I wrote: I recall that chemical binding energy maxes out at around 4eV per atom in a > material; so perhaps 10eV is a safe upper limit. Have you calculated what > 28 KJ would be, divided among the approximate number of atoms contained > within the mass that is possibly acting as a storage device? >
Here's a *very* rough calculation coming from the other direction. Suppose a high capacity battery made of pure nickel could store 10eV chemical binding energy per atom. How much nickel would you need to store 28 KJ? 28 KJ = 1.75E23 eV 1.75E23 eV / 10 eV*atom^-1 = 1.75 E22 atoms 1 mol = 6.02E23 atoms 1.75E22 atoms / 6.02E23 atoms*mole^-1 = 0.029 moles nickel 0.029 moles nickel * 58.70 g*mole^-1 = 1.70 g nickel I assume that the wire they are using is far heavier than 2 grams -- a US nickel coin, which is similar in composition to constantan, is 5g. Perhaps I have done something wrong in my calculation? Eric
