The Unfortunate Battery Tetrahedron (2015)

Liquid electrode batteries transcend the "unfortunate tetrahedron" paradigm in many ways. By isolating the reactants from the reactor, "unlimited" storage and near-instant "recharging" (exchange of discharged for charged electrode solution) are possible.

This seems to be the most promising paradigm for achieving the needed energy / power density without making a more than mediocre bomb in the process.... Unfortunately, the process is best suited to larger installations due to the inherent complexity, and scales poorly to portable applications.... So still tradeoffs, of course.