In this work, we studied the cycling behavior of Na2FeP2O7, Na2FePO4F and Na3V2(PO4)2F3 with triclinic, orthorhombic and tetragonal structure in hybrid Na/Li electrochemical cells with Li anode and LiPF6-based electrolyte. The occurrence of electrochemical Nа+ /Li+ ion exchange was established resulting in the formation of the new mixed Na-Li compositions with different degree of exchange: ∼NaLiFeP2O7, NaLiFePO4F and ∼ Na2.5Li0.5V2(PO4)2F3. All materials showed high capacity and stability upon cycling.
