A kind of single crystal nickel cobalt lithium manganate precursor and its preparation method and application

Abstract

The invention provides a single crystal nickel cobalt lithium manganate precursor and a preparation method and application thereof. The preparation method comprises the following steps: dissolving soluble nickel salt, cobalt slat, manganese salt and / or salt doped with metal ions M in deionized water to obtain a mixed salt solution; mixing the salt solution with a carbonate solution and feeding thesolutions in parallel to a reaction kettle where a surfactant is dispersed to be stirred and reacted; and then carrying out centrifugalization, washing and drying to obtain the single crystal nickelcobalt lithium manganate precursor. The chemical formula of the single crystal nickel cobalt lithium manganate precursor is NixCoyMnzM(1-x-y-z)CO3, wherein M is the doped metal ions, x is greater than0 but less than 0.8, y is greater than 0 but less than 0.4, z is greater than 0 but less than 0.4 and (1-x-y-z) is greater than or equal to 0 but less than or equal to 0.1. The preparation process issimple to operate, free of an inert atmosphere or an additive, continuous to prepare and easy to implement industrial production.

Description

technical field [0001] The invention belongs to the technical field of lithium ion batteries, and in particular relates to a precursor of single crystal nickel cobalt lithium manganese oxide and its preparation method and application. Background technique [0002] my country's new energy vehicles are in an important period of rapid development. Power batteries are the core components of new energy vehicles, and lithium-ion batteries are considered to be the first choice for automotive power batteries due to their excellent comprehensive performance. There are many types of positive electrode materials for lithium-ion power batteries, mainly including nickel-cobalt lithium manganese oxide ternary materials, lithium iron phosphate, spinel lithium manganese oxide and other new materials, among which nickel-cobalt lithium manganese oxide ternary positive electrode materials have specific capacity High, long cycle life, low toxicity, cheap and good synergistic effect of the three...

AI Technical Summary

Problems solved by technology

However, secondary spherical particles have the following problems: (1) poor mechanical strength, easy to break during electrode compaction, and exposed particles inside the material, resulting in increased side reactions and metal ion dissolution, and decreased electrochemical performance; (2) secondary spherical particles The primary particles inside and outside the particle ball are small and have many structural defects, and the structure is easy to collapse during high-voltage charging and discharging; (3) The interior of the secondary spherical particles is difficult to coat, and there are many interface side reactions during high-voltage charging and discharging, resulting in damage to the material structure; (4) The secondary ball particles are seriously inflated

Although the preparation process of the hydroxide precursor can make nickel, cobalt, and manganese uniformly distributed, the hydroxides of cobalt and manganese are easily oxidized in an alkaline environment. Get precursors with suitable particle size

In this regard, many researchers use inert gas protection, or add a reducing agent and need to monitor the reaction pH at all times, but the process control requirements are very high, and the operation is relatively cumbersome.

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