I'll have a look - thanks Paul for the ping
@jensfranke, just for the comparison of the two converters, you could use the 2564 just as well if you won't need the shutdown pin.
It'll become handy tho' if you intend to use power saving modes on the Electron, since the efficiency of these converters goes down quite a bit when the current draw sinks.
But the foremost question here seems to be how to connect the converter to your setup.
Given this thread is about the Photon it might be better to move this question into it's own thread or attach it to one of these
Where should I move this for you?
Meanwhile, in order to answer your question, could you tell how you're intending to power your Electron?
Will you have USB supply?
Will you have a LiPo connected?
If using a LiPo without USB, how will you be charging your LiPo?