To the Contrary, Propeller-Wise

Sacramento, California based CR Flight is dedicated to building highly-efficient motor/propeller combinations based on contra-rotation – propellers turning contrary to one another.  Not to be confused with counter-rotation – two propellers driven by two different engines and turning in opposite directions – contra-rotating propellers are driven in tandem by the same engine.  In the case of CR Flight, they are driven by the same electric motor.  Their web site shows a simple animation of the result.  An instructive video provides details about the benefits and drawbacks of the concept.

 

The firm’s mission statement gives a hint of its character.  “CR Flight™ partners with established industry leaders to design, patent, license, manufacture and provide the industry’s only patented counter-rotating motors to UAV/drone commercial and consumer manufacturers and wholesale distributors.  When you see the CR Flight™ name, know that the CR motor™ is manufactured under tight scrutiny for the highest quality.”

Their web site shows their three current offerings, the V-10, V-20 and V-50.  They have V-100 and V-220 models under development.  Model numbers indicate the pounds of thrust produced by the motor/propeller combination, so the V-50 can lift 50 pounds.  With 100 and 220 pounds thrust units on the way, one can see their use on commuter vehicles, ultralight and even Light Sport Aircraft.

CR Flight V-50 provides a rated 50 pounds of thrust from its two contra-rotating propellers according to the firm.  But it can hit 75 pounds with two 45-inch x 13.6-inch pitch propellers

All models now available run on 24 or 48 Volts and relatively low amperages – no more than 131.  Specifications for the V-50 show it develops a maximum thrust of 75 pounds when swinging a pair of 45-inch diameter, 13.6 inch pitch propellers. For a 1,250 gram (2.76 pound) motor, that’s not bad.  It’s putting out 5.52 kilowatts at the point.

Comparing its performance with that of a Hacker motor (a well-regarded electric model aircraft motor) shows the 1,035 gram (2.28 pound) motor’s performance not up to that claimed for the V-50.  Hacker’s Q80-8M V2 has a best output of 5.62 kW with a 24-inch diameter, 10-inch pitch propeller.  Although Hacker doesn’t list thrust, it will doubtless be lower considering the single smaller diameter, lower-pitch prop.

Contra-Rotation is Not New

Even before your editor’s time, “A contra-rotating propeller was patented by F. W. Lanchester in 1907,” according to Wikipedia.  A variety of craft used such propellers through the years, but World War 2 saw the idea come fully into play.

A cold war British bomber intended to track Russian submarines, the Avro Shackleton employed four 37.6-liter Rolls-Royce Griffon engines driving two contra-rotating, 13.6-foot propellers.  Imagine 48 cylinders powering eight propellers.  Several later marks of Spitfires flew with the engine, as well as other British aircraft.

America used contra-rotating propellers on the Northrop XB-35 flying wing, and Russia developed the Tupolev TU-95 intercontinental bomber with 16-foot propellers.  The BBC reports one drawback from those huge props going supersonic at their tips.  “The Tu-95 is considered to be the noisiest aircraft in current service; it’s even claimed that US submarines can hear the aircraft flying high overhead through their sonar domes while still underwater. Western fighter pilots who shepherded Bears over international airspace have reported being able to hear its turboprops above the sound of their own jet engines.”

Since quiet operation is essential to public acceptance of drones, it will be interesting to see if CR Flight can overcome this problem, especially at their mounts become larger, heavier, and load the propellers more.

CR Flight’s Technology

CR Flight’s web site includes a white paper on their technology.  The firm credits major differences between a conventional motor and their dual-spinning design.  “In a standard motor, the stator is stationary and propellers are
attached to the rotor. Power is transferred through electrical leads to the stator which in turn causes the rotor to spin. A single set of propellers spin to provide lift.”

Driving two propellers in opposite directions from the same motor is a neat design trick

The CR Flight system is a bit counter-intuitive, as well as contra-rotating.  “In the CR Motor, the armature and rotor are free to move independently. Power is delivered through the Rotary Transformer™ to the armature.
The armature sits on a set of bearings, the same as the rotor, allowing both to rotate in opposite directions. When power is transferred to the armature, it applies a force which drives the while the second propeller attached to the
armature is driven in the opposite direction. Both the rotor and armature are anchored to a single shaft, which is fixed to the drone.”

CR Flight claims this approach allows the motors to run much cooler, produce more thrust than conventional motors and last longer.  Their “Made in the USA” status will give them standing in what may become a more patriotic nation, and their apparent quality and time between overhauls will make them favorites with fleet operators.  We will be checking in with them.

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MAHEPA and HY4 Go High

MAHEPA (Modular Aproach to Hybrid-Electric Propulsion Architecture) is a European Union project to build emission-free aircraft.  A public flight of Pipistrel’s HY4 hydrogen-powered, four-seat aircraft was the latest demonstration of the group’s progress.

Challenging Objectives

Overall, MAHEPA hopes to accomplish five objectives:

  1. Advancing the fuel-driven serial hybrid-electric Powertrain which uses a lightweight internal combustion engine (ICE), capable of running multiple fuels as the power generation module.
  2. Advancing the reliability of zero-emission serial hybrid-electric powertrain which uses a Proton Exchange Membrane (PEM) Hydrogen Fuel Cell (FC) as the power generation module.
  3. Advancing new airborne qualified, lightweight, high-power density components such as a 200 kW+ electric motor, a 100 kW+ generator and improved power electronics using Silicon Carbide (SiC) technology to increase efficiency of power transmission due to decreased switching losses.
  4. Developing “common building blocks” solutions also for different aircraft configurations, enabling the proliferation of powertrain modules between various aircraft.
  5. Gathering, analyzing and comparing in-flight performance and emission data in order to quantify the advantages and limitations of the hydro-carbon fuel-driven and zero-emission power generation modules.

Horizon magazine reiterates the case for and the issues confronting development of such new vehicles.

An H2 Hackathon

A surfeit of talent is ready to tackle those issues, and the variety of approaches is heartening.  For HY4 as it flies currently,  The MAHEPA consortium includes Pipistrel Vertical Solutions, Compact Dynamics, DLR, H2Fly, Politecnico di Milano, TU Delft, University of Maribor and University of Ulm.

The Big Reveal

Those lucky enough to see the airplane after its Slovenian shakedown flight went to the Stuttgart Airport at the behest of this invitation.  It has, after all, a European-wide permit to fly and we be at the Stuttgart airport until May 2021.

“Dear Sir or Madam, On Friday, December 11th, 2020, the developers and sponsors of the world’s first four-seat hydrogen fuel cell aircraft Hy4 will present the sixth and latest generation of emission-free drive technology to the public at Stuttgart State Airport. The further developed Hy4 recently received a flight permit from the licensing authorities to carry out test flights. In the next ten years, the technology should mature to the point where it can be transferred to 40-seat regional aircraft. Flughafen Stuttgart GmbH, together with Ulm University, H2FLY GmbH and NOW GmbH, cordially invite you to the official presentation of the Hy4. On the occasion of the milestone reached for climate-friendly passenger flights, the Federal Transport Minister Andreas Scheuer (via video message) and the Baden-Württemberg State Transport Minister Winfried Hermann speak. The event will be broadcast live on the h2fly.de website. We look forward to your participation.”

The Long Dance Version

For Those of us unable to make it to Germany for the event, the project personnel thoughtfully made a video for us, a longer visual reprise of the first short video on this blog entry, which at about 1:17:35 dissolves to the current day – evidenced by the face masks worn by all present.  With somewhat extreme social distancing for the camera crews, speakers start Deutsche sprechen at the 1:24:10 mark.  At about 1:53:15, the press conference ends and we get yet another iteration of the HY 4 flying in sunny skies.

MAHEPA’s announcement expanded on the technology and its future possibilities.  “With the renovated and optimized fuel cell system technology developed in MAHEPA and in strong cooperation with multiple national projects, the Hy4 became the most powerful hydrogen fuel cell driven aircraft ever made, directly flying into the next era of air transport. First qualification tests and data dissemination show that the full redundant Hy4 powertrain architecture allows an upscaling of the modular technology.

“MAHEPA consortium of Pipistrel Vertical Solutions, Compact Dynamics, DLR, H2Fly, Politecnico di Milano, TU Delft, University of Maribor and University of Ulm is again demonstrating a pioneering direction towards cleaner air transport in Europe, which will be supported by novel technologies developed in the project.”

In GreenCarCongress’s article, perspicacious reader “SD” comments, “Appears to be 2 Pipistel Taurus self-launching sailplanes put together with a new center wing section with the propulsion system. A somewhat strange and not a very practical aircraft but it was probably a low cost way to get something that would fly. Note that Pipistel builds the Taurus in a battery electric self-launching version with a retracting motor and propeller. They also offer battery electric training and light sport aircraft.”

Questions of practicality aside, designer Tine Tomazic used existing Pipistrel Taurus G2 glider parts to make a four-seat entrant for 2011’s NASA Green Flight Challenge.  Originally powered by batteries and powered by a 200-horsepower motor, the G4 achieved 403.5 passenger miles per gallon equivalent (compared to a conventional fossil fuel load).  His thinking was a bit audacious but clever, NASA’s rules gauging the winner by Passenger Miles per Gallon.

Because of its demonstrated aerodynamic cleanness, it was well suited for adaptation of hydrogen power, and thus began a second career.

Plentiful Resources

The MAHEPA Project provides a bounty of material on H2 aviation.  Their web site includes a 64-page overview, Towards Climate-Neutral Aviation from the European Commission.  Downloads and Results show even more educational material.

MAHEPA seems to be, in an archaic phrase, going full steam ahead.  We look forward to their further successes.

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Airbus Goes Modular with Hydrogen Pods

Airbus announced its Zero E program in late September, showing three possible candidates for hybrid hydrogen power.  Zero E, for zero emissions, is a tall order even for one of the world’s two largest aircraft companies.  Now, the company makes yet another announcement – for a novel modular “pod” configuration – “a stand-alone propeller propulsion system powered by hydrogen fuel cells. It consists of the following elements:”

  • A propeller
  • Electric motors
  • Fuel cells
  • Power electronics
  • LH2 tank
  • A cooling system
  • A set of auxiliary equipment

Instead of housing the hydrogen fuel in the fuselage, Airbus creates a more spacious cabin by moving fuel storage to each pod.  Each pod would be identical and modular.  Components could be removed and replaced quickly, and if necessary, the entire pod could be removed for maintenance.  One startling possibility, that of dropping a pod if it caught on fire, would probably not be well received in areas of dry forests or brushland.

Liquid hydrogen and atmospheric oxygen combine in the fuel cells to generate electric current and run the motors.  Eight-bladed composite propellers shaped to “provide added thrust during the takeoff and climb-out phases of flight” would mean high performance and lower “fuel” usage.

Glenn Llewellyn, VP of Zero-Emission Aircraft, explains, “This is one option, but many more will be conceptualized before we make a final selection, a decision that is expected by 2025.”

Addison Schonland’s interview with Airbus Chief Technology Officer Grazia Vittadini sheds light on what the aviation giant hopes to accomplish with H2.  They discuss operating costs, environmental concerns, and other aspects of hydrogen use.  They mention Elring Klinger fuel cell stacks at one point, a possible indication of future suppliers.

Don’t look for this on flight lines any time soon.  Glenn Llewellyn points out, “This is one option, but many more will be conceptualized before we make a final selection, a decision that is expected by 2025.”  This is an idea pursued since at least 2018, when a recently published patent on the technology had its first application.

A Year-end Projection: Where Hydrogen May Go Next

GreenTech Media.com shows us major advances in hydrogen production and applications, something we might not have seen coming a few years ago.  It’s a year-end reminder that the future might really get better – at least in the energy field.

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Something to Lighten the Post-Holiday Letdown

Even following Boxing Day, we have a few items to re-gift to our faithful readers, and close out the season with four very light examples of electric aviation.

A-I-R ATOS

Felix Ruhle has been improving and refining a basic wing design for over a decade, growing a line of aircraft that range from simple hang-gliders to fairly sleek, self-launching, electrically-powered ultralight sailplanes.  The A-I-R factory/showroom in Halblech, Germany, one of 18 dealerships around the world, fronts a lush green meadow and houses a plethora of ATOS wings.

The ATOS wing, coming in a range of sizes, can be attached to seemingly anything from a simple jump-off-the-nearest cliff hang-gliding rig to refined, electrically-powered ultralight sailplanes.

Under development for the last few years, the ultralight sailplane merits even A-I-R’s enthusiastic approval.  “The newest development of A.I.R. is revolutionary! The foldable electric powered. nearly noiseless ultralight-aircraft is based on the proven Atos hang-gliding wings! With 3-axes-steering, real elevator, retractable landing gear and propeller, as well as a sleek closed cockpit you will enjoy to expand your cross country flights. It can be easily transported on car or in a trailer and built up by one man in approximately 15 minutes like a hang-glider.”

Falling in the 120 kilogram (264.6 pounds) empty weight that allows unregulated flight, the wing is derived from the rigid wing hang glider Atos, and has flaps, spoilers and airbrakes.  Its 14.5-meter (47.6-feet) wing gives a best glide ratio of 1:28 at 75 kilometers per hour (46.6 mph), very close to what older standard-class sailplanes could manage.  A sink rate of only 0.65 meters per second (128 feet per minute) means it can float on the lightest thermal.  It can carry up to a 110 kilogram (242.5 pound) pilot, a good load-bearing ability.

With the advantage of self-launching because of its 16-kilowatt (21.5 hp) Eck/Geiger electric motor, it can take off in only 40 meters (131 feet) and climb at 3.5 meters per second (689 feet per minute), according the A-I-R.

A-I-R recommends the craft for, “Experienced hang-gliding XC-pilots who want to make longer tracks with thermal[s] and the warranty to come back home!”   With an endurance of up to four hours and a range of 320 to 480 kilometers (200 to 300 miles), pilots can wander a long way from home.  The firm adds the plane is right for, “Glider pilots who prefer independence combined with the safety of a self launching glider and a favorable price!”

The ATOS looks to be an ideal craft for those seeking adventures without the need to drag all of ones friends and relatives along for the ride.

Two Electric Quickies

The 2011 NASA Green Flight Challenge had a promised field of a baker’s dozen entrants, although only four made the starting line.  It was a challenge, after all.  One that almost showed was the eQuickie, an electric variant of Burt Rutan’s little speedster.  An unfortunate hard landing damaged the canard’s landing gear and kept the little gem from competing.

One in Ukraine

And now, almost 10 years later, two rebirths of the idea come to light – one, from Ukraine and chief designer Yuri Yakovlev.

Aeroprakt, a successful light sport aircraft maker with over 900 examples of its high-visibility Vixens and Foxbats flying, was started by a young Yuri, who crafted a Rutan Quickie look-alike powered by an inverted two-stroke, two-cylinder engine.  After a 29 year hiatus, Yuri brought the plane back to life with an electric power plant and a six-blade propeller.  Interestingly, the blades are arrayed in two rows of three each.  A video that includes other electric aircraft switches to coverage of the electric Quickie at 1:46.  It provides interesting close-ups of batteries, propeller and motor.  YouTube has yet to provide translations, but the pictures are universally understandable.

Another video gives a glimpse of ground testing.

And another lets us follow the first takeoff and hurried landing.

To see more, check out this Facebook page, but remember to click the “translate” prompt unless you read Ukranian.

Henry Hallam’s Reverse Thrust QuickLi

Equally surprising, your editor discovered that Henry Hallam, part of Joby Aviation’s motor development team, had resurrected a Quickie, installed an Emrax motor, his own silicon carbide (SiC) controller, and as an apparent part of that controller, a propeller that can be literally reversed.

He shows a holiday-festive set of battery packs here.  “First three packs complete(ish). Each is 12s4p Sanyo NCR18650GA, monitored/balanced by an LTC6804-1. N22QE will have 27 packs total for 15.2 kWh @ 235 Wh/kg. This will give about 75 mins flight time.”  His honest energy per kilogram at the pack level is greatly appreciated.

His terse note here explains the noisy sound track: “Constant torque ramp to 5000 rpm (takeoff speed) then idle.”

Accompanying this video, his notes help make sense of the sights and sounds.  “The QuickLi (or Quick-E) is a single-seat electric self-launching motorglider. Based on the Rutan Quickie (Q1) airframe with an Emrax 208 motor (~40 kW takeoff, ~12 kW cruise) and a Catto fixed-pitch composite propeller. The motor is driven by a DIY inverter design using silicon carbide MOSFETs at 99.6% efficiency. Battery packs based on NCR18650GA cells store a total of 15 kWh at a packaged energy density of 233 Wh/kg. The electrical powertrain is designed with a semi-redundant fail-safe architecture that allows safe flight to be completed after failure of any component including battery or inverter, yet all components are used during normal operation to maximize efficiency (no hot spares).”

And Something (Almost) Lighter than Air

French company Voliris set out to win a Guinness award as the world’s smallest airship, and proudly displays the evidence of their success at the end.

Finally, something meditative and serene.  Aerosculpture blends art and technology into items of great beauty.   The firm, based in Montebourg, France, almost due south across the English Channel from Portsmouth, England, hopes to reinvigorate balloon flight in a center once part of that history.

We hope they can succeed, and bring a quiet joy to the skies over France.

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Sunseeker Duo Plays Among the Alps

Eric and Irena Raymond took a lovely Sunseeker Duo flight over the Italian alps near their home in Voghera and edited it all into a video.  They designed and built their own solar-powered airplane – Eric’s third.  He flew Sunseeker 1 across the US in 1990 in 21 hops.  A big press conference scheduled for his last landing at Kitty Hawk, NC was a big disappointment since the US invaded Kuwait that day.

Six Minutes of Great Beauty

Their airplane has solar cells arrayed across the wing and horizontal tail, a small battery pack that gets recharged while flying in the sun, and a 22 kilowatt (30 hp) motor on the tail.  Turning off the motor they can soar on winds wafting up the sides of the mountains.  Beeping and electronic noises come from an audio variometer, a sensitive indicator of whether the airplane is climbing or descending.  All the sounds are ambient.  Note how quiet the airplane is, even under power.

They use GoPro cameras on long selfie sticks mounted on the right wing and nose.  Special software allows Eric to edit out the stick itself, but not its shadow.  Eric and Irena are both professional photographers, BTW.  Their work is featured in GoPro TV commercials.

An Inside Look

 In a video made earlier this year, Eric shares background on the design of the aircraft, and gives a tour of the cockpit and the many innovations therein.

A Grand Finale

Eric’s comments for this final YouTube video might help orient the viewer  It might be a real treat on virtual reality (VR) goggles.  “After soaring over the Alps for 2.5 hours, this is a final pass over the ridge before heading home to get warmed up.  Filmed on December 13, 2020, north of Udine, Italy in the Julian pre-Alps. Best viewed on a tablet or mobile phone that can be moved around to see the views.”  This works beautifully even on a conventional computer monitor.

Just like your rear-view mirror, objects may be closer than they appear.  Pivot the view around to a rearward perspective to see how closely the Duo shadows the ridge as it descends.

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ZeroAvia Gains Backing at High Levels

“Cannot be more proud and humbled to be a part of this stellar team!”  That’s power train developer Gabriel DeVault’s response to ZeroAvia’s Chief Financial Officer Katya Akulinicheva’s enthusiastic endorsement of Bloomberg LP’s news.  She listed the investors taking an active interest in ZeroAvia, including Ecosystem Integrity Fund, Breakthrough Energy Ventures, the Amazon Climate Pledge Fund, Horizons Ventures, Shell Ventures and Summa Equity.

Already benefiting from a $16.3 million grant from Innovate UK, Aerospace Technology Institute and Department for Business, Energy and Industrial Strategy (BEIS), ZeroAvia will be able to push forward on plans to create a 19-seat hydrogen-powered commuter liner.

According to Bloomberg, “ZeroAvia aims to demonstrate that it can fly a plane 500 miles (804 kilometers) with as many as 20 seats by 2023. It wants to scale up to 1,000 miles with over 100 seats by 2030.”

With individuals such as Bill Gates and Jeff Bezos taking an interest, an aviation blog now feels a little like a financial report.  The $38 million raised from the UK government and private investors will enable ZeroAvia to replace fossil fuel burners with a hydrogen fuel-cell system.

A Full Dance Card

Val Miftakhov, ZeroAvia’s Chief Executive Officer announced that 10 airlines are ready to buy his company’s 20-seat offering when the craft is available by 2023.  That’s an ambitious schedule, and plans to work with British Airways will help push things forward.  Throughout Europe, efforts are underway to decarbonizes domestic flights, so ZeroAvia’s initial small commuter liner will fit that mission profile nicely.

Bloomberg Green reports, “ZeroAvia aims to demonstrate that it can fly a plane 500 miles (804 kilometers) with as many as 20 seats by 2023. It wants to scale up to 1,000 miles with over 100 seats by 2030.”

Greentech Media reports Val Miftakhov explaining that ZeroAvia’s first Powertrain for 20-seater planes fits a neat market niche.  “About 10,000 such planes are operating in the market today, commonly used in hub-and-spoke operations such as air freight, where the planes are returning to a central depot on fairly predictable schedules, he said. Amazon Air, the retail giant’s freight fleet, has around 70 aircraft in operation.”

To power larger craft, ZeroAvia will need higher power density fuel cells.  “The power density is around 3 kW per kilogram for a small [rotor] turbine. For a Boeing 777, that figure needs to be around 10 kW per kg. In the automotive sector today the density is 0.7 kW per kg. As we work on that, increasing it further and further, we get more segments unlocked,” [Miftakhov] said.

“We’re already flying our prototypes. We have the world’s largest hydrogen-electric aircraft in the air,” he said. “So we’re not just making projections or running around with PowerPoints; we’re actually doing it. And we have a pretty good idea how to achieve a big competitive position in three years with an actual commercial product.”

Keeping it Local

Hydrogen is a great fuel except for the lack of local filling stations that can supply it.  California, for instance, has the greatest number of H2 stations, 42.  With 8,980 fuel cell cars owned or leased in all of America, the chance of finding a station is great – if you drive in the Los Angeles, San Francisco bay area, or are on the road to Reno.  Only two other H2 stations exist in the U. S., and they probably don’t have Quickie Marts attached.  There are doubtless even fewer such stations on airports anywhere.

ZeroAvia seeks to overcome that shortage by partnering with EMEC, the European Marine Energy Center Ltd., Enapter, and Aeristech.  At a macro level, EMEC uses wave and tidal action to produce electricity and hydrogen from excess generation on Orkney Island.  The site also hosts small companies that have various systems and devices to produce H2.   Neil Kermode, Managing Director at EMEC, sees great promise in the alliance.  “As well as providing green hydrogen to demonstrate zero carbon aviation, EMEC will develop a hydrogen refueling solution capable of dispensing volumes approaching the speed of commercial aviation. This will be a major step forward for the sector.”

Possibly part of the refueling solution, Enapter is maker of a patented anion exchange membrane (AEM) electrolyzer for hydrogen production from water and electrical energy.  They have reduced the “water splitting” system to a size transportable in a van.  Their modular AEM system can be “ganged” for different sized operations.  All such production will take place on the airport where hydrogen-powered craft will be deployed, obviating the need for transport from distant sources.

Squeezing More Power from H2

ZeroAvia is also partnering with Aeristech, which makes electric superchargers.  Since the motor driving the supercharger is small, light and not directly coupled to the engine, throttle response can be quick, since the 2.5 kilowatt compressor motor can spool up from 0 to 80,000 rpm in 0.3 seconds.  Pushing additional air through a fuel cell will evidently add to the output, like raising the voltage in batteries.  The company, expanding into aerospace, will move into “an advanced facility” in the West Midlands and add “up to 60 new roles, in highly skilled areas such as power electronics and motor drive engineering.”

Aeristech’s advanced motors and controllers may point the way in new power sources while backing the hydrogen project with ZeroAvia.  All players in the enterprise seem to be creative and ambitious.  So many brilliant minds working on a common solution should lead to clean skies and pollution-free transport.

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NOTICE: We are publishing this entry despite not being able to download fixed images into the file.  We will have that repaired soon, but want the news to go out in the meantime.  Practice patience in the meantime.  Thank you. 

Joby Aviation is one of few “unicorns” in the electric Vertical Take Off and Landing (eVTOL) market, a billion-dollar enterprise.  With funding coming from Toyota, several venture capital investors, Uber and the U. S. Army, Joby seems poised to demonstrate Urban Air Mobility (UAM) in a serious way.

In 2011 JoeBen Bevirt, founder of Joby Energy, Joby Aviation, and creator of those knobby-looking tripods you see everywhere, invited Patrick McLaughlin to visit his design studio.  Your editor got to tag along.  On Woodpecker Ridge, north of Santa Cruz, JoeBen’s barn-like studio housed about a dozen engineers and designers all working on electricity-generating kites.  He wore a T-shirt reading, “If you’re not living on the edge, you’re taking up too much room.”  That edginess has helped him, in the last decade to be a major player, with now over 500 employees in the aviation sector.  JoeBen and Patrick discussed motor design and integration with a controller Patrick had built from off-the-shelf components.

Uber’s Loss is Joby’s Gain

Joby’s later success caught the eye of Uber, and their transformative deal with Joby earned attention from the world press.  The Guardian headlined it, “Uber sells loss-making flying taxi division to Joby Aviation.  Elevate disposal follows sale of autonomous vehicle division as Uber aims for profit.”

Rupert Neate, “Wealth Correspondent” for the Guardian, seems to be the proper reporter for this.  He explains, “Uber has sold its… flying taxi division, Elevate, to a Californian startup as it abandons costly side projects in an attempt to turn a profit next year.”  The term “startup” hardly qualifies, with Joby having committed aviation for at least the last ten years.

“The sale to Joby Aviation, announced late on Tuesday, comes a day after Uber ditched ambitions to develop its own self-driving car and sold its autonomous vehicle division, Advanced Technologies Group (ATG), to the startup Aurora Innovation for $4bn (£3bn).”  Uber and Joby seem committed to working together for the immediate future, with Uber investing an addition $75 million in Joby as part of an “expanded partnership.”

Dara Khosrowshahi, Uber’s chief executive, included something beyond PR-speak in his announcement. “Advanced air mobility has the potential to be exponentially positive for the environment and future generations. This deal allows us to deepen our partnership with Joby, the clear leader in this field, (italics by your editor) to accelerate the path to market for these technologies.”

While this may “elevate” Joby, Uber is cutting back on its self-driving cars development, focusing on core businesses – ride hailing and food delivery – and cutting back on costs and employees.  As Neate reports, Uber’s “robotaxis” have battled public distrust after an Uber car killed a woman crossing a street in Arizona.  Uber has also been in court with Google’s self-driving car project Waymo, over alleged technology theft.

The Airplane and Its Maker

Joby, valued at $2.6 billion earlier this year, explains its prototype “zero emissions” aircraft will carry four passengers and a pilot, have a range of up to 150 miles and a top speed of 200 mph.

Battery-powered and sporting six large rotors on pivoting mounts, Joby’s UAM was revealed after hiding in a gravel pit above Santa Cruz.  It was moved to Hollister, California for more extensive flight tests, but will be moving once again for Air Force testing.

Brian Garrett-Glaser of Verticalmag.com reports that in the same week it closed its agreements with Uber, Joby was awarded the first airworthiness approval by the U.S. Air Force of an eVTOL aircraft.  Agility Prime, an Air Force program meant to speed up development of such technology, works to support “more rapid certification” for craft such as Joby’s by the Federal Aviation Administration.  Flight testing will take place at Fort Hunter Liggett on the California coast.

JoeBen applauds the move.  “Through [the Defense Innovation Unit] and our partnership with Agility Prime, we have access to a range called Fort Hunter Liggett, where we’re able to very safely test our aircraft, and it’s been a transformative capability for us that we’re very grateful for.”  Between Joby and several other suppliers, the Pentagon plans to spend around $100 million yearly on such testing, according to the Wall Street Journal.

Whither Toyota’s Technology?

What will the money from Toyota mean?  Will Joby take on electric technology, including proposed solid-state batteries, from the automaker?  Several things suggest stumbling blocks along that path.

Toyota has a history of downplaying battery electric technology, preferring instead to develop and market a successful line of hybrid electrics.  Prius is a readily recognized brand name these days.  At the same time, the company is releasing a major redesign of its Mirai hydrogen car, despite their being few hydrogen “filling stations” outside California.  Toyota is building a significant hydrogen infrastructure at its Port of Long Beach Fuel Cell Energy Project site.

Which aspects of Toyota’s technology Joby chooses to exploit or ignore is an open question at this time.  Joby has enough of its own inventiveness from which to draw.

Joby’s Patents

EVTOL News reports on Joby’s “recent flood of patents.”  The News explains, “Like many start up technology companies, these pioneers of the eVTOL industry have kept many details of their aircraft development programs very close, in order to maintain tight control of their intellectual property (IP).”  But, as reported, recent patent applications tend to reveal more details, including Aircraft Control System and Method,” and the first publicly available drawings of the Joby 2.0 tilt-propeller eVTOL.  Of probable interest to the whole electric vehicle market, items such as the Joby Battery thermal management system and their System And Method For Aircraft Noise Mitigation will doubtless attract attention.

Other Joby patents date from 2000 and cover all aspects of Joby’s enterprises, including those flexible camera tripods and other gear.  Many are early efforts at attaining airborne electrical collection with kites, or fledgling approaches to eVTOL flight.

By no means an overnight sensation, JoeBen and his growing team are as capable as anyone of setting the course for future flight.  With all the financial assistance coming their way, they should be free to move forward.

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Quantumscape Batteries – an Emerging Answer

Hiding in plain site next to the San Jose, California International Airport, Quantumscape has been quietly developing a solid-state battery now emerging and trending toward mass production.  With backing from Volkswagen, Bill Gates and a founding member of Tesla, the battery company would make big splash if it used a liquid electrolyte.  It doesn’t.

 Wired goes a bit dramatic in describing the faults of batteries with liquid electrolytes.  “IF ELECTRIC VEHICLES are ever going to fully supplant gas guzzlers on the world’s roads, they’re going to need an entirely new type of battery. Despite steady improvements over the past decade in the energy density and lifetimes of lithium-ion batteries, the cells in new EVs still lag behind internal combustion engines on pretty much every performance metric. Most EVs have a range of less than 300 miles, it takes more than an hour to recharge their battery packs, the cells lose nearly a third of their capacity within a decade, and they pose a serious safety risk because of their flammable materials.”

Four Advantages

GreenCarCongress.com is more sanguine, but still persuasive, in its extolling the virtues of Quantumscape’s solid cells.  Explaining that Quantumscape replaces the organic separator found in conventional cells and internally creates its anode when the battery charges.  This “anode-less” approach supposedly lowers material costs, simplifies manufacturing and enables high energy density.  GreenCar lists four major advantages for the solid cells:

  • Zero excess lithium. It turns out that lithium can be too much of a good thing and excessive amounts can actually reduce the performance and even cause internal damage.
  • Long life: Eliminating reactions between liquid electrolyte and carbon in the carbon in the anode of conventional lithium cells enables Quantumscape batteries “to last hundreds of thousands of miles of driving.” Demonstrations in independent tests show Quantumscape’s cells can last over 800 cycles with greater than 80-percent capacity retention.  Consider that a battery pack enabling a week of average driving (40 mile out-and-return commute X 5 + weekend driving) allows weekly recharging.  800 weekly cycles would give a battery life of over 15 years, and the batteries would still be capable of at least five days of driving between charges.
  • Low-temperature operation: QuantumScape’s solid-state separator, designed to operate at a wide range of temperatures, has been tested to -30 degrees Celsius, temperatures that render some other solid-state designs inoperable, according to GreenCarCongress.
  • Safety: QuantumScape’s battery is fire resistant because its solid-state separator is noncombustible and isolates the anode from the cathode even at very high temperatures.

J. B. Straubel, fifth employee at Tesla and considered one of its founders, is a member of the Quantumscape’s board. He notes the anode structure in a conventional lithium-ion battery stalls progress. “Although it’s been optimized for graphite, improvements in the current technology are ‘approaching asymptotic.’”

Straubel offers some hope for energizing future aircraft.  “Jumping to 50-[percent] improvements in energy density is game changing. Those type of energy density, power density and charge rate improvements unlock lots of new applications. Electric aviation looks more viable when you have this kind of energy density and power.”

Note that anode doesn’t essentially exist until charging occurs

Quantumscape has 200 patents and a $300 plus million funding commitment from Volkswagen.  VW has an incentive to go full electric following its part in the Diesel debacle that implicated many European auto makers in scandals arising from the companies fudging their emissions data – often with onboard hardware and software.  Electric cars offer a viable “out” to achieve compliance with emissions standards and get back in good standing with the public.

A Nobel Endorsement

GreenCarReports includes this high-level endorsement.  “The hardest part about making a working solid-state battery is the need to simultaneously meet the requirements of high energy density (1,000 Wh/L), fast charge (i.e., high current density), long cycle life (greater than 800 cycles), and wide temperature-range operation. This data shows QuantumScape’s cells meet all of these requirements, something that has never before been reported. If QuantumScape can get this technology into mass production, it holds the potential to transform the industry.”

—Dr. Stan Whittingham, co-inventor of the lithium-ion battery and winner of the 2019 Nobel prize in chemistry

Let’s hope this potential can be realized quickly.

Addendum: It would be nice, in this editor’s opinion, to see hard numbers on the Watt-hours per kilogram for these batteries.

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A 5-10X Battery from Silver Oxide and Zinc

University of California at San Diego researchers headlined a report with fairly astonishing news:“A flexible screen-printed rechargeable battery with up to 10 times more power than state of the art.”  Combining their science with the manufacturing expertise of a hearing-aid battery maker, they have come up with a silver oxide and zinc battery that can be screen printed in normal lab conditions.  Normally, such production requires a sterile environment under vacuum.

So far, the battery technology seems to be limited to hearing air-sized coin cells, or in the case of UC San Diego’s work, printable displays on wearables.  On smaller scales, such batteries could be used to power Internet of Things (IOT) sensors and transmitters, alerting folks when an oven kicks on or the ketchup in the refrigerator is getting low.  One big question your editor has is whether this tech can successfully make electric vehicle batteries with significantly improved power and energy density to make a difference.

The jointly-produced paper by UC San Diego and battery maker ZPower is published in the December 7 issue of the scientific journal Joule.  Lu Yin, a co-author and Ph.D. student in Professor Joseph Wang’s UC San Diego research group, makes some graduate-level observations regarding the silver-zinc cells.  “Our batteries can be designed around electronics, instead of electronics needed to be designed around batteries.  The areal capacity for this innovative battery is 50 milliamps per square centimeter at room temperature—this is 10-20 times greater than the areal capacity of a typical Lithium ion battery. So for the same surface area, the battery described in Joule can provide 5 to 10 times more power.  This kind of areal capacity has never been obtained before.  And our manufacturing method is affordable and scalable.”

ZPower’s hearing aid batteries follow a fairly conventional coin cell configuration

The summary for the article focuses on battery performance.  “The rise of flexible electronics calls for cost-effective and scalable batteries with good mechanical and electrochemical performance. In this work, we developed printable, polymer-based AgO-Zn batteries featuring flexibility, rechargeability, high areal capacity, and low impedance. Using elastomeric composites, the current collectors, electrodes, and separators can be fabricated via a high-throughput, scalable, and layer-by-layer screen-printing process and vacuum-sealed in a stacked configuration. The batteries are customizable in sizes and capacities, with the highest obtained areal capacity of 54 mAh/cm 2 for primary applications. Advanced X-ray tomography, impedance spectroscopy, and rigorous deformation tests were used to characterize the battery. The batteries were used to power a flexible E-ink display system that requires a high-current drain and exhibited superior performance compared to commercial lithium coin cells under the same pulsed-discharge conditions. The developed battery presents a practical solution for powering a wide range of electronics and holds major implications for the future development of high-performance flexible batteries.

The battery is flexible, rechargeable and made by screen printing specially formulated inks.

With higher capacity brought about by lower impedance – resistance to alternating current – it can outperform “conventional lithium-ion batteries.  Zinc and silver in the right combination allows stability and high performance in the battery.

Jonathan Scharf, a co-first author of the Joule paper and Ph.D. candidate in the research group of UC San Diego’s nanoengineering Professor Ying Shirley Meng, sees the commercial potential for the cells in IOT applications.  “As the 5G and Internet of Things (IoT) market grows rapidly, this battery that outperforms commercial products in high current wireless devices will likely be a main contender as the next-generation power source for consumer electronics.”

Even twisted this much, battery can still light LED

Consumer-based items could include clothing, which might even fall into “smart” categories.  The team’s batteries have successfully powered a flexible display system equipped with a microcontroller and Bluetooth modules.  Think of a flight jacket that carried its own communications abilities, including an emergency location transmitter (ELT).  Suitable for fairly rough wear, the batteries hold up to flexing and twisting and maintain capacity after 80 charge/discharge cycles.  Best of all, perhaps, the batteries are not flammable – important in clothing.

Silver, Zinc and Screen Printing

Meng, director of the UC San Diego Institute for Materials Discovery and Design focused on not only performance, but the manufacturing process.  To create the battery, the researchers used a proprietary cathode design and chemistry from ZPower.  Wang and his team contributed their expertise in printable, stretchable sensors and stretchable batteries. Meng and her colleagues provided their expertise in advanced characterization for electrochemical energy storage systems and characterized each iteration of the battery prototype until it reached peak performance.”

To maintain the stability necessary for a safe battery and the desired high performance levels, the team used a proprietary lead oxide coating.  Depending on the amount of lead involved, this might make the batteries unsuitable for certain applications or environments.  The specially developed coating allows silver oxide (AgO) to be used in a special ink for printing.  Batteries can be printed onto a high-temperature tolerant polymer film in seconds and dry and ready for use in minutes.  Future possibilities include high-speed roll-to-roll printing.  This would allow scaling up operations, but to what level is unclear at this time.  UC San Diego reports, “The team is already at work on the next generation of the battery, aiming for cheaper, faster charging devices with even lower impedance that would be used in 5G devices and soft robotics that require high power and customizable and flexible form factors.”

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Graphene is fascinating stuff, with tons of promise.  Whether it can produce usable results for energy storage is still an open question. But Samsung and a startup called Real Graphene may have at least a start in that realm.  GAC, a Chinese auto firm, seems to be promising batteries before the end of what is left of this year.  There may be hope in the midst of a dark winter.

Samsung’s Lagging Promise

In 2017 a team of researchers at the Samsung Advanced Institute of Technology (SAIT) developed a “graphene ball,” promising  a 45-percent increase in capacity, and five times faster charging speeds than standard lithium-ion batteries. Hoping to power mobile devices and electric vehicles, SAIT collaborated closely with Samsung SDI* as well as a team from Seoul National University’s School of Chemical and Biological Engineering.

*Not a simple abbreviation, SDI stands for “Samsung with the initial letter S, ‘Display’ and ‘Digital’ with D and ‘Interface’ and ‘Internet Component’ with I.”  This may not be the cleanest job of corporate branding ever.

Regular lithium batteries in vehicles can take considerable time to fully charge.  “Topping off” the batteries at home from a 120-Volt outlet can take days to fully charge a long-range vehicle such as a Tesla.  According to Samsung, “In theory, a battery based on the “graphene ball” material requires only 12 minutes to fully charge. Additionally, the battery can maintain a highly stable 60 degree Celsius temperature, with stable battery temperatures particularly key for electric vehicles.”

Samsung’s graphene balls mix low-cost silica with more expensive graphene

Graphene balls mix affordable silica (SiO2) with mass synthesized graphene, and used these popcorn-ball-like spheres as both the anode protective layer and cathode materials in lithium-ion batteries.  Despite the increased charging capacity, reduced charging time (as low as 12 minutes for a full EV charge), and stable temperatures throughout all operations, we haven’t seen much from Samsung since 2018 on the subject.

Disappointing, since Dr. Son In-hyuk, who led the project on behalf of SAIT, had higher hopes for the potential outcome.  “Our research enables mass synthesis of multifunctional composite material graphene at an affordable price. At the same time, we were able to considerably enhance the capabilities of lithium-ion batteries in an environment where the markets for mobile devices and electric vehicles is growing rapidly. Our commitment is to continuously explore and develop secondary battery technology in light of these trends.”

SAIT reported its findings in a 2017 Nature Communications article, “Graphene balls for lithium rechargeable batteries with fast charging and high volumetric energy densities.”

Real Graphene Picks up the Ball

Promoting factors that make graphene a great material for batteries, Real Graphene produces an actual graphene battery product.  Their Power Banks, pocket-size recharging stations for other electronic devices, come in 60 Watt, five and 10 Amp-hour sizes, and in a 10 Amp-hour, 100 Watt model.  The smallest, G-Lite Power Bank, can be fully charged in 17 minutes, much faster than the two hours it takes to charge a similar unit with a conventional lithium-ion battery.

It can be recharged 1,000 times, three years’ use if fully charged and discharged daily.  At $59.95, it is in the middle-cost range for more conventional lithium-ion power banks.

Because graphene has very low resistance, there is little heat buildup in passing current through it.  This contributes to the possibility that graphene-enhanced batteries will last longer and pose no thermal runaway threat.  The company has ambitions to move on to bigger projects, including energy storage for electric vehicles.

Real Graphene’s CEO Samuel Gong met with Microsoft President Brad Smith at the Nixon Library in Yorba Linda, California.  Although Real Graphene is reserved about what was discussed, the firm hints that their power banks could be used to charge Microsoft’s Surface devices.  Or they might be directly integrated into MS devices.  Corporate clients would enable Real Graphene to accelerate research and development.

Challenges

With all the promising characteristics of graphene, we’re left wondering why this isn’t a commonly available material for exciting applications.  Nanowerk reports, “One of the greatest challenges being faced today in commercializing graphene is how to produce high quality material, on a large scale at low cost, and in a reproducible manner.”

Apparently, quality defects detract from promised performance.  Nanowerk lists, “…the presence of defects, impurities, grain boundaries, multiple domains, structural disorders, [and] wrinkles in the graphene sheet [which] can have an adverse effect on its electronic and optical properties.”  Using a chemical vapor deposition (CVD) process enables large size samples, but producing high quality and negligible defects is difficult.

A Ray of Light?

In what looks like a hopeful sign for “graphene-enhanced” batteries, “Chinese EV maker Guangzhou Automobile New Energy (GAC) has announced that it has developed a graphene-enhanced battery for [electric] vehicles which will be available for mass production at the end of this year.”  Announced in May, GAC reported that its graphene technology can charge batteries (assuming EV units) up to 85 percent in eight minutes.

From 2014 on, Guangzhou Automobile Group started that research, focusing on the preparation and application of 3D structural graphene (3DG) material.  GAC officially announced a “super fast-charge battery.”  Since then, the company has, “…successfully completed the testing of the battery cell, module, and battery pack samples, and carried the whole vehicle for high power charging test. Plus, the battery life and safety have reached the usage standard.”

This May 13, GAC Group’s new energy division announced graphene battery mass production will move from the laboratory to actual vehicles, starting with GAC Aion’s model lineup.  GAC’s “independent intellectual property” applies to the firm’s self-developed 3DG-based “superfast charging batteries.”  Charging to 85-percent of capacity in eight minutes, GAC’s batteries share comparable times for refueling a conventional fossil-fuel powered vehicle.

Other reports indicate the same graphene technology may be applied to hydrogen fuel-cell powered cars.  After some false starts, graphene may finally come into its own.

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