NaTFSI (CAS number: 91742-21-1) is a sodium salt containing the TFSI− anion. NaTFSI is the sodium analog of LiTFSI which is widely used as an electrolyte in sodium-ion batteries and supercapacitors. In solid-state batteries, NaTFSI provides mobile sodium ions and enhances ionic conductivity with the large and delocalized TFSI− anions that reduce lattice friction. When combined with NaTFSI, a solid-state organic ionic plastic crystal (OIPC) electrolyte demonstrates a high ionic conductivity of 10−4 S/cm, more than three orders of magnitude higher than the conductivity of the pure OIPC.
NaTFSI is also used as a precursor for salt-in-presalt (SIPS) electrolytes. NaTFSI is converted to the presalt, N,N-dimethyltrifluoromethanesulfonamide, through methylation. The prepared 0.5 M NaTFSI in presalt electrolyte solution exhibits an electrochemical stability up to 6.7 V with a Coulombic efficiency of 99.7% at 2.0 mA/cm2 and 4.0 mAh/cm2 in Na‖Al cell configuration.