U.S. Patent  Jul.  17, 2018  Sheet 12 of 16  US 10,026,995 B2  FIG. 6  10000  §tN-.iFeP01t=Corwent1ona1:GraWmeffit  Sn/NaFeP04-conventional-Volumetric  ..  Sn/NaFeP04-inventive-Gravimetric  0  o.o:::;  , ,  Sn/NaFeP04-inventive-Volumetric  :iii:: ......  i!  - ...  ..  41  cu 3  ~  8_ 1000  +--------’----1--------0,-------- 0.  -~  -~:::  ...  QI  ;  E  E  .:!  •- 0  I >  ...  C>  100  +------’---~--’~~-~-’----..._I------’  100  1000  Gravimetric energy (Wh/Kg) or Volumetric energy (Wh/l) 