Sustainable Aviation Symposium 2019

Dean Sigler Announcements, SAS, Sustainable Aviation Leave a Comment

The 2019 Sustainable Aviation Symposium is moving to a new date and location – and a new inclusiveness. The University of California, Berkeley Institute for Transportation Studies (ITS) will host the 2019 Sustainable Aviation Symposium (SAS) on October 7-8 of 2019.  SAS 2019 is focused on safe, quiet, electric aviation solutions to the most pressing problems of our age: climate change, urban surface gridlock, and the need for integrated community and urban planning to enable high proximity aviation at meaningful scale. Dr. Jasenka Rakas, founder and head of the Airport Design Studio at the University of California at Berkeley, and Sustainable Aviation Foundation founder and President Dr. Brien Seeley will co-chair the meeting that will present a challenging review of aviation’s …

Rumpled Cathodes Benefit Lithium Sulfur Batteries

Dean Sigler Batteries, Sustainable Aviation Leave a Comment

We like to think of things inside batteries as neatly organized, but Pennsylvania State University researchers may have come up with a less tidy way of making cathodes. Researchers synthesized “highly crumpled” nitrogen-doped graphene (NG) sheets with “ultrahigh pore volume” and large surface area (1,158 square meters– 12,465 square feet or about one-third the area of a football field) per gram.  This large area and high porosity “enable strong polysulfide adsorption and high sulfur content for use as a cathode material in Li-sulfur batteries.”  Interwoven rather than stacked, the wrinkled material provides ample room for “nitrogen-containing active sites.” The batteries, according to the researchers, “achieved” a high capacity of 1,226 milliamp-hours per gram and 75-percent capacity retention after 300 cycles.  …

Dendrites Grow Like Kudzu

Dean Sigler Electric Powerplants, Sustainable Aviation Leave a Comment

Getting your fiber is a good idea for digestion and general health, but what if those fibers get you first?  Or at least destroy your battery?  This is the situation as described by a report from the U.S. Department of Energy (DOE)’s Lawrence Berkeley National Laboratory (Berkeley Lab), in which the writer tells us that dendrites are hairy little lithium fibers that “sprout from the surface of the lithium electrode and spread like kudzu across the electrolyte until they reach the other electrode.” These 3D reconstructions show how dendritic structures that can short-circuit a battery form deep within a lithium electrode, break through the surface and spread across the electrolyte. Besides resembling a fast-growing invasive plant, the dendrite bridge across …

Lithium-Sulfur Achieves New Highs

Dean Sigler Electric Powerplants, Sustainable Aviation Leave a Comment

Allen Chen at the University of California at Berkeley reports that researchers at the U.S. Department of Energy’s Lawrence Berkeley National Laboratory (Berkeley Lab) “have demonstrated in the laboratory a lithium-sulfur (Li/S) battery that has more than twice the specific energy of lithium-ion batteries, and that lasts for more than 1,500 cycles of charge-discharge with minimal decay of the battery’s capacity,” the longest cycle life reported so far for any lithium-sulfur battery. Working on the premise that if electric vehicles are to have a 300-mile range, researchers explain that batteries will need to provide a cell-level specific energy of 350 to 400 Watt-hours per kilogram (Wh/kg), roughly double that of lithium-ion batteries. They should also manage at least 1,000, and preferably …