Aurora’s Odysseus – Large Enough for Its Mythic Name

Dean Sigler Electric Aircraft Materials, Electric Powerplants, Solar Power, Sustainable Aviation Leave a Comment

Named for a mythical hero like its evolutionary predecessors, Aurora Flight Science’s Odysseus is a huge, but ephemeral thing. A wingspan larger than the largest 747’s and a weight no greater than a Smart Car’s (around 1,500 pounds) means this airplane will be slow and frail.  A carbon fiber tube structure covered by lightweight Tedlar™ resembles the construction of Solar Impulse, but without the bulk of carrying a pilot. Since its antecedent was the world record holding distance champion in human-powered aircraft, the manner of flight is no surprise.  Its intended altitude is.  Odysseus takes it to the stratosphere. It’s the latest revelation in a thirty-year exploration of low-powered, extreme-endurance aircraft.  Before he founded Aurora, John Langford led a group of Massachusetts Institute of Technology (MIT) students in a four-year program that developed three human-powered craft – the Daedalus series.  In its final iteration, Daedalus set the still-extant world record for human-powered flight distance, 72 miles emulating the flight of its …

Rice Defeats Dendrites

Dean Sigler Batteries, Electric Aircraft Materials, Sustainable Aviation Leave a Comment

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. 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. 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 …

The C4V Battery – Solid-State in Production?

Dean Sigler Batteries, Electric Aircraft Components, Electric Aircraft Materials, Sustainable Aviation Leave a Comment

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. 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 …

The 17X Aluminum-Air Battery?

Dean Sigler Batteries, Electric Aircraft Materials, Sustainable Aviation Leave a Comment

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, …

Carbon Fiber and the Grand Unified Airplane

Dean Sigler Batteries, Electric Aircraft Components, Electric Aircraft Materials, Solar Power, Sustainable Aviation Leave a Comment

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 …

Promising 3D Printed Microlattice Battery

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The three biggest words in battery structures are “Area, Area, Area.”  The more anode and cathode area a battery can expose to the electrolyte that carries ions and electrons between the positive and negative ends of the battery, the better.  Most battery configurations, according to researchers at Carnegie Mellon University and Missouri University of Science and Technology, block a great deal of interaction between these elements.  Their solution is to go porous in a microlattice battery, thanks to 3D printing. Electrodes present some surface area to the electrolyte, which can only interact with the surface area presented.  Rahul Panat at Carnegie Mellon and Jonghyun Park at Missouri S & T have created a cube-shaped battery composed of microlattice electrodes which present significantly greater amounts of surface area to the electrolyte. The title of their paper (with co-author Mohammad Sadeq Saleh) brings out this “area rule”: “3D printed hierarchically-porous microlattice electrode materials for exceptionally high specific capacity and areal capacity lithium …

Funneling Light and Energy with New Materials

Dean Sigler Electric Aircraft Materials, Solar Power, Sustainable Aviation Leave a Comment

Dr. Adolfo De Sanctis, a Research Fellow in the Quantum Systems and Nanomaterials group at the University of Exeter (UK), earned his Ph. D. in physics with a dissertation on “Manipulating light in two-dimensional layered materials” (Nature Communications, May 2017).  The video below gives a short-hand view of his work. Other, less scholarly outlets (like this one) give an easy-to-read view of what he has accomplished, and why his research is of interest for many applications – including energy harvesting. Green Optimistic reports, “A team of researchers from the University of Exeter developed a solar cell with a record 60% efficiency. The idea behind this breakthrough is similar to using a ‘funnel’: corralling an amorphous collection of electrical charges into a more precise area, where they can be transferred into use. Using this idea, the researchers increased the efficiency of a solar cell from 20 to 60 percent.  The Exeter team sees their research as a ‘gateway’ for further research …

Riding the Sunshine Highway

Dean Sigler Electric Aircraft Materials, Solar Power, Sustainable Aviation Leave a Comment

Sunday, July 22 found your editor at Bend, Oregon’s High Desert Museum for the finish of the 2018 American Solar Challenge.  The race started in Omaha, Nebraska on July 14 and followed parts of the Oregon National Historic Trail and the Lewis and Clark Trail. Omaha, NE (Starting line) – July 14 Grand Island, NE (Checkpoint) – July 14 Gering, NE (Stage stop) – July 15 – 16 Casper, WY (Checkpoint) – July 16 Lander, WY (Stage stop) – July 17-18 Farson, WY (Checkpoint) – July 18 Arco, ID (Stage stop) – July 19 – 20 Mountain Home, ID (Checkpoint) – July 20 Burns, OR (Stage stop) – July 21 – 22 Bend, OR (Finish line) – July 22 Teams came from colleges and universities all over the world.  Six of the single-occupant vehicles (SOV) and one multi-occupant vehicle (MOV) managed the entire 1762.7 miles without breakdown or significant mechanical difficulties.  Considering the cars had to make it over the …

John Goodenough’s Counterintuitive Battery

Dean Sigler Batteries, Electric Aircraft Materials, Sustainable Aviation 1 Comment

A Long and Productive Life On his 96th birthday today, John Goodenough and his research team’s latest findings are the subject of much speculation.  He, fellow scientist Maria Braga, and his research team have created a battery claimed to be three times as energy dense as existing lithium-ion contemporaries, but exhibiting the counterintuitive property of improving with repeated charging cycles. Goodenough’s career began in 1943 (a year after your editor was born) with the award of his bachelor’s degree in mathematics from Yale University, followed his master’s and Ph.D. in physics from the University of Chicago in 1951 and 1952 respectively.  He worked at MIT and in 1976, left to become head of Oxford University’s Inorganic Chemistry Laboratory from 1976 to 1986.  In 1986, he assumed the Virginia H. Cockrell Centennial Chair in Engineering at the University of Texas at Austin, at an age where most men are cashing in their 401k’s. Texas Monthly comments on the counterintuitive nature of …

Peter Sripol Groundloops – But Check Out Those Motors!

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Peter Sripol is a high-energy model-airplane tester who put a twin-motor electric biplane together out of Home Depot/Lowes parts and flew it successfully.  That was a back of the envelope design that flew nonetheless. Peter did something a little more professional for his second go-round, crafting some professional-looking drawings.  Don’t look for any drawings for the earlier machine, he cautions, explaining there are none  He also wanted a pair of larger, slower turning propellers to move a large volume of air more slowly than the Rotomax 150s installed on the biplane.  He notes he’s looking for a lower kV (turns per Volt input). Peter works with Flite Test, a model airplane outfit seemingly willing to try anything.  That includes the giant cardboard twin-motored craft shown in the lead image. He apologizes for not being further along on the project, but notes he took time out to build a tank(!) for a video-game client.  Let this be a rebuke to those …