Your editor’s first outing at an electric aircraft symposium was in 2009. At that meeting, Dr. Yi Cui, Stanford professor and battery expert, talked about silicon and its energy density being so much greater than that for graphite. He predicted huge advances for battery chemistry – and now he’s delivering. His firm, Amprius, is shipping 450 Watt-hour per kilogram batteries. Unlike many such companies, Amprius is not projecting these numbers several years out, but delivering now. According to their February 8 press release, Amprius sent its first batch of the energy-dense cells, “…To an industry leader of a new generation of High-Altitude Pseudo Satellites (HAPS).” Your editor guesses that leader is Zephyr, acquired by Airbus and setting endurance records on …
EAS IX: Materials Design for Battery Breakthroughs
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 …