Amprius has announced a 500 Watt-hour per kilogram cell, essentially doubling the energy density available up to now. Remember, though, that cell-levels of energy drop as the cells are incorporated into modules and packs, carrying the burdens of containment packaging, bus bars, and battery management systems (BMS) that lower total output. Pack levels will be lower. Slow Progress This comes as the culmination of at least 14 year’s work, starting with Yi Cui’s work at Stanford University. Your editor first saw him at a 2009 CAFE Foundation symposium at the Hiller Aviation Museum in San Carlos, California. He was a proponent of the 10X battery, which at that time would have meant 10 times the energy storage of then typical cells, or around 10 times the 200 Watt-hours per kilogram then considered to be a respectable achievement. This blog reported in 2013, “According to Green Car Congress, ‘The company has also demonstrated greater than 650 and 700 Wh/L batteries with …