Recharging Technique Makes Zinc-Air Batteries a Viable Alternative

Dean Sigler Batteries, Sustainable Aviation 0 Comments

Lithium-ion and lithium-polymer batteries face several problems: they are not making great leaps forward that we hope for, they occasionally burst into flame, and they weigh too much to be all that practical in a pure-electric airplane.  Researchers peer over the alternatives, magnesium, manganese, aluminum, and now, after several false starts in recent years, zinc. University of Sydney scientists claim to have found a three-stage method of charging zinc-air cells that promises greater energy density and longevity.  One selling point – the relative abundance and low cost of zinc, such cells are cheaper to produce than lithium equivalents.  They theoretically can store up to five times more energy than lithium-ion cells, are less prone to burst into flame, and are …

Not a Goldschmied Fuselage, but Still Wonderfully Low Drag

Dean Sigler Electric Aircraft Components, Electric Powerplants, Sustainable Aviation 0 Comments

Following your editor’s blog entry on the Prandtl wing and erroneously named Goldschmied fuselage, he received this correction from Dr. Brien Seeley, President of the Sustainable Aviation Foundation and one of the creators of the body in question. “However, it is, I think, important to note:  We did not fabricate a Goldschmied body and it is incorrect to refer to ours as one. Ours is original, unique and it does not at all rely upon Goldschmied’s annual suction approach (aft boundary layer treatment). A Goldschmied body studied at Cal Poly is shown along with a link to its 205 page study.  It differs by having a pointed nose and sharp convergence at the rear annular inlet to create the concave …

Making Silicon Anodes in Large Batches

Dean Sigler Batteries, Electric Aircraft Materials, Sustainable Aviation 0 Comments

A Long-term Collaboration Dr. Jaephil Cho is a well-known battery researcher and inter-continental associate of Dr. Yi Cui of Stanford University.  The pair has collaborated on many ways to improve battery performance and longevity, and both have appeared at various electric aircraft symposia.  They have even inspired others in related research. Dr. Cho and his team at Ulsan National Institute of Science and Technology (UNIST) in South Korea announced a way to make a new generation battery anode material – a big move toward mass production of improved cells. Dr. Cho’s team of researchers affiliated with Ulsan National Institute of Science and Technology (UNIST), South Korea, claims to have made yet another step towards finding a solution to accelerate the commercialization …

Even with Batteries, Paul MacCready Was Right

Dean Sigler Batteries, Sustainable Aviation 0 Comments

Dr. Paul MacCready repeatedly urged us to do more with less, getting big results from modest use of materials.  That philosophy may be upheld yet once again by researchers from the Helmholtz-Zentrum Berlin (HZB) Institute of Soft Matter and Functional Materials. As reported here many times, people like Dr. Yi Cui at Stanford University, researchers at MIT, the Fraunhoffer Institute in Germany and many others are attempting to find the magic combination of ingredients that will allow us to transcend the weight penalty we currently trade for payload in heavier-than-desired electric aircraft. Scientists at the HZB, led by  by Prof. Matthias Ballauff have directly observed for the first time a lithium-silicon half-cell during its charging and discharge cycles.  Dr. Beatrix-Kamelia …

Battery 500 Consortium – A Budget Program with Potentially Big Payback

Dean Sigler Batteries, Sustainable Aviation 0 Comments

The federal government is creating yet another round of incentives to “spark” development of “significantly smaller, lighter and less expensive batteries.” A consortium of researchers led by Pacific Northwest National Laboratory (PNNL) will receive up to $10 million a year over five years to perk up battery performance, with the goal of creating a 500 Watt-hour per kilogram battery pack, about three times that of currently available commercial offerings.  The new batteries should be “reliable, safe and less expensive,” according to consortium director and PNNL materials scientist Jun Liu.  Research will come from partners nation-wide, including: Brookhaven National Laboratory Idaho National Laboratory SLAC National Accelerator Laboratory Binghamton University (State University of New York) Stanford University University of California, San Diego …

Yi Cui and team Devise a 10X Anode

Dean Sigler Batteries, Electric Aircraft Components, Sustainable Aviation 0 Comments

Batteries are complex things to design and make, with materials scientists and chemists facing unlimited numbers of options for materials choices, formulations and proportions, and manufacturing techniques that will make hoped-for performance attainable on a commercial level. Yi Cui and a distinguished array of undergraduate and graduate students at Stanford University have written 320 academic research papers since 2000, with the rate of publication seeming to increase every year. To put icing on that multi-layered cake, Dr. Cui has helped found his own battery company, Amprius, using his depth of knowledge to take batteries in directions interesting enough to draw the attention of well-known investors – including Stanford.  The only recent information on the web site today shows the firm …

Caging Silicon Anodes with Graphene

Dean Sigler Announcements, Batteries, Sustainable Aviation 0 Comments

Dr. Yi Cui of Stanford University has expanded the idea of “battery” to include conductive ink on paper, fruit-like clusters of energy-storing capsules, and now, nano-sized graphene cages in which the energy can romp like a hamster in a plastic ball.  He will be on hand at this year’s Sustainable Aviation Symposium on May 6, at the Sofitel San Francisco Bay hotel. His pioneering work with silicon as an electrode material goes back at least ten years, and has focused on overcoming silicon’s two major problems in battery use.  Silicon expands and begins breaking down during repeated charge-discharge cycles.  It reacts with battery electrolyte to form a coating that progressively destroys performance.  The combination of crumbling and coating finally makes the …

Potassium Graphite Batteries?

Dean Sigler Electric Aircraft Materials, Electric Powerplants, Sustainable Aviation 0 Comments

The greatest obstacle to discovery is not ignorance – it is the illusion of knowledge. Daniel J. Boorstin Oregon State University researchers in Corvallis, Oregon have worked around an intellectual roadblock they say has kept potassium from serious consideration as a battery material for over eight decades.  This could be good news, since potassium is more plentiful and lower cost than lithium, and according to OSU scientists, almost as energetic. Xiulei (David) Ji, the lead author of the study and an assistant professor of chemistry in the College of Science at Oregon State University. points out that potassium-ion batteries haven’t been considered since the Hoover administration. Ji said, “For decades, people have assumed that potassium couldn’t work with graphite or …

EAS IX:  Materials Design for Battery Breakthroughs

Dean Sigler Electric Aircraft Components, Electric Powerplants, Sustainable Aviation 0 Comments

Dr. Yi Cui’s presentation title ended with, “from Fundamental Science to Commercialization,” an indication of the long, tough road that new developments are forced to take.  Considering that Sony introduced the Lithium battery as a commercial entity in 1991 (and that following at least an 18-year slog from laboratory to mass production), mostly incremental changes have come for the chemistry, echoing Dr. Cui’s pronouncement at EAS III that lithium batteries followed a “growth curve” of about eight percent per year, meaning that about every nine years, they should double in performance. Cui’s estimate has been borne out in reality, Nature magazine reporting in 2014, “Modern Li-ion batteries hold more than twice as much energy by weight as the first commercial …

Keeping Battery Fires at Bay

Dean Sigler Electric Powerplants, Sustainable Aviation 0 Comments

Fires on or in aircraft are anathema, leaving a pilot and passengers with few options. Even a laptop starting to smoke in the cabin will cause an emergency descent and a diversion to the nearest airport. As designers incorporate larger lithium batteries into new aircraft (and they are essential to motor-driven planes), the need to keep things from self-igniting becomes imperative. Researchers at Stanford University and the Department of Energy’s SLAC National Accelerator Laboratory, working with funding from the Joint Center for Energy Storage Research (JCESR) discovered, “That adding two chemicals to the electrolyte of a lithium metal battery prevents the formation of dendrites – ‘fingers’ of lithium that pierce the barrier between the battery’s halves, causing it to short …