A preparation method of a high-density ternary composite material

Abstract

The invention belongs to the field of lithium ion battery material preparation, in particular to a preparation method of a high-density ternary composite material. A manufacture process comprise thatfollowing steps: At first, that nano cobalt salt and the nano manganese salt are deposited on the surface of the nickel salt as a core by a gas atomization method to obtain a composite body, Then it is added to the ball mill containing alkaline solution and ball milled, then lithium salt is added to ball milled, sintered, and finally carbon-nitrogen material is deposited on the surface of the ballmill by chemical vapor deposition method, and finally the ternary composite material with carbon-nitrogen substance on the surface is obtained. As the ternary composite material prepared by the invention adopts the twice vapor deposition method, the contact area between the materials is increased, the porosity is reduced, the vibrating density of the material is improved, the probability of the nickel material directly contacting with the electrolyte and the outside is reduced, and the cycle performance is improved.

Description

Technical field [0001] The invention belongs to the field of preparation of lithium ion battery materials, specifically a high-density LiNi x Co y Mn 1-x-y O 2 Ternary composite material and its preparation method. Background technique [0002] With the market's improvement in the range, fast charging technology and safety performance of electric vehicles, lithium-ion batteries equipped with electric vehicles are required to have higher energy density, high rate performance, high safety performance and long service life. The ternary cathode material has become the main cathode material on the market due to its high energy density and long cycle life. The current preparation method of ternary cathode material is mainly by mixing nickel, cobalt, and manganese salts, and adding lithium salt for sintering It has defects such as changes in the lattice structure, especially the high nickel ternary cathode material. Due to the change of the surface microstructure of the material during ...

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Problems solved by technology

The ternary cathode material has become the main cathode material on the market due to its high energy density and long cycle life. The current preparation method of the ternary cathode material is mainly by mixing nickel, cobalt, and manganese salts, and adding lithium salts for sintering. It is prepared, and it has defects such as lattice structure changes, especially high-nickel ternary positive electrode materials. Due to the change of the surface microstructure of the material during the first charging process, the first charge and discharge efficiency of the battery of the ternary material is not high, and the first effect Generally, it is less than 90%, and it will have a side reaction with HF in the organic electrolyte during the cycle, causing the dissolution of Ni and Mn, thus affecting its electrochemical performance. The reason is that the nickel in the ternary material directly interacts with the electrolyte Contact will produce a large side reaction and the strong water absorption of the nickel material will cause the material to fail during the charge and discharge process and affect the cycle performance

At the same time, because the nickel-cobalt-manganese in the ternary material is prepared by the solid phase method, the contact area between the material and the material is large, the porosity is high, and the tap density is low, which affects the energy density of the material.

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