Devices according to Hu’s invention have a significant advantage over other existing energy storage systems, such as batteries, and power generation systems, such as combustion engines and fuel cells. The relative location of different energy systems are identified in terms of specific power and a specific energy in two Regone Energy Plots in FIG. 7 and FIG. 8. These plots demonstrate converters according to the Hu's design are more powerful, while being smaller than other existing power systems. (click images to enlarge)
Thermionic emission refers to the flow of electrons from a metal or metal oxide surface, caused by thermal vibrational energy overcoming the electrostatic forces holding electrons to atoms or molecules at the surface. This effect increases dramatically with increasing temperature (1000-3000 K), but is always present at temperatures above absolute zero. The science dealing with this phenomenon is thermionics. The charged particles are referred to as thermions.
Owen Willans Richardson worked with thermionic emission and received a Nobel prize in 1928 for his work on the thermionic phenomenon. Regarding Richardson's Law, in any metal, there are generally one or two electrons per atom that are free to move from atom to atom. This is sometimes referred to as a "sea of electrons". Their velocities follow a statistical distribution, rather than being uniform, and occasionally an electron will have enough velocity to exit the metal without being pulled back in.