Rice Defeats Dendrites

Dr. James Tour of Rice University makes news regularly with different ways of making better batteries.  His latest, a thin-film coating of carbon nanotubes, will enable lithium metal batteries to potentially achieve their full potential.

Rice University chemist James Tour, left, graduate student Gladys López-Silva and postdoctoral researcher Rodrigo Salvatierra use a film of carbon nanotubes to prevent dendrite growth in lithium metal batteries, which charge faster and hold more power than current lithium-ion batteries. Photo by Jeff Fitlow

According to the Tour Laboratory, that potential is worth considering.  “Lithium metal charges much faster and holds about 10 times more energy by volume than the lithium-ion electrodes found in just about every electronic device, including cellphones and electric cars.”  This promise is offset by problems with dendrite growth, the intrusion of tooth-like projections from the surface of the anode metal.  If these growths expand far enough, they poke through the battery’s electrolyte and severely limit battery life.  Worst of all, if the dendrites reach the cathode, they short out the battery, and possibly cause thermal runaway and  fires.

Microscope images of lithium metal anodes after 500 charge/discharge cycles in tests at Rice University show the growth of dendrites is quenched in the anode at left, protected by a film of carbon nanotubes. The unprotected lithium metal anode at right shows evidence of dendrite growth. (Credit: Tour Group/Rice University)

Tour and his student researchers have found that coating the lithium metal electrodes with a thin layer of carbon nanotubes keeps dendrites under control, and allows fast charging and an extended number of charge-discharge cycles.

Tour explained a surprising aspect of the team’s solution. “What we’ve done turns out to be really easy.  You just coat a lithium metal foil with a multiwalled carbon nanotube film. The lithium dopes the nanotube film, which turns from black to red, and the film in turn diffuses the lithium ions.”

Researchers explain, “When the battery is in use, the film discharges stored ions and the underlying lithium anode refills it, maintaining the film’s ability to stop dendrite growth.”

An illustration shows how lithium metal cathodes developed at Rice University are protected from dendrite growth by a film of carbon nanotubes. (Credit: Tour Group/Rice University)

Rice postdoctoral researcher Rodrigo Salvatierra, co-lead author of the paper with graduate student Gladys López-Silva explains, “Physical contact with lithium metal reduces the nanotube film, but balances it by adding lithium ions. The ions distribute themselves throughout the nanotube film.

After stopping dendrite growth for 580 charge-discharge cycles, a sulfurized-carbon film helped the full lithium metal test cells retain 99.8 percent of their coulombic efficiency, “the measure of how well electrons move within an electrochemical system.”

Current research is just the latest in several breakthroughs announced by the school.  Last May, the Tour Laboratory announced development of a graphene nanotube hybrid lithium metal battery with three times the energy density of a conventional lithium-ion cell.  Another development, the use of asphalt, of all things, to help lithium batteries charge faster was announced last October.

Co-authors of the paper, published in Advanced Materials, are Rice alumni Almaz Jalilov of the King Fahd University of Petroleum and Minerals, Saudi Arabia; Jongwon Yoon, a senior researcher at the Korea Basic Science Institute; and Gang Wu, an instructor, and Ah-Lim Tsai, a professor of hematology, both at the McGovern Medical School at the University of Texas Health Science Center at Houston. Tour is the T.T. and W.F. Chao Chair in Chemistry as well as a professor of computer science and of materials science and nanoengineering at Rice.

The research was supported by the Air Force Office of Scientific Research, the National Institutes of Health, the National Council of Science and Technology, Mexico; the National Council for Scientific and Technological Development, Ministry of Science, Technology and Innovation and Coordination for the Improvement of Higher Education Personnel, Brazil; and Celgard, LLC.

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Fred To Receives a Well-Deserved Award

Fred To (pronounced Toe) lives in England and was one of a small group who built and flew the world’s first solar-powered airplane in December 1978. They flew just a few months before Larry Mauro lofted his solar-riser in April 1979. Both airplanes were limited by the technology of the day, lithium-ion batteries still over a decade away, and the best solar cells achieving less than five-percent efficiency. Fred wrote to tell your editor of the award.

Fred To stands on stage with Prince Albert of Monaco, a patron to green aviation

“I was in Montreux Switzerland a few weeks ago, and on the 22nd of October I received an award from prince Albert II of Monaco for Solar One, which is now formally accepted as the first solar powered aircraft to fly. It was a great occasion and my family are so proud. All the great past pioneers were there and it was an honor to meet them; now I have new friends from all over the world. ”

The occasion, described on Raphael Domjan’s SolarStratos web site, commemorated pioneers in solar energy.  “HSH Prince Albert II of Monaco attended the grand opening of the ‘Pioneers and Adventurers of Solar Energy’ exhibition at the PlanetSolar Foundation hosted by the Fairmont Montreux Palace Hotel. Foundation director, Raphaelle Javet, our very own eco-explorer and Foundation president, Raphael Domjan, and a group of solar energy pioneers gave the Prince a preview of the exhibition.”

Fred wit some of his new friends in the SolarStratos hangar

Surrounded by his family and relishing his new friendships, Fred had what looks to be a great evening and some interesting trips to workshops of fellow innovators.  Inexplicably, Eric Raymond of Sunseeker fame does not seem to have been in attendance.

Self-effacing as always, Fred shared the glory of the moment. “I accepted this award on behalf of my late partner David Williams, also on behalf of Larry Mauro and all the other pioneers present there at the ceremony. I pointed out that not many of those present would have even heard of Larry Mauro. To the credit of the organizers, they also mentioned Larry in their book for that occasion. And to think that my ex-wife and David’s widow Anne both used to say that David and I were playing at building aeroplanes and not earning a living. I’m glad that I was also a film maker and so there is a video record of the project.” His half-hour film shows the efforts he and David Williams exerted to bring the project to fruition.

After this achievement, what was Fred to do? He followed up with dozens of other amazing flying machines, including an inflatable flying wing that featured the first fly-by-wire control system.

Popular Science, in its March, 1982 issue, noted the most impressive part of a most impressive project. “The most intriguing feature of the design is that flight control by the pedaler is not necessary. The 11 electric model airplane servos that operate the ailerons, elevator and rudders can be remotely-controlled with a transmitter by a ‘pilot’ on the ground.”

Phoenix Prototype on London Docklands, March 1982

Fred had the first “fly-by-wire” aircraft in the world, brought about by the airplane’s extreme flexibility that obviated the use of conventional control cables. That extreme flexibility led to extreme crashworthiness, the aircraft (and pedaler) surviving several short plummets to earth with a flubber-like resilience.

These excursions into human-powered flight led to Fred’s long-term association with what became the British Human Powered Flying Club. His work with inflatable craft led to an association with Prospective Concepts, a Swiss firm that often astounds with its flying creations. He helped create a flying Stingray that swept its way through Czech and Swiss skies with over 300 flights from 1995 through 2000.

Commentary with the video explains, “Res Kammer worked side by side with Fred To to develop cutting patterns for all fabrics and the construction of this prototype for Prospective Concepts in Switzerland. The workshop was based at Burgdorf. Alan and Fred To shared the camera work. The pneumatic management was designed and produced by Hansueli Ammann. Thomas Rozhon, Jorg Kammer and Stepfan Zechner did all the cutting and gluing. The fabric was obtained from Greengate polymer in the UK.”

Prospective Concepts had some interesting prospects in mind for the Stingray, although they don’t seem to have yet been realized. A “new and improved version” is to have pneumatic controls, a cabin integrated into the weight-bearing geometry, electric ducted fan propulsion and “a multifunctional landing gear.”

Whatever comes of his enormously creative machines, Fred will continue with more surprises for all of us. These surprises will be quietly astonishing, joyful things, reminding us all of what dreams can become.

This Just In!

Fred sent an additional detail about his inflatable wing this morning.  “I am now trying to develop a smaller version of Phoenix, it will be machine made and will be 0.8 scale of the original, weight will go down a lot and I hope it could be sold cheaply. The owner will only need to order a replacement wing if it is damaged. I’m starting to get a small team together and find a backer.”

The original Phoenix was a hand-made effort, with Fred recruiting some talented seamstresses to sew a complex inflatable structure together.  Machine production could bring production costs down considerably.  Since the original could be rolled up and transported on Fred’s compact car, the 80-foot version should be even more portable.  At one point, Fred had considered putting an electric motor on Phoenix to assist the human power plant.

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The Diamond/Siemens Hybrid Test Bed

One should follow Dr. Frank Anton’s Twitter account – or at least check it occasionally.  Dr. Anton is head of Siemen’s Electric Aviation Division and posts new developments regularly.  Siemens is supplying motors to Diamond Aircraft’s prototype hybrid, a tidy tri-motor if you count the engine/generator in the nose of the formerly single-engine airplane.

Diamond/Siemens DA-40 reconfigured with canard-mounted motors.  Photo: Diamond Aircraft

Partnered with Austria’s Diamond Aircraft Industries GmbH, Siemens motors powered an adaptation of their DA40 four-seat airplane.  A Diesel engine/generator in the nose of the formerly single-engine machine charges two 12-kilowatt batteries behind the passenger compartment and provides power to the two Siemens motors on the canard.  The whole thing looks a bit like a large economy-size Cri-Cri.

Started in 2013, the project is under the supervision and finance of the Bundesministerium für Wirschaft und Energie (BMWi, German Ministery of Economics) and the Forschungsförderungsgesellschaft GmbH, FFG (Society for the development of the research, Austria). The project has been split into two main work packages.

Siemens AG was responsible for the design and development of the electric powertrain, done within the framework of the German LuFo program, run under the DLR, Germany’s NASA.  Diamond Aircraft was responsible for the reconfiguration of the aircraft and installation of the hybrid-electric powertrain.  Diamond partnered with the TERA Group and the Johannes Kepler Universität Linz to perform aerodynamic analysis of powerplants and airframe.

Modified DA40 in front of Austria’s Diamond Aircraft factory. Photo: Diamond Aircraft

With a 110 kilowatt (147.4 horsepower generator in the nose and two motors on the canard putting out a combined 150 kilowatts, a pilot has a range of choices that allow safe flight.  Diamond reports, “With a dedicated power lever, the pilot can control the energy flow between the generator, batteries and motor. The pilot can select either pure electric mode (generator off), cruise mode (generator provides all power to the motor), and charge mode (generator charges the batteries). Pure electric, the aircraft has an endurance of approximately 30 minutes. The hybrid system extends this to 5 hours.”

Diamond’s test pilot Ingmar Mayerbuch’s smile reflects success of initial flight.  Photo: Diamond Aircraft

Diamond’s test pilot, Ingmar Mayerbuch, was satisfied with the system and the results of his 20-minute outing in the hybrid.  “The first flight exceeded all our expectations. The combination of the hybrid powertrain and the configuration of the aircraft is just perfect. We reached 130 knots at medium power output and climbed to an altitude of 3,000 feet.”  Ingmar was able to try out all three power modes during the October 31st flight.

Siemens and Diamond anticipate a five-percent growth per year in air traffic over the coming decades.  Each firm realizes it needs to take responsibility to counter growing aircraft emissions.  Until batteries are able to pull all the weight of that charge, we will probably see hybrid aircraft of varied configurations to increase fuel efficiency and lower emissions.

This configuration provides added safety, with the airplane capable of a safe landing even with partial systems’ failure.  Dr. Anton sees the reduced use of fossil fuels, the economy of operation and the safety of the approach as good omens for the future.  He explains, ““Serial-hybrid electric propulsion systems and distributed propulsion architectures for us are the key to a more sustainable flight future also in higher power classes. The Diamond flying testbed will help us to understand the requirements for these new propulsion technologies and to be prepared for the challenges of larger-scale applications.”

He sums it all up in an October 30 Tweet.

#HybridElectricPropulsion technology for #eAircraft is more than just a compromise until batteries improve. Many advantages of its own. Distributed propulsion with cables instead of shafts. Battery as backup power. Low noise. Better fuel economy.

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Richard Glassock, Jeff Zaltman and Air Race E

Richard Glassock and Beacons of Excellence

Richard Glassock is an Australian scholar and designer currently living in Nottingham, England, working as a Professor at the University of Nottingnam.  One if the founding lights in the Outback Joe competions, in which teams launched autonomuous aircraft into remote parts of Australia to find the eponymous character and deliver aid, he was on the forefront of things to come.

Richard Glassock’s electric motorglider would take parties of six to cloudbase

Later, he designed a twin-motored sailplane to take parties of six or eight to cloudbase, a perfect outing for kid’s parties or adult’s anniversary celebrations.  He was part of a team that designed a modern hybrid parachute jump plane, optimized for rapid turnarounds.  His motorcycle range extender would enable a pilot to ride to the airport in style, and when connected to an electric or hybrid aircraft, provide long range – and at the end of the flight – a ride home.

Jam-pakced motorcycle range extender would get pilot to the airport, two passengers to aerial destination

Not only a professor, Richard is project lead for this Beacon of Excellence project – one of several at the University.  (The other Beacons are dedicated to eradicating human slavery worldwide, improving food security, creating precision medical imaging, developing carbon-neutral chemicals, and making smart products in smart factories.)    “Through strategic investment in facilities, talent and research programs, and collaboration with academic and industrial partners, the University of Nottingham is at the forefront of this exciting revolution in aerospace transport.”

Richard Glassock (left) with Jeff Zaltman and Air Race E Cassutt racer being modified for electric flight

Richard will be developing a motor, controller, battery and support system for Air Race E, a racing platform in which all aircraft will use the same power system, much like current Formula 1 racers use a Continental O-100 as their base powerplant.  These systems will go into what will undoubtedly be a new series of unique race planes, much like the range of craft we see at the Reno Air Races and other outings.

Jeff Zaltman and Air Race E

Expanding air racing worldwide, Jeff Zaltman is the Chief Executive for Air Race 1 and the recently announced Air Race E.  Both feature groups of eight airplanes  flying around a closed circuit about 30 feet above the ground and at 400 kilometers per hour (248 mph).

Zaltman, a Navy veteran, decided to become involved in competitive aviation after seeing the Reno Air Races.  To provide publicity and to manage air races and other such events, he founded The Flying Aces in 2003.  He was successful in negotiating “an exclusive broadcast contract with the World Air Sports Federation for every aerial world championship—including hang gliding, hot air balloons, blimps, skydiving, helicopters and more.”

Moving into creating an international racing program, he started Air Race 1 in 2013 and  managed Virgin Racing’s Formula E team starting in 2016.  Perhaps inspired by this new type of motorsport, Zaltman decided to form Air Race E, with competition closely matching that of the fossil-fuel-burning racers.  Like Formula 1/Formula E ground-bound races, Air Race 1 and E events will take place at the same venues, helping boost attendance and maintaining the quality of competition.  Zaltman sees the electric racers extending their popularity and influence beyond that of the internal-combustion craft.

Formula Air Racing Association president Des Hart  may agree. “It is crucial that we have a structure like Air Race E in place to provide the leading edge to development while propelling the sport and inspiring audiences.  The electric revolution is poised to change aviation, and Air Race E will play an important role in the advancement of technology.”

Jeff Zaltman shares this enthusiasm.  “Since the announcement of the Air Race E series we have been overwhelmed by the response of innovators and leaders within the aviation sector and we are delighted to be working with the pioneering University of Nottingham Beacon Program to help drive change within the industry.”

Look for such partnerships between industry and academia to help create the next generation of electric power systems and develop new forms of competition that will help prove their designs.

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The C4V Battery – Solid-State in Production?

Jeffrey Engler of Wright Electric posted an item about Charge CCCV, LLC (C4V) which “demonstrated a prototype of its new Solid State Battery (SSB) at the NY BEST 2018 Fall Conference in New York.  The Company’s SSB solution delivers higher performance, higher density, lower cost batteries that promise to require significantly less charging time than others.”  The startup announced a 380 Watt-hour-per-kilogram battery already in production.  Since your editor tends to become a bit snarky about the usual two-to-five-year period of anticipation before these numbers become reality, he rushed to check out the claims.

Will the one gigawatt-hour plant be open by 2019 – or 2021. Differences between the time scale and C4V’s text leads to some confusion – at least for your editor

Plausible Numbers, but Uncertain Time Frame

The firm’s numbers are not wildly excessive, and they seem to be getting funding and finding partnerships with established companies.  The video is not great proof of anything other than that a metal box with the company’s logo exists.  Their web site gives credibility to their ability to produce actual batteries.

According to C4V, “Approximately 80% of the cost to produce lithium ion cells originates from four major components: the anode, cathode, separator, and electrolyte.”  The company has “discovered, patented and commercially developed” anodes, cathodes and at least 15 other sub-component for their batteries and created means of manufacturing cylindrical, pouch and prismatic cells.  Their approach avoids high temperatures and chemically toxic treatments of materials and provides high yields for components.  The company says they have achieved 70-percent yields compared to 40-percent for similar processes for the industry in general.  Their processes also use less energy and allow lower costs for final products.

Their chart of projected energy densities seems at odds with some of the company’s texts, but the more conservative numbers are probably plausible.  Overcoming one major problem in creating silicon electrodes, C4V says its, “…composite silicon technology prevents catastrophic volume expansion via nano-structuring. By allowing the primary particles to expand internally and not crack, structural integrity is maintained and improved performance is achieved.”  This ability to retain silicon’s structure despite its swelling and flexing under charge and discharge has plagued battery developers for years.  C4V’s solution, if as effective as claimed, would be a major breakthrough.

In its second generation, C4V hopes to expand the temperature range in which its electrolyte can operate.  This is a constraint in conventional liquid electrolyte batteries, but C4V is pushing toward higher percentages of solid-state materials.  The company will also focus on optimizing electrode formulations.

Third generation cells will be available commercially in 2025, taking us to a seven-year wait.  C4V diminishes our hopes for a near-term battery with which to power our aircraft and give our cars 500-mile range.  “Our initial tests from Generation 3 batteries demonstrate energy densities and volumetric capacities of 400Wh/kg and 800 Wh/L. We confidently project these unique batteries will be ready for volume manufacturing by 2025 along with a stable supply chain.”

But Wait! or But…Wait?

This seems to contrast with the overview for their technology, which states the current energy density of 380 Wh/kgC4V adds that they have been able to replace up to 80-percent of liquid electrolytes.  Further, they state, “the Company is already targeting a 400Wh/kg and 750 Wh/liter milestone within the next six month timeframe before commercial process optimization starts. In the first half of 2019, C4V plans to announce the availability of its commercial cells to the market.”

Imperium 3 batteries will be available in several formats

With others such as OXIS Energy and Sion Power pushing those (or better) energy and volumetric densities, C4V possibly needs to update their time scale.  It also needs to reconcile visual charts with their texts, with the hope that will clear up what seem to be inconsistencies in their presentations.

The firm has partnerships with “Magnis Resources, an Australian company specializing in end-to-end sourcing of raw materials for LIB manufacturing, and Boston Energy and Innovation, an ethical investment house responsible for financing and fostering sustainable energy solutions.”  That group will produce an Imperium 3 battery line by 2021 at a planned gigafactory, probably in in the state of North Rhine Westphalia Germany.

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Terrafugia’s TF-2

Terrafugia, unabashedly calling its vehicles “flying cars” in many of its public pronouncements, has floated a concept that is a serious departure from their two previous designs.  The TF-2 will be the equivalent of a shuttle bus, but with an aerial means of making a longer haul than mere in-town hops.

Started by MIT graduates, many of them members of the rocketry club, Terrafugia has managed to garner an enormous number of media hits.  It even became a possible Christmas gift in the 2010 Hammacher Schlemmer Christmas catalog.

Hammacher Schlemmer offered early version of Transition in its 2010 catalog

It flew its Transition before the crowds at AirVenture in 2013, and was able to obtain certification as a Light Sport Aircraft since then, but with a slightly higher than original LSA weight allowance.  That seems to be moot at this point, since the FAA is going to allow LSA pilots to fly aircraft up to 3,600 pounds.

Popular Science reported in 2014, “To meet highway-safety requirements, the Transition needs to be heavier than the 1,320-pound limit the FAA has set for LSAs, which lead Terrafugia to apply for a waiver from the limit in 2014. The stall speed of the flying car is also inevitably going to be above the 45-kt. maximum for LSAs, but certain automotive safety features like a safety cage and crumple zone could be beneficial in general aviation, leading the FAA to waive the weight and stall-speed limits for the Transition. It’s a big win for the car, which still faces a host of challenges before it can really come to market.”  Because it’s a flying car, the craft has airbags, something not widely adopted in airplanes.

Features in the promised 2019 production models will include a hybrid-electric motor combining an internal combustion engine and a LiFePO4 (lithium iron phosphate) battery.  The throttle will include a boost feature “for a brief burst of extra power while flying.”  The interior will seat two in front of an “intuitive user interface experience.”  Three rearview cameras in drive mode will add to driving safety. Dynon will provide Electrical Flight Information Sytems (EFIS) and BRS will supply a full frame parachute system.

With its purchase by China’s Geely Holding Group (also owner of Volvo and Lotus car groups), Terrafugia has since introduced a concept vehicle, the T-FX.  It seems to be the combination of SUV and flying taxi, able to be kept in the garage and lofting its passengers skyward with a few touches of buttons and probably autonomous controls and navigation.  It’s the best of the Jetsons and early Popular Mechanics covers.

Popular Mechanics promoted home-bound flight vehicles throughout its history.  You can visit the actual machine in the Hiller Aviation Museum in San Carlos, California

A hybrid, the TF-X would fly with a 300-horsepower (220 kilowatt) engine and two electric motors for a combined output of a megawatt (1,341 horsepower).  These are projected to give a top speed of 200 miles per hour, a cruise speed of 160 mph, and enable a 500-mile range.  The highly automated control system would allow a new pilot to learn to fly the TF-X in about five hours, according to the maker.

The T-FX has caused some Tweets, mainly about where it is in its stage of development.  Donald Bensen asked: @Terrafugia when will the TF-X appear at either an auto show or an air show? Would love to check it out.

He received this response: The TF-X is still in concept at this point but check out our newest item at http://terrafugia-tf2.com  ! #ExcitingThingsAreHappening! #FlyingHigh

That Tweet seems to be a bit of a diversion, but it points to another Terrafugia concept, the TF-2.

There seem to be several renditions of the TF-2, each carrying a similar “LPP” cargo pod.  One is a tilt rotor machine, with two large Osprey-like fans and a single large propeller in the tail to propel the machine forward.  The TF-2 shown in the first video has the two large tilt rotors, for instance, but at least two configurations.

LPP pod can carry either passengers or cargo

eVTOL.news reported the aircraft would have a maximum takeoff weight of 7,500 to 8,000 pounds (3,400 to 3.630 kilograms) with a payload of 900 to 1,100 pounds (400-500 kg.) including a 30-minute fuel reserve.  It could carry its four passengers or cargo 240 to 300 nautical miles (445 to 555 kilometers) at a maximum cruising speed of 170 to 180 knots (315 to 333 kilometers per hour).  eVTOL.news estimates the cost per flight hour at $380 to $420.  That would average out to $95 to $105 per flight hour per passenger – not bad for at least 240 miles door-to-door, or at least between in-town landing zones.

TF-2 in two of its variants, leaving outsiders to ponder which will become the production vehicle

The current video shows a multi-rotor TF-2 with four vertical lift rotors and one rearward-facing propulsors (the vocabulary is still under development).  The number and arrangement vary in different renderings, making it a guessing game until the prototype is unveiled.

With a large infusion of cash from Geely, Terrafugia seems to be taking a new course, possibly a more realistic one than their original vision.

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The 17X Aluminum-Air Battery?

Jaephil Cho has a surprise for us – an aluminum-air battery that is potentially (no pun intended) more energetic than gasoline.  Director of the Research Center for Innovative Battery Technologies and Professor in the School of Energy and Chemical Engineering, at Ulsan National Institute of Science and Technology (UNIST), Cho and his students have released over 350 papers, including one titled, “Seed-mediated atomic-scale reconstruction of silver manganate nanoplates for oxygen reduction towards high-energy aluminum-air flow batteries.”

While such titles might not get him on the NY Times best-seller list, Cho is widely respected, UNIST reporting he has been named to the 2017 Highly Cited Researchers List in materials science, a second such honor for him.

Professor Cho’ Surprise

Professor Cho’s paper (in full) describes the aluminum flow battery he and his team developed.  According to the UNIST News Center, “…Compared to the existing lithium-ion batteries (LIBs), the new battery outperforms the others in terms of higher energy density, lower cost, longer cycle life, and higher safety.  One drawback – the battery is a primary storage device, meaning it cannot be recharged.  It can be readily swapped out of its host vehicle, though.

Even better, it’s more powerful than gasoline – on a pound-for-pound (or kilogram-for-kilogram) basis.  Cho explains, “Gasoline has an energy density of 1,700 [Watt-hours per kilogram], while an aluminum-air flow battery exhibits a much higher energy densities of 2,500 Wh/kg with its replaceable electrolyte and aluminum.   This means, with 1[kilogram] of aluminum, we can build a battery that enables an electric car to run up to 700 [kilometer] (434 miles).”

Electrochemical performance of aluminum–air flow batteries. A Schematic of the aluminum–air flow battery (AAFB) system, which includes a single stack cell, one electrolyte tank, and circulation pump. ORR indicates oxygen reduction reaction. bPower density curves of flow cells using the pristine air electrode, silver manganate nanoplate (SMNp), and Pt/C with 6 M KOH electrolyte (scan rate of 0.1 mA s−1). C Discharge curves using the pristine air electrode, SMNp, and Pt/C at 100 mA cm−2. D Mechanical charge and discharge tests using the SMNp and Pt/C at 25 mA cm−2, where the aluminum and electrolyte were replaced every cycle.  Illustration and caption: UNIST

Possible Israeli Competition

An Israeli firm, Phinergy, promotes its aluminum-air battery as delivering eight kilowatt-hours per kilogram, capable of driving a small car 1,000 kilometers (620 miles) and being recharged in three minutes.  Comparisons are difficult since Phinergy does not have hard data on its web site.  Earlier reports show that Eviation showed interest in powering its aircraft with Phinergy cells, though.  “EViation says that the battery is ‘coupled with a high power rechargeable battery buffer, and managed by a clever mission specific power analytic algorithm.  This unique technology provides high energy density ‘at a cost that beats gas, and with zero emissions.’”  Little new has been heard from the battery company until this last February, when it formed a joint venture with China’s Yunnan Aluminum.  The combined company, Yunnan Phinergy Chuang Neng Metal Air Battery Co Ltd, will have a registered capital of 813.82 million yuan ($128.97 million).

The Israelis were probably drawn to aluminum for the same reasons Cho’s team was – such batteries are potentially “lighter, cheaper, and have a greater capacity than a traditional LIB (lithium-ion battery).”

Innovative Design with Strong Results

Aluminum batteries using “traditional” electrolytes faced problems with high anode costs and difficulties removing byproducts when they were discharged.  Professor Cho and his team developed a flow-based aluminum-air battery to continuously circulate the electrolytes, solving these issues.  The battery and its electrolytes are also fire and explosion proof.

Formation of the stripe pattern and dislocation. a, b Schematic of the synthesis process (a) of the bulk manganese oxides (BM), polyhedron manganese oxide (PM), and silver manganate nanoplate (SMNp), and the summary of the catalytic effects (b) of the SMNp. c–e Scanning electronic microscopy (SEM) images of the BM (c), PM (d), and SMNp (e) showing plate-like structures with silver nanoparticles. f, g High-resolution transmission electron microscopy (HR-TEM) images of the SMNp (f) and high-magnified image (g) of the box in f, which shows zigzag atomic arrangements with intragranular cracking. Fast Fourier transform (FFT) image of g presents the lattice planes of (–100) and (001) along the [010] zone, indicating the orthorhombic structure of Ag2MnO4. h, I Inverse FFT images of applied masks at the blue circle (h) and red circle (i) in g, showing a wide range of dislocations with defects. The dislocations are shown by circles and edge dislocations are represented by a T-shaped symbol. The upper right insets in h and I indicate the applied masks and the lattice spacing of the (101) plane is denoted as the left inset in h. Scale bars, 5 μm (c), 500 nm (d), 200 nm (e), 100 nm (f), 4 nm (g), and 1 nm (h, i).  Illustration and caption: UNIST

According to UNIST, this increased the discharge capacity of aluminum-air flow battery 17 times compared to conventional aluminum air batteries.  “…The capacity of [the] newly developed silver-manganese oxide-based catalysts was comparable to that of the conventional platinum catalysts (Pt/C).  As silver is 50 times less expensive than platinum, it is also competitive in terms of the price.”

Their silver nanoparticle seed-mediated silver manganate nanoplate architecture for the oxygen reduction reaction (ORR allows silver atoms to migrate into the available crystal lattice and rearrange the manganese oxide structure, thus creating abundant surface dislocations.

Comparison of electrode properties and battery performance. A Electrical conductivity of the Ag nanoparticle, bulk manganese oxides (BM), polyhedron manganese oxide (PM), silver manganate nanoplate (SMNp), and Pt/C-loaded air electrodes. b Precious metal dissolution tests in aluminum–air flow batteries (AAFBs) using the SMNp and Pt/C with 6 M KOH electrolyte after 6 h of discharging at 50 mA cm−2. c, d  Comparison of the gravimetric energy density (c) among gasoline with theoretical and practical value, AAFBs with Pt/C and SMNp (at 50 mA cm−2), and comparison of the gravimetric energy density (d) between zinc–air flow batteries (ZAFBs) and AAFBs with the SMNp at 100 mA cm−2. Illustration and caption: UNIST

Jaechan Ryu, first author of the study says, “This innovative strategy prevented the precipitation of solid by-product in the cell and dissolution of a precious metal in air electrode.  We believe that our AAFB (aluminum air flow battery) system has the potential for a cost-effective and safe next-generation energy conversion system.”

One aspect of the study deserves more attention, in your editor’s opinion.  The definition of energy density for “gasoline (practical)” could use a layman’s explanation.  We know that batteries traditionally have had lower energy densities than gasoline or other fossil fuels, but made up for that by the fact that internal combustion engines use only a quarter to a third of that energy in useful work, the rest consumed by heat exchanges and mechanical inefficiencies.  Cho’s work here puts his battery at a level with or superior to gasoline in practical terms.

For a discussion of the practical limits and applications of battery energy densities, see this discussion from GreenTransportation.info.  Your editor found their motto, “Why and how to joyfully move our butts around town, without mucking the place up,” to his liking.

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2018 Electric Aircraft Symposium Now On Line

If you could not attend AirVenture 2018, the CAFE Foundation has recorded and made available all 19 presentations from the Electric Aircraft Symposium.  Hosted by Yolanka Wulff, CAFE’s Executive Director, this high-level course in revolutionary aerodynamics, futuristic thinking and potential rules and regulations for all this creativity, EAS 2018 drew a wealth of great speakers.

You can tap into this wealth here.  Enjoy learning about the turbulent history of VTOL flight from Todd Hodges, a retired engineer from NASA Langley.  He explores why otherwise brilliantly engineered vertical takeoff and landing machines failed, and ends with a note of hope, with DEP and DEAC allowing configurations that solve a lot of problems.

Willi Tacke, Founder and Organizer of the e-Flight-Expo and CEO of Flying Pages GmbH, an international publisher of light aircraft directories in four languages, gave a review of what’s flying now.

Keeping it real, Michael Friend, Chief Engineer for Future Platforms (Retired) for Boeing Commercial Airplanes, and responsible for the first fuel-cell powered aircraft, brings his practical experience toBalancing Optimism and Realism in Electric Aircraft Design.”

Gilles Rosenberger, industrial engineer for the Airbus E-Fan project and CEO of Faraday, takes a daring look at the future, attempting to predict where electric flight will be in 2028.

Kevin Noertker, Co-founder and CEO of Ampaire, and sponsor of the Symposium, discusses, “Accelerating the World’s Transition to Sustainable Aviation”  He shows a series of logical steps Ampaire is taking to make their future craft a reality.

Ampaire’s Kevin Noertker explains his firm’s design to a group of Boy Scouts

Josh Portlock, Founder and Chairman of Electro.Aero.Pty.Ltd in Australia, talks about his career in electric aviation, including making the first electric aircraft cross-country flight on his home turf.  He discusses two major building blocks to sustainable aviation, electrofans and universal charging – while showing the multiplicity of plugs available today.

Bye Aerospace CEO George Bye gives a background and forecast for his two- and four-seat Sun Flyers.

Rosenberger, Noertker and Portlock engage in a panel discussion about their experiences as Electric Aircraft Developers.

Omer Bar-Yohay, Co-founder and CEO of Eviation, discusses his firm’s nine-seat, autonomously-controlled electric aircraft, designed from the beginning to have ultralight construction and a powerful battery installation.  He anticipates manned flight tests in 2019 and production in 2022, and his talk emphasizes how valuable partnerships can make that happen.

Carl Dietrich, C0-founder and CTO for Terrafugia, reveals a surprising new design for the company, the TF-2, a three-part solution to interfacing ground and air transport.

All these new designs will need powerplants, and Luciano Serra, Director for Certification and Safety for MagniX, an Australian motor developer producing light-weight motors from 265 to 560 kilowatts (355 to 751 shp).  He lays out “traps” on the way to certification and discusses a cooperative approach between developers and regulators to helping avoid them.

While many speakers discuss hardware, Tom Gunnarson, former FAA regulator and now Lead of Regulatory Affairs for Kitty Hawk, unsurprisingly talks about rules and regulations, and how industry and regulators will need to work together to create rules for a much-changed operating environment.

Kenneth I. Swartz, Board Member of the Vertical Flight Society; and President of Aeromedia Communications discusses the history of the American Helicopter Society, founded in 1943, and its transformation to the Vertical Flight Society.  He shows the massive changes in technology, and approaches to selling that technology to the public.

Aurora Flight Sciences has pioneered in everything from human-powered flight to eVTOL technology.  Ed Lovelace, a Technical Fellow in High-Power Electrical Systems for the firm, discusses Aurora’s history and its commitment to Large Scale, On-Demand Urban Air Mobility.

With an ever-growing number of lives saved by his BRS ballistic recovery parachutes, Boris Popov, the Founder of BRS Aerospace, is looking at how to bring down eVTOL craft safely.  Designs are necessarily different for these mostly multi-rotor craft, and include laser warning systems to alert those of the ground of a descending eVTOL.

What Path to Scale for Aerial Ridesharing will we follow?  Adam Warmoth, Vehicle Requirements Lead for Uber Elevate, answers those questions – explaining how we will go from small to large scale operations in this new transportation paradigm.

Stan Ross, Founder and CEO of EFX Applied Technology, shows how his firm’s products literally shine a light on danger zones.  IPAS (Intelligent Proximity Alert System) will be useful as growing numbers of passengers arrive and depart on multi-rotor vehicles.

EFX’s laser displays literally illuminate danger areas

Finally, how will we pay for all this new stuff?  Peter Shannon, Managing Director of the appropriately named Levitate Capital, will provide “An Investor’s Perspective to the Opportunity in Advanced Aerial Mobility.”

You can access this resource at any time, and learn from the experts in their fields.  These are opportunities not to be missed.

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Carbon Fiber and the Grand Unified Airplane

Your editor has long held the belief that we are on the threshold of creating a Grand Unified Airplane, a craft that would draw all its energy from solar cells, the flexing of its wings, the air passing over its form, and the very act of flight itself.  It seems to become less of a science fiction ideal and more of real-world possibility every day.  Carbon fiber could be part of that possibility.

What if your airplane were its own battery?  Think of the weight savings and potential endurance and range.  Your editor became fascinated with 2010 research done by Dr. Emile Greenhalgh of Imperial University in London, who developed a structural sandwich with carbon fiber outer layers and a fiberglass core.  It could be used for body panels on a car, inspiring Volvo to become involved and proceed with initial tests.

Since those early tests, other researchers have duplicated and expanded the research, with Dr. Leif Asp of Chalmers University in Gothenburg, Sweden; and Dr. Angela Belcher of MIT adding to our knowledge of these exciting materials.

Dr. Leif Asp at Chalmers

Dr. Asp, Professor of Material and Computational Mechanics at Chalmers University of Technology and an associate of Dr. Greenhalgh’s, has found that carbon fiber can work as battery electrodes and store energy directly.  He explains possible applications: “A car body would then be not simply a load-bearing element, but also act as a battery.  It will also be possible to use the carbon fiber for other purposes such as harvesting kinetic energy, for sensors or for conductors of both energy and data. If all these functions were part of a car or aircraft body, this could reduce the weight by up to 50 percent.”

Leif Asp with a bobbin of carbon fiber yarn. The electrodes in a structural lithium ion battery consist of carbon fiber yarn arranged in a grid in a polymer. Every length of yarn consists of 24,000 individual carbon fibers

Heading a multidisciplinary group of researchers who recently published a study on how the microstructure of carbon fibers affects their electrochemical properties. The team determined some important facts regarding fiber orientation.  “They discovered that carbon fibers with small and poorly oriented crystals have good electrochemical properties but a lower stiffness in relative terms. If you compare this with carbon fibers that have large, highly oriented crystals, they have greater stiffness, but the electrochemical properties are too low for use in structural batteries.”

Gothenburg’s approach to incorporating structural batteries as part of a car, similar to Greenalgh’s earlier design

Dr. Asp notes that stiffness is not a big deterrent for the use of less stiff fiber in cars, and even the stiffer fiber that would be favored for aircraft is still probably energetic enough for aircraft use.  “…The types of carbon fiber with good electrochemical properties had a slightly higher stiffness than steel, whereas the types whose electrochemical properties were poor are just over twice as rigid as steel.”  He adds that for aircraft use,  “It may be necessary to increase the thickness of carbon fiber composites, to compensate for the reduced stiffness of structural batteries. This would, in turn, also increase their energy storage capacity.”  Increased weight leading to increased power and range would not be a deal killer in this application, if carbon’s low weight to strength is taken into account.

Dr. Asp thinks the key to design is optimizing vehicles at the system level – based on weight, strength, stiffness and electrochemical properties.  The auto industry, used to optimizing individual components, will have to change its design philosophies to accommodate less efficient structural batteries as energy storage devices, “but since they have a structural load-bearing capability, very large gains can be made at system level.”

Adding a safety factor, he continues, “…The lower energy density of structural batteries would make them safer than standard batteries, especially as they would also not contain any volatile substances.”

The team’s paper, “Graphitic microstructure and performance of carbon fibre Li-ion structural battery electrodes,” can be found in the journal Multifunctional Materials.

Dr. Angela Belcher at MIT

Dr. Belcher has been working with combinations of seemingly disparate elements for the last decade, having explored making batteries with viruses, studying how to emulate seashells in growing structures and energy storage components, and even using nanotubes and viruses on search and destroy missions against cancer cells.  Her ability to investigate unlikely combinations led to her winning a MacArthur Fellowship in 2004.  This 2011 TED Talk gives a hint of why she would be awarded a “genius grant.”

Her current work in batteries, cancer research and organic structures are all linked, as the earlier video suggests.

Dr. Belcher’s research in structural batteries shows how much that effort has led to something that might be part of a Grand Unified Airplane.  “Currently 60-90% of the weight of the battery package in an electric car or an Unmanned Aerial Vehicle (UAV) is inactive – does not contribute to energy storage.  This project is developing a structural approach to build vehicle components from materials that do contribute to energy storage, which will enable electrical vehicles with longer battery lifetime.”

See Kieran Strobel, a Research Associate at ,  present their project at IdeaStream 2018 below.

Medium.com’s Neo.Life link reports, “Belcher also still does energy research, engineering viruses to generate materials that could be used as part of low-carbon energy systems. She teaches, promotes science in grade schools, and tends to two boys whom she describes as her ‘favorite biomaterials.’ But the ovarian cancer research is not just a one-off. She’s working on improving the efficiency of the technology, extending it to other kinds of cancer, and possibly developing a diagnostic tool or screening tool for high-risk women in the future.

“’I don’t have the answer,’ she says. ‘But I have the commitment.’”

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Eraole in Flight – Further and Higher

Eraole is a unique machine in a sea of unique craft.  Powered by a combination of sunlight, Total biofuel, and hydrogen, Raphael Dinelli’s tandem-winged biplane has been under development for many years.  With it, Raphael hopes to cross the Atlantic in 2019, Duplicating Charles Lindbergh’s 1927 flight at about half the Spirit of the Spirit of St. Louis’s speed.

Eraole’s first flight took place in 2016.  The video will allow you to compare its look then with its changed appearance today.

Changes of Plane, Changes of Plans

Dinelli’s original plan for the flight included the use of an algae-derived fuel to run Eraole’s engine/generator.  As reported by La Tribune, though, “For four years, the Ocean Vital Foundation conducted research with the Fermentalg research laboratory in Libourne to produce a fuel based on micro-algae.

“’Despite the additives that could be added, the oil froze at altitude and became impossible to use,’ says Raphael Dinelli, who had to bring himself to fill up at … Total.”

The Biojet fuel will provide about 70 percent of the energy necessary for flight, with solar cells adding 25-percent.  The remaining five percent will come from a hydrolysis process  that will produce hydrogen to help power the motor.

“We are now using Biojet oil, produced by the manufacturer from recycled sugarcane waste. To this, we add a hydrogen doping, obtained by separating hydrogen molecules contained in the vegetable oil and in water. For now, we do not store in a fuel cell, it may come…

During the last two years, Dinelli added struts between the lower front wing and the upper rear wing, possibly to stiffen the two light, independent structures.

Testing for the Big Challenge

On September 8, Dinelli flew eight hours and reached 7,040 feet. He reported, “At this height, I was able to cross airliners.  It was pretty impressive!” Flying where airliners crossed his path and setting personal best records that day gave him the necessary encouragement to tackle the Latécoère Raid, a voyage down the edges of France, Spain, and Northern African countries to Dakar, Senegal.  The route honored the early Aeropostale aviators such as Pierre-Georges Latécoère,  Jean Mermoz and Antoine de Saint-Exupéry.

Septe,ber 8 flight set eraole record for altitude, duration

While still in France with his airplane, Dinelli had a wonderful experience.  “A huge surprise tonight after an extraordinary performance of the France Vertical Perpignan Patrol. The Pilots of the bam came to see and listen to the operation of Eraole. They gave me all their support and encouragement. I am extremely proud to receive so many compliments of the excellence of the French Pilotage, what a happiness. I will dream all night of a future electric flight patrol – go.  be crazy 😁 eraolelement your Raphael”  (It might benefit from a better translation than computers can givc.)

Members of France’s Air Force Demonstration Team were fascinated by Eraole

Jean-Marie Urlacher

Jean-Marie Urlacher, a highly-skilled aviation photographer, praised Dinelli’s project – and Dinelli.  “A modern day adventurer is clearing a new era of aviation. At the controls of his project Eraole, Raphaël Dinelli former navigator of the Vendée Globe (a racing sailboat), inventor, engineer and now official test pilot of its prototype, flies without any polluting emissions.  A complex challenge that he meets with a tiny team of great talents.  They were few to believe, they are more and more to follow him.  A unique project in the world to support: Challenge Eraole.”

Image: Jean-Marie Urlacher

Abel Sevellec 

Dinelli’s friend Abel Sevellec wrote this poetic homage to Dinelli, appropriate for their mutual love of the French aviation pioneer and writer Antoine de Saint-Exupéry following their voyage down the west African coast.

“It is this marvelous encounter that I have made in these landscapes of sand and sky where wild regions of the soul and the colors of time lend themselves to confidences. They reveal to us the invisible bonds that bind us to the planet and the greatness of man. This is how Raphael, in the footsteps of Charles Lindbergh, [will] attempt in 2019 the crossing of the North Atlantic with his electric-hybrid aircraft Eraole.  Always further, always more innovative, it will come into play, in a total commitment, to take a decisive step towards the future. Towards a clean planet.

“But to accomplish his mission Raphael needs, as with each challenge, a favorable wind as a sign of destiny to get his project off the ground and to overcome all the difficulties.  It’s impressive to hear him talk about all the parameters to master to achieve this.  We wish him this state of grace to crown his efforts and this astonishing passion that devours him and transports him.  This something that drives him to succeed [is] still the impossible because the man never gives up to follow the star which illuminates his way.”

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