Cheap Hydrogen, Anyone?

Dean Sigler Electric Powerplants, Sustainable Aviation Leave a Comment

Researchers in Glasgow and at Stanford University have devised ways to decouple oxygen and hydrogen from water without resort to expensive extraction or storage techniques.  Both breakthroughs involve low-cost materials, low-energy requirements, and the production of clean hydrogen through what should be renewable energy resources. The latter overcomes one major objection to hydrogen production.  As Professor Lee Cronin of the University of Glasgow’s School of Chemistry explains, “Around 95% of the world’s hydrogen supply is currently obtained from fossil fuels, a finite resource which we know harms the environment and speeds climate change. Some of this hydrogen is used to make ammonia fertilizer and as such, fossil hydrogen helps feed more than half of the world’s population. “The potential for reliable hydrogen production from renewable sources is huge. The sun, for example, provides more energy in a single hour of sunlight than the entire world’s population uses in a year. If we can tap and store even a fraction of …

Longer Life and More Energy

Dean Sigler Electric Powerplants, Sustainable Aviation Leave a Comment

Who wouldn’t want both?  Researchers in Germany and America are making great inroads on lithium battery energy density, while  adding some hope that batteries may someday outlast the vehicle in which they are installed. Ulm, Germany, where the Berblinger Competition encourages economical flight, may be a resource for making such flight possible.  The Zentrum für Sonnenenergie- und WasserstoffForschung Baden-Württemberg (Centre for Solar Energy and Hydrogen Research Baden-Württemberg, ZSW), has announced what they claim to be world-beating cells in terms of cycle life. Dr. Margret Wohlfahrt-Mehrens, Head of the Accumulator Material Research Department in Ulm reports, “After 10,000 complete charging and discharging cycles with a complete charge and discharge cycle per hour (2 C), our lithium batteries still have more than 85 % of the initial capacity.” This would be equivalent to a full charge and discharge cycle every day for over 27 years. With active materials exclusively from Germany, the Ulm battery competes with those manufactured in Asia for power …

Hydrogen as a Biofuel?

Dean Sigler Electric Powerplants, Sustainable Aviation 1 Comment

While we’ve written recently about “artificial leaves” that emulate the photosynthesis of their real counterparts, researchers have announced the discovery of a way to extract hydrogen from any plant, which “could help end our dependence on fossil fuels,” according to Y. H. Percival Zhang, associate professor of biological systems engineering in the College of Agriculture and Life Sciences and the College of Engineering at Virginia Polytechnic Institute and State University (Virginia Tech). The school describes the process as a “breakthrough that has the potential to bring a low-cost, environmentally friendly fuel source to the world.”  Zhang has been working on the problem for over seven years, and like many pioneers, has endured the critical appraisal of those not in tune with his aspirations. Esquire magazine in its November 2006 issue labeled Zhang’s early iteration of his idea to break down plant sugars to create cheap cellulosic ethanol and possibly even hydrogen as the “Crazy idea of the year: “sugar cars.”  …

Alchemy with Thin Film Structures

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The blog has looked at several recent attempts to pull electricity from solar cells that have the ability to capture a broad range of light wavelengths.  These are based on everything from layers of graphene and zinc nano-wires, to an exotic subwavelength  plasmonic cavity, to straining solar cells to form wide bandgap funnels which capture light’s energy. Joining these efforts along with those of researchers in America and Germany, colleagues at the Vienna University of Technology are testing single atomic layers of oxide heterostructures, a new class of materials, to “create a new kind of extremely efficient ultra-thin solar cells.” Professor Karsten Held from the Institute for Solid State Physics at the University, explains, “Single atomic layers of different oxides are stacked, creating a material with electronic properties which are vastly different from the properties the individual oxides have on their own.”  Researchers used large-scale computer simulations to discover that these layered structures “hold great potential for building solar cells.” …

Solid, Man! Electrolytes Go Granular

Dean Sigler Electric Powerplants, Sustainable Aviation Leave a Comment

Most liquid battery electrolytes that conduct ions between anode and cathode also carry with them a flammability problem, especially as chemists try to pack more power into smaller batteries.  Recent fires which have grounded all Boeing 787s in the world highlight the danger. The blog has noted before the dangers of overcharging lithium batteries and especially of leaving even model airplane sized packs lying about unattended during charging. Oak Ridge National Laboratory researchers claim to have demonstrated safety advantages with a nanoporous electrolyte, according to a January 23, 2013 release.  ORNL’s Chengdu Liang says, “To make a safer, lightweight battery, we need the design at the beginning to have safety in mind.  We started with a conventional material that is highly stable in a battery system – in particular one that is compatible with a lithium metal anode.” In line with objectives set by Secretary of Energy Steven Chu, using pure lithium metal as an anode could produce batteries with …

Imperfect Carbon as Good as Pricy Platinum

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The expense of platinum catalysts has been an impediment to the development of fuel cells and metal-air batteries.  Scientists at Stanford University may have found an inexpensive, higher-performance alternative in “unzipped” carbon nanotubes that show an imperfect face to the world. Findings published in the May 27 online version of the journal Nature Nanotechnology quote chemistry professor Hongjie Dai, co-author of the paper.  “Platinum is very expensive and thus impractical for large-scale commercialization. Developing a low-cost alternative has been a major research goal for several decades.” With platinum ranging from almost $800 to over $2,200 an ounce, carbon nanotubes, with their conductivity and inexpensive production costs provide a desirable combination of performance and price. Nanotubes are rolled-up sheets of graphene, a one-atom thick layer of pure carbon – 10,000 times narrower than a human hair. Dai’s team nested two or three nanotubes, each smaller than the next layer outward, an amazing feat considering the submicroscopic size of the tubes.   To …