Preparation method of high-voltage lithium cobalt oxide cathode material

Abstract

The invention discloses a preparation method of a high-voltage lithium cobalt oxide cathode material which comprises the steps: (1) mixing cobaltosic oxide containing doped element M, a lithium source, oxide containing doped element M', a grain refiner and a fluxing agent to obtain a primary mixture; (2) sintering and smashing the primary mixture to obtain primary sintered powder; (3) mixing the primary sintered powder with a coating material to obtain a secondary mixture; (4) sintering and smashing the secondary mixture to obtain the lithium cobalt oxide cathode material. According to the preparation method disclosed by the invention, the problem of microscale segregation of distribution of doped elements in the product is solved by two modes of doped element premixing and dry-method mixing; a coulter type mixing technology is utilized to solve the problem of segregation of different matters in material mixing; the grain refiner and the fluxing agent are combined for use to synthesizea material in a mixed morphology; technologies such as dual effects of doped element surface crystallization catalysis and the coating material and the like are utilized; thus, performance of the high-voltage lithium cobalt oxide is obviously improved.

Description

technical field [0001] The invention belongs to the anode material of a lithium ion battery, in particular to a preparation method of a high-voltage lithium cobaltate anode material. Background technique [0002] With the rapid development of electronic technology, the replacement of 3C products is becoming more and more frequent, and the development of lithium-ion battery cathode materials with higher energy density and better cycle performance has become the goal pursued by the lithium battery industry. Lithium cobalt oxide (LiCoO 2 ) has the advantages of high specific capacity, high compaction density, high volumetric energy density, and simple production process. It is widely used in consumer electronics products such as smartphones, tablet computers, and notebooks, and has become the most commonly used lithium-ion battery cathode for commercialization. one of the materials. The theoretical capacity of lithium cobalt oxide is 274mAh / g. During normal use, only half of ...

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Problems solved by technology

High-voltage lithium cobalt oxide with single crystal morphology is generally obtained by sintering at high temperature (>1050°C) and long time (>12h) in one sintering process. The specific surface area of ​​the single crystal material obtained by this method is smaller than that of The side reaction of the electrolyte is reduced, and the cycle performance is improved; however, due to the large single particle size, the material has poor rate and low first Coulombic efficiency, which reduces the energy utilization rate of the material

The high-voltage lithium cobalt oxide with a similar single crystal morphology is generally obtained by sintering at a lower temperature (<1000°C) and for a shorter time (<8h) at one time. The single crystal-like material obtained by this method is obtained by The secondary ball composed of large primary particles has a better magnification and higher primary Coulombic efficiency due to the small size of the primary particles; but its specific surface area is large and the side reaction with the electrolyte increases, and because it Secondary spherical particles are easy to crack when the stage is rolled, causing degradation of cycle performance

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