Lithium oxide-containing positive electrode material precursor and lithium oxide-containing positive electrode material, preparation method and application thereof, positive electrode sheet and application thereof

Abstract

The present invention relates to the technical field of lithium-ion batteries, and discloses a lithium oxide-containing positive electrode material precursor and a lithium oxide-containing positive electrode material, a preparation method and application thereof, a positive electrode sheet and application thereof. The compressive strength index Δλ (P 100 ) satisfies: Δλ(P 100 )≥60%+(y / x)×5%; where y / x is the molar ratio of Mn / Ni in the positive electrode material. This lithium oxide-containing positive electrode material has high compressive strength and stability. During the electrode sheet manufacturing process, it can withstand high pressure with only minor fracture and can continuously undergo lithium ion extraction and insertion reactions without severe cracking.

Description

Technical Field

[0001] The present invention relates to the technical field of lithium-ion batteries, and in particular to a lithium oxide-containing positive electrode material precursor and a lithium oxide-containing positive electrode material, a preparation method and application thereof, a positive electrode sheet and application thereof. Background Art

[0002] In recent years, new energy vehicles, as a national strategic emerging industry to cope with environmental pollution and energy crisis, have shown a good situation of vigorous development. Lithium-ion batteries, as a new energy carrier with excellent comprehensive performance, are widely used in electric vehicles, energy storage power stations, communications and digital electronic products and other markets.

[0003] In lithium-ion batteries, the positive electrode is the core key material of lithium-ion batteries and directly determines the technical performance level of the battery. Among the commonly used lithium-ion battery positive electrode materials, LiNi with a layered structure 1-x-y Co x Mn y O2(NCM) and LiNi 1-x-y Co x Al y O2 (NCA) and lithium-rich manganese-based materials (LMR) have attracted much attention and research due to their high specific capacity and energy density. However, in order to obtain higher volume energy density and comprehensive electrochemical performance, the positive electrode material must be rolled with greater intensity during the production of battery pole pieces to obtain a high electrode density. Low-strength positive electrode materials will be fractured or crushed in this process, increasing the contact area with the electrolyte and side reactions, resulting in poor cycle performance and rate performance. In addition, during battery use, Li + Repeated intercalation and deintercalation will cause the volume of the layered structure to expand and contract, resulting in pulverization of the low-strength positive electrode material, insufficient contact between particles, continuous formation of new electrolyte layers and increased side reactions, causing battery performance deterioration and failure.

[0004] Therefore, developing new preparation methods and regulating the microstructure of layered positive electrode materials to enhance the compressive strength or particle strength of positive electrode materials are of great significance for achieving long cycle life, high specific capacity, and high rate performance of batteries. Summary of the Invention

[0005] The purpose of the present invention is to overcome the defects of the prior art in that lithium-containing metal oxide materials break during the electrode sheet manufacturing process or secondary particles break during the charge and discharge cycle, resulting in poor rate performance, deteriorated cycle performance, and reduced safety performance. The present invention provides a lithium-containing oxide positive electrode material precursor and a lithium-containing oxide positive electrode material and their preparation methods and applications, a positive electrode sheet and their applications. The lithium-containing oxide positive electrode material has high compressive strength and stability, can withstand high pressure during the electrode sheet manufacturing process with only a small degree of breakage, and can continuously carry out lithium ion extraction / intercalation reactions without serious rupture.

[0006] In order to achieve the above object, the present invention provides a lithium oxide positive electrode material in the first aspect, wherein the compressive index Δλ (P 100 ) satisfies: Δλ(P 100 )≥60%+(y / x)×5%;

[0007] Wherein, y / x is the molar ratio of Mn / Ni in the positive electrode material.

[0008] The second aspect of the present invention provides a lithium oxide positive electrode material precursor, wherein the compressive index Δλ′ (P 50 ) satisfies: Δλ′(P 50 )≥35%+(v / u)×8%;

[0009] Wherein, v / u is the molar ratio of Mn / Ni in the precursor.

[0010] A third aspect of the present invention provides a method for preparing a lithium oxide-containing positive electrode material, wherein the preparation method comprises:

[0011] S1: uniformly mixing a precursor having a chemical formula shown in formula (1), a lithium source, and an optional additive containing element M2, and performing a first sintering in an atmosphere furnace to obtain a primary sintered material having a chemical formula shown in formula (2);

[0012] S2: uniformly mixing the primary sintered material with an additive containing the element M′, and performing a second sintering on the mixed material in an atmosphere furnace to obtain a lithium-containing metal oxide having the chemical formula shown in formula (3);

[0013] Ni u Mn v M 1γ (OH)2, formula (1);

[0014] Among them, u + v + γ = 1, 0.2 < u < 1, 0 < v ≤ 0.75, 0 ≤ γ ≤ 0.35, and M1 is selected from at least one element of Al, Zr, Nb, Ti, Y, Sc, Cr, Co, W, Mg, Na, La, Os, Pr, Re, Ru, Sr, Sm, Ta, and B;

[0015] Li[Li a Ni x Mn y M j O2, Formula (2);

[0016] Li[Li a Ni x Mn y M j O2@M′, Formula (3);

[0017] Among them, in Formulas (2) and (3):

[0018] a + x + y + j = 1, 0 ≤ a ≤ 0.3, 0.2 < x < 1, 0 < y ≤ 0.75, 0 < j ≤ 0.35;

[0019] M includes the M1 element in the precursor and the M2 element introduced during the first sintering process;

[0020] M1 and M2 are the same or different, and each is selected from at least one element of Al, Zr, Nb, Ti, Y, Sc, Cr, Co, W, Mg, La, Os, Pr, Re, Ru, Sr, Sm, Ta, and B;

[0021] In Formula (3):

[0022] M′ is an oxide, phosphide, sulfide, fluoride, or chloride containing at least one element of Al, Zr, Nb, Ti, Y, Sc, Cr, Co, W, Mg, La, Os, Pr, Re, Ru, Sr, Sm, Ta, and B, and the molar content of the cation in M′ is w, 0 < w / (a + x + y + j) ≤ 0.1.

[0023] The fourth aspect of the present invention provides a lithium-containing oxide cathode material prepared by the preparation method of the lithium-containing oxide cathode material described above.

[0024] The fifth aspect of the present invention provides a positive electrode sheet, which, based on the total weight of the positive electrode sheet, contains at least 90 wt% of the lithium-containing oxide cathode material;

[0025] Among them, the lithium-containing oxide cathode material is the lithium-containing oxide cathode material described above.

[0026] A sixth aspect of the present invention provides a use of the aforementioned lithium oxide-containing positive electrode material, the aforementioned lithium oxide-containing positive electrode material precursor, or the aforementioned positive electrode sheet in a lithium-ion battery.

[0027] Through the above technical solution, the present invention has the following advantages:

[0028] (1) The lithium oxide-containing positive electrode material and precursor provided by the present invention achieve high crystallinity and densification of the precursor by controlling a specific microstructure, thereby improving the compressive strength index of the positive electrode material;

[0029] (2) The present invention can improve the compressive index, cycle life and safety performance of the material by using appropriate modifiers and doping elements;

[0030] (3) The sintering system in the preparation process of the lithium-containing metal oxide of the present invention affects the compressive index of the material. Therefore, when selecting the sintering system, the cost, the compressive index of the material, the physical indicators of the material and the electrochemical properties are taken into consideration. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 Schematic diagram comparing the charge and discharge curves of Example 5 and Comparative Example 1;

[0032] Figure 2 Schematic diagram comparing the cycle performance of Example 5 and Comparative Example 1;

[0033] Figure 3 2 is a schematic diagram comparing the charge and discharge curves of Example 5 and Comparative Example 2;

[0034] Figure 4 Schematic diagram comparing the cycle performance of Example 5 and Comparative Example 2;

[0035] Figure 5 Schematic diagram comparing the charge and discharge curves of Example 5 and Comparative Example 3;

[0036] Figure 6 Schematic diagram comparing the cycle performance of Example 5 and Comparative Example 3;

[0037] Figure 7 Schematic diagram comparing the charge and discharge curves of Example 5 and Comparative Example 4;

[0038] Figure 8 Schematic diagram comparing the cycle performance of Example 5 and Comparative Example 4;

[0039] Figure 9 Schematic diagram comparing the charge and discharge curves of Example 9 and Comparative Example 5;

[0040] Figure 10 Schematic diagram comparing the cycle performance of Example 9 and Comparative Example 5;

[0041] Figure 11 Schematic diagram comparing the charge and discharge curves of Example 9 and Comparative Example 6;

[0042] Figure 12 Schematic diagram comparing the cycle performance of Example 9 and Comparative Example 6;

[0043] Figure 13 Schematic diagram comparing the charge and discharge curves of Example 9 and Comparative Example 7;

[0044] Figure 14 It is a schematic diagram comparing the cycle performance of Example 9 and Comparative Example 7. DETAILED DESCRIPTION

[0045] The endpoints of the ranges and any values ​​disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoints of each range, the endpoints of each range and individual point values, and the individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered to be specifically disclosed herein.

[0046] Conventional lithium-ion battery lithium-ion metal oxide materials have to withstand high pressure during the preparation of electrode sheets and continuous charge and discharge cycles. Due to insufficient compressive strength or unstable structure, the materials may break, which increases side reactions with the electrolyte, accelerates the consumption of the electrolyte and the dissolution of transition metal cations in the positive electrode material, resulting in decreased cycle performance, safety performance and capacity, and even battery failure.

[0047] As mentioned above, the first aspect of the present invention provides a lithium oxide positive electrode material, wherein the compressive index Δλ (P 100 ) satisfies: Δλ(P 100 )≥60%+(y / x)×5%;

[0048] Wherein, y / x is the molar ratio of Mn / Ni in the positive electrode material.

[0049] In addition, in the present invention:

[0050]

[0051] in It refers to the D5 value of the cumulative distribution of particles of the material in the natural state without external mechanical pressure (i.e. P = 0 MPa). It refers to the D5 value of the cumulative particle distribution of the material under P = n Mpa, and D5 refers to the particle size value at which the cumulative volume distribution of the particles is 5%.

[0052] For example, the compression index Δλ(P 100) is calculated as follows:

[0053]

[0054] According to the present invention, preferably, the compressive strength index Δλ(P 200 ) of the positive electrode material satisfies: Δλ(P 200 ) ≥ 45% + (y / x) × 5%.

[0055] According to the present invention, more preferably, the compressive strength index Δλ(P 300 ) of the positive electrode material satisfies: Δλ(P 300 ) ≥ 35% + (y / x) × 5%.

[0056] It should be noted that according to the present invention, Δλ(P 100 ) represents the compressive strength index of the material when the pressure P = 100 Mpa; Δλ(P 200 ) represents the compressive strength index of the material when the pressure P = 200 Mpa; and so on.

[0057] The positive electrode material provided by the present invention has excellent compressive strength, is not prone to cracking, has a stable structure, few side reactions, and excellent safety performance and capacity retention rate during the application as a positive electrode.

[0058] According to the present invention, the lithium-containing oxide positive electrode material has the chemical formula shown in formula (3):

[0059] Li[Li a Ni x Mn y M j O2@M′, formula (3);

[0060] Wherein, a + x + y + j = 1, 0 ≤ a ≤ 0.3, 0.2 < x < 1, 0 < y ≤ 0.75, 0 < j ≤ 0.35, M is selected from at least one element of Al, Zr, Nb, Ti, Y, Sc, Cr, Co, W, Mg, La, Os, Pr, Re, Ru, Sr, Sm, Ta, and B, and M′ is an oxide, phosphide, sulfide, fluoride, or chloride containing at least one element of Al, Zr, Nb, Ti, Y, Sc, Cr, Co, W, Mg, La, Os, Pr, Re, Ru, Sr, Sm, Ta, and B, and the molar content of cations in M′ is w, 0 < w / (a + x + y + j) ≤ 0.1.

[0061] According to the present invention, preferably, 0.02 ≤ a ≤ 0.3, 0.3 < x < 0.9, 0.05 < y ≤ 0.68, 0 < j ≤ 0.3, 0.001 < w / (a + x + y + j) ≤ 0.02.

[0062] According to the present invention, M is selected from at least one element of Zr, Nb, Ti, Y, Sc, Cr, Co, W, Mg, La, Ta and B, and M′ is an oxide, phosphide, sulfide or fluoride containing at least one element of Zr, Nb, Ti, Y, Sc, Cr, Co, W, Mg, La, Ta and B.

[0063] In the present invention, the inventors of the present invention found that:

[0064] By using appropriate modifiers, the compressive strength and stability of the material particles can be enhanced, the DC internal resistance and gas production of the material during the cycle can be reduced, and the cycle life of the material can be improved.

[0065] By doping with elements such as Ti, Sc, Zr, W, Mg, Y, Co, Cr, and Ta, the crystal structure of the material can be stabilized, the microstructure of the material can be improved, and the compressive index, cycle life, and safety performance of the material can be improved. Doping with elements such as Ti, Zr, Nb, La, W, Co, and B will form lithium-containing compounds (such as LiNbO3 or Li2ZrO3 or Li4Ti5O 12 or Li3BO3 or LaNiO3, etc.), stabilizes the surface structure of the material particles or the interface strength between the particles or the grain boundary structure between the primary grains, improves the material's compressive index and cycle life, and can accelerate the transfer of lithium ions between particles and between interfaces, thereby improving the material's rate performance. The positive electrode material provided by the present invention is also characterized by:

[0066] According to the present invention, the tap density of the positive electrode material is ≥1.7 g / cm 3 , preferably ≥2g / cm 3 , more preferably ≥2.4g / cm 3 .

[0067] According to the present invention, the compaction density of the positive electrode material is ≥2.8g / cm 3 , preferably ≥3g / cm 3 , more preferably ≥3.2g / cm 3 .

[0068] According to the present invention, the content of surface-soluble alkali in the positive electrode material satisfies the following conditions:

[0069] Li2CO3≤1wt%, LiOH≤0.5wt%;

[0070] Preferably, Li2CO3≤0.5wt%, LiOH≤0.4wt%;

[0071] More preferably, Li2CO3≤0.3wt%, LiOH≤0.3wt%;

[0072] More preferably, Li2CO3≤0.2wt%, LiOH≤0.2wt%.

[0073] According to the present invention, the half maximum width (FWHM) of the (003) crystal plane of the positive electrode material obtained by XRD is (003) and the half maximum width (FWHM) of the (104) crystal plane (104) The following conditions are met:

[0074] 0.10≤FWHM (003) ≤0.25, preferably 0.13≤FWHM (003) ≤0.22;

[0075] 0.20≤FWHM (104) ≤0.50, preferably 0.22≤FWHM (104) ≤0.42.

[0076] According to the present invention, the peak area S of the (003) crystal plane of the positive electrode material obtained by XRD is (003) The peak area S of (104) crystal plane (104) The following conditions are met:

[0077] 1.1≤S (003) / S (104) ≤1.8, preferably 1.2≤S (003) / S (104) ≤1.6.

[0078] In addition to using appropriate additives, the present invention also achieves high crystallinity and densification of the precursor by controlling the morphology and microstructure of the precursor, thereby improving the compressive index of the positive electrode material.

[0079] The second aspect of the present invention provides a lithium oxide positive electrode material precursor, wherein the compressive index Δλ′ (P 50 ) satisfies: Δλ′(P 50 )≥35%+(v / u)×8%;

[0080] Wherein, v / u is the molar ratio of Mn / Ni in the precursor.

[0081] According to the present invention, preferably, the compressive index Δλ′ (P 100 ) satisfies: Δλ′(P 100 )≥25%+(v / u)×8%.

[0082] According to the present invention, it should be noted that Δλ′(P 50 ) represents the compressive index of the precursor material when the pressure is P = 50 MPa; Δλ′(P100 ) represents the compressive strength index of the precursor material when the pressure P = 100 MPa; and so on.

[0083] In the present invention,

[0084]

[0085] where refers to the D5 value of the particle cumulative distribution of the precursor material under natural state without external mechanical pressure (i.e., P = 0 MPa), refers to the D5 value of the particle cumulative distribution of the precursor material at P = n MPa.

[0086] For example, the compressive strength index Δλ′(P 50 ) of the precursor is calculated as follows:

[0087]

[0088] According to the present invention, the precursor has the chemical formula shown in formula (1):

[0089] Ni u Mn v M γ (OH)2, formula (1);

[0090] where u + v + γ = 1, 0.2 < u < 1, 0 < v ≤ 0.75, 0 ≤ γ ≤ 0.35, and M is selected from at least one element of Al, Zr, Nb, Ti, Y, Sc, Cr, Co, W, Mg, Na, La, Os, Pr, Re, Ru, Sr, Sm, Ta, and B;

[0091] Preferably, 0.3 ≤ u ≤ 0.9, 0.05 ≤ v ≤ 0.68, 0 ≤ γ ≤ 0.3, and M is selected from at least one element of Ti, Al, Zr, W, Co, Nb, La, Na, and Mg. In the present invention, doping elements such as Ti, Al, Zr, W, Co, Nb, La, Na, and Mg can stabilize the internal or surface structure of the precursor micro-region.

[0092] The precursor material provided by the present invention is further characterized in that:

[0093] According to the present invention, in a more preferred case, the tap density of the precursor ≥ 1.2 g / cm 3 , preferably ≥ 1.6 g / cm 3 , and more preferably ≥ 2 g / cm 3 .

[0094] According to the present invention, the BET value of the specific surface area of the precursor satisfies: BET ≤ 30 m 2 / g, preferably, BET≤25m 2 / g.

[0095] According to the present invention, the particle size distribution coefficient K of the precursor 90 Satisfy: 0.5≤K 90 ≤1.6; K 90 =(D 90 -D 10 ) / D 50 , D 10 、D 50 and D 90 The particle sizes are 10%, 50% and 90% of the cumulative volume distribution, respectively.

[0096] According to the present invention, the half maximum width (FWHM) of the (001) crystal plane of the precursor obtained by XRD is (001) , FWHM of (100) crystal plane (100) and the half maximum width (FWHM) of the (101) crystal plane (101) The following conditions are met:

[0097] 0.3≤FWHM (001) ≤1, preferably, 0.5≤FWHM (001) ≤0.8; that is, the FWHM of the precursor material provided by the present invention measured by X-ray diffractometer (001) 2θ is not less than 0.3 and not more than 1, preferably not less than 0.5 and not more than 0.8;

[0098] 0.10≤FWHM (100) ≤0.5, preferably 0.25≤FWHM (100) ≤0.35;

[0099] 0.30≤FWHM (101) ≤1.0, preferably 0.4≤FWHM (101) ≤0.8.

[0100] According to the present invention, the peak area S of the (001) crystal plane of the precursor obtained by XRD is (101) The peak area S of (101) crystal plane (104) Meet the following conditions: S (001) / S (101) ≥2.0.

[0101] According to the present invention, the integrated area S of the (001) crystal plane of the precursor obtained by XRD is (101) The integral area S of the (101) crystal plane (104) Meet the following conditions: S (001) / S (101) ≥2.0.

[0102] The present invention also provides a method for preparing a lithium oxide positive electrode material precursor, wherein the preparation method comprises:

[0103] (1) contacting and mixing a solution or suspension of a nickel salt, a manganese salt, and a compound containing M to obtain a mixed salt solution;

[0104] (2) The mixed salt solution, precipitant solution, and complexing agent solution are simultaneously fed into a reactor for crystallization reaction, and the obtained slurry is subjected to solid-liquid separation, washing, heat treatment, and screening to obtain a lithium oxide-containing positive electrode material precursor.

[0105] In the present invention, the inventors of the present invention have found that: for metal hydroxide precursors, during the mixing and sintering process, due to insufficient compressive strength of the precursor, cracks may occur, resulting in reduced compressive strength, reduced tap density, and reduced electrochemical performance of the prepared positive electrode material. In the present invention, by controlling the precursor synthesis process, such as the concentration and type of the complexing agent, the concentration of the precipitant, the stirring intensity, the reaction temperature, the additives, the solid content, and the feed rate, it is possible to achieve high crystallinity and densification of the precursor synthesis, regulate the particle size distribution and specific surface area of ​​the precursor, thereby improving the crystallinity, tap density, and compressive index of the precursor material; it is also possible to improve the compressive index of the precursor by adding suitable additives and regulating the microstructure and morphology of the precursor.

[0106] According to the present invention, nickel salt, manganese salt or additive containing M element is dissolved in a molar ratio of u:v:γ to form a mixed salt solution with a concentration of 1-3 mol / L, the compound containing M is added to water to prepare an M solution or suspension with a certain concentration, the base is dissolved to form an alkaline solution with a concentration of 2-10 mol / L, and the complexing agent is dissolved to form a complexing agent solution with a concentration of 2-13 mol / L.

[0107] According to the present invention, the solid content of the slurry is 200-1000 g / L, preferably 300-800 g / L.

[0108] According to the present invention, a mixed salt solution of Ni and Mn, an alkali solution, a complexing agent solution, and an M solution are respectively added to a reactor with an overflow pipe through respective liquid inlet pipes in parallel, the stirring speed is kept constant, and the inlet flow rates of the mixed salt solution, the precipitant solution, the complexing agent solution, and the M solution are controlled.

[0109] According to the present invention, the reaction conditions include: reaction temperature of 40-70° C., reaction pH of 10.6-12.5, and reaction time of 5-100 h.

[0110] According to the present invention, the nickel salt is one or more of nickel sulfate, nickel chloride, nickel nitrate and nickel acetate.

[0111] According to the present invention, the manganese salt is one or more of manganese sulfate, manganese chloride, manganese nitrate, and manganese acetate.

[0112] According to the present invention, the compound containing M is one or more of sulfates, chlorides, nitrates, acetates, citrates, carbonates, phosphates, oxalates, and fluorides containing the M element.

[0113] According to the present invention, the precipitating agent is an alkaline substance, and the alkali is one or more of sodium hydroxide, potassium hydroxide, and lithium hydroxide.

[0114] According to the present invention, the complexing agent is one or more of salicylic acid, ammonium sulfate, ammonium chloride, ammonia water, sulfosalicylic acid, and ethylenediaminetetraacetic acid.

[0115] According to the present invention, the sintering regime (including sintering temperature, heating rate, sintering atmosphere, etc.) during the preparation of the lithium-containing metal oxide is also very important and will affect the compressive index of the material.

[0116] The third aspect of the present invention provides a method for preparing a lithium-containing oxide cathode material, wherein the preparation method includes:

[0117] S1: Mix the precursor having the chemical formula shown in formula (1), a lithium source, and an optional additive containing element M2 evenly, and perform a first sintering on the mixed material in an atmosphere furnace to obtain a first sintered material having the chemical formula shown in formula (2);

[0118] S2: Mix the first sintered material with an additive containing element M′ evenly, and perform a second sintering on the mixed material in an atmosphere furnace to obtain a lithium-containing metal oxide having the chemical formula shown in formula (3);

[0119] Ni u Mn v M 1γ (OH)2, formula (1);

[0120] Wherein, u + v + γ = 1, 0.2 < u < 1, 0 < v ≤ 0.75, 0 ≤ γ ≤ 0.35, and M1 is selected from at least one element of Al, Zr, Nb, Ti, Y, Sc, Cr, Co, W, Mg, Na, La, Os, Pr, Re, Ru, Sr, Sm, Ta, and B; [[ID=​​​​​​​​​​​​​​​​​y M j ]O2@M′, formula (3);

[0123] Among them, in formula (2) and formula (3):

[0124] 0≤a≤0.3,0.2 <x<1,0<y≤0.75,0<j≤0.35;

[0125] M includes the M1 element in the precursor and the M2 element introduced during the first sintering process;

[0126] M1 and M2 are the same or different, and are each selected from at least one element of Al, Zr, Nb, Ti, Y, Sc, Cr, Co, W, Mg, La, Os, Pr, Re, Ru, Sr, Sm, Ta and B;

[0127] In formula (3):

[0128] M' is an oxide, phosphide, sulfide, fluoride or chloride containing at least one element of Al, Zr, Nb, Ti, Y, Sc, Cr, Co, W, Mg, La, Os, Pr, Re, Ru, Sr, Sm, Ta and B, and the molar content of the cation in M' is w, 0 <w / (a+x+y+j)≤0.1。

[0129] According to the present invention, the sources of the M element in the positive electrode material include the M1 element in the precursor and the additive containing the M2 element introduced during the first sintering process.

[0130] According to the present invention, the lithium source is at least one of lithium hydroxide, lithium carbonate, and lithium nitrate;

[0131] According to the present invention, the additive containing the element M2 is selected from at least one of oxides, hydroxides, oxyhydroxides, phosphates, fluorides, borides, and carbonates containing the element M2.

[0132] According to the present invention, the M1 element and the M2 element are the same as or different from the M element, and each is selected from at least one element of Al, Zr, Nb, Ti, Y, Sc, Cr, Co, W, Mg, La, Os, Pr, Re, Ru, Sr, Sm, Ta and B.

[0133] According to the present invention, the additive containing element M' is selected from at least one of oxides, hydroxides, oxyhydroxides, phosphates, fluorides, borides, nitrides, carbonates and oxalates containing element M'.

[0134] According to the present invention, the molar ratio of the amount of the lithium source to the sum of the amounts of the precursor and the additive containing the element M2, Li / (Ni+Mn+M1+M2), is 1-1.85, preferably 1-1.5.

[0135] According to the present invention, the additive containing the element M2 is added in an amount according to M2 / (Ni+Mn+M1+M2) of 0.0005-0.3, preferably 0.001-0.2.

[0136] According to the present invention, the molar ratio of the amount of the additive containing the element M' to the amount of the primary sintering material is M' / (Ni+Mn+M1+M2) in the range of 0-0.1, preferably 0.001-0.02.

[0137] According to the present invention, when the molar ratio of Ni / Mn is greater than 1, that is, x / y>1, the relationship between the first sintering temperature T1 and the Ni content satisfies: 550×(2-x)≤T1≤400×(3-x)°C, and the sintering time is 6-20h, preferably 8-15h.

[0138] According to the present invention, when the molar ratio of Ni / Mn is ≤1, that is, y / x≥1, the relationship between the first sintering temperature T2 and the Mn content satisfies: 500×(1+y)≤T2≤650×(1+y)°C, and the sintering time is 6-20h, preferably 8-15h.

[0139] According to the present invention, when x is less than 0.5, the first and second sintering atmospheres are air; when 0.5≤x<0.6, the first and second sintering atmospheres are air or a mixture of air and oxygen; when x≥0.6, the first and second sintering atmospheres are oxygen or a mixture of oxygen and air.

[0140] A fourth aspect of the present invention provides a lithium-containing oxide positive electrode material prepared by the aforementioned method for preparing a lithium-containing oxide positive electrode material.

[0141] A fifth aspect of the present invention provides a positive electrode sheet, wherein, based on the total weight of the positive electrode sheet, the positive electrode sheet comprises at least 90 wt% of a lithium oxide-containing positive electrode material; the lithium oxide-containing positive electrode material is the lithium oxide-containing positive electrode material described above.

[0142] According to the present invention, preferably, the mass proportion of the positive electrode material is not less than 95%.

[0143] According to the present invention, the electrode density of the positive electrode is ≥2.8g / cm 3 , preferably ≥3.2g / cm 3 , more preferably ≥3.5g / cm 3 .

[0144] A sixth aspect of the present invention provides a use of the aforementioned lithium oxide-containing positive electrode material, the aforementioned lithium oxide-containing positive electrode material precursor, or the aforementioned positive electrode sheet in a lithium-ion battery.

[0145] The present invention will be described in detail below through examples.

[0146] In the following examples and comparative examples:

[0147] Unless otherwise specified, all raw materials are commercially available.

[0148] In the following examples, the performance involved is achieved by:

[0149] (1) Phase test: obtained by using a SmartLab 9kW X-ray diffractometer from Rigaku Corporation;

[0150] (2) Morphology test: obtained by scanning electron microscope S-4800 model of Hitachi HITACHI, Japan;

[0151] (3) Particle size test: obtained by using the Marvern Hydro 2000mu laser particle size analyzer;

[0152] (4) Specific surface area: measured by a Tristar II 3020 surface area tester from Micromertics, USA;

[0153] (5) Tap density: measured by a BT-30 tap density tester from Baxter;

[0154] (6) Compacted density: measured using a powder impedance tester model MCP-PD51 from Mitsubishi Chemical, Japan;

[0155] (7) Compression index test: The material is compressed to a specific pressure using a 4350 manual tablet press from Carver, USA. The particle size of the material after fracturing is tested and the compression index is calculated by substituting it into the compression index formula;

[0156] (8) Surface residual alkali test: measured by titration using Metrohmm888 professional Tirando intelligent potentiometric titrator;

[0157] (9) Thermal stability test: obtained by using a Mettler TGA-DSC3 thermogravimetric analyzer;

[0158] (10) Electrochemical performance test:

[0159] The electrochemical properties of the prepared lithium oxide-containing cathode material were tested on 2025-type button batteries using the Xinwei battery testing system. Specifically:

[0160] 1) The preparation process of 2025 button battery is as follows:

[0161] Preparation of electrode sheets: The lithium oxide-containing positive electrode material, carbon black, polyvinylidene fluoride are fully mixed with an appropriate amount of N-methylpyrrolidone in a certain mass ratio to form a uniform slurry, which is then coated on aluminum foil, dried at 120°C, rolled, and punched to form a positive electrode sheet with a diameter of 11 mm.

[0162] Assemble the battery: the negative electrode uses a Li metal sheet with a diameter of 17 mm and a thickness of 1 mm; the separator uses a polyethylene porous membrane with a thickness of 25 μm; the electrolyte uses an equal mixture of 1 mol / L LiPF6, ethylene carbonate (EC) and diethyl carbonate (DEC).

[0163] The positive electrode sheet, separator, negative electrode sheet and electrolyte were assembled into a 2025 button cell in an Ar gas glove box with a water content and an oxygen content of less than 5 ppm. The cell at this time was regarded as an unactivated cell.

[0164] 2) Electrochemical performance test:

[0165] When the molar ratio of Ni / Mn is greater than 1, that is, x / y>1, the button cell test conditions are as follows: after making the button cell, let it stand for 2 hours. After the open circuit voltage stabilizes, it is charged to a cut-off voltage of 4.3V at a current density of 0.1C at the positive electrode, then charged at a constant voltage for 30 minutes, and then discharged to a cut-off voltage of 3.0V at the same current density; the same method is repeated once, and the battery at this time is regarded as an activated battery. Using the activated battery, the charge and discharge test is carried out in the voltage range of 3.0-4.3V, at 25℃, in the charge and discharge range of 3.0-4.3V, and 0.1C to evaluate the charge and discharge capacity of the material; using the activated battery, the charge and discharge test is carried out at 0.1C, 0.2C, 0.33C, 0.5C, and 1C, and the ratio of 1C capacity to 0.1C capacity is used to evaluate the rate performance of the material; in the range of 3.0-4.4V, 1C cycles are repeated 80 times to evaluate the cycling performance of the material.

[0166] When the molar ratio of Ni / Mn is not greater than 1, that is, x / y≤1, the button cell test conditions are as follows: after making the button cell, let it stand for 2 hours. After the open circuit voltage stabilizes, it is charged to a cutoff voltage of 4.6V at a current density of 0.1C at the positive electrode, then charged at a constant voltage for 30 minutes, and then discharged to a cutoff voltage of 2.0V at the same current density; the same method is repeated once, and the battery at this time is regarded as an activated battery. Using the activated battery, the charge and discharge test is carried out in the voltage range of 2.0-4.6V, at 25℃, the charge and discharge range of 2.0-4.6V, and 0.1C to evaluate the charge and discharge capacity of the material; using the activated battery, the charge and discharge test is carried out at 0.1C, 0.2C, 0.33C, 0.5C, and 1C, and the ratio of 1C capacity to 0.1C capacity is used to evaluate the rate performance of the material; the cycling performance of the material is evaluated by 80 cycles in the range of 2.0-4.6V and 0.5C.

[0167] Example 1

[0168] This embodiment is intended to illustrate the lithium oxide positive electrode material prepared by the present invention.

[0169] Nickel sulfate and manganese sulfate were dissolved in a metal molar ratio of 5:3 to obtain a 2 mol / L mixed salt solution, cobalt sulfate and aluminum sulfate were dissolved in a metal molar ratio of Co / (Ni+Mn+Co+Al)=0.18 and Al / (Ni+Mn+Co+Al)=0.02 to obtain a 2 mol / L mixed salt solution, sodium hydroxide was dissolved to form an alkaline solution with a concentration of 6 mol / L, and ammonia water was dissolved to form a complexing agent solution with a concentration of 5 mol / L.

[0170] Then, 20L of mixed salt solution, alkali solution and complexing agent solution were added to the reactor in parallel to react. The stirring speed was kept constant at 600 rpm during the process. At the same time, the flow rate of the mixed salt solution was controlled to 300mL / h, the reaction pH was controlled to 11.6, the reaction temperature was 50°C, the concentration of ammonia in the reaction system was controlled to 9g / L, the reaction was carried out in N2 gas, the reaction was allowed to stand for 60h, the solid content was 500g / L, the slurry obtained by the precipitation crystallization reaction was subjected to solid-liquid separation and washing, and then dried at 105°C for 10h, and spherical Ni was obtained after sieving. 0.5 Mn 0.3 Co 0.18 Al 0.02 (OH)2 precursor material, denoted as P-1.

[0171] The precursor P-1, lithium carbonate, additives TiO2 and WO3 were mixed uniformly in a high-speed mixer according to the ratio of Li:(Ni+Mn+Co+Al+Ti+W)=1.03, Ti:(Ni+Mn+Co+Al+Ti+W)=0.003, W:(Ni+Mn+Co+Al+Ti+W)=0.002; the temperature was raised to 920°C in an air atmosphere, maintained for 10 hours, and cooled naturally to obtain a primary sintered positive electrode material Li[Li0Ni 0.4975 Mn 0.2985 Co 0.1791 Al 0.0199 Ti 0.003 W 0.002 ]O2, recorded as S-1.

[0172] The primary sintering material S-1, additives Nb2O5 and La2O3 were mixed uniformly according to the ratio of Nb:(Ni+Mn+Co+Al+Ti+W)=0.002 and La:(Ni+Mn+Co+Al+Ti+W)=0.002; the temperature was raised to 650℃ in air atmosphere, maintained for 6h, and cooled naturally to obtain the secondary sintering positive electrode material Li[Li0Ni 0.4975 Mn 0.2985 Co 0.1791 Al 0.0199 Ti 0.003 W 0.002 ]O2@Nb 0.002 La 0.002 , denoted as FS-1.

[0173] Examples 2-14

[0174] This embodiment is intended to illustrate the lithium oxide positive electrode material prepared by the present invention.

[0175] The lithium oxide-containing positive electrode material was prepared in the same manner as in Example 1, except that the precursor preparation process, the preparation process of the primary sintered positive electrode material, and the preparation process of the secondary sintered positive electrode material were different, as shown in Table 1.

[0176] Table 1

[0177]

[0178]

[0179] Table 1 (continued)

[0180]

[0181]

[0182] Table 1 (continued)

[0183]

[0184]

[0185] In Table 1, unless otherwise specified, all ratios and dosage ratios are molar ratios.

[0186] Comparative Example 1

[0187] The same synthesis method and conditions as in Example 5 were used, except that the first sintering temperature was adjusted to 600° C. The obtained positive electrode material was designated D-1, as shown in Table 2.

[0188] Comparative Example 2

[0189] The same synthesis method and conditions as in Example 5 were used, except that the first sintering temperature was adjusted to 900° C. The obtained positive electrode material was designated D-2, as shown in Table 2.

[0190] Comparative Example 3

[0191] The same synthesis method and conditions as in Example 5 were used, except that the additives rhenium oxide and salinityl oxide were not added in the preparation process of the primary sintering positive electrode material. The obtained positive electrode material was designated D-3, as shown in Table 2.

[0192] Comparative Example 4

[0193] The same synthesis method and conditions as in Example 5 were used, except that the additives tungsten nitride and aluminum fluoride were not added in the preparation process of the secondary sintered positive electrode material. The obtained positive electrode material was recorded as D-4, as shown in Table 2.

[0194] Comparative Example 5

[0195] The same synthesis method and conditions as in Example 9 were used, except that the solid content in the precursor preparation process was adjusted to 150 g / L. The obtained positive electrode material was designated D-5, as shown in Table 2.

[0196] Comparative Example 6

[0197] The same synthesis method and conditions as in Example 9 were used, except that the additives tungsten oxide and aluminum oxyhydroxide were not added in the preparation process of the primary sintering positive electrode material. The obtained positive electrode material was designated D-6, as shown in Table 2.

[0198] Comparative Example 7

[0199] The same synthesis method and conditions as in Example 9 were used, but the preparation process of the secondary sintering positive electrode material was removed. The obtained positive electrode material was recorded as D-7, as shown in Table 2.

[0200] Table 2

[0201]

[0202]

[0203] Table 2 (continued)

[0204]

[0205]

[0206] Test Example 1

[0207] The performance of the lithium oxide positive electrode material precursors prepared in Examples 1-14 and Comparative Examples 1-7 were tested, and the results are shown in Table 3; and the performance of the lithium oxide positive electrode materials prepared in Examples 1-14 and Comparative Examples 1-7 were tested, and the results are shown in Table 4 and Table 5.

[0208] Table 3

[0209]

[0210]

[0211] Table 4

[0212]

[0213] Table 4 (continued)

[0214]

[0215]

[0216] Table 4 (continued)

[0217]

[0218] Table 5

[0219]

[0220]

[0221] Test Example 2

[0222] The lithium oxide-containing positive electrode materials prepared in Examples 1-14 and Comparative Examples 1-7 were used as positive electrode sheets of lithium ion batteries to prepare lithium ion batteries. The performance of the lithium ion batteries was tested, and the results are shown in Table 6.

[0223] Table 6

[0224] lithium-ion batteries Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Example 7 <![CDATA[Polar plate density (g / cm 3 )]]> 3.2 3.2 3.5 3.4 3.6 3.3 3.5 0.1C discharge capacity (mAh / g) 173.1 181.3 192.3 208.7 225.2 228.3 233.5 1C discharge capacity (mAh / g) 158.6 167.1 176.5 192.2 214.3 216.2 218.5 1C capacity / 0.1C capacity (%) 91.6 92.2 91.8 92.1 95.1 94.7 93.6 Capacity retention rate (%) 99.1 95.2 94.8 99.0 94.6 96.3 93.3

[0225] Table 6 (continued)

[0226]

[0227] Table 6 (continued)

[0228] lithium-ion batteries Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Comparative Example 5 Comparative Example 6 Comparative Example 7 <![CDATA[Pole piece density (g / cm 3 )]]> 3.2 3.6 3.5 3.3 2.8 2.8 2.9 0.1C discharge capacity (mAh / g) 216.9 208.3 221.7 214.3 240.9 241.9 233.0 1C discharge capacity (mAh / g) 190.9 188.5 200.2 194.4 203.3 198.8 190.3 1C capacity / 0.1C capacity (%) 88.0 90.5 90.3 90.7 84.4 82.2 81.7 Capacity retention rate (%) 86.7 85.9 87.5 86.6 88.0 89.0 89.9

[0229] In addition, in the present invention, Figure 1 Schematic diagram comparing the charge and discharge curves of Example 5 and Comparative Example 1; Figure 1 It can be seen that by comparing the charge and discharge curves of Example 5 and Comparative Example 1, it can be seen that the 0.1C discharge capacity (225.2 mAh / g) of the positive electrode material provided in Example 5 is higher than the 0.1C discharge capacity (216.9 mAh / g) of the positive electrode material D-1 obtained when the first sintering temperature is too low (600°C).

[0230] Figure 2 Schematic diagram comparing the cycle performance of Example 5 and Comparative Example 1; Figure 2 Comparing the cycling performance of Example 5 and Comparative Example 1, it can be seen that the capacity retention rate of Example 5 (94.6%) is significantly higher than that of the positive electrode material provided by D-1 (86.7%). This is because when the sintering temperature is too low, the primary grain growth is incomplete, resulting in a low compressive index and unstable structure, thus showing low capacity and cycling performance.

[0231] Figure 3 Schematic diagram comparing the charge and discharge curves of Example 5 and Comparative Example 2; Figure 3 It can be seen that by comparing the charge and discharge curves of Example 5 and Comparative Example 2, it can be seen that the 0.1C discharge capacity (225.2 mAh / g) of the positive electrode material provided in Example 5 is higher than the 0.1C discharge capacity (208.3 mAh / g) of the positive electrode material D-2 obtained when the first sintering temperature is too high (900°C).

[0232] Figure 4 Schematic diagram comparing the cycle performance of Example 5 and Comparative Example 2; Figure 4 Comparing the cycling performance of Example 5 and Comparative Example 2, it can be seen that the capacity retention rate of Example 5 (94.6%) is significantly higher than that of the positive electrode material provided by D-2 (85.9%). This is because when the sintering temperature is too high, the primary grain growth is excessive, which also leads to a low compressive index and unstable structure, resulting in low capacity and cycling performance.

[0233] Figure 5 Schematic diagram comparing the charge and discharge curves of Example 5 and Comparative Example 3; Figure 5It can be seen that by comparing the charge and discharge curves of Example 5 and Comparative Example 3, it can be seen that the 0.1C discharge capacity of Example 5 (225.2 mAh / g) is higher than the 0.1C discharge capacity (221.7 mAh / g) of the positive electrode material D-3 obtained when rhenium oxide and samarium oxide additives are not added in the first sintering.

[0234] Figure 6 Schematic diagram comparing the cycle performance of Example 5 and Comparative Example 3; Figure 6 It can be seen that by comparing the cycling performance of Example 5 and Comparative Example 3, the capacity retention rate of Example 5 (94.6%) is significantly higher than the capacity retention rate of the positive electrode material provided by D-3 (87.5%). The above shows that the addition of rhenium oxide and salinityl oxide additives during the first sintering can improve the material's capacity and cycling performance. This is because appropriate doping modification can improve the material's microstructure and form lithium-containing compounds on the particle surface or between particles, both of which help to improve the material's compressive strength index, thereby improving the positive electrode material's electrochemical properties such as capacity and cycling performance.

[0235] Figure 7 Schematic diagram comparing the charge and discharge curves of Example 5 and Comparative Example 4; Figure 7 It can be seen that by comparing the charge and discharge curves of Example 5 and Comparative Example 4, it can be seen that the 0.1C discharge capacity of Example 5 (225.2 mAh / g) is significantly higher than the 0.1C discharge capacity (214.3 mAh / g) of the positive electrode material D-4 obtained when no tungsten nitride or aluminum fluoride additives are added in the second sintering.

[0236] Figure 8 Schematic diagram comparing the cycle performance of Example 5 and Comparative Example 4; Figure 8 Comparing the cycling performance of Example 5 and Comparative Example 4 reveals that the capacity retention rate of Example 5 (94.6%) is significantly higher than that of the positive electrode material provided by D-4 (86.6%). This demonstrates that the addition of tungsten nitride and aluminum fluoride additives during the second sintering step can improve the material's capacity and cycling performance. This is because they can form a stable coating on the material surface, improve the material's surface microstructure, and reduce surface side reactions. This also helps improve the material's compressive strength, thereby enhancing the positive electrode material's electrochemical properties, such as capacity and cycling performance.

[0237] Figure 9 Schematic diagram comparing the charge and discharge curves of Example 9 and Comparative Example 5; Figure 9 It can be seen that by comparing the charge and discharge curves of Example 9 and Comparative Example 5, it can be seen that the 0.1C discharge capacity (250.7 mAh / g) of Example 9 is significantly higher than the 0.1C discharge capacity (240.9 mAh / g) of the positive electrode material D-5 obtained when the solid content is reduced to 150 g / L in the precursor preparation process.

[0238] Figure 10 Schematic diagram comparing the cycle performance of Example 9 and Comparative Example 5; Figure 10 It can be seen that by comparing the cycle performance of Example 9 and Comparative Example 5, it can be seen that the capacity retention rate of Example 9 (93.9%) is significantly higher than the capacity retention rate of the positive electrode material provided by D-5 (88.0%). This is because the low solid content will lead to poor crystallinity and density of the precursor, and changes in morphology and microstructure, thus showing a low compressive index, resulting in deterioration of the electrochemical properties such as capacity and cycle performance of the material.

[0239] Figure 11 Schematic diagram comparing the charge and discharge curves of Example 9 and Comparative Example 6; Figure 11 It can be seen that by comparing the charge and discharge curves of Example 9 and Comparative Example 6, it can be seen that the 0.1C discharge capacity of Example 9 (250.7 mAh / g) is significantly higher than the 0.1C discharge capacity (241.9 mAh / g) of the positive electrode material D-6 obtained when tungsten oxide and aluminum hydroxide additives are not added in the first sintering.

[0240] Figure 12 Schematic diagram comparing the cycle performance of Example 9 and Comparative Example 6; Figure 12 It can be seen that by comparing the cycling performance of Example 9 and Comparative Example 6, it can be seen that the capacity retention rate of Example 9 (93.9%) is significantly higher than the capacity retention rate of the positive electrode material provided by D-6 (89.0%). The above shows that the addition of tungsten oxide and aluminum oxyhydroxide additives during the first sintering can improve the material's capacity and cycling performance. This is because appropriate doping modification can improve the material's microstructure and form lithium-containing compounds on the particle surface or between particles, both of which help to improve the material's compressive strength index, thereby improving the electrochemical properties of the positive electrode material, such as capacity and cycling performance.

[0241] Figure 13 Schematic diagram comparing the charge and discharge curves of Example 9 and Comparative Example 7; Figure 13 It can be seen that by comparing the charge and discharge curves of Example 9 and Comparative Example 7, it can be seen that the 0.1C discharge capacity of Example 9 (250.7 mAh / g) is significantly higher than the 0.1C discharge capacity (233.0 mAh / g) of the positive electrode material D-7 obtained without the second sintering process.

[0242] Figure 14 is a schematic diagram comparing the cycle performance of Example 9 and Comparative Example 7; Figure 14It can be seen that by comparing the cycle performance of Example 9 and Comparative Example 7, it can be seen that the capacity retention rate of Example 9 (93.9%) is significantly higher than the capacity retention rate of the positive electrode material provided by D-7 (89.9%). The above shows that the second sintering can effectively improve the capacity and cycle performance of the material. This is because the second sintering process can form a stable coating layer on the surface of the material and rearrange the atoms on the surface of the material, improve the surface microstructure of the material, reduce the surface side reactions of the material, and improve the compressive index of the material, thereby improving the electrochemical properties such as the capacity and cycle performance of the positive electrode material.

[0243] The preferred embodiments of the present invention are described in detail above, but the present invention is not limited thereto. Within the technical concept of the present invention, various simple variations of the technical solution of the present invention may be made, including combining the various technical features in any other appropriate manner. These simple variations and combinations should also be regarded as the contents disclosed by the present invention and fall within the scope of protection of the present invention.

Claims

1. A lithium oxide positive electrode material, characterized in that The compressive index Δλ (P 100 ) satisfies: Δλ(P 100 )≥60%+(y / x)×5%; where y / x is the molar ratio of Mn / Ni in the cathode material; Among them, the compression index Δλ(P 100 ) is calculated as: in It refers to the D5 value of the cumulative distribution of particles of the material in the natural state without external mechanical pressure, that is, P = 0Mpa. Refers to the D5 value of the cumulative distribution of particles of the material at P = 100Mpa. D5 refers to the particle size value at which the cumulative volume distribution of particles is 5%; where the lithium-containing oxide cathode material has the chemical formula shown in formula (3): Li[Li a Ni x Mn y M j O2@M′, formula (3); where 0 ≤ a ≤ 0.3, 0.2 < x < 1, 0 < y ≤ 0.75, 0 < j ≤ 0.35, M is selected from at least one element of Al, Zr, Nb, Ti, Y, Sc, Cr, Co, W, Mg, La, Os, Pr, Re, Ru, Sr, Sm, Ta, and B, M′ is an oxide, phosphide, sulfide, fluoride, or chloride containing at least one element of Al, Zr, Nb, Ti, Y, Sc, Cr, Co, W, Mg, La, Os, Pr, Re, Ru, Sr, Sm, Ta, and B, the molar content of cations in M′ is w, and 0 < w / (a + x + y + j) ≤ 0.

1.

2. The lithium oxide positive electrode material according to claim 1, wherein The compressive index Δλ (P 200 ) satisfies: Δλ(P 200 )≥45%+(y / x)×5%; And / or, the compressive index Δλ (P 300 ) satisfies: Δλ(P 300 )≥35%+(y / x)×5%.

3. The lithium oxide positive electrode material according to claim 1, wherein 0.02 ≤ a ≤ 0.2, 0.3 < x < 0.9, 0.05 < y ≤ 0.68, 0 < j ≤ 0.3, 0.001 < w / (a + x + y + j) ≤ 0.02, M is selected from at least one element of Zr, Nb, Ti, Y, Sc, Cr, Co, W, Mg, La, Ta, and B, and M′ is an oxide, phosphide, sulfide, or fluoride containing at least one element of Zr, Nb, Ti, Y, Sc, Cr, Co, W, Mg, La, Ta, and B.

4. The lithium-containing oxide positive electrode material according to any one of claims 1 to 3, wherein The compaction density of the lithium oxide positive electrode material is ≥2.8 g / cm 3 ; And / or, the tap density of the lithium oxide positive electrode material is ≥1.7 g / cm 3 ; and / or, the content of surface soluble base of the lithium-containing oxide cathode material satisfies the following conditions: Li2CO3 ≤ 1 wt%, LiOH ≤ 0.5 wt%; and / or, The half maximum width (FWHM) of the (003) crystal plane of the lithium oxide positive electrode material obtained by XRD is (003) and the half maximum width (FWHM) of the (104) crystal plane (104) The following conditions are met: 0.10≤FWHM (003) ≤0.25; 0.20≤FWHM (104) ≤0.50; and / or, The peak area S of the (003) crystal plane of the lithium oxide positive electrode material obtained by XRD (003) The peak area S of (104) crystal plane (104) The following conditions are met: 1.1≤S (003) / S (104) ≤1.8。 5. The lithium oxide positive electrode material according to claim 4, wherein The compaction density of the lithium oxide-containing positive electrode material is ≥3 g / cm 3 ; And / or, the tap density of the lithium oxide positive electrode material is ≥2g / cm 3 ; and / or, the content of surface soluble base of the lithium-containing oxide cathode material satisfies the following conditions: Li2CO3 ≤ 0.5 wt%, LiOH ≤ 0.4 wt%; and / or, The half maximum width (FWHM) of the (003) crystal plane of the lithium oxide positive electrode material obtained by XRD is (003) and the half maximum width (FWHM) of the (104) crystal plane (104) The following conditions are met: 0.13≤FWHM (003) ≤0.22; 0.22≤FWHM (104) ≤0.42; and / or, The peak area S of the (003) crystal plane of the lithium oxide positive electrode material obtained by XRD (003) The peak area S of (104) crystal plane (104) The following conditions are met: 1.2≤S (003) / S (104) ≤1.6。 6. The lithium oxide positive electrode material according to claim 5, wherein The compaction density of the lithium oxide positive electrode material is ≥3.2 g / cm 3 ; And / or, the tap density of the lithium oxide positive electrode material is ≥2.4 g / cm 3 ; and / or, the content of surface soluble base of the lithium-containing oxide cathode material satisfies the following conditions: Li2CO3 ≤ 0.3 wt%, LiOH ≤ 0.3 wt%.

7. The lithium oxide positive electrode material according to claim 6, wherein: The content of surface soluble base of the lithium-containing oxide cathode material satisfies the following conditions: Li2CO3 ≤ 0.2 wt%, LiOH ≤ 0.2 wt%.

8. A lithium oxide positive electrode material precursor, characterized in that: The compressive index Δλ′ (P 50 ) satisfies: Δλ′(P 50 )≥35%+(v / u)×8%; where v / u is the molar ratio of Mn / Ni in the precursor; The compressive index Δλ′ (P 50 ) is calculated as follows: in It refers to the D5 value of the particle cumulative distribution of the precursor material in the natural state without external mechanical pressure, that is, P = 0MPa. It refers to the D5 value of the cumulative distribution of the particles of the precursor material under P = 50 MPa, and D5 refers to the particle size value at which the cumulative volume distribution of the particles is 5%; where the precursor has the chemical formula shown in formula (1): Ni u Mn v M 1γ (OH)2, formula (1); where u + v + γ = 1, 0.2 < u < 1, 0 < v ≤ 0.75, 0 ≤ γ ≤ 0.35, and M1 is selected from at least one element of Al, Zr, Nb, Ti, Y, Sc, Cr, Co, W, Mg, Na, La, Os, Pr, Re, Ru, Sr, Sm, Ta, and B.

9. The precursor according to claim 8, wherein The compressive index Δλ′ (P 100 ) satisfies: Δλ′(P 100 )≥25%+(v / u)×8%.

10. A method for preparing the lithium oxide positive electrode material according to any one of claims 1 to 7, characterized in that: The described preparation method includes: S1: Mix the precursor with the chemical formula shown in formula (1), a lithium source, and an optional additive containing element M2 evenly, and conduct the first sintering in an atmosphere furnace to obtain a first sintered material with the chemical formula shown in formula (2); S2: Mix the first sintered material with an additive containing element M′ evenly, and conduct the second sintering on the mixed material in an atmosphere furnace to obtain a lithium-containing metal oxide with the chemical formula shown in formula (3); Ni u Mn v M 1γ (OH)2, formula (1); where \(u + v+\gamma=1\), \(0.2\lt u\lt1\), \(0\lt v\leq0.75\), \(0\leq\gamma\leq0.35\), and \(M1\) is selected from at least one element of \(Al\), \(Zr\), \(Nb\), \(Ti\), \(Y\), \(Sc\), \(Cr\), \(Co\), \(W\), \(Mg\), \(Na\), \(La\), \(Os\), \(Pr\), \(Re\), \(Ru\), \(Sr\), \(Sm\), \(Ta\), and \(B\); Li[Li a Ni x Mn y M j O2; Formula (2); Li[Li a Ni x Mn y M j O2@M′, formula (3); where, in formula (2) and formula (3): \(a + x + y + j = 1\), \(0\leq a\leq0.3\), \(0.2\lt x\lt1\), \(0\lt y\leq0.75\), \(0\lt j\leq0.35\); \(M\) includes the element \(M1\) in the precursor and the element \(M2\) introduced during the first sintering process; \(M1\) and \(M2\) are the same or different, and each is selected from at least one element of \(Al\), \(Zr\), \(Nb\), \(Ti\), \(Y\), \(Sc\), \(Cr\), \(Co\), \(W\), \(Mg\), \(La\), \(Os\), \(Pr\), \(Re\), \(Ru\), \(Sr\), \(Sm\), \(Ta\), and \(B\); In formula (3): \(M'\) is an oxide, phosphide, sulfide, fluoride, or chloride containing at least one element of \(Al\), \(Zr\), \(Nb\), \(Ti\), \(Y\), \(Sc\), \(Cr\), \(Co\), \(W\), \(Mg\), \(La\), \(Os\), \(Pr\), \(Re\), \(Ru\), \(Sr\), \(Sm\), \(Ta\), and \(B\), and the molar content of cations in \(M'\) is \(w\), \(0\lt w / (a + x + y + j)\leq0.1\).

11. The preparation method according to claim 10, wherein When the molar ratio of \(Ni / Mn\) is greater than 1, that is, \(x / y\gt1\), the relationship between the sintering temperature \(T1\) of the first sintering and the \(Ni\) content satisfies: \(550\times(2 - x)\leq T1\leq400\times(3 - x)\ ^{\circ}C\), and the sintering time is \(6 - 20h\); and / or, when the molar ratio of \(Ni / Mn\)\(\leq1\), that is, \(y / x\geq1\), the relationship between the sintering temperature \(T2\) of the first sintering and the \(Mn\) content satisfies: \(500\times(1 + y)\leq T2\leq650\times(1 + y)\ ^{\circ}C\), and the sintering time is \(6 - 20h\); and / or, when \(x\lt0.5\), the atmosphere of the first and second sintering is air; when \(0.5\leq x\lt0.6\), the atmosphere of the first and second sintering is air or a mixture of air and oxygen; when \(x\geq0.6\), the atmosphere of the first and second sintering is oxygen or a mixture of oxygen and air.

12. The preparation method according to claim 11, wherein The relationship between the sintering temperature \(T1\) of the first sintering and the \(Ni\) content satisfies: the sintering time is \(8 - 15h\); and / or, when the molar ratio of \(Ni / Mn\)\(\leq1\), that is, \(y / x\geq1\), the relationship between the sintering temperature \(T2\) of the first sintering and the \(Mn\) content satisfies: the sintering time is \(8 - 15h\).

13. A lithium-containing oxide cathode material prepared by the preparation method of the lithium-containing oxide cathode material according to any one of claims 10 - 12.

14. A positive electrode sheet, characterized in that: Based on the total weight of the positive electrode sheet, it contains at least 90wt% of the lithium-containing oxide cathode material; where, the lithium-containing oxide cathode material is the lithium-containing oxide cathode material according to any one of claims 1 - 7 and 13.

15. The positive electrode sheet according to claim 14, wherein: The density of the positive electrode is ≥2.8g / cm 3 .

16. The positive electrode sheet according to claim 15, wherein: The density of the positive electrode is ≥3.2g / cm 3 .

17. The positive electrode sheet according to claim 16, wherein: The density of the positive electrode is ≥3.5g / cm 3 .

18. An application of the lithium-containing oxide cathode material according to any one of claims 1 - 7 and 13, the precursor of the lithium-containing oxide cathode material according to claim 8 or 9, or the positive electrode sheet according to any one of claims 14 - 17 in a lithium-ion battery.

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