Nickel-manganese-based layered oxide material containing trivalent nickel, and preparation method therefor and use thereof

Abstract

Disclosed in the present invention is a method for suppressing voltage attenuation of a nickel-manganese-based layered oxide material with anionic redox by utilizing Ni3+. The sodium content of the material is adjusted, Ni3+ is introduced into the material to serve as an Mn4+ / Mn3+ redox barrier, and redox of Mn4+ / Mn3+ is replaced with redox of Ni3+ / Ni2+, so that the voltage attenuation of the nickel-manganese-based layered oxide material with anionic redox can be effectively suppressed without sacrificing the capacity density of the material and increasing the synthesis cost of the material.

Description

A nickel-manganese-based layered oxide material containing trivalent nickel, and its preparation method and application Technical Field

[0001] The present invention belongs to the field of electrochemical technology and specifically relates to a method for 3+ A method for suppressing voltage decay in nickel-manganese-based layered oxide materials with anionic redox properties. Background Art

[0002] Lithium-ion batteries, currently used as electrochemical energy storage devices, are widely used in daily life due to their high energy density, excellent cycle stability, long cycle life, compact size, light weight, and pollution-free properties. Since their commercialization in the early 1990s, lithium-ion batteries have dramatically changed people's lives. However, lithium is present in the Earth's crust at a low abundance (0.065%) and is geographically unevenly distributed (70% of lithium resources are in South America). The growing demand for lithium in power batteries and the developing large-scale energy storage market is driving increasing demand for lithium worldwide. This will lead to a continuous rise in the price of lithium carbonate, making it difficult to meet the cost requirements of large-scale energy storage. Therefore, scientists have turned their attention to sodium-ion batteries. Sodium is in the same main group as lithium and has similar properties to lithium. Its abundance in the Earth's crust is much higher than lithium, at approximately 2.32%, providing an ample reserve for the development of sodium-ion batteries. From a cost perspective, sodium-ion batteries have great potential for large-scale energy storage. In addition, in addition to the low price of sodium ions, the positive and negative current collectors of sodium-ion batteries can both use aluminum foil, while the negative electrode of lithium-ion batteries can only use copper. Obviously, copper is much more expensive than aluminum, so the raw material cost is low and easy to obtain. These advantages make sodium-ion batteries increasingly attract widespread attention around the world.

[0003] Further research found that by introducing anionic redox into layered oxide cathode materials, the cost of sodium ion batteries can be effectively reduced and the use of precious metals such as nickel can be reduced. However, layered oxide cathode materials with anionic redox have irreversible oxygen release and Mn 4+ / Mn 3+The gradual activation of redox reactions leads to a serious voltage decay problem in the material, and the energy density of the assembled battery continues to decrease. Therefore, the voltage decay problem of layered oxide materials with anionic redox reactions is one of the urgent issues to be solved in the commercialization of positive electrode materials for sodium-ion batteries. Currently, the commonly used methods to improve the voltage decay of such materials include reducing the charge cut-off voltage, optimizing the composition of the materials, and increasing the proportion of variable-valence transition metals. These methods can reduce the degree of anion oxidation during the charging process to a certain extent, thereby reducing the structural distortion of the material and irreversible oxygen release, thereby improving the material's cycle stability and suppressing the voltage decay problem. However, the existing modification methods have sacrificed the energy density of the material or increased the production cost of the positive electrode material to a certain extent. Summary of the Invention

[0004] The purpose of this section is to summarize some aspects of the embodiments of the present invention and briefly introduce some preferred embodiments. Some simplifications or omissions may be made in this section and the abstract and title of this application to avoid obscuring the purpose of this section, the abstract and the title of the invention, and such simplifications or omissions should not be used to limit the scope of the present invention.

[0005] In view of the above problems and / or the problems existing in the prior art, the present invention is proposed.

[0006] Therefore, the purpose of the present invention is to overcome the deficiencies in the prior art and provide a 3+ Nickel-manganese-based layered oxide materials with anionic redox properties.

[0007] In order to solve the above technical problems, the present invention provides the following technical solutions: a 3+ The nickel-manganese-based matrix oxide material with anionic redox properties is characterized in that the Ni 3+ The general chemical formula of the nickel-manganese-based layered oxide material with anionic redox is: Na a Ni b+c Mn d M e O 2+β .

[0008] As a preferred embodiment of the material of the present invention, in which: in the nickel-manganese based layered oxide material, Ni, Mn, and M jointly occupy the transition metal ion position in the crystal structure; M is an element that dopes and replaces the transition metal position, including one or more non-metallic elements of Group IA, Group IIA, Group IIIA, Group IV, Group VA, or Group VIA, and one or more transition metal elements of the fourth period and the fifth period; the space group of the nickel-manganese based layered oxide material is P63 / mmc or P63 / mcm or or P63 / mmc with Mixed, the corresponding structure is P2 phase or O3 phase or P2 / O3 mixed phase.

[0009] As a preferred embodiment of the material of the present invention, wherein: the chemical formula Na a Ni b+c Mn d M e O 2+β , where a, b, c, d, e, and 2+β are the molar percentages of the corresponding elements, and each component in the general chemical formula satisfies the conservation of charge and stoichiometry; b+c+d+e=1, and a+2b+3c+4d+me=2(2+β); 0.66≤a≤1; 0<b≤0.5; 0<c≤0.5; 0<d≤0.8; 0<e≤0.65; -0.05≤β≤0.05; m is the valence state of M.

[0010] As a preferred embodiment of the material of the present invention, wherein: in the general chemical formula, 0<c≤0.1.

[0011] Another object of the present invention is to overcome the deficiencies in the prior art and provide a 3+ The preparation method of the nickel-manganese-based layered oxide material with anionic redox is characterized in that the preparation method is one of a solid phase method, a sol-gel method, a spray drying method, and a coprecipitation method.

[0012] As a preferred embodiment of the preparation method of the present invention, the solid phase method is:

[0013] preparing cathode material precursors;

[0014] ball milling to obtain precursor powder;

[0015] heat-treating the precursor powder;

[0016] Grind the heat-treated precursor powder to obtain the Ni 3+ Nickel-manganese-based layered oxide materials with anionic redox properties.

[0017] As a preferred embodiment of the preparation method of the present invention, the positive electrode material precursor is prepared by uniformly mixing 90wt% to 110wt% of the required sodium stoichiometric amount of sodium carbonate, the required stoichiometric amount of nickel oxide, and the required stoichiometric amount of manganese and M oxide or carbonate.

[0018] As a preferred embodiment of the preparation method of the present invention, the precursor powder is subjected to heat treatment, wherein the heat treatment is carried out in air or oxygen atmosphere, the heat treatment temperature is 600-1000° C., and the heat treatment time is 2-24 hours.

[0019] Another object of the present invention is to overcome the deficiencies in the prior art and provide a sodium ion secondary battery, characterized in that: the positive electrode sheet of the sodium ion secondary battery comprises: a current collector, a conductive additive coated on the current collector, a binder and a conductive additive containing Ni 3+ Nickel-manganese-based layered oxide materials with anionic redox properties.

[0020] As a preferred embodiment of the sodium ion secondary battery of the present invention, wherein: the sodium ion secondary battery containing Ni 3+ The nickel-manganese-based layered oxide material with anionic redox properties is prepared by the preparation method according to any one of claims 5 to 8.

[0021] As a preferred application of the sodium ion secondary battery of the present invention, the sodium ion secondary battery is used for large-scale energy storage equipment such as solar power generation, wind power generation, smart grid peak regulation, distributed power stations, backup power supplies or communication base stations.

[0022] Beneficial effects of the present invention:

[0023] The present invention appropriately reduces the added sodium source content during the synthesis of the nickel-manganese-based layered oxide material with anionic redox, so that after the synthesis step, manganese is in the highest valence state of +4. In order to maintain charge conservation, part of the nickel is oxidized to +3. By this method, Ni is appropriately introduced into the material. 3+ As Mn 4+ / Mn 3+ Redox barrier, utilizing Ni 3+ / Ni 2+ The redox substitution of Mn 4+ / Mn 3+ The redox reaction of nickel-manganese-based layered oxide materials with anionic redox can effectively suppress the voltage decay without sacrificing the energy density of the material and increasing the synthesis cost of the material. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. Those skilled in the art can also derive other drawings based on these drawings without inventive effort. Among them:

[0025] FIG1 is an XRD pattern of the synthetic material of the present invention.

[0026] FIG2 is an electrochemical comparison diagram of the synthetic material of the present invention.

[0027] FIG3 is a comparison diagram of the cycle stability and average discharge voltage of the synthetic material of the present invention. DETAILED DESCRIPTION

[0028] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are described in detail below in conjunction with the embodiments of the specification.

[0029] In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention may also be implemented in other ways different from those described herein. Those skilled in the art may make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0030] Secondly, the term "one embodiment" or "embodiment" herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The phrase "in one embodiment" appearing in various places throughout this specification does not necessarily refer to the same embodiment, nor does it refer to a separate or selective embodiment that is mutually exclusive of other embodiments.

[0031] The raw materials used in the embodiments of the present invention are all commercially available.

[0032] Example 1

[0033] A Ni-containing 3+ The method for preparing a nickel-manganese-based layered oxide material with anionic redox reaction comprises the following steps:

[0034] (1) Preparation of cathode material precursor:

[0035] 89.03 g of sodium carbonate, 26.66 g of nickel oxide, 120.49 g of manganese dioxide and 13.45 g of lithium carbonate were mixed uniformly.

[0036] (2) Preparation of precursor powder

[0037] The cathode material precursor was ball-milled and mixed using a planetary ball mill PM100 to obtain precursor powder.

[0038] (3) Heat treatment

[0039] The precursor powder is placed in a muffle furnace or a tube furnace and heat treated at 850°C in an air or oxygen atmosphere for 12 hours.

[0040] (4) Grinding the precursor powder after heat treatment to obtain the Ni 3+ Nickel-manganese-based layered oxides with anionic redox properties Na 0.80 Ni (Ⅱ) 0.12 Ni (Ⅲ)0.05 Mn 0.66 O2 material, its XRD spectrum is shown in Figure 1.

[0041] Example 2

[0042] This embodiment provides a Ni 3+ The preparation method of the nickel-manganese-based layered oxide material with anionic redox reaction is specifically a sol-gel method, comprising the following steps:

[0043] 137.81 g of sodium acetate, 63.11 g of nickel acetate, 239.82 g of manganese acetate, and 24.02 g of lithium acetate were dissolved in water and mixed to form a precursor solution;

[0044] Stirring at 50°C to 100°C, adding an appropriate amount of chelating agent, and evaporating to dryness to form a precursor gel;

[0045] The precursor gel was placed in a crucible and pre-fired at 500 °C in an oxygen atmosphere for 2 hours;

[0046] Heat treatment at 850°C in air or oxygen atmosphere for 12 hours;

[0047] Grind the heat-treated precursor powder to obtain the Ni 3+ The nickel-manganese-based layered oxide material with anionic redox properties, the product obtained in this embodiment is the same as that in Example 1.

[0048] Example 3

[0049] This embodiment provides a Ni 3+ The preparation method of the nickel-manganese-based layered oxide material with anionic redox reaction is specifically a spray drying method, comprising the following steps:

[0050] 89.03g of sodium carbonate, 26.67g of nickel oxide, 120.49g of manganese dioxide, and 13.45g of lithium carbonate were mixed to form a precursor;

[0051] Add ethanol or water to the precursor and stir evenly to form a slurry;

[0052] The slurry is spray-dried to obtain a precursor powder;

[0053] Heat treatment at 850℃ for 12 hours;

[0054] Grind the heat-treated precursor powder to obtain the Ni 3+ The nickel-manganese-based layered oxide material with anionic redox properties, the product obtained in this embodiment is the same as that in Example 1.

[0055] Example 4

[0056] This embodiment provides a Ni3+ The preparation method of the nickel-manganese-based layered oxide material with anionic redox is specifically a co-precipitation method, comprising the following steps:

[0057] 55.25 g of nickel sulfate and 209.29 g of manganese sulfate were dissolved in 10 L of deionized water to form solutions;

[0058] The solution was slowly added dropwise to the ammonia solution using a peristaltic pump to generate a precipitate;

[0059] The obtained precipitate was washed with deionized water, dried, and evenly mixed with 89.03 g of sodium carbonate and 13.45 g of carbonic acid to obtain a precursor;

[0060] The precursor was placed in a crucible and heat treated at 850°C for 12 hours to obtain a precursor powder;

[0061] Grind the heat-treated precursor powder to obtain the Ni 3+ The nickel-manganese-based layered oxide material with anionic redox properties, the product obtained in this embodiment is the same as that in Example 1.

[0062] Comparative Example 1

[0063] In this comparative example, the solid phase method described in Example 1 was used to prepare a nickel-manganese-based layered oxide material having anionic redox properties, comprising:

[0064] 94.59 g Na2CO3 (analytical grade), 13.45 g Li2CO3 (analytical grade), 26.66 g NiO (analytical grade), and 120.49 g MnO2 (analytical grade) were mixed and ground in an agate mortar for half an hour to obtain a precursor;

[0065] The precursor was transferred to an Al2O3 porcelain boat and treated at 850℃ for 12 hours to obtain a black powder layered oxide material Na 0.85 Ni (Ⅱ) 0.17 Mn 0.66 O2, its XRD spectrum is shown in Figure 1. From the XRD spectrum, Na 0.85 Ni (Ⅱ) 0.17 Mn 0.66 The crystal structure of O2 is a P2 phase layered oxide.

[0066] Example 5

[0067] A method for preparing a sodium ion secondary battery comprises the following steps:

[0068] (1) Preparation of positive electrode sheet

[0069] The layered oxide materials prepared in Example 1 and Comparative Example 1 were used as active materials for the positive electrode materials of the battery to prepare sodium ion batteries:

[0070] The prepared cathode material powder was mixed with acetylene black and binder polyvinylidene fluoride (PVDF) in a mass ratio of 80:10:10, and an appropriate amount of N-methylpyrrolidone (NMP) solution was added. The mixture was ground in a dry environment at room temperature to form a slurry.

[0071] Then the slurry was evenly coated on the current collector aluminum foil and dried under an infrared lamp before being cut into (8×8) mm 2 The pole piece;

[0072] The electrode was dried at 110°C under vacuum conditions for 10 hours and then transferred to a glove box for use.

[0073] (2) The assembly of the simulated battery was carried out in a glove box with an Ar atmosphere, using metallic sodium as the counter electrode and 1 M NaClO4 / diethyl carbonate (DEC) solution as the electrolyte to assemble into a CR2032 button cell.

[0074] Charge and discharge tests were conducted using a constant current charge and discharge mode at a current density of C / 10. With a discharge cut-off voltage of 2.5V and a charge cut-off voltage of 4.2V, the test results are shown in Figures 2 and 3. It can be seen that the first-cycle discharge capacities of Example 1 and Comparative Example 1 are similar, while Example 1 significantly outperforms Comparative Example 1 in terms of capacity retention and voltage retention.

[0075] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, and all of these should be included in the scope of the present invention.

Claims

1. A nickel-manganese-based oxide material containing trivalent nickel and having anionic redox properties, characterized in that: The general chemical formula of the nickel-manganese-based oxide material containing trivalent nickel and having anionic redox is: Na a Ni b+c Mn d M e O 2+β .

2. The material according to claim 1, characterized in that: In the nickel-manganese-based layered oxide material, Ni, Mn, and M jointly occupy the transition metal ion position in the crystal structure; M is an element that is doped to replace the transition metal position, including one or more non-metallic elements of group IA, group IIA, group IIIA, group IV, group VA, or group VIA, and one or more transition metal elements of the fourth period and the fifth period; the space group of the nickel-manganese-based layered oxide material is P63 / mmc or P63 / mcm or or P63 / mmc with Mixed, the corresponding structure is P2 phase or O3 phase or P2 / O3 mixed phase.

3. The material according to claim 1, characterized in that: The chemical formula Na a Ni b+c Mn d M e O 2+ β , in , a, b, c, d, e, 2+β are the molar percentages of the corresponding elements respectively. Each component in the general chemical formula satisfies the conservation of charge and stoichiometry; b+c+d+e=1, and a+2b+3c+4d+me=2(2+β); 0.66≤a≤1; 0<b≤0.5; 0<c≤0.5; 0<d≤0.8; 0<e≤0.65; -0.05≤β≤0.05; m is the valence state of M.

4. The material according to claim 3, characterized in that: In the general chemical formula, 0<c≤0.

1.

5. The method for preparing the nickel-manganese-based layered oxide material containing trivalent nickel and having anionic redox as claimed in claims 1 to 4, characterized in that: The preparation method is one of a solid phase method, a sol-gel method, a spray drying method and a co-precipitation method.

6. The method for preparing the nickel-manganese-based layered oxide material containing trivalent nickel and having anionic redox as claimed in claim 5, characterized in that: The solid phase method is: preparing a cathode material precursor; Ball milling to obtain precursor powder; heat treating the precursor powder; The precursor powder after heat treatment is ground to obtain the nickel-manganese-based layered oxide material with trivalent nickel and anionic redox.

7. The preparation method according to claim 6, characterized in that: The positive electrode material precursor is prepared by a preparation method comprising uniformly mixing 90wt% to 110wt% of sodium carbonate of the required stoichiometric amount of sodium, the required stoichiometric amount of nickel oxide, and the required stoichiometric amount of manganese and M oxide or carbonate.

8. The preparation method according to claim 6, characterized in that: The precursor powder is subjected to heat treatment, wherein the heat treatment is carried out in air or oxygen atmosphere, the heat treatment temperature is 600-1000° C., and the heat treatment time is 2-24 hours.

9. A sodium ion secondary battery, characterized in that: The positive electrode plate of the sodium ion secondary battery includes: a current collector, a conductive additive coated on the current collector, a binder, and a nickel-manganese-based layered oxide material with anionic redox containing trivalent nickel, wherein the nickel-manganese-based layered oxide material with anionic redox containing trivalent nickel is prepared by the preparation method described in any one of claims 5 to 8.

10. The sodium ion secondary battery according to claim 9, characterized in that: The sodium ion secondary battery can be used for solar power generation, wind power generation, smart grid peak regulation, distributed power stations, backup power supplies or large-scale energy storage equipment for communication base stations.

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