GO-induced preparation of flake-shaped Na3V2(PO4)3@rGO as high-rate and long-life cathodes for sodium-ion batteries

Abstract

NASICON-type Na₃V₂(PO₄)₃ (NVP) has attracted significant attention as a cathode material for sodium-ion batteries (SIBs) due to its three-dimensional open frameworks. However, its low electronic conductivity severely limits its reversible capacity and rate capability. Herein, two-dimensional graphene oxide (GO) as a desired self-template was rationally utilized to inductively prepare flake-shaped NVP@rGO (reduced GO) composites via a facile sol–gel route and solid-state reaction. The highly conductive graphene network offers fast electron transfer, whereas the rGO-induced lamellar structure benefits the Na⁺ migration during redox reactions. As expected, the as-prepared NVP@rGO electrode exhibited excellent rate capability (large reversible capacity of ∼80 mA h g⁻¹ even at 100C, charge/discharge only in 36 s) and superior cycling stability (71% capacity retention after 10 000 cycles). Importantly, this proposed strategy can be readily extended to prepare other types of cathode and anode materials with a flake-shaped structure for advanced SIBs.