NOVELTY - A cathode material comprises phosphate-containing compound of formula comprising micrometer-sized secondary particles composed of crystalline nanometer-sized primary particles. The crystalline nanometer-sized primary particles have particle size of 10-500 nm and micrometer-sized secondary particles have particle size of larger than 1 microns. The phosphate-containing compound is coated with silicon carbide, boron nitride, or metal oxide.    USE - For use in manufacturing a cathode for a rechargeable battery of large current output or for series or parallel rechargeable battery units.    ADVANTAGE - The cathode material has relatively small particle size, excellent conductivity that can satisfy electrochemical properties and can be produced by economical and environmental friendly method. The coating compound being dispersed in and coated on the particles of the phosphate-containing compound improves the conductivity of the cathode material and the diffusion rate of the metal ions of the phosphate-containing compound. The cathode made from such cathode material has good electrochemical reversibility, structural stability, and thermostability.    DETAILED DESCRIPTION - A cathode material comprises phosphate-containing compound of formula A3xM2y(PO4)3 comprising micrometer-sized secondary particles composed of crystalline nanometer-sized primary particles. The crystalline nanometer-sized primary particles have particle size of 10-500 nm and micrometer-sized secondary particles have particle size of larger than 1 microns. The phosphate-containing compound is coated with silicon carbide, boron nitride, or metal oxide of formula M'aOb.    A=Group IA, IIA, or IIIA;    M or M'=Group IIA, IIIA, IVA, or Va, or transition metal elements;    x=more than 0 up to 1.2;    y=1.2-1.8;    a=more than 0 up to 7; and    b=more than 0 up to 6.    INDEPENDENT CLAIMS are included for:    (1) a cathode for rechargeable battery, comprising an electrode plate coated with the cathode material; and    (2) a rechargeable battery.    DESCRIPTION OF DRAWING(S) - The drawing shows a schematic sectional view to illustrate the structure of a cathode for rechargeable battery.    Electrode plate (1)    Coating layer (2)