are extremely inexpensive compared with lithium.

That means Stanford team’s new electrode is for working in a potassium battery.  “It fits perfectly – really, really nicely,” said Cui. “Potassium will just zoom in and zoom out, so you can have an extremely high-power battery.”  Potassium is much less expensive than lithium.

The speed of the electrode is further enhanced because the particles of electrode material that Wessell synthesized are tiny even by nanoparticle standards — a mere 100 atoms across.  Those modest dimensions mean the ions don’t have to travel very far into the electrode to react with active sites in a particle to charge the electrode to its maximum capacity, or to get back out during discharge.

Cui’s research group has a lot of recent research effort on batteries including lithium with the focus on high energy density, a lot of power in a small size.  For portable electronics that’s a primary concern.  But as the power need increases the size can be larger.  For grid storage size and portability hardly matter.  It’s the cost and the cycle times to replacement that matter.

Here’s the known catch – the sole significant limitation to the new electrode for potassium electrolyte is that its chemical properties cause it to be usable only as a high voltage electrode. But every battery needs two electrodes – a high voltage cathode and a low voltage anode — in order to create the voltage difference that produces the  electricity to flow. The researchers need to find another material to use for the anode before they can build an actual battery.

But Cui said they have already been investigating various materials for an anode and have some promising candidates.
Cui and Wessells point out that other electrode materials have been developed that show tremendous promise in laboratory testing but would be difficult to produce commercially. That should not be a problem with their electrode.

Wessells has been able to readily synthesize the new electrode material in gram quantities in the lab. He said the process should easily be scaled up to commercial levels of production. “We put chemicals in a flask and you get this electrode material. You can do that on any scale,” he said.  “There are no technical challenges to producing this on a big-enough scale to actually build a real battery.”

Even though they haven’t constructed a full battery yet, the performance of the new electrode is so superior to any other existing battery electrode that Robert Huggins, an emeritus professor of materials science and engineering who worked on the project, said the electrode “leads to a promising electrochemical solution to the extremely important problem of the large number of sharp drop-offs in the output of wind and solar systems” that result from events as simple and commonplace as a cloud passing over a solar farm.

The Stanford group is on to something more basic with the crystalline copper hexacyanoferrate structure. It’s a clue to finding other crystalline constructions to answer the low volt electrode question.  There is sure to be someone realizing the science could yield low cost electrodes for even denser lithium-ion electrolytes.

It would be quite something if the major electrolyte chemistries were to have electrode pairs with recharge cycles in the tens of thousands at very fast charge rates.  The effect would change the economics in more than just cost per watt hours, but the need for watt hour capacity.

Imagine – trading up the cell phone and keeping the battery, the major cost component, for several models.  Manufactures and consumers have to love that idea.

Go Stanford.

Graphene Sheets Sandwich Silicon. An artist representation of the graphene sheet with its holes, silicon and lithium ions.

The scientists combined two chemical engineering approaches to address two major battery limitations — energy capacity and charge rate — in one design. In addition to better batteries for cellphones and iPods, the technology could pave the way for more efficient, smaller batteries for electric cars.

Lithium-ion chemical batteries charge through a reaction in which lithium ions are sent between the anode and the cathode ends of the battery. As energy in the battery is used, the lithium ions travel from the anode through the electrolyte to the cathode.  As the battery is recharged, they travel in the reverse direction.

Lithium battery performance is set in two ways. Its energy capacity — how long a battery can maintain its charge voltage — is limited by the charge density, or how many lithium ions can be packed into the anode or cathode. Meanwhile, a battery’s charge rate — the speed at which it recharges — is limited by another factor: the speed at which the lithium ions can make their way from the electrolyte into the anode.

Harold H Kung, lead author of the paper says, “We have found a way to extend a new lithium-ion battery’s charge life by 10 times. Even after 150 charges, which would be one year or more of operation, the battery is still five times more effective than lithium-ion batteries on the market today.”

The better current rechargeable batteries’ anode is made of layer upon layer of carbon-based graphene sheets that can only accommodate one lithium atom for every six carbon atoms. To increase energy capacity, scientists have previously experimented with replacing the carbon with silicon, as silicon can accommodate much more lithium: four lithium atoms for every silicon atom.  But silicon expands and contracts dramatically in the charging process, which fragments the electrode destroying its charge capacity rapidly.

Kung’s research team’s techniques solve the problem with sandwiched clusters of silicon between the graphene sheets.  This stabilizes the silicon allowing a greater number of lithium atoms in the electrode while utilizing the flexibility of graphene sheets to accommodate the volume changes of silicon during use.

Current battery charge rate speed is a result of the shape of the graphene sheets: they are extremely thin — just one carbon atom thick — but by comparison, very long. During the charging process, a lithium ion must travel all the way to the outer edges of the graphene sheet before entering and coming to rest between the sheets. And because it takes so long for lithium to travel to the middle of the graphene sheet, a sort of ionic traffic jam occurs around the edges of the material.

Kung’s team uses a chemical oxidation process to create miniscule holes (10 to 20 nanometers) in the graphene sheets — termed “in-plane defects” — so the lithium ions would have a “shortcut” into the anode and be stored there by reaction with the silicon. This reduced the time it takes the battery to recharge by up to 10 times.

Kung says, “Now we almost have the best of both worlds. We have much higher energy density because of the silicon, and the sandwiching reduces the capacity loss caused by the silicon expanding and contracting. Even if the silicon clusters break up, the silicon won’t be lost.”

That’s half the challenge – The Northwestern team will begin studying changes in the cathode that could further increase effectiveness of the batteries. They also will look into developing an electrolyte system that will allow the battery to automatically and reversibly shut off at high temperatures — a safety mechanism that could prove vital in electric car applications.

This looks like a very strong improvement that might only require a processing step for making the holes and adding silicon, which isn’t expensive.  The main question is still the total recharges to full voltage – a serious matter when the application is a major investment such as an electric vehicle.

For now though, the team’s paper is sure to get intense study by the lithium battery industry – it’s a big improvement.