High-nickel positive electrode material, nickel-cobalt precursor material, preparation method of high-nickel positive electrode material, preparation method of nickel-cobalt precursor material and lithium ion battery

Abstract

The invention discloses a high-nickel positive electrode material, a nickel-cobalt precursor material, a preparation method of the high-nickel positive electrode material, a preparation method of thenickel-cobalt precursor material and a lithium ion battery. The high-nickel positive electrode material is of a core-shell structure, the core is formed by aggregating primary particles with gradientdoped M element, and M comprises Al and / or Mn. The solid spheres and hollow spheres are contained in the primary particles, the sphere centers of the solid spheres or the hollow spheres are the spherecenters of the primary particles, and the radius of the solid sphere is 0-1 / 5 but not 0 of the radius of the primary particle. The outer spherical surface of the hollow sphere is the spherical surface of the primary particle, and the thickness of the spherical shell of the hollow sphere is 0-1 / 6 but not 0 of the radius of the primary particle. In the primary particles, the content of M is sequentially reduced from outside to inside, the molar ratio of the M element in the solid sphere to all elements in the high-nickel positive electrode material is 0.075%-0.75%, and the molar ratio of the Melement in the solid sphere to the M element in the hollow sphere is 1 / 3-1 / 2. The high-nickel positive electrode material disclosed by the invention is higher in specific capacity, good in cycling stability and better in rate capability.

Description

technical field [0001] The invention relates to a high-nickel positive electrode material, a nickel-cobalt precursor material, a preparation method, and a lithium ion battery. Background technique [0002] With the increasing popularity of electric vehicles, consumers have higher and higher requirements for their cruising range and service life. As the main power source of electric vehicles, the energy density and cycle performance of power lithium-ion batteries have the most direct impact on the range and life of electric vehicles. Among them, the cathode material is the key to ensure the excellent performance of lithium-ion batteries. However, at present, the cathode materials commonly used in power batteries are mainly lithium iron phosphate and ternary cathode materials. Lithium iron phosphate is difficult to meet the requirements of battery energy density due to its low specific capacity, and ternary cathode materials are poor in stability during cycling. There is a l...

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Problems solved by technology

[0006] The technical problem to be solved by the present invention is to overcome the excessive introduction of inert elements in the prior art, which reduces the specific capacity of high-nickel positive electrode materials, hinders the transmission of lithium ions and affects the rate performance; and it is difficult to prepare a uniform and complete surface. The high-nickel positive electrode material of the cladding layer causes the defect that the durability of the high-nickel positive electrode material is poor, and a kind of high-nickel positive electrode material, nickel-cobalt precursor material and preparation method, lithium-ion battery are provided

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