I've found that the only bottleneck limiting my space travel while using my Ion Engine crafts is the lack of Xenon gas. I think I have a solution- a type of drill that could be added to your spacecraft, that when deployed, would use a high amount of electricity to drill into planets. This drill would gradually dig up Xenon Gas to use in your space missions.
It wouldn't make anything too easy, because you'd still have to make your way to a moon or planet for the drill to have any use.
Please consider up-voting if you think this would be useful.