Modified lithium ion battery ternary positive electrode material and preparation method thereof

Abstract

The invention relates to a modified lithium ion battery ternary positive electrode material and a preparation method of the modified lithium ion battery ternary positive electrode material. The chemical generation formula of the material is as follows: LiNiaCo<1-a-b>MnbBxO2 / TiO2, wherein a is more than 0 and less than 1, b is more than 0 and less than 1, (1-a-b) is more than 0 and less than 1, x is more than 0.005 and less than 0.1, and the TiO2 is a cladding layer. The soluble nickel salt, cobalt salt and manganese salt are prepared into a mixed salt solution, the mixed salt solution is reacted with a mixed alkaline solution prepared by mixing the NaOH and ammonium hydroxide, after being filtered, washed and dried, the reaction product is mixed with a boronic compound and roasted for 4h to 12h at the temperature of 300 to 800 DEG C under an air atmosphere, then the roasted product is ball milled with the lithium salt to be uniformly mixed together, the mixture is coated with titanium dioxide after being calcined at the high temperature to obtain the modified lithium ion battery ternary positive electrode material. The prepared boron doping modified ternary positive electrode material is high in specific capacity and good in cycling performance.

Description

technical field [0001] The invention relates to the technical field of lithium-ion battery cathode materials, in particular to a modified lithium-ion battery ternary cathode material and a preparation method thereof. Background technique [0002] As a new type of green secondary battery, lithium battery has the advantages of small size, light weight, large specific capacity, long cycle life, small self-discharge and no memory effect. It has been widely used in portable mobile electronic products and electric vehicles, etc. In the field of lithium-ion batteries, cathode materials, as one of the core components of lithium-ion batteries, greatly affect the performance of lithium-ion batteries. [0003] At present, the most researched lithium-ion cathode materials in the market mainly include lithium cobaltate, lithium nickelate and lithium manganate. Lithium cobaltate is the earliest material for industrialization and commercialization, but cobalt is highly toxic, cobalt resou...

AI Technical Summary

Problems solved by technology

[0004] Although the ternary cathode material has many advantages above, due to the Ni 2+ with Li + The ionic radius is closer to the cation mixing phenomenon, which makes the material prone to lithium precipitation in the air, resulting in the deterioration of the electrochemical performance of the material.

The main solution currently used is bulk doping of materials, but there are certain defects in doping: on the one hand, the doping of inactive material elements will lead to the loss of battery capacity; Spherical or quasi-spherical secondary particles are used. During the charging and discharging process of the battery, the surface of the secondary particles is in contact with the electrolyte, and the surface of the active particle of the positive electrode material is eroded by fluoride and dissolved by transition metal ions, resulting in the collapse of the surface structure and deterioration of cycle performance.

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