Preparation method of high-rate, high-compaction and high-voltage lithium cobalt oxide positive electrode material

Abstract

The invention discloses a preparation method of a high-rate, high-compaction and high-voltage lithium cobalt oxide positive electrode material, the particle size D50 of the positive electrode material is 6.0-11.0 mu m, the compaction density is 3.7-3.95 g / cm < 3 >, and the preparation method comprises the following steps: (1) mixing a cobalt source, a lithium source, a compound of doped elements M and M'and ingredients to obtain a primary mixture; (2) sintering the primary mixture to obtain a primary sintered material of lithium cobalt oxide, and crushing and grading to obtain a primary sintered graded material; (3) performing high-speed mixing on the primary sintering graded material and a coating material ingredient to obtain a secondary mixture; and (4) sintering the secondary mixture, crushing, grading, demagnetizing and sieving to obtain the lithium cobalt oxide positive electrode material with high magnification, high compaction and high voltage. The process is simple and easy to control, low in production cost, green and environment-friendly and high in production efficiency, and the positive electrode material which is uniform in product component, narrow in particle size distribution, high in crystallinity and excellent in physical and chemical performance and electrochemical performance can be prepared.

Description

technical field [0001] The invention belongs to the field of lithium-ion battery materials, and in particular relates to a preparation method of a high-rate, high-pressure, high-voltage lithium cobaltate cathode material. Background technique [0002] Since the commercialization of lithium-ion batteries, because of their advantages such as high working voltage, high energy density, long service life, wide working temperature range, no memory effect and no pollution, they have been widely used in the fields of communication, mobile and electric tools. At present, it is the general trend to increase the charge and discharge voltage of the positive electrode material to increase the energy density of the battery. Most of the batteries of high-end electronic products have been replaced with batteries with a charge cut-off voltage of 4.4V and higher, which temporarily alleviates the user's concern about the battery capacity. However, when the battery is exhausted, it takes at lea...

AI Technical Summary

Problems solved by technology

Polycrystalline lithium cobalt oxide has good rate performance due to its small primary particles, but due to its large specific surface area, it is easy to cause electrochemical side reactions between the material and the electrolyte under high voltage, and the aggregate particles are broken during the cycle. , pulverization and detachment make the exposed fresh internal surface continue to react with the electrolyte, resulting in the formation of other phases, resulting in deterioration of electrical properties

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