Abstract: A composite cathode material, a preparation method thereof, and an application thereof are provided. The composite cathode material of the present application includes: a conductive core, and a cathode material coating layer covering the conductive core. The composite cathode material further includes a conductive skeleton. One end of the conductive skeleton is in contact with the conductive core, and an other end of the conductive skeleton at least extends into the cathode material coating layer. The composite cathode material of the present application has high conductivity, structural stability, and compaction density, and has high cycle performance and electrochemical performance. The preparation method of the composite cathode material can ensure that the structure and electrochemical performance of the prepared composite cathode material are stable, and the efficiency is high, thus saving production costs.

Abstract: A low water content cathode material, a preparation method thereof, and a lithium-ion battery are provided. The low water content cathode material includes: a cathode material core, and an outer film layer being coated outside the cathode material core, in which, the outer film layer includes at least one carbon-based layer formed by an oxygen-free carbon source. In the preparation method, by coating a cathode material precursor with an oxygen-free carbon source, a resulting cathode material itself has a water content of 600 ppm or below and has the function of a protective film, such that the cathode material has low water absorption when exposed to a humid environment, and can improve the safety performance of a lithium-ion battery.

Abstract: The application discloses a single-core multi-shell lithium manganese iron phosphate cathode material and a preparation method thereof, and a secondary battery. The composite material includes: a carbon-coated lithium iron phosphate core, and a plurality of lithium manganese iron phosphate cladding layers cladded on an outer surface of the carbon-coated lithium iron phosphate core. Each of the plurality of lithium manganese iron phosphate cladding layers includes lithium manganese iron phosphate particles and a carbon material coated on the lithium manganese iron phosphate particles. The lithium manganese iron phosphate particles in the plurality of the lithium manganese iron phosphate cladding layers have particle sizes increase in a radial direction from inside to outside.

Abstract: The present application belongs to battery materials, and in particular, to a lithium-containing multi-phosphate cathode material and a preparation method therefor, and a secondary battery. The lithium-containing multi-phosphate cathode material includes a single-core multi-shell lithium manganese iron phosphate composite material, the composite material includes a core of lithium iron phosphate or lithium manganese iron phosphate, N lithium manganese iron phosphate coating layers coated on an outer surface of the core, and a carbon coating layer coated on an outermost layer of the composite material; N is an integer greater than or equal to 1; a manganese content in the N lithium manganese iron phosphate coating layers successively increases in a radially outward direction, and a particle size of the lithium manganese iron phosphate particles in the N lithium manganese iron phosphate coating layers successively decreases in the radially outward direction.