▎ 摘　　要

NOVELTY - A reduced graphene oxide coated microsphere nanomaterial (I) is new; with diameter of 1-3 mu m with surface area of 97.9 m2/g and graphene coating layer thickness of 2-4 nm. USE - Reduced graphene oxide coated microsphere nanomaterial used as sodium ion cathode active material (claimed). ADVANTAGE - The product has high reversible capacity, good circulation stability and high rate performance, has simple preparation and has high product yield. DETAILED DESCRIPTION - A reduced graphene oxide coated microsphere nanomaterial of formula (Na4MnV(PO4)3rGO) (I) is new; with diameter of 1-3 mu m with surface area of 97.9 m2/g and graphene coating layer thickness of 2-4 nm. An INDEPENDENT CLAIM is included for preparation of reduced graphene oxide coated microsphere nanomaterial.