This research will appear after you have scanned naturally appearing vis crystals and after scanning Vis crystals among other Thaumcraft ores. This may pop up later on in your thaumcraft journey.
These batteries will slowly store vis (up to 10) and in turn that vis can be released in the local arua by applying a redstone signal. This can be handy for when the aura is low and you need a boost for charing up items or crafting.
The cube will slowly go more and more blue as more and more vis is stored in the battery: