Composite lithium nickel manganese oxide positive electrode material, method for producing the same, and positive electrode sheet for lithium ion batteries

Abstract

The present application provides a composite lithium nickel manganese oxide positive electrode material, a manufacturing method thereof, and a positive electrode sheet for lithium ion batteries. The composite lithium nickel manganese oxide positive electrode material includes a lithium nickel manganese oxide coated with a lithium ion conductor. Here, the mass ratio of the lithium ion conductor to the lithium nickel manganese oxide is (0.01-1):(99.99-99). The lithium ion conductor includes a lithium metal salt, and the lithium ion diffusion rate of the lithium ion conductor is 10 -5 The composite lithium nickel manganese oxide positive electrode material provided by the present application includes a lithium ion conductor having lithium ion transport properties, which accelerates the lithium ion transport rate, improves the kinetic properties of the material, and reduces the DC internal resistance of the battery.

Description

[Technical Field]

[0001] The present invention relates to the technical field of lithium ion batteries, for example, to composite lithium nickel manganese oxide positive electrode materials, and more particularly to composite lithium nickel manganese oxide positive electrode materials and methods for producing the same, and positive electrode sheets for lithium ion batteries. [Background technology]

[0002] Spinel lithium nickel manganese oxide has been applied to high-energy density power battery systems due to its relatively high reaction potential (>4.6 V) and relatively high theoretical specific capacity (>140 mAh / g). However, due to the high reaction potential (>4.6 V), the synthesized particles are often relatively large in size to reduce side reactions between the cathode material and the electrolyte, which slows the movement of lithium ions within the material and results in relatively poor kinetics.

[0003] How to effectively improve the dynamic performance of the material, promote the diffusion of lithium ions on the surface of the material, accelerate the lithium ion migration rate in the material, and reduce the DC internal resistance of the battery is a technical problem that needs to be solved as soon as possible for lithium nickel manganese oxide materials. Summary of the Invention

[0004] The following is a brief summary of the subject matter described in the detailed description. This summary is not intended to limit the scope of the claims.

[0005] To address the shortcomings of the related art, the present invention provides a composite lithium nickel manganese oxide cathode material, a manufacturing method thereof, and a cathode sheet for a lithium ion battery. The surface of the cathode is coated with a lithium ion conductor having a relatively fast lithium ion transport ability, thereby effectively improving the kinetic performance of the material and reducing the DC internal resistance of the battery.

[0006] In a first aspect, embodiments of the present application provide a composite lithium nickel manganese oxide cathode material, the composite lithium nickel manganese oxide cathode material comprising a lithium nickel manganese oxide coated with a lithium ion conductor; the mass ratio of the lithium ion conductor to the lithium nickel manganese oxide is (0.01 to 1):(99.99 to 99), The lithium ion conductor contains a metal salt of lithium, and the lithium ion diffusion rate of the lithium ion conductor is 10 -5 greater than mS / cm.

[0007] The mass ratio of the lithium ion conductor to the lithium nickel manganese oxide is (0.01 to 1):(99.99 to 99), and may be, for example, 0.01:99.99, 0.1:99.9, 0.2:99.8, 0.5:99.5, or 1:99, but is not limited to the recited values, and other unrecited values ​​within the numerical range also apply.

[0008] The lithium ion diffusion rate of the lithium ion conductor is 10 -5 greater than mS / cm, e.g., 1.2 × 10 -5 mS / cm, 2 × 10 -5 mS / cm, 1 × 10 -4 mS / cm, 1 × 10 -3 mS / cm or 1 x 10 -2 It may be mS / cm, but is not limited to the recited values, and other unrecited values ​​within the range of values ​​also apply.

[0009] The lithium ion conductor is Li2WO4, LiCoO2, Li 1.3 Al 0.3 Ti 1.7 (PO4)3, Li 1.5 Al 0.5 Ge 1.5 (PO4)3, Li 0.34 La 0.56 TiO3, Li 6.5 La3Zr 1.5 Ta 0.5 O12 or Li 6.5 La3Zr 1.5 Nb 0.5 O 12 Exemplary but non-limiting combinations include Li2WO4 and LiCoO2, Li 1.3 Al 0.3 Ti 1.7 (PO4)3 and Li 1.5 Al 0.5 Ge 1.5 (PO4)3 combination, Li 1.3 Al 0.3 Ti 1.7 (PO4)3 and Li 0.34 La 0.56 Combination of TiO3, Li 1.3 Al 0.3 Ti 1.7 (PO4)3 and Li 6.5 La3Zr 1.5 Ta 0.5 O 12 Combination of Li 1.3 Al 0.3 Ti 1.7 (PO4)3 and Li 6.5 La3Zr 1.5 Nb 0.5 O 12 Combination of Li 1.5 Al 0.5 Ge 1.5 (PO4)3 and Li 0.34 La 0.56 Combination of TiO3, Li 1.5 Al 0.5 Ge 1.5 (PO4)3 and Li 6.5 La3Zr 1.5 Ta 0.5 O 12 Combination of Li 1.5 Al 0.5 Ge 1.5 (PO4)3 and Li 6.5 La3Zr 1.5 Nb 0.5 O 12 Combination of Li 0.34 La 0.56 TiO3 and Li 6.5 La3Zr 1.5 Ta 0.5O 12 Combination of Li 6.5 La3Zr 1.5 Ta 0.5 O 12 and Li 6.5 La3Zr 1.5 Nb 0.5 O 12 Combination of Li 1.3 Al 0.3 Ti 1.7 (PO4)3, Li 1.5 Al 0.5 Ge 1.5 (PO4)3 and Li 0.34 La 0.56 Combination of TiO3 or Li 1.5 Al 0.5 Ge 1.5 (PO4)3, Li 0.34 La 0.56 TiO3, Li 6.5 La3Zr 1.5 Ta 0.5 O 12 and Li 6.5 La3Zr 1.5 Nb 0.5 O 12 Includes a combination of:

[0010] The lithium ion conductor provided by the present application is coated on the surface of a lithium nickel manganese oxide positive electrode material to form a composite material. The presence of the lithium ion conductor promotes the diffusion of lithium ions on the surface of the lithium nickel manganese oxide, accelerating the migration rate of the lithium ions, thereby effectively reducing the DC resistance of the battery and improving the power performance of the battery.

[0011] Preferably, the lithium ion conductor is Li2WO4 and / or Li 1.3 Al 0.3 Ti 1.7 Contains (PO4)3.

[0012] Preferably, the chemical formula of the lithium nickel manganese oxide is LiNi x Mn 2-xO4, where 0.2≦x≦0.8, and may be, for example, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, or 0.8, but is not limited to the recited values, and other unrecited values ​​within the numerical range also apply, and preferably LiNi 0.5 Mn 1.5 It is O4.

[0013] Preferably, the composite lithium nickel manganese oxide cathode material comprises a secondary spherical morphology and / or a single crystal morphology.

[0014] Preferably, when the composite lithium nickel manganese oxide cathode material is in the form of secondary spheres, the particle size D 50 is 18 μm to 35 μm, and may be, for example, 18 μm, 20 μm, 25 μm, 30 μm, or 35 μm, but is not limited to the recited values, and other unrecited values ​​within the numerical range also apply.

[0015] Preferably, when the composite lithium nickel manganese oxide cathode material is in the form of a single crystal, the particle size D 50 is 5 μm to 16 μm, and may be, for example, 5 μm, 8 μm, 10 μm, 15 μm, or 16 μm, but is not limited to the recited values, and other unrecited values ​​within the numerical range also apply.

[0016] In a second aspect, the present invention provides a method for producing the composite lithium nickel manganese oxide cathode material according to the first aspect, the method comprising: mixing a lithium source, a nickel source, a manganese source and a coating material to obtain a precursor material; and sintering the precursor material to obtain the composite lithium nickel manganese oxide cathode material.

[0017] The method for producing the composite lithium nickel manganese oxide positive electrode material provided by the present application can be produced by mixing the coating material with a lithium source, a nickel source, and a manganese source, and then co-sintering them in one step.

[0018] Preferably, the lithium source comprises a combination of at least one of an oxide, hydroxide, nitrate, acetate or phosphate of lithium, and typical but non-limiting combinations include a combination of an oxide and hydroxide of lithium, a combination of a nitrate and acetate of lithium, a combination of an acetate and phosphate of lithium, a combination of a hydroxide and nitrate of lithium, a combination of a nitrate and acetate of lithium, a combination of an oxide, hydroxide and nitrate of lithium, a combination of an oxide, acetate and phosphate of lithium, a combination of an oxide, hydroxide, nitrate and acetate of lithium, a combination of a hydroxide, nitrate, acetate and phosphate of lithium, or a combination of an oxide, hydroxide, nitrate, acetate and phosphate of lithium.

[0019] Preferably, the nickel source comprises a combination of at least one of an oxide, hydroxide, nitrate, acetate, or phosphate of nickel, and typical, but non-limiting, combinations include a combination of an oxide and hydroxide of nickel, a combination of a nitrate and acetate of nickel, a combination of an acetate and phosphate of nickel, a combination of a hydroxide and nitrate of nickel, a combination of a nitrate and acetate of nickel, a combination of an oxide, hydroxide, and nitrate of nickel, a combination of an oxide, acetate, and phosphate of nickel, a combination of an oxide, hydroxide, nitrate, and acetate of nickel, a combination of a hydroxide, nitrate, acetate, and phosphate of nickel, or a combination of an oxide, hydroxide, nitrate, acetate, and phosphate of nickel.

[0020] Preferably, the manganese source comprises a combination of at least one or two of an oxide, hydroxide, nitrate, acetate, or phosphate of manganese, and typical, but non-limiting, combinations include a combination of an oxide and hydroxide of manganese, a combination of a nitrate and acetate of manganese, a combination of an acetate and phosphate of manganese, a combination of a hydroxide and nitrate of manganese, a combination of a nitrate and acetate of manganese, a combination of an oxide, hydroxide, and nitrate of manganese, a combination of an oxide, acetate, and phosphate of manganese, a combination of an oxide, hydroxide, nitrate, and acetate of manganese, a combination of hydroxide, nitrate, acetate, and phosphate of manganese, or a combination of oxide, hydroxide, nitrate, acetate, and phosphate of manganese.

[0021] Preferably, the coating material comprises a lithium ion conductor precursor and / or a lithium ion conductor.

[0022] Preferably, the lithium ion conductor precursor comprises a Li2WO4 precursor and / or a LiCoO2 precursor.

[0023] Preferably, the Li2WO4 precursor comprises any one or a combination of at least two of an oxide, hydroxide, carbonate, or acetate of W, such as a combination of an oxide and hydroxide of W, a combination of a carbonate and acetate of W, a combination of an oxide and carbonate of W, a combination of an oxide and acetate of W, a combination of a hydroxide and carbonate of W, a combination of a hydroxide and acetate of W, a combination of an oxide, hydroxide, and carbonate of W, a combination of a hydroxide, carbonate, and acetate of W, or a combination of an oxide, hydroxide, carbonate, or acetate of W, preferably any one or a combination of at least two of WO3, WO2, or H2W2O7.

[0024] Preferably, the LiCoO precursor comprises any one or a combination of at least two of an oxide, hydroxide, carbonate, or acetate of Co, such as a combination of an oxide and hydroxide of Co, a combination of a carbonate and acetate of Co, a combination of an oxide and carbonate of Co, a combination of an oxide and acetate of Co, a combination of a hydroxide and carbonate of Co, a combination of a hydroxide and acetate of Co, a combination of an oxide, hydroxide, and carbonate of Co, a combination of a hydroxide, carbonate, and acetate of Co, or a combination of an oxide, hydroxide, carbonate, or acetate of Co, preferably CoO, CoCO, or CoOOH.

[0025] Preferably, the lithium ion conductor is Li 1.3 Al 0.3 Ti 1.7 (PO4)3, Li 1.5 Al 0.5 Ge 1.5 (PO4)3, Li 0.34 La 0.56 TiO3, Li 6.5 La3Zr 1.5 Ta 0.5 O 12 or Li 6.5 La3Zr 1.5 Nb 0.5 O 12 or a combination of at least two of the following, for example, Li 1.3 Al 0.3 Ti 1.7 (PO4)3 and Li 1.5 Al 0.5 Ge 1.5 (PO4)3 combination, Li 1.3 Al 0.3 Ti 1.7 (PO4)3 and Li 0.34 La 0.56 Combination of TiO3, Li 1.3 Al 0.3 Ti 1.7 (PO4)3 and Li 6.5 La3Zr 1.5 Ta 0.5 O 12 Combination of Li 1.3 Al0.3 Ti 1.7 (PO4)3 and Li 6.5 La3Zr 1.5 Nb 0.5 O 12 Combination of Li 1.5 Al 0.5 Ge 1.5 (PO4)3 and Li 0.34 La 0.56 Combination of TiO3, Li 1.5 Al 0.5 Ge 1.5 (PO4)3 and Li 6.5 La3Zr 1.5 Ta 0.5 O 12 Combination of Li 1.5 Al 0.5 Ge 1.5 (PO4)3 and Li 6.5 La3Zr 1.5 Nb 0.5 O 12 Combination of Li 0.34 La 0.56 TiO3 and Li 6.5 La3Zr 1.5 Ta 0.5 O 12 Combination of Li 6.5 La3Zr 1.5 Ta 0.5 O 12 and Li 6.5 La3Zr 1.5 Nb 0.5 O 12 Combination of Li 1.3 Al 0.3 Ti 1.7 (PO4)3, Li 1.5 Al 0.5 Ge 1.5 (PO4)3 and Li 0.34 La 0.56 Combination of TiO3 or Li 1.5 Al 0.5 Ge 1.5 (PO4)3, Li 0.34 La 0.56 TiO3, Li 6.5 La3Zr 1.5 Ta 0.5 O 12 and Li 6.5 La3Zr 1.5Nb 0.5 O 12 It may be a combination of the above.

[0026] The sintering temperature is 620°C to 880°C, and may be, for example, 620°C, 650°C, 700°C, 750°C, 800°C, or 880°C, but is not limited to the recited values, and other unrecited values ​​within the numerical range also apply.

[0027] Preferably, the sintering time is 15 to 40 hours, and may be, for example, 15 hours, 20 hours, 25 hours, 30 hours, 35 hours, or 40 hours, but is not limited to the recited values, and other unrecited values ​​within the range of values ​​also apply.

[0028] The coating described in the present application includes a spot coating and / or a surface coating. 670℃ and a sintering time of 22 to 27 hours are preferred, and Li 1.3 Al 0.3 Ti 1.7 (PO4)3 gives the cathode material both "dot coating" and "plane coating" forms, which has the property of allowing fast lithium ion migration on the surface while protecting the main body of the material.

[0029] The dot-like coating means that the coating material is dispersed in dots on the surface of the positive electrode material.

[0030] The planar coating means that the coating material is distributed planarly on the surface of the positive electrode material.

[0031] In a third aspect, embodiments of the present application provide a method for producing a composite lithium nickel manganese oxide cathode material according to the first aspect, the method comprising: mixing lithium nickel manganese oxide with a coating material to obtain a mixture; and sintering the mixture to obtain the composite lithium nickel manganese oxide positive electrode material.

[0032] The method for producing the composite lithium nickel manganese oxide positive electrode material provided by the present application can also be used to produce the coated positive electrode material by mixing the coating material with the finished lithium nickel manganese oxide material and sintering it.

[0033] Preferably, the coating material comprises a lithium ion conductor precursor and / or a lithium ion conductor.

[0034] Preferably, the lithium ion conductor precursor comprises a Li2WO4 precursor and / or a LiCoO2 precursor.

[0035] Preferably, the Li2WO4 precursor comprises any one or a combination of at least two of an oxide, hydroxide, carbonate, or acetate of W, such as a combination of an oxide and hydroxide of W, a combination of a carbonate and acetate of W, a combination of an oxide and carbonate of W, a combination of an oxide and acetate of W, a combination of a hydroxide and carbonate of W, a combination of a hydroxide and acetate of W, a combination of an oxide, hydroxide, and carbonate of W, a combination of a hydroxide, carbonate, and acetate of W, or a combination of an oxide, hydroxide, carbonate, or acetate of W, preferably any one or a combination of at least two of WO3, WO2, or H2W2O7.

[0036] Preferably, the LiCoO precursor comprises any one or a combination of at least two of an oxide, hydroxide, carbonate, or acetate of Co, such as a combination of an oxide and hydroxide of Co, a combination of a carbonate and acetate of Co, a combination of an oxide and carbonate of Co, a combination of an oxide and acetate of Co, a combination of a hydroxide and carbonate of Co, a combination of a hydroxide and acetate of Co, a combination of an oxide, hydroxide, and carbonate of Co, a combination of a hydroxide, carbonate, and acetate of Co, or a combination of an oxide, hydroxide, carbonate, or acetate of Co, preferably CoO, CoCO, or CoOOH.

[0037] Preferably, the lithium ion conductor is Li 1.3 Al 0.3 Ti 1.7 (PO4)3, Li 1.5 Al 0.5 Ge 1.5 (PO4)3, Li 0.34 La 0.56 TiO3, Li 6.5 La3Zr 1.5 Ta 0.5 O 12 or Li 6.5 La3Zr 1.5 Nb 0.5 O 12 or a combination of at least two of the following, for example, Li 1.3 Al 0.3 Ti 1.7 (PO4)3 and Li 1.5 Al 0.5 Ge 1.5 (PO4)3 combination, Li 1.3 Al 0.3 Ti 1.7 (PO4)3 and Li 0.34 La 0.56 Combination of TiO3, Li 1.3 Al 0.3 Ti 1.7 (PO4)3 and Li 6.5 La3Zr 1.5 Ta 0.5 O 12 Combination of Li 1.3 Al0.3 Ti 1.7 (PO4)3 and Li 6.5 La3Zr 1.5 Nb 0.5 O 12 Combination of Li 1.5 Al 0.5 Ge 1.5 (PO4)3 and Li 0.34 La 0.56 Combination of TiO3, Li 1.5 Al 0.5 Ge 1.5 (PO4)3 and Li 6.5 La3Zr 1.5 Ta 0.5 O 12 Combination of Li 1.5 Al 0.5 Ge 1.5 (PO4)3 and Li 6.5 La3Zr 1.5 Nb 0.5 O 12 Combination of Li 0.34 La 0.56 TiO3 and Li 6.5 La3Zr 1.5 Ta 0.5 O 12 Combination of Li 6.5 La3Zr 1.5 Ta 0.5 O 12 and Li 6.5 La3Zr 1.5 Nb 0.5 O 12 Combination of Li 1.3 Al 0.3 Ti 1.7 (PO4)3, Li 1.5 Al 0.5 Ge 1.5 (PO4)3 and Li 0.34 La 0.56 Combination of TiO3 or Li 1.5 Al 0.5 Ge 1.5 (PO4)3, Li 0.34 La 0.56 TiO3, Li 6.5 La3Zr 1.5 Ta 0.5 O 12 and Li 6.5 La3Zr 1.5Nb 0.5 O 12 It may be a combination of the above.

[0038] The sintering temperature is 350 to 700°C, and may be, for example, 350°C, 400°C, 450°C, 500°C, 550°C, 600°C, or 700°C, but is not limited to the recited values, and other unrecited values ​​within the numerical range also apply.

[0039] The sintering time is 6 to 25 hours, and may be, for example, 6 hours, 10 hours, 15 hours, 20 hours, or 25 hours, but is not limited to the recited values, and other unrecited values ​​within the numerical range also apply.

[0040] The coating described in the present application includes a spot coating and / or a surface coating. 660℃ and a sintering time of 22 to 26 hours are preferred, and Li 1.3 Al 0.3 Ti 1.7 (PO4)3 gives the positive electrode material both a "dot-like coating" and a "plane coating" form, which has the property of allowing fast lithium ion migration on the surface while protecting the main material.

[0041] In a fourth aspect, the present invention provides a cathode sheet for a lithium-ion battery comprising the composite lithium nickel manganese oxide cathode material described in the first aspect.

[0042] The numerical ranges described in this application include not only the point values ​​recited above, but also any point values ​​within the numerical ranges that are not further recited, and in the interest of page count and conciseness of description, this application does not exhaustively recite the specific point values ​​included in the ranges.

[0043] Compared with the related art, the advantageous effects of the embodiments of the present application are as follows:

[0044] (1) The composite lithium nickel manganese oxide positive electrode material provided in the embodiments of the present application includes a lithium ion conductor with relatively fast lithium ion transport ability, which is coated on the surface of the lithium nickel manganese oxide, effectively improving the kinetic performance of the material and reducing the DC internal resistance of the battery.

[0045] (2) The examples of this application provide two methods for preparing composite lithium nickel manganese oxide cathode materials, which effectively realize the coating of a lithium ion conductor with relatively fast lithium ion transport ability, improve the stability of the material, and the material exhibits excellent electrochemical performance, simple manufacturing processes, and high production efficiency.

[0046] Once you have read and understood the detailed explanation, you will understand other aspects as well. DETAILED DESCRIPTION OF THE INVENTION

[0047] In the prior art, a common method for coating lithium nickel manganese oxide with a lithium ion conductor is to use Li2ZrO3 or Li5La obtained by reacting zirconia with a lithium source. 3.5 Zr 1.5 O 10 The lithium nickel manganese oxide positive electrode material obtained by this method often has a relatively large particle size to reduce side reactions between the positive electrode material and the electrolyte, which slows the movement of lithium ions inside the material and results in relatively poor kinetics, resulting in low DC internal resistance and low rate performance at low temperatures.

[0048] To solve the above technical problems, the present application provides a lithium nickel manganese oxide positive electrode material, a manufacturing method thereof, and a positive electrode sheet for a lithium ion battery, which is coated on the surface with a lithium ion conductor having a relatively fast lithium ion transport ability, thereby effectively improving the kinetic performance of the material and reducing the DC internal resistance of the battery.

[0049] The present application will be described in more detail through the following specific embodiments, however, the following examples are merely simple examples of the present application and do not represent or limit the scope of protection of the present application, which shall be determined by the scope of the claims.

[0050] Example 1

[0051] This embodiment provides a composite lithium nickel manganese oxide positive electrode material, which is a lithium nickel manganese oxide (LiNi) coated with a lithium ion conductor (Li2WO4). 0.5 Mn 1.5 O4, and the lithium ion conductor Li2WO4 and lithium nickel manganese oxide LiNi 0.5 Mn 1.5 The mass ratio of O4 is 0.5:99.5.

[0052] The method for producing the composite lithium nickel manganese oxide positive electrode material includes the following steps: Ni(NO3)2, Mn(NO3)4, LiNO3, and WO3 are mixed to obtain a precursor material; the obtained precursor material is sintered at a temperature of 700°C for 25 hours to obtain the composite lithium nickel manganese oxide positive electrode material; the obtained composite lithium nickel manganese oxide positive electrode material has a particle size D 50 The particles are in the form of secondary spheres of 25 μm in diameter, and the coating state is a dot-like coating and a surface-like coating.

[0053] Example 2

[0054] This embodiment provides a composite lithium nickel manganese oxide positive electrode material, which contains a lithium ion conductor Li 1.3 Al 0.3 Ti 1.7 (PO4)3 coated lithium nickel manganese oxide LiNi 0.5 Mn 1.5 O4, and the lithium ion conductor Li 1.3 Al0.3 Ti 1.7 (PO4)3 and lithium nickel manganese oxide LiNi 0.5 Mn 1.5 The mass ratio of O4 is 0.8:99.2.

[0055] The method for preparing the composite lithium nickel manganese oxide cathode material includes the following steps: 1.3 Al 0.3 Ti 1.7 (PO4)3 is mixed to obtain a precursor material. The obtained precursor material is sintered at a temperature of 650°C for 35 hours to obtain the composite lithium nickel manganese oxide positive electrode material. The obtained composite lithium nickel manganese oxide positive electrode material has a particle size D 50 The coating is in the form of a single crystal of 10 μm, and the coating state is a dotted coating. is .

[0056] Example 3

[0057] This embodiment provides a composite lithium nickel manganese oxide positive electrode material, which is a lithium nickel manganese oxide LiNi coated with a lithium ion conductor LiCoO2. 0.5 Mn 1.5 O4, and the lithium ion conductor LiCoO2 and lithium nickel manganese oxide LiNi 0.5 Mn 1.5 The mass ratio of O4 is 0.2:99.8.

[0058] The method for producing the composite lithium nickel manganese oxide positive electrode material includes the following steps: NiO, MnO, LiO, and CoO are mixed to obtain a precursor material; the obtained precursor material is sintered at a temperature of 880°C for 15 hours to obtain the composite lithium nickel manganese oxide positive electrode material; the obtained composite lithium nickel manganese oxide positive electrode material has a particle size D 50 The particles are in the form of secondary spheres of 18 μm in size, and the coating state is a planar coating.

[0059] Example 4

[0060] This embodiment provides a composite lithium nickel manganese oxide positive electrode material, which is a lithium nickel manganese oxide LiNi coated with a lithium ion conductor. 0.5 Mn 1.5 O4, and the lithium ion conductor is a 1:1 mass ratio of Li 1.5 Al 0.5 Ge 1.5 (PO4)3 and Li 0.34 La 0.56 TiO3, and the lithium ion conductor and lithium nickel manganese oxide LiNi 0.5 Mn 1.5 The mass ratio of O4 is 1:99.

[0061] The method for producing the composite lithium nickel manganese oxide cathode material includes the following steps: 0.5 Mn 1.5 O4 and Li 1.5 Al 0.5 Ge 1.5 (PO4)3, Li 0.34 La 0.56 The resulting mixture is sintered at a temperature of 350°C for 25 hours to obtain the composite lithium nickel manganese oxide positive electrode material. The resulting composite lithium nickel manganese oxide positive electrode material has a particle size D 50 The particles are in the form of secondary spheres of 35 μm in size, and the coating state is a dot-like coating.

[0062] Example 5

[0063] This embodiment provides a composite lithium nickel manganese oxide positive electrode material, which is a lithium nickel manganese oxide LiNi coated with a lithium ion conductor. 0.5 Mn 1.5 O4, and the lithium ion conductor is a 1:1 mass ratio of Li 6.5 La3Zr 1.5 Ta 0.5 O12 and Li 6.5 La3Zr 1.5 Nb 0.5 O 12 and the lithium ion conductor and lithium nickel manganese oxide LiNi 0.5 Mn 1.5 The mass ratio of O4 is 0.01:99.99.

[0064] The method for producing the composite lithium nickel manganese oxide cathode material includes the following steps: 0.5 Mn 1.5 O4 and Li 6.5 La3Zr 1.5 Ta 0.5 O 12 or Li 6.5 La3Zr 1.5 Nb 0.5 O 12 The resulting mixture is sintered at a temperature of 700°C for 6 hours to obtain the composite lithium nickel manganese oxide positive electrode material. The resulting composite lithium nickel manganese oxide positive electrode material has a particle size D 50 is in the form of a single crystal of 5 μm, and the coating state is a spot coating and a planar coating.

[0065] Example 6

[0066] This embodiment provides a composite lithium nickel manganese oxide positive electrode material, which contains a lithium ion conductor Li 1.3 Al 0.3 Ti 1.7 (PO4)3 coated lithium nickel manganese oxide LiNi 0.5 Mn 1.5 O4, and the lithium ion conductor Li 1.3 Al 0.3 Ti 1.7 (PO4)3 and lithium nickel manganese oxide LiNi 0.5 Mn 1.5 The mass ratio of O4 is 0.8:99.2.

[0067] The method for preparing the composite lithium nickel manganese oxide cathode material includes the following steps: 1.3 Al 0.3 Ti 1.7 (PO4)3 is mixed to obtain a precursor material. The obtained precursor material is sintered at a temperature of 620°C for 40 hours to obtain the composite lithium nickel manganese oxide positive electrode material. The obtained composite lithium nickel manganese oxide positive electrode material has a particle size D 50 The coating is in the form of a single crystal of 10 μm in size, and the coating state is a dot-like coating.

[0068] Example 7

[0069] This embodiment provides a composite lithium nickel manganese oxide cathode material, and the chemical formula of the lithium nickel manganese oxide is LiNi 0.2 Mn 1.8 Except for O4, the other ingredients and manufacturing method are the same as in Example 1.

[0070] Example 8

[0071] This embodiment provides a composite lithium nickel manganese oxide cathode material, and the chemical formula of the lithium nickel manganese oxide is LiNi 0.8 Mn 1.2 Except for O4, the other ingredients and manufacturing method are the same as in Example 1.

[0072] Example 9

[0073] This example provides a composite lithium nickel manganese oxide positive electrode material, and the components and contents of the composite lithium nickel manganese oxide positive electrode material are the same as those in Example 1.

[0074] The method for producing the composite lithium nickel manganese oxide cathode material includes the following steps:

[0075] LiNi 0.5 Mn 1.5O4 and WO3 are mixed to obtain a mixture. The obtained mixture is sintered at a temperature of 400°C for 15 hours to obtain the composite lithium nickel manganese oxide positive electrode material. The obtained composite lithium nickel manganese oxide positive electrode material has a particle size D 50 The particles are in the form of secondary spheres of 20 μm in size, and the coating state is a dot-like coating.

[0076] Example 10

[0077] This example provides a composite lithium nickel manganese oxide cathode material, precursor Except for the material being WO2, the other ingredients and manufacturing method are the same as in Example 1.

[0078] Example 11

[0079] This example provides a composite lithium nickel manganese oxide cathode material, precursor Except for the material being WO2, the other ingredients and manufacturing method are the same as in Example 8.

[0080] Example 12

[0081] This example provides a composite lithium nickel manganese oxide cathode material, precursor Except for the material being H2W2O7, the other ingredients and manufacturing method are the same as in Example 1.

[0082] Example 13

[0083] This example provides a composite lithium nickel manganese oxide cathode material, precursor Except for the material being H2W2O7, the other ingredients and manufacturing method were the same as in Example 8.

[0084] Example 14

[0085] This example provides a composite lithium nickel manganese oxide positive electrode material, and the components and content of the composite lithium nickel manganese oxide positive electrode material are the same as those in Example 2.

[0086] The method for producing the composite lithium nickel manganese oxide cathode material includes the following steps: 0.5 Mn 1.5 O4 and Li 1.3 Al 0.3 Ti 1.7 (PO4)3 to obtain a mixture. The obtained mixture is sintered at a temperature of 400°C for 15 hours to obtain the composite lithium nickel manganese oxide positive electrode material. The obtained composite lithium nickel manganese oxide positive electrode material has a particle size D 50 The particles are in the form of secondary spheres of 18 μm in size, and the coating state is a dot-like coating.

[0087] Example 15

[0088] This example provides a composite lithium nickel manganese oxide cathode material, but the lithium ion conductor is Li 1.5 Al 0.5 Ge 1.5 Except for (PO4)3, the other components and contents are the same as in Example 1.

[0089] The method for preparing the composite lithium nickel manganese oxide cathode material includes the following steps: Ni(NO3)2, Mn(NO3)4, LiNO3 and Li 1.5 Al 0.5 Ge 1.5 (PO4)3 is mixed to obtain a precursor material. The obtained precursor material is sintered at a temperature of 700°C for 25 hours to obtain the composite lithium nickel manganese oxide positive electrode material. The obtained composite lithium nickel manganese oxide positive electrode material has a particle size D 50 The particles are in the form of secondary spheres of 25 μm in size, and the coating state is a dot coating and a surface coating.

[0090] Example 16

[0091] This example provides a composite lithium nickel manganese oxide cathode material, but the lithium ion conductor is Li 0.34 La 0.56Except for TiO3, the other components and contents are the same as in Example 1.

[0092] The method for preparing the composite lithium nickel manganese oxide cathode material includes the following steps: Ni(NO3)2, Mn(NO3)4, LiNO3 and Li 0.34 La 0.56 The resulting precursor material is sintered at a temperature of 700°C for 25 hours to obtain the composite lithium nickel manganese oxide positive electrode material. The resulting composite lithium nickel manganese oxide positive electrode material has a particle size D 50 The particles are in the form of secondary spheres of 25 μm in size, and the coating state is a dot coating and a surface coating.

[0093] Example 17

[0094] This example provides a composite lithium nickel manganese oxide cathode material, but the lithium ion conductor is Li 6.5 La3Zr 1.5 Ta 0.5 O 12 Except for this, the other components and contents are the same as in Example 1.

[0095] The method for preparing the composite lithium nickel manganese oxide cathode material includes the following steps: Ni(NO3)2, Mn(NO3)4, LiNO3 and Li 6.5 La3Zr 1.5 Ta 0.5 O 12 The resulting precursor material is sintered at a temperature of 700°C for 25 hours to obtain the composite lithium nickel manganese oxide positive electrode material. The resulting composite lithium nickel manganese oxide positive electrode material has a particle size D 50 The particles are in the form of secondary spheres of 25 μm in size, and the coating state is a dot coating and a surface coating.

[0096] Example 18

[0097] This example provides a composite lithium nickel manganese oxide cathode material, but the lithium ion conductor is Li 6.5 La3Zr 1.5 Nb 0.5 O 12 Except for this, the other components and contents are the same as in Example 1.

[0098] The method for preparing the composite lithium nickel manganese oxide cathode material includes the following steps: Ni(NO3)2, Mn(NO3)4, LiNO3 and Li 6.5 La3Zr 1.5 Nb 0.5 O 12 The resulting precursor material is sintered at a temperature of 700°C for 25 hours to obtain the composite lithium nickel manganese oxide positive electrode material. The resulting composite lithium nickel manganese oxide positive electrode material has a particle size D 50 The particles are in the form of secondary spheres of 25 μm in size, and the coating state is a dot coating and a surface coating.

[0099] Comparative Example 1

[0100] This comparative example is the lithium nickel manganese oxide LiNi 0.5 Mn 1.5 Provide O4.

[0101] The method for producing the lithium nickel manganese oxide includes the following steps: Ni(NO3)2, Mn(NO3)4, and LiNO3 are mixed to obtain a precursor material, and the obtained precursor material is sintered at a temperature of 700°C for 25 hours to obtain the lithium nickel manganese oxide LiNi 0.5 Mn 1.5 Got O4.

[0102] Comparative Example 2

[0103] This comparative example provides a composite lithium nickel manganese oxide cathode material, which is made of Li2WO4 and lithium nickel manganese oxide LiNi 0.5 Mn 1.5The other ingredients and manufacturing method were the same as in Example 1, except that O4 was in a mass ratio of 1.5:98.5.

[0104] The positive electrode materials obtained in Examples 1 to 18 and Comparative Examples 1 and 2 were mixed with conductive carbon black, conductive carbon tubes, N-methylpyrrolidone solvent, and polyvinylidene fluoride in a mass ratio of 99:1:0.5:40:1 to produce positive electrode pieces. The resulting positive electrode pieces were mounted in 1 Ah pouch batteries. After formation and aging, the batteries were charged to a voltage of 4.9 V at a rate of 0.33 A at 25°C and discharged to 3.1 V at 0.33 A to obtain a capacity C0. After this, the batteries were fully charged to 4.9 V.

[0105] Low-temperature DCR test: The battery is placed in a thermostatic box at 0°C and maintained for 1 hour. Then, the battery's state of charge is adjusted to 50% SOC. The battery is then discharged at a current density of 4C (based on C0) for 30 seconds. The voltage difference before and after the discharge is divided by the current density to determine the direct current resistance (DCR) of the battery at the temperature and state of charge (SOC).

[0106] Low temperature capacity retention: The battery is placed in a thermostatic box at -20°C for 1 hour, then discharged to 3.1V at a current of 0.33A to obtain the capacity C1. C1 / C0 is the low temperature capacity retention of the battery.

[0107] Cycle capacity retention: The battery was charged at 0.33 A and discharged at 1 A during a charge-discharge cycle at 25°C. The cycle voltage range was from 3.1 V to 4.9 V. The initial 1 A discharge capacity was recorded as C2, and the 200th 1 A discharge capacity was recorded as C3. C3 / C2 was the cycle capacity retention of the battery.

[0108] Energy density calculation: C0 x discharge plateau voltage / battery weight.

[0109] The above results are shown in Table 1.

[0110] [Table 1]

[0111] The results in Table 1 reveal the following:

[0112] (1) As can be seen from Examples 1 to 6, the composite lithium nickel manganese oxide positive electrode material and manufacturing method thereof, as well as the positive electrode sheet for lithium ion batteries provided herein, are coated on the surface with a lithium ion conductor having a relatively fast lithium ion transport ability, thereby effectively improving the kinetic performance of the material and reducing the DC internal resistance of the battery. The resulting positive electrode material has low DC internal resistance, high capacity, high capacity retention, and high energy density.

[0113] (2) As can be seen from the comparison of Example 1 with Examples 7 and 8, the lithium nickel manganese oxide LiNi x Mn 2-x O4 has a value of 0.2≦x≦0.8, and by coating the surface with a lithium ion conductor having a relatively fast lithium ion transport ability, the kinetic performance of the material is effectively improved and the DC internal resistance of the battery is reduced, and the resulting positive electrode material has low DC internal resistance, high capacity, high capacity retention, and high energy density.

[0114] (3) As can be seen from the comparison between Example 1 and Example 9, and between Example 2 and Example 13, the two manufacturing methods provided by the present application can both produce composite lithium nickel manganese oxide cathode materials with low resistance and high rate performance.

[0115] (4) As can be seen from the comparison of Example 1 with Examples 10 to 13, WO3, WO2 or H2W2O7 provided by the present application precursor material By doing so, it is possible to produce a composite lithium nickel manganese oxide positive electrode material having low resistance and high rate performance.

[0116] (5) As can be seen from the comparison of Example 1 with Examples 15 to 18, the present invention provides Lithium ion conductor Li 1.5 Al0.5 Ge 1.5 (PO 4 ) 3. Li 0.3 4La 0.56 TiO3, Li 6.5 La3Zr 1.5 Ta 0.5 O 12 or Li 6.5 La3Zr 1.5 Nb 0.5 O 12 By using as a coating material, it is possible to produce a composite lithium nickel manganese oxide cathode material having low resistance and high rate performance.

[0117] (6) As can be seen from Example 1 and Comparative Example 1, when the lithium ion conductor is not used for coating, the resulting cathode material has a high low-temperature resistance and a low rate performance. This indicates that using the lithium ion conductor provided by the present application as a coating material is advantageous for producing a cathode material with a low low-temperature resistance and a high rate performance, thereby improving the stability and cycle performance of the battery.

[0118] (7) As can be seen from Example 1 and Comparative Example 2, when the mass ratio of the coated lithium ion conductor to the lithium nickel manganese oxide is not within the range of (0.01-1):(99.99-99), the resulting positive electrode material has high low-temperature resistance and low rate performance. This indicates that the content of the lithium ion conductor provided by the present application is advantageous for producing a positive electrode material with high low-temperature resistance and low rate performance, thereby improving the stability and cycle performance of the battery.

[0119] The specific embodiments described above further illustrate the objectives, technical solutions and beneficial effects of the present application. It should be understood that the above are only specific embodiments of the present application and are not intended to limit the present application, and any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present application shall fall within the scope of protection of the present application.

Claims

1. a lithium nickel manganese oxide coated with a lithium ion conductor; the mass ratio of the lithium ion conductor to the lithium nickel manganese oxide is (0.01 to 1):(99.99 to 99), The lithium ion conductor contains a metal salt of lithium, and the lithium ion diffusion rate of the lithium ion conductor is 10 －５ greater than mS / cm, The lithium ion conductor is Li ２ WO ４ , Li ６．５ La ３ Zr １．５ Ta ０．５ O １２ and Li ６．５ La ３ Zr １．５ Nb ０．５ O １２ Mixture with Li １．５ Al ０．５ Ge １．５ (P.O. ４ ) ３ , Li ０．３４ La ０．５６ TiO ３ , Li ６．５ La ３ Zr １．５ Ta ０．５ O １２ , or Li ６．５ La ３ Zr １．５ Nb ０．５ O １２ and The coating is a combination of dot-like and planar coating on the surface of the lithium nickel manganese oxide. Composite lithium nickel manganese oxide cathode material.

2. The chemical formula of the lithium nickel manganese oxide is LiNi ｘ Mn ２－ｘ O ４ 2. The composite lithium nickel manganese oxide positive electrode material according to claim 1, wherein 0.2≦x≦0.

8.

3. The chemical formula of the lithium nickel manganese oxide is LiNi ０．５ Mn １．５ O ４ 3. The positive electrode material of composite lithium nickel manganese oxide according to claim 2, wherein

4. the composite lithium nickel manganese oxide positive electrode material comprises a secondary spherical morphology and / or a single crystal morphology; When the composite lithium nickel manganese oxide positive electrode material is in the form of a secondary sphere, the particle size D50 is 18 μm to 35 μm; 4. The composite lithium nickel manganese oxide positive electrode material according to claim 1, wherein the composite lithium nickel manganese oxide positive electrode material has a particle size D50 of 5 μm to 16 μm when in single crystal form.

5. mixing a lithium source, a nickel source, a manganese source and a coating material to obtain a precursor material; and sintering the precursor material to obtain the composite lithium nickel manganese oxide cathode material.

6. The method of claim 5 , wherein the lithium source comprises any one or a combination of at least two of an oxide, hydroxide, nitrate, acetate, or phosphate of lithium.

7. The method according to claim 5 or 6, wherein the nickel source comprises any one or a combination of at least two of nickel oxide, hydroxide, nitrate, acetate, or phosphate.

8. The method according to any one of claims 5 to 7, wherein the manganese source comprises any one or a combination of at least two of oxide, hydroxide, nitrate, acetate, or phosphate of manganese.

9. the coating material comprises a lithium ion conductor precursor and / or a lithium ion conductor; The lithium ion conductor precursor is Li ２ WO ４ Contains a precursor, The Li ２ WO ４ 9. The method of claim 5, wherein the precursor comprises an oxide, hydroxide, carbonate or acetate of W.

10. The Li ２ WO ４ The precursor is WO ３ , W.O. ２ or H ２ W ２ O ７ 10. The method of claim 9, comprising any one or a combination of at least two of the following:

11. mixing lithium nickel manganese oxide with a coating material to obtain a mixture; and sintering the mixture to obtain the composite lithium nickel manganese oxide positive electrode material.

12. The method of claim 11 , wherein the coating material comprises a lithium ion conductor precursor and / or a lithium ion conductor.

13. The lithium ion conductor precursor is Li ２ WO ４ The method of claim 12 comprising a precursor.

14. The Li ２ WO ４ The method of claim 13, wherein the precursor comprises any one or a combination of at least two of an oxide, hydroxide, carbonate, or acetate of W.

15. The Li ２ WO ４ The precursor is WO ３ , W.O. ２ or H ２ W ２ O ７ The method of claim 14, comprising any one or a combination of at least two of the following:

16. A positive electrode sheet for a lithium ion battery, comprising a positive electrode material of the composite lithium nickel manganese oxide according to any one of claims 1 to 4.

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