> We use lithium batteries for reasons related to physical rules like electro-negativity (I'm too long from my chemistry to do more than throw out the right terms).

Electronegativity is the tendency of elements to hold onto elements in a chemical bond, which determines the primary character of a bond (ionic or covalent) as well as things like dipole moments. What you actually want is redox potential, how much energy you can get out of reducing or oxidizing an ion in the reduction or oxidation half-reaction.