[quote=@duck55223] The description that has been given for antimatter capacitors still seems to imply that the Morteans have the capability to use pure antimatter as a fuel source. I would make the argument that antimatter would be much more difficult to work with and contain then negative energy(what with the whole will explode and destroy everything). [/quote]We can produce antimatter even in the modern days, LHC for example did experiments with that. We don't have the faintest idea how to even generate negative energy, actually we can't even prove it exists. Antimatter is actually damn easy to use in comparison as it's really just getting it to react with normal matter in a controlled form. Containment also only requires electromagnetic fields. Sure, accomplishing that in modern times is hit with issues but that doesn't even approach the problem of containing a type of energy that we don't even have any experimental data on. Antimatter catalyzed fusion reactions are about as down to Earth as you can get for sci-fi power generation. Long story short antimatter batteries and capacitors are hilariously low tech. Their point is also not to get net energy gain but to earn an instantaneous power surge or just have a compact energy storage at hand. Now if you have Star Trek style antimatter reactors then that's a whole other can of worms and I suppose you are thinking of that.