Several sources report on Samsung’s announcement that they have developed a new technology that enables them to coat silicon battery cathodes with high crystal graphene, virtually doubling the capacity of lithium-ion batteries. Of course, Samsung relates this immediately to their popular smartphones and tablets, but the significance of this is not lost on electric vehicle designers. Doubling the range of EVs “without adding a single pound of weight” would be a true game changer. But don’t get excited too quickly. Silicon electrodes have been a major research effort for people like Dr. Yi Cui, who spoke at this year’s Electric Aircraft Symposium. Issue surrounding their successful use have included silicon’s expansion when being charged and contraction when being discharged. This errant flexibility causes eventual disintegration of the electrodes and shuts down the battery. Attempts to use silicon nanowires still have led to embrittlement. Kompulsa.com reports Cho Jin-young from BusinessKorea explaining, “Currently, the development of high-capacity battery materials has been mostly done …
Recycling Lithium Batteries and Adding Seeds and Pine Resin – Better than Mining?
Recycling is good. Those empty beverage cans we turn in at the supermarket come back to us, newly reformed and filled with our favorite drinks – all at about 1/10th the energy cost of making the cans from fresh bauxite and generating all the electricity necessary for new aluminum stock. Besides, aluminum ore is a limited resource, and finding and mining fresh supplies is ever harder and more expensive. Lithium is an even more severe problem. Used rechargeable batteries other scarce minerals such as cobalt, manganese and lithium-based electrolytes. Most of the world’s supply of lithium seems to be in places not necessarily allied with U. S. interests. Battery University says 70-percent of the world’s supply is in Bolivia, Argentina, Chile, Australia and China. Bolivia’s salt flats are in a mostly inaccessible area and would require building of major roads and extraction facilities. Unfortunately that country is not on good terms with the United States. China will want to protect its …
Flexibly Keeping Batteries from Blowing their Cool
Meltdown – not a term one wants to hear when confronting an obstinate boss or while levitating in his or her new Tom Swift Electric Octo-copter. But it is a real specter confronting electric vehicle users, and one amplified to positive levels of terror in flight. Two groups of researchers have come up with novel ways of quelling that terror and getting rid of the normally flammable electrolyte that helps make lithium battery fires truly memorable. If researchers at Chapel Hill and Washington State University are successful in their research, that acid electrolyte can be replaced with something safer and as a bonus in both cases, batteries using these new substances will perform better and longer. Researchers at the University of North Carolina at Chapel Hill, led by chemist Joseph DeSimone, Chancellor’s Eminent Professor of Chemistry in UNC’s College of Arts and Sciences and the William R. Kenan Jr. Distinguished Professor of Chemical Engineering at N.C. State University and of …
Cheap, and It Gets Better With Age
Mixing a form of rust and water might help to make inexpensive battery electrodes with long cycle lives a real possibility. If they have much higher energy densities than more expensive “conventional” electrodes used in lithium batteries, so much the better. Zhaolin Liu of the A*STAR (Agency for Science, Technology and Research) Institute of Materials Research and Engineering, Singapore; Aishui Yu of Fudan University, China, and co-workers have created an electrode material that’s not only inexpensive, but scalable to large-scale manufacturing. Normally, lithium batteries “shuttle” lithium ions between two electrodes connected in a circuit. According to A*STAR, “During charging, lithium ions escape from the cathode, which is made from materials such as lithium cobalt oxide. The ions migrate through a liquid electrolyte and into the anode, which is usually made of graphite riddled with tiny pores. When the battery discharges, the process runs in reverse, generating an electrical current between the electrodes.” That norm for lithium batteries tends to reduce …
Another Two-Seat Electric Airplane from China
China has a second two-seat electric airplane, the Rui Xiang RX1E, a high-wing, side-by-side craft similar to Yuneec’s E430. Both are cantilever, high-winged configurations, with the Yuneec sporting a V-tail and the RX1E a T-tail. Besides the difference in alphabetical empennages, perhaps something gets lost in translation, with several news items offering slightly different versions of this story. The English language version of the China News Service calls the RX1E China’s first electric aircraft, although it’s being introduced at least four years after the E430. Most reports agree that it is designed by the Liaoning General Aviation Institute and that Shenyang Aircraft Manufacturing Co., Ltd. Under the Rui Xiang General name is responsible for manufacturing. Made of carbon fiber composite material, the RX1E uses a 10 kilowatt-hour lithium battery, enough for a 40-minute flight. Charging takes one-and-a-half hours and restores enough energy to make a 40-minute flight – all for about 5 yuan (80 cents). China News Service reports, “The …
Unzipped Nanotubes Show Energetic Promise
Rice University, supported by the Air Force Office of Scientific Research (AFOSR), has demonstrated “a way to boost the efficiency of the ubiquitous lithium ion (LI) battery by employing ribbons of graphene that start as carbon nanotubes.” The AFOSR explains, “Four years ago, [Rice chemist James] Tour’s research team demonstrated that they could chemically unzip cylindrical shaped carbon nanotubes into soluble graphene nanoribbons (GNR) without compromising the electronic properties of the graphitic structure. A recent paper by the Tour team, published in IEEE Spectrum and partially funded by AFOSR, showed that GNR can significantly increase the storage capacity of lithium ion (Li-ion) by combining graphene nanoribbons with tin oxide. “By producing GNR in bulk, a necessary requirement for making this a viable process, the Tour team mixes GNR and 10 nanometer wide particles of tin oxide to create a slurry. GNRs, a single atom thick and thousands of times longer than they are wide, not only separate and support the …
EMG-5 Electric Motorglider
This isn’t Brian Carpenter’s first time at the small airplane rodeo. He’s built at least a dozen aircraft, designed several from scratch, and even entertained the hosts of TV’s Mythbusters series with a series of rides in his team’s ultralights. His latest creation at Tangent Aircraft is a sleek Part 103 ultralight that seems to break or bend the rules on several fronts, presenting a twin-pivoting-motored, Fowler-flapped, retractable-gear craft that would seem to be too complex to fall into legal 103 status – or even into something the average novice private pilot would be allowed to fly. The 36-foot span and 105-square-foot wing would seem too fast to meet stall limits. Carpenter explained his design philosophy to your editor a few days ago, and he said the greatest challenge of meeting part 103 regulations was attaining the stall speed requirement with the small wing area. Normal, unflapped ultralights need about 140 square feet to meet the 27.6 mph stall speed. …
Better Batteries: Enviable Achievement from Envia
Envia, a startup battery company in Newark, California, has announced a much-anticipated breakthrough in lithium-polymer storage cell energy density. Although tested to 300 charge/discharge cycles, the new battery should show at least 1,000 successful cycles before we get too excited. Excitement will build, though, as the announced 400 Watt-hours per kilogram doubles the current energy density standard for lithium batteries. This would reduce a Leaf’s battery pack from about 600 pounds to 300 pounds, or keeping the same weight, double the car’s range to about 250 miles. Dr. Brien Seeley points out that the Green Flight Challenge-winning Pipistrel G4 could have traversed 400 miles with a reserve on such batteries. According to Envia, quoting from the official report, “’The Naval Surface Warfare Center, Crane Division (NSWC Crane) Test & Evaluation Branch was tasked by Advanced Research Products Agency – Energy (ARPA-E) to perform Verification & Validation testing on two high capacity lithium ion pouch type cells, manufactured by Envia Systems …
Better Batteries: Powers of Ten
The CAFE Foundation in its Electric Aircraft Symposia has put forth the idea of the 10X battery for many years. Dr. Seeley therefore found a great deal of excitement in the following news. Researchers at Northwestern University in Evanston, Illinois have perhaps achieved part of that dream, with a graphene and silicon anode that yields a 10-times-faster charge and can hold a charge 10 times greater than that of a typical lithium-ion battery. Claiming their technology will be on the market in three to five years, the researchers have published a paper describing the research in the journal Advanced Energy Materials. A University press release explains. “’We have found a way to extend a new lithium-ion battery’s charge life by 10 times,’ said Harold H. Kung, lead author of the paper. ‘Even after 150 charges, which would be one year or more of operation, the battery is still five times more effective than lithium-ion batteries on the market today.’ (Meaning …
Taking it to eXtremes
“If I were to make a prediction, I’d think there’s a good chance that it is not batteries. But capacitors.” Karl Young, CEO of eXtreme Capacitor, Inc. started his presentation at the fifth annual Electric Aircraft Symposium with these words from Tesla Motor’s Elon Musk. The reference to capacitors superseding batteries as an energy source for electric cars came from Musk’s address at the Cleantech Forum in San Francisco on 16 March 2011. Young’s talk before the April 29 gathering in Santa Rosa, California detailed the double-layer supercapacitors his company produces, and what Young feels are the advantages these have over “traditional” lithium and other batteries. He is “trying to overcome the issues of batteries,” including, according to Young, their weight, slow charge and discharge times, their short operational lifetimes (typically 500 to 3,000 cycles), and their toxicity and flammability. Young contrasted that with the specifications for his eXtreme X-Cap™ “double-layer capacitor-based energy storage technology,” which can last through over …
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