First, let’s get the new acronym out of the way.  The solar-powered flyer recently setting records in Dubai is part of the Airbus High Altitude Pseudo-Satellite (HAPS) program.  One headline led off with “What’s the HAPS?” leaving your editor saddened by not having thought of it first.  Such craft were previously referred to as HALEs (High Altitude Long Endurance) platforms.

It’s also part of the Emirates Institution for Advanced Science and Technology (EIAST), a kind of Middle-Eastern STEM program promoting technological advancement and sustainable development in Dubai and the United Arab Emirates (UAE).

The airplane set three world records in 2010, flying over the desert Southwest in America as part of Qinetiq’s development program.  It managed 336 hours 22 minutes and 8 seconds then, but has added a record 61,696 feet altitude to its accomplishments during a 23 hour, 47 minute flight over Dubai, the highest flight so far in the UAE.

Zephyr team comprises British and Dubai-an members.  Note extremely thin solar film on wing, launch rig under aircraft

Zephyr team comprises British and  Emirati members. Note extremely thin solar film on wing, launch rig under aircraft

Gizmag noted the flight was the first time a HAPS flight has been authorized by a civil authority, sanctioned by the Dubai Civil Aviation Authority (DCAA).  Zephyr flew close to one of the three busiest airports in the world “without affecting civil air traffic.”

British team members were from Airbus, which acquired the Qinetiq Zephyr project in 2013, as explained in this Astrium statement: “Airbus’ subsidiary Astrium has been working on HAPS since 2008 in cooperation with the group’s defense subsidiary Cassidian and Innovation Works. For several years the program was managed as a cross-divisional nursery project, integrated a team of space and aviation specialists. In 2013 Astrium, now part of Airbus Defense and Space acquired the Zephyr assets from QinetiQ, integrating the Zephyr staff into Airbus’ HAPS organization.”

Zephyr 7 on launch to yet another extended flight

Zephyr 7 on launch to yet another extended flight

Airbus explains the multi-faceted leadership roles involved in this effort: “The flight, which was executed for the UK Ministry of Defence (UK MOD), was approved in controlled airspace, which required the close cooperation of the Military Aviation Authority (MAA), the Type Airworthiness Authority (TAA) and the Unmanned Aerial Systems (UAS) team of the MOD Defence Equipment and Support Group, leading to the Zephyr 7 being assigned its military registration, PS001 – the first Pseudo-Satellite registered.”

This complex organization coordinated operations with Dubai’s civil and military authorities, managing to loft the 22.5-meter (70-foot) span, 50 kilogram (110 pound) craft into airspace well above civilian flights.

Chris Kelleher, Technical Director of the Airbus HAPS program reported, “The flight in Dubai demonstrated the ability of Zephyr to operate in regions of the world’s most crowded airspaces. I am immensely grateful for the support and diligence of the Dubai CAA and other authorities in working closely with the combined EIAST Airbus Team to ensure a safe and successful stratospheric flight. With all systems working well in temperatures ranging between +40° C and -80° C (104° F and -112° F) and up to a maximum altitude of 61,696 feet, this flight further reinforces confidence in Zephyr for users and regulators.”

It also marked winter-time operation of the large vehicle, with shorter days to illuminate solar cells and recharge batteries.  The fact that flight could continue through the night highlights the efficiency and capabilities of these systems.

Young workers help prepare Zephyr 7 for record flight

Young workers help prepare Zephyr 7 for record flight

The HAPS device carried a full-HD video system with a 30X zoom lens capable of resolving objects as small as 10 centimeters (4 inches) depending on altitude.  In future, the EIAST/Airbus team will test thermal imaging, environmental monitoring, emergency services supports, the creation of temporary communications networks and the enhancement of navigation systems.

This most recent flight allowed over 250 hours of flight testing of the Zephyr 7 prototype, which will now be used to refine the final design of Zephyr 8, the next-generation HAPS vehicle currently being developed by Airbus.

Besides British and UAE participation, an American company, Sion Power, provided the lithium sulfur (Li-S) batteries that helped keep the plane aloft for its 11-day mission.  The custom-built pack used Sion’s 350 Watt-hour per kilogram cells, more energy dense than commercially available lithium-ion cells.  Sion Power’s CEO, Dr. Dennis Mangino, noted, “As a winter flight, the aircraft flew longer on the batteries than on the solar array, a world first.”

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Last year, Oak Ridge National Laboratory (ORNL) announced that researchers had “successfully demonstrated that lithium-sulfur battery technology can indeed outdo lithium-ion on several fronts.”   Theoretically, lithium-sulfur batteries could be four times as energy dense as today’s lithium-ion batteries, but that promise had yet to be demonstrated.  ORNL took initial steps toward that goal, and within the last few months researchers at Vanderbilt University have shown a strong lead in forming lithium-sulfur batteries with commercial potential.

Sion Power shows high energy density of Li-S cells compared to conventional lithium-ion cells

Sion Power shows high energy density of Li-S cells compared to conventional lithium-ion cells

Echoing work done at Sakti3, ORNL researchers demonstrated an all-solid-state lithium-sulfur cell, addressing flammability issues shared by batteries with solid electrolytes.  Using lithium polysulfidophosphates (LPSPs) in the cathode, and which have ionic conductivities eight times higher than that of lithium sulfide (Li2S) the team coupled that with a lithium anode to create “an energy-dense, all solid battery.”  Energy density was a noteworthy 1,200 mili-Amp-hours per gram, about 7 to 8.5 times that of conventional lithium batteries.

A number of blogs repeated the slightly overheated lines from the Vanderbilt University press release: “A fevered search for the next great high-energy, rechargeable battery technology is on. Scientists are now reporting they have overcome key obstacles toward making lithium-sulfur (Li-S) batteries, which have the potential to leave today’s lithium-ion technology in the dust. Their study appears in the American Chemical Society journal Nano Letters.”

Double encapsulation of lithium-sulfur in carbon shells allows high output and longevity

Double encapsulation of lithium-sulfur in carbon shells allows high output and longevity.  Note Coulombic efficiency after multiple charge/discharge cycles

PR-speak aside, the accomplishments of Xingcheng Xiao, Weidong Zhou, Mei Cai and their colleagues result from looking for lighter and less expensive materials to replace the metal oxide in lithium-ion batteries.  They faced the problem that lithium-sulfur compounds escape from their surroundings, causing batteries to lose charge quickly.  This meant coming up with a way to encapsulate the active ingredients.

Researchers “made tiny, hollow shells out of carbon, which is conductive. They then coated them with a polymer to help confine the Li-S compounds inside. When tested, the structures kept up a high-energy storage capacity (630 mAh/g versus less than 200 mAh/g of lithium-ion batteries) over 600 cycles of fast charging and discharging.”

Happy with their results, the team published its findings under the title, “Polydopamine-Coated, Nitrogen-Doped, Hollow Carbon–Sulfur Double-Layered Core–Shell Structure for Improving Lithium–Sulfur Batteries,” in the ACS journal Nano Letters. They apparently had help from General Motors Global Research & Development Center in Warren, Michigan, showing the automaker’s “fevered search” for better batteries.

Myriad other projects are attacking the problem of making lithium-sulfur batteries a practical reality, and we may soon have commercial validation of their efforts.  The blog will continue to report on these and other efforts.

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Learning About Energy Regeneration from Birds

Phil Barnes has one of the most fascinating web sites on the Internet, combining his aerodynamic expertise and love of soaring birds with his radical approach to staying up perpetually (or until the pilot grows exhausted).  Albatross, birds he’s studied for decades, soar along the tops of ocean waves, seeking food for themselves and their broods, often traveling thousands of miles before setting down.  They have the advantage of bifurcated brains, able to stay awake in one hemisphere of the brain while the other hemisphere nods off, a trait they share with dolphins.

Phil Barnes unveils his latest iteration of his Regenosaur at the ESA Western Workshop

Phil Barnes unveils his latest iteration of his Regenosaur at the ESA Western Workshop

Would it be possible for humans to tap the energy in the air to soar for indefinite periods?  Could truly fuel-free flight be a reality?  Phil is betting both sides of his brain on an affirmative answer to that.

His presentation at this year’s Experimental Soaring Association Western Workshop in Tehachapi, California was more than an addendum to previous work in this area, but an expansion of the concept of regenerative soaring he and Taras Kiceniuk have pursued independently for years.  Taras has demonstrated the plausibility of the idea with a model of his Regenerator aircraft, actually increasing the amount of energy stored in the airplane’s batteries after a long flight.

Highlights of Regenosaur design

Highlights of Regenosaur design

Phil Barnes’ latest iteration of his “Regenosaur” aircraft uses ideas from the Toyota Prius battery boost system, where 200 Volts rises to 600, propeller concepts that change the operation and “look” of formerly familiar propulsion systems, and application of the flying modes employed by large birds in using the least energy for the greatest gain.  The airplane is not only different from what we’re used to, but the manner of flying becomes a new arena in which to explore regenerative soaring.

Regenosaur will share characteristics with large soaring birds, but won't have to land to refuel

Regenosaur will share characteristics with large soaring birds, but won’t have to land to refuel

Flight takes place in five stages; climb, cruise, pinwheel (at which the eight-bladed “propeller” virtually disappears from the equation and the airplane flies at maximum lift-to-drag), regeneration at maximum efficiency and minimum sink, and regeneration at maximum capacity and minimum sink.

Phil explains the distinctions for the two latter conditions: “Although we include max-capacity regen here for study, only max-efficiency regen has competitive flight performance. In particular, while battery energy storage rate (last row) is highest with max-capacity regeneration, the total energy rate (dzt/dt) increases most rapidly with max-efficiency regen. Nevertheless, max-capacity regeneration proves useful in many scenarios, including strong wave lift, slope lift, and final descent. Indeed, if the last encountered updraft is near the airport, landing with significant reserve could become routine. As already noted, ground windmilling (with a safety perimeter) may be sufficient to prevent loss of charge between flights. “

Phil discusses use of a Toyota Prius-like boost circuit in place of a "chopper" or pulse-width modulation approach to controlling current flow to motors

Phil discusses use of a Toyota Prius-like boost circuit in place of a “chopper” or pulse-width modulation approach to controlling current flow to motors.  See his paper on his web site for a full explanation

Regenosaur’s success will depend on its being able to exploit rising air currents at a rate that will enable batteries to be recharged within the time frame of each thermal.  The goal is to land with stored energy equal to or better than that on takeoff.  A bird can find food to replenish its energy reserves.  Regenosaur will feed from the air itself.  This, coupled with the possibilities offered by new lightweight and reasonably efficient solar cells, could bring a new and exciting technology into sport and competitive soaring.

 

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OOPs!… She Did It Again! 270 MPH for Eva

Eva Håkansson not only drives her Killajoule racing sidecar at hellacious speeds, but built it, wired the battery pack and now campaigns it with a five-person crew – including herself and her husband Bill Dube’.  Over the Labor Day weekend, she topped 240 mph in her little bullet.  Not content with only four miles per minute, she and Bill returned for even more speed on September 13.

Business Insider reported, “But Håkansson and Dube knew their creation could go even faster. So last week, they returned to the Bonneville and upped the ante even more by hitting a whopping 270.224 mph. ‘The computer model showed a possible maximum speed of ~270 mph,’ Håkansson wrote in her blog. ‘For the first time ever, practice agreed with theory. We were both pleasantly surprised. It doesn’t happen very often, for sure’”   Eva headlined the blog entry, “Now it’s starting to feel fast…”

A red dress for 240 mph, a white dress for 270.  What color will she wear for 300?

A red dress for 240 mph, a white dress for 270. What color will she wear for 300?  Photo: Killacycle Racing

A123 supplied 14 Amp-hour pouch cells for the record attempts.  Eva reports, “They are _really_ stiff. We attribute the remarkable top speed to the low sag of these cells under load. We made greater than 700 Amp (25 C) looong pulls from the 2P[arallel] pack which resulted in less than 10 Celsius temperature rise.”  Pulling 25 times the rated charge/discharge rate for the cells is the kind of extreme demand that model aircraft pilots ask of their battery packs in aerobatics competitions.

The battery pack consists of four modules of 56 cells each – two in parallel, 28 in series weighing 300 pounds and producing 375 Volts while storing 10 kilowatt hours of energy.  The four modules have enough energy for one run at full tilt, and all four modules are swapped at the end of the run so the fresh pack can power Killajoule for the return run.  Batteries are recharged with a 12 kilowatt Manzanita Micro charger running on bio-diesel fuel, making the operation as green as possible.

Eva, Bill and team celebrate record.  Note salt clinging to undersides of vehicles

Eva, Bill and team celebrate record. Note salt clinging to undersides of vehicles.  Photo: Killacycle Racing

Eva and Bill are quite happy with all the equipment on the vehicle.  Everything performed flawlessly during the runs, including the 500 horsepower EVO motor and dual Rinehart controllers.  Eva notes that the internal combustion powered machines around them “had small armies for support teams,” while their five-person team merely cleaned the salt from the exterior of the vehicle, swapped batteries and refilled the ice in the cooling system for each run.

Eva and Bill are retiring the bike for the season, reasoning that the extra 10 percent of available power will not result in a notable increase in speed, power required increasing by the cube of the speed.  Instead, they anticipate returning to the salt flats next year with a well-calculated campaign to hit at least 300 mph (300 being such a nice, round number according to Eva).  We can only wish them continued safe running and ever-better adventures.

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California Institute of Technology (CalTech) floats this imaginary trial balloon to elicit interest in a new material developed by materials scientist Julia Greer and her colleagues.  “Imagine a balloon that could float without using any lighter-than-air gas. Instead, it could simply have all of its air sucked out while maintaining its filled shape. Such a vacuum balloon, which could help ease the world’s current shortage of helium, can only be made if a new material existed that was strong enough to sustain the pressure generated by forcing out all that air while still being lightweight and flexible.”

Not only are the scientists achieving the strong, lightweight part of the equation, they are “on the path” to making their new material “non-breakable” and able to return to its original size and shape when squished.

As described in her talk shown above, she and her group turned to architectural solutions, only making their bridge-like trusses at the nano scale – where things work very differently.  It’s a bit like the material side of quantum mechanics.  In this case, ceramics, normally extremely strong but exceedingly brittle, become flexible like NERF (Non-Expanding Recreational Foam for those who wondered what the name meant) – not a typical ceramic reaction to compression.

A Greer Lab nanolattice compressed

A Greer Lab nanolattice compressed.  Notice the scale of these cubes

Greer’s ceramic contains about 99.9 percent air and is deposited on a sub-microscopic scaffold that gives the material its structural shape.   She performed earlier magic working with researchers at HRL Laboratories making a microlattice of hollow metal tubes.  The blog reported on that in 2011.

Turning this same type of structural concept to ceramics presented challenges, though.  Greer says,“Ceramics have always been thought to be heavy and brittle. We’re showing that in fact, they don’t have to be either. This very clearly demonstrates that if you use the concept of the nanoscale to create structures and then use those nanostructures like LEGO® to construct larger materials, you can obtain nearly any set of properties you want. You can create materials by design.”

Schematic showing the fabrication process for hollow ceramic nanolattices. The nanolattices are first written out of a photopolymer using two-photon lithography direct laser writing. The polymer scaffolds are coated using atomic layer deposition (ALD) and the underlying polymer is exposed to air using focused ion beam milling. The polymer is then removed using O2 plasma etching, leaving behind a hollow ceramic nanolattice. Credit: Lucas Meza; Caltech

Schematic showing the fabrication process for hollow ceramic nanolattices. The nanolattices are first written out of a photopolymer using two-photon lithography direct laser writing. The polymer scaffolds are coated using atomic layer deposition (ALD) and the underlying polymer is exposed to air using focused ion beam milling. The polymer is then removed using O2 plasma etching, leaving behind a hollow ceramic nanolattice. Credit: Lucas Meza; Caltech

Greer’s team made the ceramic nano-trusses by 3-D “printing” with polymers using something called two-photon interference lithography.  They then coated the lattice with a ceramic such as alumina.  After that, the team etched out the polymer with an oxygen plasma, ending up with a lattice of hollow ceramic tubes.

Different tube wall thicknesses can control how the material fails.  Thick walls cause the ceramic to shatter under pressure, much like a tea cup when dropped.  Thinner walls, around 10 nanometers thick, buckle under compression but recover their shape when the pressure is removed.  Some structures could be compressed by as much as 85 percent and still recover.

Greer’s lab showed that by changing the thickness of the tube walls, it’s possible to control how the material fails. When the walls are thick, the ceramic shatters under pressure as expected. But trusses with thinner walls, just 10 nanometers thick, buckle when compressed and then recover their shape.  The team produced hollow-tube alumina structures with walls ranging in thickness from 5 to 60 nanometers and tubes from 450 to 1,380 nanometers in diameter.

Surprisingly, the density of the ceramics used can be compared to balsa wood, although the ceramics in their nanolattice structures would have better strength- and stiffness-to-weight ratios than the wood.

Greer thinks the applications for this technique are practically limitless, including the making of artificial bones that might have better characteristics than the real thing.  The scaffold alone could allow a patient’s own cells to coat the lattice.  Because coatings could include conductive materials, Greer is working with Bosch in Germany to find possible applications for this nano-technology in batteries.  The ultra-porous nature of the lattices would certainly seem to allow extremes of lithium intercalation.

The Greer lab is also investigating ways to produce these structures at mass scales, with processes like roll printing as one possibility.

Lucas R. Meza is lead author on their paper, “Strong, Lightweight and Recoverable Three-Dimensional Ceramic Nanolattices,” Others include co-author Satyajit Das.

Imagine a future, as Greer says, in which a giant cargo airplane would weigh no more than the scale model of that craft.  This is not idle speculation, because Dennis Bushnell, Chief Scientist at NASA’s Langley Research Center has posited the identical possibility.  This type of thinking will change the way in which we think of structures, propulsion, and a host of other elements.  This could get interesting.

One more thing, unrelated to the topic of structures and nanomaterials: Julia Greer is also an accomplished pianist, According to her CalTech biography.  “Julia has also been pursuing her ‘secondary career’ as a concert pianist – having studied at the Moscow’s Gnessin School of Music, the Eastman School of Music, the San Francisco Conservatory of Music, and at Stanford. She has performed numerous solo recitals (most recently at Caltech’s ‘Off the Clock’ event in 2011), chamber music concerts (most recently in Lagerstrom Series at Caltech with violinist C. Kovalchik), as well as a soloist with an orchestra (most recent performance of Brahms’ Piano Concerto No. 2 with the Redwood Symphony).”

She appeared as a guest on a Discovery Channel show in the spring of 2012, hosted by Adam Savage and Jamie Hyneman from Mythbusters!

 

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For the last 60 years, your editor remembers the oft-repeated advice from garage mechanics and now lithium-ion advocates that slow charging is the way to make your batteries last for many cycles.  Where does this put Tesla, for instance, with its 20-minute Superchargers?  Are you damaging your expensive cells by being in a hurry?

Batteries under test at SLAC with different voltages and currents flowing through them

Batteries under test at SLAC with different voltages and currents flowing through them

In yet another example of counter-intuitive thinking at work, researchers at SLAC, the National Accelerator Laboratory at located on the Stanford University campus have challenged several tenets of conventional battery wisdom.  According to PC World, their work, “published on Sunday in the Journal, Nature Materials, challenges the commonly held notion that slowly charging a battery helps prolong its life and that it’s damaging to a battery if a large amount of energy is withdrawn in a short time.”

William Chueh, a senior author of the paper and researcher at the Stanford Institute for Materials and Energy Sciences (SIMES), told the magazine, “’We’ve always thought of a battery as a [single] device, but inside an iPhone battery there are a few trillion particles.’”  He pointed out that usually scientists look at how the entire battery behaves instead of looking at the individual particles within the battery.

In a Stanford press release, Chueh added, “The fine detail of what happens in an electrode during charging and discharging is just one of many factors that determine battery life, but it’s one that, until this study, was not adequately understood. We have found a new way to think about battery degradation.”

This may inform scientists working on commercial development of lithium-ion batteries, showing possible new ways to design electrodes and promote more uniform charging and discharging that will extend battery life, according to Stanford.

X-ray microscope snapshot of nanoparticles in a battery midway through charging. Particles range from fully charged (green) to intermediate charge (orange/yellow) to drained of charge (red). The scalebar equals 500 nm. (SLAC National Accelerator Laboratory)

X-ray microscope snapshot of nanoparticles in a battery midway through charging. Particles range from fully charged (green) to intermediate charge (orange/yellow) to drained of charge (red). The scalebar equals 500 nm. (SLAC National Accelerator Laboratory)

Using the particle accelerator at the Department of Energy’s SLAC facility in Menlo Park, California, the team was able to see individual nanoparticles in the slices of the batteries under test, much like an MRI on a human.  As the batteries were charged and discharged, the team got a first-time look at the internal processes of the test cells.

Unlike the animations we often see of neatly marching electrons filing through the battery, individual particles get charged for brief periods, after which the current passes to the next particle.  These quick particle-by-particle actions were a surprise, “because rapid charging was also thought to be damaging to batteries.”

Slow charging is usually a relatively low-temperature process, so the battery is protected from thermal damage, but researchers found “The uniformity of each particle’s charge seems to be more important than the speed of the charge.”

Researchers think they can add life to batteries by charging them differently; making lithium-ion batteries that now manage a few years last up to 10 years.  The uniform charging causes less localized heating in the cell and slows degradation, even at high charging rates.

Another aspect of battery design, anodes and cathodes, swell and shrink during charging and discharging, absorbing and releasing electrolyte.  If battery makers can spread the work around to more of the billions of nanoparticles of lithium iron phosphate that make up these electrodes, they have another way to make the battery last longer.  When only a few of the particles carry the charge/discharge load, they tend to crack and break down quickly.  Uniform loading across the entire electrode will lessen stresses and prolong the system’s life.  Researchers found that real-life observations matched data from a model developed at MIT.

The team thinks their research will benefit both stationary and mobile battery applications, with improved batteries better able to handle power surges on the grid or sudden demands by a driver (or pilot).  Before such applications become commonplace, the team must run more tests, trying their modified electrodes through thousands of cycles to simulate hoped-for endurance and performance.  Not content to rest on their academic laurels, the team is talking with companies in the consumer electronics and automotive industries, presumable about commercialization of their final products.

The team included members from the Massachusetts Institute of Technology, Sandia National Laboratories, Samsung Advanced Institute of Technology America and Lawrence Berkeley National Laboratory.

Their paper, “Current-induced transition from particle-by-particle to concurrent intercalation in phase-separating battery electrodes,” can be found here.

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Aside from Lucas di Grassi  and Audi  Sport ABT winning the first Formula E race in Beijing, China over the weekend, it would have been almost unremarkable except for the last-lap, last corner collision between Nicolas Prost and Nick Heidfeld.  The spectacular crash was TV news worthy, and despite the initial friction during and after the crash, Prost and Heidfeld both sent mea culpa apologies to each other via social media.  Formula e races, so far, seem fairly civilized affairs.

35 of the other 40 starters, all essentially alike aside from their team paint jobs, crossed the finish line unscathed and having burned nothing but rubber during their 45 minutes around the 3.44 kilometer (2.13 miles) track.  Even the charger used to “fuel up” the racers burns pollution-free glycerin provided by Aquafuel, a British-based specialist in renewable fuels, according to Formula E Holdings.

Aquafuel explains that, “Glycerin is a by-product of biodiesel production.  For every 9 gallons of biodiesel, 1 gallon of crude glycerin is produced.  Glycerin’s density and high oxygen content offer the potential of exceptionally clean combustion, with much lower emissions than burning diesel fuel.  Aquafuel’s technology has turned that potential into practical reality.”  Glycerin can also be derived from animal fat in a rendering plant, rendering the plant into an essentially self-fueling enterprise.  Its promoters claim the fuel can be made from algae grown in salt or brackish water, and requires no otherwise potable water or necessary agricultural land – a huge benefit in the fight to feed everyone while still powering the world.

A single generator charges all 40 cars “from flat to full in 50 minutes and with automated precise power controls, can be relied upon to ensure no car is given additional power.”  This macro-battery management system ensures that all cars are indeed equal off the line.  Competitors need to manage their energy use, though.  One finisher lost out on a higher standing because of using two percent more energy than allowed for the full circuit.

The cars are serious competition vehicles, able to accelerate from 0 to 100 kilometers per hour (62 mph) in just three seconds.  Because batteries run down quickly under the extremes imposed by racing, each team’s two drivers also have two cars, and switch from the depleted vehicle of the first half of their run into a freshly-charged duplicate for the second half of the race.  This mid-race car swap is one of the quirkier elements of this new style of racing, but was chosen over swapping batteries – considered the riskier option by rule makers.

Because Williams joined the competition only 15 months before the series scheduled opening (the original supplier backed out), their 300 kilogram (660 pound) battery pack was a rush order.  It’s roughly the same weight and holds approximately the same energy as a Leaf battery pack at 28 kilowatt hours vs. the Leaf’s 24 kWh.  Since the Leaf pack can be replaced for $5,500, the Williams Formula E cells might be a little pricier.

The FIA (Fédération Internationale de l’Automobile) Formula E  web site lists maximum power as 200 kilowatts, equivalent to 270 brake horsepower, which in power saving race mode is limited to 150 kW, or 202.5 bhp.  In another quirky feature of Formula E, fans can vote for their favorite car or driver and allow boosts in power to 180 kW for five seconds.  The additional 30 kW (40.5 bhp) should be about like a kinetic energy recovery system in a “conventional” Formula 1 car.  Having its activation be spectator based will add an element of possible fickleness in relative performance between cars.

Renault Formula E chassis, two per team - in this case the Andretti Autosport group

Renault Formula E chassis, two per team – in this case the Andretti Autosport group

All the cars racing this season are the same Renault chassis vehicles with the same battery and motor limitations.  Season two will allow other builders to participate, and with modified rules, we might see a truly new racing technology.  Experience gained here will surely translate into lighter, more powerful batteries and motors that may find their way into future aircraft, with Williams already working with a British air-racing team.

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Cheap Hydrogen, Anyone?

Researchers in Glasgow and at Stanford University have devised ways to decouple oxygen and hydrogen from water without resort to expensive extraction or storage techniques.  Both breakthroughs involve low-cost materials, low-energy requirements, and the production of clean hydrogen through what should be renewable energy resources.

The latter overcomes one major objection to hydrogen production.  As Professor Lee Cronin of the University of Glasgow’s School of Chemistry explains, “Around 95% of the world’s hydrogen supply is currently obtained from fossil fuels, a finite resource which we know harms the environment and speeds climate change. Some of this hydrogen is used to make ammonia fertilizer and as such, fossil hydrogen helps feed more than half of the world’s population.

Professor Lee Cronin in his Glasgow laboratory

Professor Lee Cronin in his Glasgow laboratory

“The potential for reliable hydrogen production from renewable sources is huge. The sun, for example, provides more energy in a single hour of sunlight than the entire world’s population uses in a year. If we can tap and store even a fraction of that in the coming years and decrease our reliance on fossil fuels it will be a tremendously important step to slowing climate change.”

Their new method, according to Professor Cronin and his team, produces hydrogen 30 times faster than current state-of-the-art methods which involve electrolysis, and often rely on fossil fuels to power the operation.  Current approaches often use proton exchange membrane electrolyzers (PEMEs) with precious metal catalysts to generate the hydrogen.  These catalysts are held in high-pressure containers and the process requires large electric currents – something not always available from renewable sources.

The Glasgow method works at atmospheric pressures and low voltages, solving problems normally found “with generating electricity from renewable sources such as solar, wind or wave energy.”

It overcomes the issue of needing to immediately use the hydrogen or store it, usually an involved process.  Professor Cronin explained the method and the advantages of the new approach. “The process uses a liquid that allows the hydrogen to be locked up in a liquid-based inorganic fuel. By using a liquid sponge known as a redox mediator that can soak up electrons and acid we’ve been able to create a system where hydrogen can be produced in a separate chamber without any additional energy input after the electrolysis of water takes place.

“The link between the rate of water oxidation and hydrogen production has been overcome, allowing hydrogen to be released from the water 30 times faster than the leading PEME process on a per-milligram-of-catalyst basis.”

The research was produced as part of the University of Glasgow Solar Fuels Group, which is working to create artificial photosynthetic systems which produce significant amounts of fuel from solar power.  This effort is similar to work done by Dr. Daniel Nocera at MIT and Harvard in the United State.

Professor Cronin along with Dr. Greig Chisholm, Dr. Mark Symes and Benjamin Rausch contributed to the paper, “Decoupled catalytic hydrogen evolution from a molecular metal oxide redox mediator in water splitting,” published in Science

Stanford University researchers, headed by Hongjie Dai, obviously looking for similar low-voltage results, have crafted a water splitter that runs on an ordinary AAA battery hooked up to low-cost nickel and iron electrodes used to bubble oxygen and hydrogen from the water at room temperature.

Dai explained, “It’s been a constant pursuit for decades to make low-cost electrocatalysts with high activity and long durability.  When we found out that a nickel-based catalyst is as effective as platinum, it came as a complete surprise.”

Stanford's triple-A battery-powered water splitter

Stanford’s triple-A battery-powered water splitter

Stanford graduate student Ming Gong, co-lead author of the study, found the nickel equivalency to platinum – at least as far as water splitting goes. Stanford reports, “Ming discovered a nickel-metal/nickel-oxide structure that turns out to be more active than pure nickel metal or pure nickel oxide alone,” Dai said. “This novel structure favors hydrogen electrocatalysis, but we still don’t fully understand the science behind it.”

Not only is the nickel/nickel-oxide catalyst significantly lower in cost, it “significantly lowers the voltage required to split water, which could eventually save hydrogen producers billions of dollars in electricity costs.”  Gong’s next goal is to improve the durability of the device to prevent regular swapping out of defunct electrodes.  Researchers also plan on developing a solar powered system, to do away with constantly having to replace those little batteries.

Not content with just providing hydrogen for California’s planned fleet of fuel-cell cars, the team notes that the same device can produce chlorine gas and sodium hydroxide, an important industrial chemical.  Their device and its operation are described in their paper in the August 22 issue of the journal Nature Communications.

“Hydrogen is an ideal fuel for powering vehicles, buildings and storing renewable energy on the grid,” said Dai. “We’re very glad that we were able to make a catalyst that’s very active and low cost. This shows that through nanoscale engineering of materials we can really make a difference in how we make fuels and consume energy.”  The team, unlike that in Glasgow, fails to mention how the hydrogen produced will be stored, at least in their paper’s abstract.

Dai and Gong worked with Wu Zhou, Oak Ridge National Laboratory (co-lead author); Mingyun Guan, Meng-Chang Lin, Bo Zhang, Di-Yan Wang and Jiang Yang, Stanford; Mon-Che Tsai and Bing-Joe Wang, National Taiwan University of Science and Technology; Jiang Zhou and Yongfeng Hu, Canadian Light Source Inc.; and Stephen J. Pennycook, University of Tennessee.

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Where Are They Now? The Electric Phoenix

MGM COMPRO, a Czechoslovakian motor and electronics supplier, announced that they had participated in finally making the Phoenix motorglider an electric machine.  Jim Lee and co-pilot Jeff Shingleton had originally intended to fly the airplane at the Green Flight Challenge three years ago, but contented themselves with competing in the Rotax-powered machine and “only” winning third place in the event.  Their competing did elicit a great deal of interest in the machine, though.

MGM says, “We are very glad that we can present you a very successful project, [the] U-15 Phoenix of the Czech entrepreneur Martin Stepanek.  MGM COMPRO plays a decisive role in a development of industrial controllers for this fully electric aircraft.

Phoenixes Rotax and electrically powered show earlier low-wing configuration for electric version

Phoenixes Rotax and electrically powered show earlier low-wing configuration for electric version

As described in the blog three years ago, the electric PhoEnix is a “nice airplane,” and one that would take many willing pilots on many cross-country jaunts.  Martin originally planned to use a Czech industrial motor for power, but ended up developing his own powerplant that would allow use of a controllable-pitch and feathering propeller.  He turned to MGM COMPRO for the motor controller, an industrial model HBC 280120, and uses two lithium-ion battery packs to give an hour’s endurance.

Martin and his team have planned a 6-day flight around the Czech Republic, cruising at about 120 kilometers per hour (74.4 mph) for an hour at a time.  Depending on reports, recharging can take one to 2.4 hours, so several hops could be accomplished in a day.

Three-view shows mid-wing configuration of electric Phoenix

Three-view shows mid-wing configuration of electric Phoenix

The two-seat motorglider has a wingspan of 14.5 meters (47.56 feet) and a length of 6.5 meters (21.32 feet).  Its empty weight of 300 kilograms (660 pounds) includes 34 kilograms (74.8 pounds) of batteries, not the 110 pounds reported for the round-Czechoslovakia trip.  Differing from the Rotax-powered version in having mid-fuselage-mounted wings rather than low wings and in seeming to have the retractable gear earlier planned, the sharp-nose vehicle shows several aerodynamic improvements that would allow it to take full advantage of its electric power.

Martin Stepanek is not new to all this, having worked on sailplanes during his mandatory army service in 1998 and 1999, and studying at the Aeronautical University in Brno (1993-1998). From 1999 to 2007 he worked at Urban Air on the Samba and Lambada ultralight motorgliders.   In 2008 he stared development of the Light Sport Aircraft, motorglider Phoenix and by 2009 was test flying  the machine.  By 2011, he was doing initial test flights of the electric version.

He showed the airplane at this year’s Aero Expo at Friedrichshafen and told reporters he was studying allowing the propeller to windmill in thermals to regenerate power for the batteries.  This should expand the range and endurance well beyond one hour, since Jim Lee has one video showing him flying 127 miles in the later afternoon without power in his demonstrator.

These types of aircraft are enormously adaptable, and with soaring capabilities can expand a pilot’s repertoire and skills.  It’s great to see this “new” airplane three years later.

NOTE: Please check out the comment from the airplane’s designer below for current information on the power system.

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Recycling Tires for Battery Anodes

Old tires are hard to get rid of, and left in small mountains in salvage yards, can self-incinerate, causing massive clouds of dangerous smoke and lakes of toxic goo. Fires can last for months, virtually unassailable by fire fighters. Some still structurally sound tires can be re-treaded and gain a new life on the road.  Others, well past their usable life, are shredded and added to an asphalt mix to have a new life as the road.

Not so funny in real life, the Springfield tire fire has been burning since 1989 on the TV program, The Simpsons

Not so funny in real life, the Springfield tire fire has been burning since 1989 on the TV program, The Simpsons

They might also end up lithium-ion batteries.  According to Oak Ridge National Laboratory, “Recycled tires could see new life in lithium-ion batteries that provide power to plug-in electric vehicles and store energy produced by wind and solar, say researchers. By modifying the microstructural characteristics of carbon black, a substance recovered from discarded tires, a team is developing a better anode for lithium-ion batteries.”

A team led by Parans Paranthaman and Amit Naskar is developing a better anode, the negatively-charged electrode, for lithium-ion batteries.   They have created carbon black from waste tires in a “small, laboratory-scale battery” that gives a reversible capacity higher than that from commercial graphite materials – the anode contributing about 390 milliamp hours per gram after 100 cycles.   Researchers think this is attributable to the “unique” microstructure of the carbon black produced from the waste tires.

Process uses an airless fire to create unique  carbon black for battery anodes

ORNL process uses an airless fire to create unique carbon black for battery anodes

ORNL reports, “’This kind of performance is highly encouraging, especially in light of the fact that the global battery market for vehicles and military applications is approaching $78 billion and the materials market is expected to hit $11 billion in 2018,’ Paranthaman said.”

Naskar added that with anodes accounting for 11 to 15 percent of the battery materials,   “This technology addresses the need to develop an inexpensive, environmentally benign carbon composite anode material with high-surface area, higher-rate capability and long-term stability.”

Paranthaman, Naskar and co-authors Zhonghe Bi, Yunchao Li, Sam Akato, Dipendu Saha, Miaofang Chi and Craig Bridges published their paper titled “Tailored Recovery of Carbons from Waste Tires for Enhanced Performance as Anodes in Lithium-Ion Batteries,”  in the journal, RSC Advances.  The team, “envision[s] batteries featuring this technology being highly marketable.” 

ORNL reports the team is “working with David Wood and Jianlin Li on a pilot manufacturing process to scale up the recovery of material and demonstrate applications as anodes for lithium-ion batteries in large-format pouch cells. Researchers expect these batteries to be less expensive than those manufactured with commercial carbon powders.”

Although the batteries will probably not be as powerful as those with silicon-based electrodes, they will provide an inexpensive route to EV adoption with performance that may be usable even in aircraft.

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