Small-particle ternary precursor and preparation method thereof

Abstract

The invention relates to a small-particle ternary precursor and a preparation method thereof, the ternary precursor is NixCoyMnzZrk (OH) 2, x is more than or equal to 0.70 and less than 0.98, y is more than 0 and less than 0.30, z is more than 0.01 and less than 0.30, k is more than 0.001 and less than 0.006, and x + y + z + k is equal to 1; and D50 is 3-5 [mu] m. The preparation method comprises the following steps: 1, preparing a mixed solution of Ni, Co, Mn, zircon salt, ethanol, hydrogen peroxide, an additive and urea; preparing a mixed salt solution of Ni, Co, Mn and zircon salt; preparing a sodium hydroxide or potassium hydroxide solution as a precipitator; and preparing an ammonia water solution as a complexing agent; 2, putting the mixed solution into a hydrothermal kettle, carrying out hydrothermal reaction at 120-200 DEG C for 12-18 hours, and carrying out centrifugal washing to obtain an intermediate; 3, adding the intermediate as a seed crystal into a reaction kettle, and adding a precipitator, pure water and a complexing agent to prepare a base solution; wherein the pH value of the base solution is 11.20-11.80, and the temperature is 55-75 DEG C; 4, continuously adding the mixed salt solution, a precipitant and a complexing agent into the reaction kettle at the flow speed of 200-800 mL / min for coprecipitation; and 5, carrying out filter pressing, washing and drying on the co-precipitation product to obtain the internally loose ternary precursor. By adding the zirconium element, the cycle performance is effectively improved. The prepared ternary positive electrode material can relieve volume expansion generated by charging and discharging, and the electrochemical performance is improved.

Description

technical field [0001] The invention relates to the technical field of cathode materials for lithium ion batteries, in particular to a small particle ternary precursor and a preparation method thereof. Background technique [0002] The rapid development of new energy vehicles has led to a rapid increase in the demand for lithium-ion battery cathode materials, especially power-type cathode materials. Among many cathode materials, ternary materials are known as the preferred materials for lithium batteries because of their low price and stable performance, especially power-type ternary cathode materials. [0003] Although ternary cathode materials have many advantages, there are still some defects to be solved. For example, the ternary cathode material tends to generate large internal stress during the charging and discharging process, causing the primary particles of the material to be crushed and dissolved, which in turn leads to poor cycle performance and rate performance....

AI Technical Summary

Problems solved by technology

[0003] Although ternary cathode materials have many advantages, there are still some defects to be solved.

For example, ternary cathode materials tend to generate large internal stress during charging and discharging, causing the primary particles of the material to be crushed and dissolved, which in turn leads to poor cycle performance and rate performance.

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