Nickel-cobalt composite oxide, nickel-cobalt doped oxide and preparation method thereof

Abstract

The invention discloses a nickel-cobalt composite oxide and a nickel-cobalt doped oxide. The molecular formula of the nickel-cobalt composite oxide can be represented by a general formula NixCo(3-x)O4+ / -z, wherein x is more than or equal to 1.8 and less than or equal to 2.7, and z is more than or equal to 0 and less than or equal to 0.5; and the molecular formula of the nickel-cobalt doped oxide can be represented by a general formula NixCo(3-x-y)MyO4+ / -z, wherein the x is more than or equal to 1.8 and less than or equal to 2.7, y is more than or equal to 0.03 and less than 0.3, and z is morethan or equal to 0 and less than or equal to 0.5. The invention also discloses a method for preparing the nickel-cobalt composite oxide and the nickel-cobalt doped oxide. The nickel-cobalt composite oxide and the nickel-cobalt doped oxide have the advantages of excellent sphericility degree, high density, complete crystal and good activity.

Description

technical field [0001] The invention belongs to the field of preparation of functional powder materials, and more specifically relates to a preparation method of a matrix material of a positive electrode material of a lithium ion battery. Background technique [0002] Lithium-ion battery lithium nickel cobalt oxide cathode material has a capacity 20% higher than that of lithium cobalt oxide and lithium nickel cobalt manganese oxide in addition to having a working voltage platform similar to lithium cobalt oxide and lithium nickel cobalt manganese oxide. It has become an important research and application direction for power batteries and high energy density battery materials. At present, the precursors used for lithium nickel cobaltate are spherical nickel-cobalt hydroxide or nickel-cobalt oxide. However, due to the disadvantages of high alkalinity, strong water absorption, high activity during charge and discharge, poor structural stability, and many side reactions with th...

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Problems solved by technology

The patent with the publication number CN1770511 discloses a method for preparing a nickel-cobalt-containing multi-element metal oxide and a method for surface coating modification thereof, in which nickel-cobalt and another transition metal composition are mixed into a solution, and the solution is mixed with hydroxide Sodium forms hydroxide in an inert atmosphere, then mixes lithium hydroxide with it, and finally calcines at high temperature to form lithium nickel cobalt oxide. The precursor of this method is prepared in an inert atmosphere; the patent publication number is CN200710054759.8 The literature discloses a spherical nickel-cobalt-manganese oxyhydroxide and its preparation method. The spherical nickel-cobalt-manganese hydroxide matrix is ​​first synthesized, and then chemically oxidized in an aqueous phase system. This method is easy to oxidize the spherical surface, but difficult to oxidize the interior. The degree of oxidation is not high; the patent with the publication number CN1765749 discloses mixed metal hydroxides and their preparation and use, which is to continuously react nickel cobalt hydroxide and sodium aluminate in the pipeline, so that aluminum is deposited on hydrogen as aluminum hydroxide Oxides nickel-cobalt surfaces, forming mixed metal hydroxides, but the coated aluminum in this method significantly reduces the capacitive activity of the material

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