Reading NFC tags from the front of the phone
With the backing of dotVezz, summing up from the comments:

Considering the specifications, this is quite unlikely:


range of the NFC signal is limited to a max of 10 cm on "clear view" (see Wikipedia)
material with a greater density will reduce this even more: air ~ 0.001 g/cm3 versus Lithium ~ 0.53 g/cm3 makes rawly a 500-times-density difference, so a factor of 10 (as I mentioned in my comment) probably is a huge under-estimation
even calculating with a factor of ~10, this would reduce the range to below 1 cm. And you will rather have to more than double that factor.


With few devices being thinner than .8 mm, your wish is close to impossible of being fulfilled.