A kind of preparation method of lithium aluminate/lithium carbonate coating NCA cathode material

Abstract

The invention belongs to the technical field of lithium battery positive electrodes, and in particular relates to a LiAlO 2 / Li 2 CO 3 The preparation method of the coated NCA positive electrode material includes the following steps: (1) preparing to weigh the organic lithium salt and the organic aluminum salt, and dissolving the two in an ethanol solution to prepare a mixed ethanol solution; (2) in an inert gas In the environment, the NCA ternary material powder is added to the mixed ethanol solution obtained in step (1), ultrasonically treated for 30-180 min, and then vacuum dried; (3) the resultant of step (2) is heated to 300° C. It is obtained by calcining at this temperature for 2-5 hours and then grinding; the method of the invention is simple and convenient, the coating method has only two steps, and no complicated operation equipment is required, which is suitable for industrial production.

Description

technical field [0001] The invention belongs to the technical field of lithium battery cathodes, and in particular relates to a preparation method of lithium aluminate / lithium carbonate-coated NCA cathode materials. Background technique [0002] Lithium-ion batteries have the advantages of high working voltage, high specific energy, long cycle life, and low pollution. Currently, they are widely used in the field of electric vehicles and energy storage. High nickel ternary cathode material LiNi 0.8 co 0.15 al 0.05 o 2 (NCA), as a high-capacity, high-energy-density cathode material, has a ternary synergistic effect, and combines the advantages of traditional cathode materials such as lithium nickelate, lithium manganate, and lithium cobaltate, and has high energy density. , long cycle life, relatively low cost and other characteristics, it has great advantages in becoming the next generation of power battery cathode materials. However, the structural stability and rate pe...

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Problems solved by technology

[0003] However, currently Al 2 o 3 The method of coating NCA is cumbersome and does not have the feasibility of mass production

For example, Zhang Zhengguo (China Ceramics, 2015,8,19) used Al(NO 3 ) 3 Coating the NCM material improves the rate performance and separator passability of the NCM cathode material, but the method is relatively cumbersome. At the same time, the coating modification of the oxide on the surface of the NCA material still faces a series of challenges, mainly including: (1 ) Surface coating can only slow down the dissolution of metal ions to a certain extent, and cannot fundamentally solve the problem of capacity fading; (2) Due to the poor adhesion between the oxide coating layer and the surface of the positive electrode material, after a long time It is easy to fall off after charging and discharging; (3) The oxide itself is an inactive substance, although the cycle performance of the electrode material is improved, but the discharge specific capacity of the electrode material has a certain loss; (4) due to the coating modification The uniformity of the cladding layer has high requirements, and the uniformity of the cladding layer prepared by the general process needs to be improved, and the process required for the high-uniformity cladding layer is more complicated and the preparation cost is higher

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