NaTi2(PO4)3/N-doped hard carbon nanocomposites with sandwich structure for high-performance Na-ion full batteries

The well‐matched technology of cathode and anode in Na‐ion full batteries is highly challenging yet critically important in practical applications. Here, the high‐performance Na‐ion full batteries are developed by using NaTi2(PO4)3/N‐doped mesoporous hard carbon hybrid anode and porous Na3V2(PO4)3 cathode. The different anodes are designed for well‐matched Na‐ion full batteries. The unique sandwich and mesoporous structural features endow the hybrid anode with a high reversible capacity (240 mAh g−1 at 1 C), high rate performance (109.7 mAh g−1 at 100 C), ultrahigh energy/power densities (76.56 Wh kg−1/5104 W kg−1) and a long cycle‐life (capacity retention of 92.1 % after 1000 cycles at 100 C) in a half cell. In a full battery this hybrid anode can also deliver a higher capacitive contribution (79.5–87.7 %) and high energy/power densities (104 Wh kg−1/5256 W kg−1). This design provides a promising pathway for developing high performance and low‐cost Na‐ion full batteries.