EAS IX:  Materials Design for Battery Breakthroughs

Dean Sigler Electric Aircraft Components, Electric Powerplants, Sustainable Aviation Leave a Comment

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 versions sold by Sony in 1991 — and are ten times cheaper. But they are nearing their limit. Most researchers think that improvements to Li-ion cells can squeeze in at most 30% more energy by weight.” Cui spoke of attempting …

Thomas Alva Would Be Proud

Dean Sigler Electric Powerplants, Sustainable Aviation Leave a Comment

The best batteries as now produced use expensive materials and processes to achieve high energy density.  Could a century-old idea be resurrected to provide an inexpensive alternative to today’s costly electric storage devices?   Science Daily reports on a recent attempt to improve on a proven technology. Stanford University’s Hongjie Dai, professor of chemistry and head of a research group, is working with the Edison battery, named for Thomas Alva Edison, and using the nickel-iron electrodes Edison favored, but with a modern twist to overcome one of its disadvantages. Stanford’s news bulletin quotes Dai.  “The Edison battery is very durable, but it has a number of drawbacks. A typical battery can take hours to charge, and the rate of discharge is also very slow.” Powering electric vehicles in the early 1900s, Edison’s battery is used today in limited instances to store surplus electricity from solar panels and wind turbines where charging and discharge speeds are not a major consideration.  Dai’s …

Dr. Jaephil Cho’s Powerful Silicon Nanotubes

Dean Sigler Sustainable Aviation 1 Comment

Shortly before appearing at the fourth Annual Electric Aircraft Symposium at Rohnert Park, California, Dr. Jaephil Cho was interviewed by Esther Levy of Material Views, an online resource dealing with, as the title implies, high-technology materials.  Dr. Cho, Dean of the new Interdisciplinary School of Green Energy at Ulsan National Institute of Science & Technology (UNIST), works with lithium-ion cells, and along with Dr. Yi Cui of Stanford University, is considered among the most forward thinking researchers in the field. Where Dr. Cui’s efforts are related to development of better cathodes, Dr. Cho’s work focuses on improving anode performance. Their efforts have led to an 80-percent improvement in cathode performance, as reported in Dr. Cui’s presentation at EAS III, and a 62-percent improvement in anode performance, according to Dr. Cho’s report at EAS IV. Considering that “normal” battery advancement has been on the order of 10 percent per year for the last few decades, either of these announcements should be …

The Painted Battery

Dean Sigler Uncategorized Leave a Comment

Dr. Yi Cui, assistant professor of materials science and engineering at Stanford University, is a battery scientist extraordinaire, and a presenter at last April’s Third Annual Electric Aircraft Symposium. His paper was well received, one in which he discussed how breakthroughs in his lab could lead to an 80-percent improvement in battery capacity for the same weight as current units. He has topped himself with an extraordinary approach to manufacturing batteries. Imagine painting an ordinary piece of paper with a coating of carbon nanotubes and silver nanowires, and ending up with a very thin battery or supercapacitor. This video, courtesy of Stanford University, shows that process, and includes Dr. Cui lighting an LED with a small square of paper. He and his colleagues have abused the battery, washing it with acid and crumbling it, but it still produces current. He notes that they haven’t tried burning it.  Dr. Cui predicts that such batteries could be good for 40,000 cycles, a huge leap …