Dr. Cui’s Pomegranate-inspired Battery Bears Fruit

Dean Sigler Electric Powerplants, Sustainable Aviation 0 Comments

Dr. Yi Cui seems to get inspiration from food.  A few years ago, his research team came up with a “yolk-shell structure” that helped contain the high amount of lithium that silicon anodes were able to absorb.  That battery design promised much, and an embellishment of that design seems to hold even greater promise. His newest effort, working at Stanford University with the Department of Energy’s SLAC National Accelerator Laboratory, features an electrode “designed like a pomegranate – with silicon nanoparticles clustered like seed in a tough carbon rind.”  This approach, according to its inventors, overcomes several remaining obstacles to the use of silicon in a new generation of lithium-ion batteries. Yi said the battery’s efficiency and longevity are promising.  …

Airliners Get Better Mileage than Cars, and Trains do Even Better

Dean Sigler Diesel Powerplants, Electric Powerplants, GFC, Sustainable Aviation 0 Comments

Airliners beat cars in fuel economy, especially on longer trips.  That would not be news to attendees at recent Electric Aircraft Symposia, where speakers like Ilan Kroo, Stanford University professor and aircraft designer, have brought that message home. One of Kroo’s slides, shown below in a 2009 lecture (It’s nearly an hour, but worth a look and listen), lists a “narrow-body” airliner (in this case a Boeing 737-800) as able to fly one passenger coast-to-coast on 29 gallons of fuel, at about 81 passenger miles per gallon.  A person carpooling his or her four-passenger Prius and driving responsibly could beat that (although not in the five hours required for the jet to make the total flight), but most trips are solo …

Unique, From A (for Aerodynamics) to Zee

Dean Sigler Electric Powerplants, Sustainable Aviation 0 Comments

Ilan Kroo, according to his biography page, is a Professor of Aeronautics and Astronautics at Stanford University, an advanced cross-country hang glider pilot, and designer of the Swift flying wing hang glider, unmanned aerial vehicles, a flying Pterosaur replica, America’s Cup sailboats, and high-speed research aircraft.  Currently on a leave of absence from Stanford, he has started Zee Aero, “a bay area start-up company focusing on bringing new technologies to civil aircraft.” Zee Aero, on its first of five sparse web pages, proclaims, “We’re creating an entirely new aircraft,” a heady claim considering the lack of supporting descriptions or illustrations.  But other sources have been made available, including Zee’s patent applications, which show a slim tricycle-gear fuselage surmounted by variously …

Batteries That Heal Themselves

Dean Sigler Electric Powerplants, Sustainable Aviation 0 Comments

Alert reader Colin Rush provided this breaking development in battery science. Regular readers will remember Dr. Yi Cui’s name.  He’s a Stanford University scientist who has worked with paper batteries, much more powerful electrodes, and means of helping batteries stay together under the continuous strain of expanding and contracting during charging and discharging.  He explained that at the third annual Electric Aircraft Symposium at the Hiller Aviation Museum, and has since adopted several tactics to overcome that problem.  One commercial outgrowth of his work, Amprius, is working on commercial production that benefits from his insights. Since that internal flexing eventually leads to cracking of electrodes, Dr. Cui’s latest announcement brings some hope that such things can not only be overcome, …

Breaking Up Isn’t So Hard to Do

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A great deal of the research on lithium batteries goes into figuring out how to keep them together for the greatest number of charge-discharge cycles.   Unfortunately, the active compounds in these batteries that give the greatest energy storage capacity or power output, also tend to be those compounds that come unglued under stress. Taking high-resolution 3D movies with X-ray tomography (somewhat like the CAT scans used on human subjects), researchers at the Swiss Light Source, a mecca for seeing the unseeable, have witnessed the expansion and contraction of the internal structure of lithium-ion batteries, while the batteries are operating. Stanford University’s Dr. Cui has explained that the expansion and contraction of batteries leads to their eventual failure, but until now, …

Lithium Gets a Good Wrap

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Shadi Dayeh, professor in the Department of Electrical and Computer Engineering at the UC San Diego Jacobs School of Engineering, has been designing new electrode architectures that could solve one of lithium batteries’ biggest problems.  When lithium diffuses across the surface of a lithium-ion battery electrode, it causes the electrode to expand and contract depending on its charging or discharging.  This eventually leads to cracking and ultimate disintegration of the anode or cathode – weakening and finally disabling the battery. Dayeh, working with colleagues at the University and Sandia and Los Alamos National Laboratories, came up with nanowires that, “Block diffusion of lithium (Li) across their silicon surface and promote layer-by-layer axial lithiation of the nanowire’s germanium core.” Seeing possibilities …

Stanford scientists develop high-efficiency zinc-air battery

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Battery researchers, including those at Stanford University, have been focusing for years on improving lithium batteries of multiple chemistries.  While IBM tries to create the 500-mile battery based on lithium-air reactions, and ReVolt in Portland works on perfecting a long-lasting zinc-air cell, Stanford researcher Hongjie Dai and his team claim to have “developed an advanced zinc-air battery with higher catalytic activity and durability than similar batteries made with costly platinum and iridium catalysts.” The resulting battery, detailed in the May 7 online edition of the journal Nature Communications, could be the forerunner of something with greater endurance and lower cost than current efforts. Mark Schwartz, writing for Stanford, quotes Dai, a professor of chemistry at the University and lead author of …

A Milestone on the Road to Dr. Cui’s 10X Battery

Dean Sigler Electric Powerplants, Sustainable Aviation 1 Comment

Seeing the Amprius web site, one would never know that some “dramatic improvements” promised in the terse announcement might mean so much in terms of true breakthroughs. Neatly centered, Amprius’ total web site is a few  lines of discrete text. Amprius is a leading Lithium-Ion battery developer Amprius’s silicon technology was originally developed at Stanford University and enables dramatic improvements in the energy density and specific energy of Lithium-Ion batteries. Amprius is backed by some of the world’s leading investors, including Trident Capital, VantagePoint Venture Partners, IPV Capital, Kleiner Perkins Caufield & Byers, and Dr. Eric Schmidt. Amprius, Inc., 225 Humboldt Ct. Sunnyvale, CA 94089 But the battery manufacturer has two first-generation product offerings with volumetric energy densities of 580 …

Peel-and-Stick Solar Cells Make Debut

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The U. S. Department of Energy’s National Renewable Energy Laboratory (NREL) and Stanford University have teamed up to create what may be the thinnest of thin solar cells – a peel-and-stick decal. One micron thick, the decal-like  peel-and-stick, or water-assisted transfer printing (WTP), technologies were developed by Stanford researchers and have been used for nanowire based electronics.  Meeting at a conference where both made presentations, Stanford’s Xiaolin Zheng talked about her peel-and-stick technology, and NREL principal scientist Qi Wang spoke on his team’s research in thin-film amorphous solar cells. Zheng realized that the NREL had the type of solar cells needed for her peel-and-stick project, according to the NREL announcement. The NREL press release explains, “The university and NREL showed …

On a Clear Day, I Can See My iPad

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Dr. Brien Seeley, President of the CAFE Foundation, shared the news of an exciting breakthrough that could make the see-through parts of an airplane’s solar collectors.  Most solar collectors have a black or near-black look because they are absorbing light in the visible spectrum.  Pulling energy from infrared or ultraviolet spectra invisible to the human eye allows Ubiquitous Energy’s Clearview Power translucent film of to be laid over iPad and Kindle screens and keep them charged constantly. Consider the possibilities of such films covering the Plexiglas or carbonate canopies on aircraft.  Even those portions could then be energy collectors.  On craft such as electric sustainer motor powered sailplanes, the glazed area comprises a large part of the total fuselage surface …