context: Typical NASICON compounds (such as a NVP cathode and a NTP anode) suffering from severe performance degradation in aqueous electrolytes were employed. The crystal structures, X-ray diffraction (XRD) patterns and SEM images of the prepared NVP/C and NTP/C are shown in Fig. S7.† In Fig. S8,† all of the materials have two featured Raman shifts, in which the G-band (ordered graphitic structure) peak is at 1590 cm−1 and the D-band (disordered portion) is at 1352 cm−1. The thin carbon layer provides good electro-conductivity to NVP/C and NTP/C. In addition, the carbon content of the NVP/C and NTP/C composites measured by elemental analysis (Table S2†) and TG analysis (Fig. S9†) is approximately 3.5 wt%.