At only 20wH/l for this battery, and with the grid and metal parts still visible, this "transparent" battery does nothing great.

The energy density is laughable.

Early technology takes some polishing before it fully realizes its potential.

Rest assured we already have (almost) transparent conductor technology available. Used in LCD screens for electrodes around the liquid crystal and barely discernible; they work well enough for that use. Add 2 and 2, and with a bit of luck you may get 22 :-)

I'll take my visible 2D batteries for 24wH any day. :D

The list of futuristic gadgets this technology enables is extremely underwhelming.

Example: "Transparent e-readers so you can watch the ground as you walk and read"

What sci-fi are they might be referring to? I don't remember seeing transparent batteries on Star Trek...

>> ... make sci-fi gadgets a reality ...

Sci-Fi gadgets ARE already a reality.