Fabrication and performances of all solid-state symmetric sodium battery based on NASICON-related compounds

The electrochemical performance of a novel all solid-state sodium-ion symmetrical battery with Na₃Zr₂Si₂PO ₁₂ (NASICON) as a solid electrolyte and Na₃V ₂(PO₄)₃ (NVP) as the active electrode material was examined. The all solid-state cell was fabricated by a combination of screen printing and hot pressing. The electrochemical characterization of the NVP active material in the metallic sodium half-cells at 80 °C indicated that this NASICON-related phosphate undergoes reversible sodium extraction/insertion reactions at electrode potentials of 1.6 and 3.4 V vs. Na. These insertion properties allowed the NVP to function successfully as the active material for both the positive and negative electrodes in a sodium-ion cell configuration. A charge-discharge cycling test of the fabricated symmetrical all solid-state cell was carried out at room temperature within the voltage range of 0.01 and 1.9 V. It was found that the cell can work as a secondary battery and showed first discharge capacities of 68 and 32 mAh g^-1 at the current densities of 1.2 and 10 μA cm^-2, respectively. Furthermore, the lack of reactivity between the all-solid-state cell components during long-term cycling was confirmed.