It’s a good week when at least three battery developments show promise for electric vehicle use in the near future. One advanced lithium-ion battery from France, a dual-carbon battery from Japan, and a supercapacitor that one can wrap around one’s finger comprise the trio. French Lithium-Tin Dioxide “Synthesizing nanoparticles of tin dioxide (SnO2) in the pores of a carbonaceous material,” researchers at the Institute of Materials Science of Mulhouse and Charles Gerhardt Institute of Montpellier, part of an electrochemical energy storage consortium called RS2E, have found the material to have “remarkable properties.” Their work is the subject of a patent and published in the journal, Advanced Energy Materials. Researchers, hoping to obtain better performance that that achieved with carbon electrodes, tested combinations of nickel (Ni), iron (Fe), cobalt (Co), and other materials before hitting on tin dioxide as a material of choice. All have (theretically) far greater electrochemical storage capacity than graphite, but expand and contract during charging and discharging of the battery, …
EAS VIII: Calin Gologan and George Bye Make a Sunlit Announcement
Calin Gologan of PC-Aero GMBH in Germany and George Bye of Bye Aerospace in Colorado made an auspicious announcement about practical solar-electric propulsion advances for manned and unmanned aircraft. Their presentation at the eighth annual Electric Aircraft Symposium pointed toward a possible rebirth in flight training at prices not seen in decades. Their two companies are forging an alliance called the Aero Electric Aircraft Corporation (AEAC), which will produce a two-seat, side-by-side sport and training aircraft called the Sun Flyer. As stated in their press release, “The Company will bring to market the first U.S.-sponsored, practical all-electric airplane serving the training, recreational and general aviation markets.” Gologan and Bye’s talk at the Symposium focused on their joint plans to create practical solar-electric propulsion advances in manned and unmanned small aircraft. Each partner has demonstrated experience in forging new directions for electric light aircraft. Calin Gologan’s PC-Aero, for instance, consults on propulsion, structures and aerodynamics, and has produced Elektra One, a …
Suppressing Those Pesky Dendrites
Dendrites in the human body are tree-branch-like protuberances that help transmit synapses, defined as tiny transmitters and receivers for chemical messages between the cells. In this setting they are beneficial and necessary for brain and nervous system development. In batteries, however, such protuberances send mixed and negative messages that short out connections between the components of the host battery. This is a serious enough issue that it’s kept lithium-metal batteries from serious development, dendrites growing between dissimilar metals being a malady of such cells, and even causing fires that make lithium batteries a bit fearsome. The blog has reported on efforts by Berkeley Lab researchers to reduce dendrite growth. To enable visualization of these growths, Clare Grey, a professor of chemistry at Cambridge University, teamed up with NYU chemist Alexej Jerschow to develop a way of imaging batteries through magnetic resonance imaging (MRI). As Popular Mechanics explained in 2012, “These moss-like crystalline growths, called dendrites, are the bane of battery builders. …
EAS VIII: Sebastian Thrun Updates Us
Sebastian Thrun is best known for his leadership in the “Google Cars” program, fielding self-driving Priuses in the San Francisco Bay area and having the cars demonstrate a spotless accident record (except for those caused by other drivers running into them.) He shared the current status of that project with attendees at the eighth annual CAFE Foundation Electric Aircraft Symposium in late April. He’s also been responsible for Google Glass, those controversial mega-spectacles that have furnished stand-up comics with new realms of material, although the last laugh may be on scoffers as these ingenious devices point the way toward wearable computers. Thrun’s also created a new type of open university – one that takes advantage of the online experience. “Udacity was born out of a Stanford University experiment in which Sebastian Thrun and Peter Norvig offered their ‘Introduction to Artificial Intelligence’ course online to anyone, for free. Over 160,000 students in more than 190 countries enrolled and not much later, …
Klaus Burkhard and the Archaeopteryx
Klaus Burkhard is a sailplane pilot exploiting the air currents over his native Germany in 120-kilogram (264-pound) ultralight machines (most of which weigh far less) – which may become a part of an increasingly electrified sport. He wrote this to your editor in response to recent coverage of the electric version of a record-setting ultralight sailplane. “I just came over your interesting website, reading your blog about the Swiss Archaeopteryx, where you described the Archaeopteryx as a high-end hang-glider, publishing a picture from an older version in ‘open’ variety. “Of course the Archaeopteryx is classified as hang-glider in the OLC (on-line competition) and also as Class-2 hang-glider within FAI-regulations, as it´s foot-launchable and foot-landable as well, both basic requirements for FAI Class-2. “Since the Archaeopteryx is -contrary to normal hang-gliders- three-axis aerodynamically controlled by elevator, rudder and flaperons, it´s an Ultralight-Glider of the best with fantastic flying-abilities, outstanding flying-performance and uncritical in any situation. L/D is 29 in race-covering. “In 2012 …
EAS VIII: High Torque, Efficiency and Powerful Motors
David Calley heads Planet Rider LLC, a design group working on a highly innovative three-wheel commuter vehicle that combines pedaling, electric power and aerodynamics to make for an exciting ride. Any resemblance between this machine and the average e-bike is like the difference between an early Rogallo wing and the Archaeopteryx. He has made a significant notch in fuel savings for big rig trucks with the angular extensions you see on tailgates of trailers cruising America’s highways. Fuel savings of five percent or more are a boon to fleet operators, thanks to Calley’s patented design, now manufactured by ATDynamics. He is also a member of the CAFE Foundation’s advisory board. Thus, it was informative to see his presentation at the eighth annual Electric Aircraft Symposium. His work on low-RPM motors using his simple transverse flux motor design enables excellent power and high torque from light-weight, compact motors. This fits the need to swing big, slow propellers for applications such as …
EADS Developing Line of Production Light Electric Aircraft
European Aeronautic Defence and Space Company (EADS) has been heating up some batteries lately, announcing production plans for the E-Fan prototype unveiled at the 2012 Paris Air Show and showing a four-seat derivative, the 4.0. Both share the twin-motor ducted fan configuration that makes the trainer and light electric airplane look like an A-10 Warthog, but with much less fearsome aspects. Tony Osborne, reporting in the May 8 online Aviation Week and Space technology, reports, “To produce Europe’s first wholly electric-powered aircraft the Airbus Group is partnering with French industry and entering the light aircraft market. A new subsidiary, VoltAir [lovely French pun], will be set up in the coming months to develop and produce the two-seat E-Fan 2.0 and the four-seat E-Fan 4.0. The two models are being aimed at the general aviation market, and officials say prices will be competitive with those of current piston-engine light aircraft—around $300,000—but with operating costs that are less than a fraction of …
EAS VIII: Barnaby Wainfan and ESTOL Possibilities
Barnaby Wainfan is an aeronautical engineer with Northrop Grumman and famous for at least two things: his Edison 2, a light car with incredibly low Cd that won the Progressive Automotive X-Prize in the Mainstream class and his FMX-4 Facetmobile, an airplane that looks like a private pilot’s F-117 and flies stably and safely. (Video courtesy of Barnaby Wainfan.) Wainfan told the eighth annual Electric Aircraft Symposium audience that short takeoff and landing (STOL) performance is relatively easy, requiring low wing loading and high power. Efficient (e)STOL is harder. The problem is getting a reasonable cruise speed and good range with the big wing required for short takeoffs and the high drag required for short landings. He advised his audience to specify the mission, not the aircraft – with the final airplane flowing from the mission. Short takeoff rolls require light wing loading to allow early liftoff at low speeds, and allow best propeller efficiency. High power allows quick acceleration …
“Double-Duty” Electrolyte Extends Battery Longevity
Morgan McCorkle at the Department of Energy’s Oak Ridge National Laboratory in Tennessee reports that researchers there have developed a lithium-carbon fluoride battery with a thiophosphate electrolyte that generates 26 percent higher capacity than its theoretical maximum if all the components acted independently. This serendipitous outcome causes researcher Chengdu Liang to say, “This bi-functional electrolyte revolutionizes the concept of conventional batteries and opens a new avenue for the design of batteries with unprecedented energy density.” We’ve become accustomed to thinking that a battery’s “three main components – the positive cathode, negative anode, and ion-conducting electrolyte – can play only one role in the device.” ORNL’s battery has a specially-developed solid electrolyte that functions as an ion conductor, and also serves as a cathode supplement, boosting the cell’s capacity and extending the life of the battery. The big drawback at this time is the single-use nature of the battery – a primary unit that is not rechargeable (so far). The lithium …
EAS VIII: High Efficiency Forward Swept Propellers at Low Speed
Working with Craig D. Paxton, Peter J. Gryn, Erisa K Hines, and Ulises Perez, Dr. Ge-Cheng Zha of the University of Miami Department of Aeronautics and a NASA Innovative Advanced Concepts (NIAC) Fellow, has worked on a method to improve propeller efficiency and reduce blade stall using a forward tangential swept configuration. Dr. Zha wowed EAS VII attendees last year with his astonishing high-lift, high-speed wing design. This year, he gave hope for advanced propeller design. The professor and his team are trying to increase general aviation fuel efficiency and reduce pollution. Propellers, imparting the energy from the engine or motor to the air, are a good place to start. Most current propellers are axial and are straight bladed or have blades with a backward sweep, the well-known scimitar blade shape. This approach mimics the advantages gained from swept wings. Zha’s team borrowed from turbofan technology to develop forward tangential swept propellers. They might have looked at sailplanes like the …