Molten salt electrolyte based on alkali bis(fluorosulfonyl)imides for lithium batteries

- A LiFSI and KFSI eutectic molten salt electrolyte is prepared.
- Binary phase diagram and transport properties are measured.
- It shows wide electrochemical window and can passivate Al film.
- It is compatible with cathode but incompatible with anode.
- An irreversible reduction reaction occurs at 1.8 V vs. Li+/Li.