An LMFP composite positive electrode particle with a high performance conductive carbon structure, which is used in a positive electrode of a solid-state or semi-solid battery. The composite positive electrode particle includes an LMFP particle and a conductive layer coated on an outer surface of the LMFP particle. The conductive layer includes a plurality of carbon agglomerates, lithium ion conductor particles and conductive carbons. The carbon agglomerates are formed by a dehydration reaction of carbohydrates, water-soluble fibers or amino acid polymers. The lithium ion conductor particles are formed by a first oxide or phosphate capable of conducting lithium ions, or by a second oxide with a garnet structure or a perovskite structure. The conductive carbons are formed by at least one of graphite, graphene, nanoscale amorphous carbon, and carbon nanotube with a length less than or equal to 1 μm.
