High-power long-circulation nickel-cobalt-manganese ternary positive electrode material and preparation method thereof

Abstract

The invention provides a high-power long-circulation nickel-cobalt-manganese ternary positive electrode material and a preparation method thereof, the high-power long-circulation nickel-cobalt-manganese ternary positive electrode material is composed of secondary particles, and the primary particles forming the secondary particles are strip-shaped; the D50 particle size of the secondary particles is controlled to be 2.0-5.0 [mu] m, the secondary particles are of an inner hollow structure, the outer wall thickness d1 of the secondary particles is 0.3-1.1 [mu] m, the wall-to-pore ratio R of the secondary particles is 0.1-0.7, and the wall-to-pore ratio R is equal to d1 / (D50-2d1). The preparation method comprises the following steps: S1, synthesizing a nickel-cobalt-manganese hydroxide precursor by adopting a coprecipitation method, and growing and forming a layer of compact shell on the surface of a loose inner core; s2, mixing the precursor, a lithium salt and a dopant, and sintering after uniform mixing; and S3, crushing and dissociating the sintered product, mixing with the coating, and sintering after uniformly mixing. By controlling the wall-to-pore ratio, the morphology and the primary particle arrangement mode, the processing performance of the material is improved, meanwhile, high power and long cycle performance can be considered, and the performance requirements of HEV type batteries are met.

Description

technical field [0001] The invention belongs to the technical field of positive electrode materials for lithium batteries, and in particular relates to a high-power long-cycle nickel-cobalt-manganese ternary positive electrode material and a preparation method thereof. Background technique [0002] HEV hybrid technology is the most effective energy-saving technology for internal combustion engine vehicles at this stage. Due to the application characteristics and performance requirements of HEV hybrid technology, there are high requirements for high power and long cycle performance of lithium-ion battery cathode materials. In order to meet the needs of lithium-ion batteries High power requirements can realize the rapid de-intercalation of lithium ions in the cathode material. The existing material design solutions reduce the diffusion path of lithium ions by designing small particle hollow materials to meet the high rate performance of materials, but small particles also have ...

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Problems solved by technology

[0002] HEV hybrid technology is the most effective energy-saving technology for internal combustion engine vehicles at the present stage. Due to the application characteristics and performance requirements of HEV hybrid technology, there are high requirements for high power and long cycle performance of lithium-ion battery cathode materials. In order to meet the requirements of lithium-ion batteries High power requirements, to achieve rapid deintercalation of lithium ions in the positive electrode material, the existing material design solutions design small particle hollow materials to reduce the diffusion path of lithium ions, to meet the high rate performance of the material, but small particles also have a larger The specific surface area has more surface active sites. During use, the electrolyte is prone to side reactions. At the same time, the hollow material structure has intrinsic defects. Compared with solid materials, the structure is easy to collapse during processing and use, which deteriorates the material performance. Affect the service life of the material, the power and cycle performance of the current material cannot be well balanced

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