CN117038964A - Ultra-high-capacity positive electrode material, preparation method thereof, positive electrode and sodium ion battery - Google Patents

Ultra-high-capacity positive electrode material, preparation method thereof, positive electrode and sodium ion battery Download PDF

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Publication number
CN117038964A
CN117038964A CN202311280150.8A CN202311280150A CN117038964A CN 117038964 A CN117038964 A CN 117038964A CN 202311280150 A CN202311280150 A CN 202311280150A CN 117038964 A CN117038964 A CN 117038964A
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positive electrode
electrode material
equal
precursor
sodium
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范未峰
洪菲菲
向伟
张萍
张彬
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Yibin Libao New Materials Co Ltd
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Yibin Libao New Materials Co Ltd
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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/36—Selection of substances as active materials, active masses, active liquids
    • H01M4/48—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides
    • H01M4/52—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides of nickel, cobalt or iron
    • H01M4/525—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides of nickel, cobalt or iron of mixed oxides or hydroxides containing iron, cobalt or nickel for inserting or intercalating light metals, e.g. LiNiO2, LiCoO2 or LiCoOxFy
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01G—COMPOUNDS CONTAINING METALS NOT COVERED BY SUBCLASSES C01D OR C01F
    • C01G53/00—Compounds of nickel
    • C01G53/40—Nickelates
    • C01G53/42—Nickelates containing alkali metals, e.g. LiNiO2
    • C01G53/44—Nickelates containing alkali metals, e.g. LiNiO2 containing manganese
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/05—Accumulators with non-aqueous electrolyte
    • H01M10/052—Li-accumulators
    • H01M10/0525—Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/13—Electrodes for accumulators with non-aqueous electrolyte, e.g. for lithium-accumulators; Processes of manufacture thereof
    • H01M4/131—Electrodes based on mixed oxides or hydroxides, or on mixtures of oxides or hydroxides, e.g. LiCoOx
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/36—Selection of substances as active materials, active masses, active liquids
    • H01M4/48—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides
    • H01M4/50—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides of manganese
    • H01M4/505—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides of manganese of mixed oxides or hydroxides containing manganese for inserting or intercalating light metals, e.g. LiMn2O4 or LiMn2OxFy
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M2004/026—Electrodes composed of, or comprising, active material characterised by the polarity
    • H01M2004/028—Positive electrodes
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02E60/10—Energy storage using batteries

Abstract

The invention relates to the technical field of positive electrode materials of sodium ion batteries, and discloses a positive electrode material with ultra-high capacity, a preparation method of the positive electrode material, a positive electrode and a sodium ion battery. The disclosed positive electrode material has the chemical formula: na (Na) x Ni y Mn z M 1‑y‑z O 2 (M=at least one of Co, fe or Mg) 0.3.ltoreq.x≤0.7，0.25≤y≤0.5，0.5≤z≤0.75，1‑y‑zLess than or equal to 0.05; the positive electrode material phase composition has P3 phase with space group R3m, and the P3 phase is distributed in the inner core area of crystal grain and its content is greater than or equal to 50% of the total weight of the composition; the positive electrode material has a micron-sized secondary particle morphology assembled from primary platelet-shaped grains that continuously penetrate from the interior to the exterior of the particle. The disclosed preparation method comprises mixing the precursor with a sodium source and sintering. The positive electrode material provided by the invention has higher capacity than a conventional sodium ion battery.

Description

Ultra-high-capacity positive electrode material, preparation method thereof, positive electrode and sodium ion battery
Technical Field
The invention relates to the technical field of positive electrode materials of sodium ion batteries, in particular to a positive electrode material with ultrahigh capacity, a preparation method of the positive electrode material, a positive electrode and a sodium ion battery.
Background
The sodium ion battery has an electrochemical principle similar to that of a lithium ion battery, and has high abundance of sodium element resources, low price and wide application prospect in the field of large-scale energy storage. The positive electrode materials of sodium ion batteries are generally classified into three types, namely layered oxides, polyanion compounds, prussian blue and analogues thereof. The layered oxide positive electrode has simple preparation method, relatively high specific capacity and voltage, is an ideal positive electrode material for sodium ion batteries, and has great research and application values.
Currently, nickel manganese-based layered oxides are attracting wide attention in the field of sodium ion battery cathode materials. In particular, the nickel-manganese-based layered oxide with low nickel and rich manganese adopts a higher content of Mn element as a redox couple, so that the cost advantage of the sodium ion battery can be further improved. However, the capacity of most low-nickel manganese-rich layered oxide sodium-electricity anode materials is only 110-140 mAh g -1 It is difficult to make the energy density of sodium ion batteries competitive with lithium iron phosphate. In order to improve the competitive advantage of the nickel-manganese-based layered oxide sodium-electricity positive electrode material, a low-nickel-manganese-rich layered oxide sodium-electricity positive electrode material with higher capacity and cycle stability needs to be developed.
In view of this, the present invention has been made.
Disclosure of Invention
The invention aims to provide a high-capacity positive electrode material, a preparation method thereof, a positive electrode and a sodium ion battery.
The invention is realized in the following way:
in a first aspect, the present invention provides a layered oxide positive electrode material for a sodium ion battery having an ultra-high capacity, the layered oxide positive electrode material having a chemical formula: na (Na) x Ni y Mn z M 1-y-z O 2 Wherein M is at least one of Co, fe or Mg, x is more than or equal to 0.3 and less than or equal to 0.7,0.25, y is more than or equal to 0.5, z is more than or equal to 0.5 and less than or equal to 0.75,1-y-z is more than or equal to 0.05;
the positive electrode material phase composition is provided with a P3 phase with a space group R3m, wherein the P3 phase in the positive electrode material is distributed in the inner core area of the crystal grain, and the content of the P3 phase is more than or equal to 50%; the positive electrode material has a micron-sized secondary particle morphology assembled from primary platelet-shaped grains that continuously penetrate from the interior to the exterior of the particle.
In an alternative embodiment, the secondary particle agglomerate particle size D10 of the positive electrode material is more than or equal to 3 mu m, D50=5-10 mu m, and D90 is less than or equal to 11 mu m; the length of the primary flaky grains is 1.5-6 mu m.
In a second aspect, the present invention provides a method for preparing a positive electrode material according to the foregoing embodiment, including:
mixing and sintering a precursor and a sodium source according to the molar ratio of transition metal element to sodium of 1:0.3-0.7, wherein the chemical formula of the precursor is as follows:
Ni y Mn z M 1-y-z (OH) 2 wherein M is at least one of Co, fe and Mg, y is more than or equal to 0.25 and less than or equal to 0.5, z is more than or equal to 0.5 and less than or equal to 0.75,1-y-z is more than or equal to 0.05;
the morphology of the precursor is secondary particle morphology assembled by strip-shaped primary grains;
the sintering temperature is 600-950 ℃ and the sintering time is 8-15 h.
In an alternative embodiment, the method further comprises preparing a precursor before sintering, wherein the preparation method of the precursor comprises the following steps:
controlling the temperature of liquid in the reaction kettle to be 45-55 ℃, the initial ammonia value to be 0.2-0.4 mol/L and the pH to be 10-12;
continuously introducing mixed metal salt solution, precipitant solution and ammonia liquor into the reaction kettle to carry out precipitation reaction; and (3) reducing the pH value at a rate of 0.01-0.03 per hour after the precipitation reaction starts, increasing the ammonia value in the reaction kettle after the particles D50 grow to 1/3-1/2 of the final target particle size, wherein the increasing amount is 0.05-0.2 mol/L per hour, and forming for 1-3 hours after the particles grow to the target particle size. And (3) aging, solid-liquid separating, washing and drying the obtained precipitate to obtain the precursor.
In an alternative embodiment, before the precipitation reaction, water accounting for 30-80% of the volume of the reaction kettle is introduced into the reaction kettle.
In an alternative embodiment, the precipitant solution is sodium hydroxide solution; the metal salt solution is a salt solution in which Ni and Mn ions are dissolved, or a salt solution in which Ni, mn and M ions are dissolved.
Alternatively, the mixed metal salt solution is a sulfate solution.
In an alternative embodiment, the stirring speed in the reaction vessel is 200-400 rpm during the precipitation reaction.
In an alternative embodiment, inert gas is introduced under the liquid level of the reaction kettle in the precipitation reaction process; optionally, the inert gas is nitrogen.
In a third aspect, the present invention provides a positive electrode, prepared using a positive electrode material according to the previous embodiments or a positive electrode material prepared by a preparation method according to any one of the previous embodiments.
In a fourth aspect, the present invention provides a sodium ion battery comprising a positive electrode as in the previous embodiments.
The invention has the following beneficial effects:
the positive electrode material obtained by the design has lower sodium proportion, so that the positive electrode material (up to 197 mAh g -1 ) Has a higher positive electrode material (110-140 mAh g) -1 ) Higher discharge capacity. Meanwhile, the flaky primary grains of the positive electrode material continuously penetrate from the inside of the particles to the outer surface, so that sodium ions are easily deintercalated in the charge and discharge process; the P3 phase is distributed in the inner core area, and the content of the P3 phase exceeds 50%, so that the charge-discharge capacity of the positive electrode material can be further improved.
The precursor of the secondary particles assembled by the strip-shaped primary grains can be synthesized by the preparation method, and the precursor of the morphology has better porosity and is beneficial to completing the sodium intercalation reaction of the precursor in a larger temperature interval; the precursor with the morphology also has longer primary grain size, so that the primary grain of the positive electrode formed by mixing and sintering the precursor and a sodium source penetrates from the center to the surface, thereby facilitating the sodium ion deintercalation in the charge and discharge process. The P3 phase generated by sintering is concentrated in the positive electrode material crystal at a low temperature of 600-950 ℃ for a short time, and the positive electrode material with proper P3 phase content is obtained, so that the positive electrode material of the sodium ion battery with ultrahigh discharge capacity and better cycle performance is obtained.
Drawings
In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings that are needed in the embodiments will be briefly described below, it being understood that the following drawings only illustrate some embodiments of the present invention and therefore should not be considered as limiting the scope, and other related drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.
FIGS. 1 to 2 are SEM images of the precursor of example 1 and example 9, respectively;
fig. 3 to 5 are SEM images of the precursors prepared in comparative examples 2 to 4, respectively;
fig. 6 to 14 are SEM images of the positive electrode materials prepared in examples 1 to 9, respectively;
fig. 15 to 21 are SEM images of the positive electrode materials prepared in comparative examples 1 to 7, respectively;
FIG. 22 shows XRD patterns of two positive electrode materials prepared in examples 1 and 2;
FIG. 23 is an XRD pattern of the positive electrode material obtained in example 3;
FIG. 24 is an XRD pattern of the positive electrode materials prepared in examples 4 to 7;
FIG. 25 is an XRD pattern of the positive electrode materials prepared in comparative examples 5 to 7;
fig. 26 is an XRD pattern of the positive electrode materials prepared in comparative examples 1 and 2.
Detailed Description
In order to make the objects, technical solutions and advantages of the embodiments of the present invention more clear, the technical solutions of the embodiments of the present invention will be clearly and completely described below. The specific conditions are not noted in the examples and are carried out according to conventional conditions or conditions recommended by the manufacturer. The reagents or apparatus used were conventional products commercially available without the manufacturer's attention.
The high-capacity positive electrode material, the preparation method thereof, the positive electrode and the sodium ion battery provided by the embodiment of the invention are specifically described below.
The high-capacity positive electrode material provided by the embodiment of the invention has the chemical formula: na (Na) x Ni y Mn z M 1-y-z O 2 Wherein M is at least one of Co, fe or Mg, x is more than or equal to 0.3 and less than or equal to 0.7,0.25, y is more than or equal to 0.5, z is more than or equal to 0.5 and less than or equal to 0.75,1-y-z is more than or equal to 0.05;
the positive electrode material phase composition is provided with a P3 phase with a space group R3m, wherein the P3 phase in the positive electrode material is distributed in the inner core area of the crystal grain, and the content of the P3 phase is more than or equal to 50%; the positive electrode material has a micron-sized secondary particle morphology assembled from flaky primary grains which continuously penetrate from the inside to the outside of the particle.
The high-capacity positive electrode material provided by the embodiment of the invention has a low sodium proportion, so that the positive electrode material has a high capacity, and the flaky primary grains of the positive electrode material continuously penetrate from the inside of the particles to the outer surface, thereby being beneficial to sodium ion deintercalation in the charge and discharge process; the higher P3 phase content is distributed in the inner core region, and the content exceeds 50%, so that the charge-discharge capacity of the positive electrode material can be further improved.
Further, the granularity D10 of the secondary particle aggregate of the positive electrode material is more than or equal to 3 mu m, D50=5-10 mu m, and D90 is less than or equal to 11 mu m; the length of the primary flaky grains is 1.5-6 mu m. The flaky primary crystal grains have larger sizes, penetrate from the center to the surface of the particles, and ensure that the positive electrode material has higher charge-discharge capacity.
The preparation method of the positive electrode material provided by the embodiment of the invention comprises the following steps:
mixing and sintering a precursor and a sodium source according to the molar ratio of transition metal element to sodium of 1:0.3-1:0.7, wherein the chemical formula of the precursor is as follows:
Ni y Mn z M 1-y-z (OH) 2 wherein M is at least one of Co, fe and Mg, y is more than or equal to 0.25 and less than or equal to 0.5, z is more than or equal to 0.5 and less than or equal to 0.75,1-y-z is more than or equal to 0.05;
the morphology of the precursor is secondary particle morphology assembled by strip-shaped primary grains;
the sintering temperature is 600-950 ℃ and the sintering time is 8-15 h.
The precursor has the shape of secondary particles assembled by strip-shaped primary grains, has better porosity, and is beneficial to completing the precursor sodium intercalation reaction in a larger temperature interval; the precursor with the morphology also has longer primary grain size, and the mixed sintering of the precursor and a sodium source is beneficial to the penetration of the primary grain of the anode from the center to the surface, thereby being beneficial to the sodium ion deintercalation in the charge and discharge process. And sintering is carried out at a low temperature of 600-950 ℃ for a short time, so that the generated P3 phase is concentrated in the middle of the positive electrode material crystal, and the positive electrode material with proper P3 phase content is obtained, thereby ensuring that the sodium ion battery with ultra-high discharge capacity is obtained.
The preparation method specifically comprises the following steps:
s1, preparing a precursor
Dissolving metal salt in deionized water according to a proper molar ratio to prepare a mixed metal salt solution (such as sulfate solution); sodium hydroxide is dissolved in water to prepare a precipitant solution; and mixing the concentrated ammonia water with deionized water to prepare ammonia liquor serving as a complexing agent.
Introducing deionized water accounting for 30-80% (such as 30%, 40%, 50%, 60%, 70% or 80%) of the volume of the reaction kettle into the reaction kettle;
heating in a water bath to maintain the temperature of the liquid in the reaction kettle to be 45-55 ℃ (for example, 45 ℃, 50 ℃ or 55 ℃), and starting stirring at 600 rpm;
the prepared ammonia liquid is introduced into a reaction kettle, so that the initial ammonia value in the reaction kettle is 0.2-0.4 mol/L (for example, 0.2mol/L, 0.3mol/L or 0.4 mol/L); introducing the prepared precipitant solution into a reaction kettle, and adjusting the pH value in the reaction kettle to 10-12 (for example, 10, 10.5, 11, 11.5 or 12); during this period, inert gas (such as nitrogen) is introduced below the liquid level of the reactor, and the flow rate of the inert gas can be, for example, 0.2m 3 /h。
Continuously introducing mixed metal salt solution, precipitant solution and ammonia liquor into the reaction kettle to carry out constant-temperature precipitation reaction, continuously introducing inert gas below the liquid level in the whole feeding process, controlling the oxygen content in the kettle to be below 2%, and controlling the stirring rotation speed to be 200-400 rpm (for example, 200rpm, 300rpm or 400 rpm).
After the precipitation reaction starts, controlling the pH to be reduced by 0.01-0.03 (for example, 0.01, 0.02 or 0.03) per hour, reducing the pH value, raising the ammonia value in the reaction kettle after the particles D50 grow to about 1/3-1/2 (for example, 1/3 or 1/2) of the final target particle size, and forming for 1-3 h (1 h, 2h or 3 h) after the particles D50 grow to the target particle size, wherein the raising amount is 0.05-0.2 mol/L (for example, 0.05mol/L, 0.08mol/L, 0.1mol/L, 0.15mol/L or 0.2 mol/L) per hour. And (3) aging, solid-liquid separating, washing and drying the obtained precipitate to obtain the precursor.
After the precipitation is started, the growth of primary crystal grains of the precursor is regulated and controlled by reasonably regulating and controlling the ammonia value, the pH value and the like in the reaction kettle, so that the secondary spherical hydroxide precursor with better porosity assembled by the strip-shaped primary crystal grains is generated, and the longer primary crystal grain size of the precursor is beneficial to the penetration of the primary crystal grains of the anode prepared by subsequent sintering from the center to the surface, thereby being beneficial to the sodium ion deintercalation in the charge and discharge process.
S2, preparing the anode by mixing and sintering
Placing the precursor and a sodium source into a mixer according to the molar ratio of transition metal element to sodium of 1:0.3-0.7 (for example, 1:0.3, 1:0.4, 1:0.5, 1:0.6 or 1:0.7), and uniformly mixing for 10-15 min (for example, 10min, 12min or 15 min) at about 4800rpm to obtain a mixture;
and placing the mixture into a tube furnace, controlling the temperature to be 600-950 ℃ (for example, 600 ℃, 700 ℃, 800 ℃, 900 ℃ or 950 ℃), and sintering for 8-15 hours (for example, 8 hours, 10 hours, 12 hours or 15 hours) to obtain the anode material.
And (3) taking the precursor with the special structure prepared in the step S1 as a Ni-Mn source, adopting lower sodium content and lower calcination temperature, regulating and controlling the morphology and phase composition of the material in a larger composition interval, and controlling the content and distribution area of the P3 phase, so as to obtain the sodium-ion battery layered anode material with ultrahigh discharge capacity.
The features and capabilities of the present invention are described in further detail below in connection with the examples.
Example 1
The embodiment provides a preparation method of a layered oxide positive electrode material of a sodium ion battery with ultrahigh capacity, which comprises the following steps:
(1) Dissolving nickel sulfate and manganese sulfate in deionized water according to a molar ratio of 0.25:0.75 to prepare a mixed metal salt solution with total ion concentration of 1 mol/L;
(2) Preparing sodium hydroxide into a 2mol/L precipitant solution;
(3) Preparing 4mol/L complexing agent solution from ammonia water and deionized water;
(4) 70L of deionized water is added into a reaction kettle which is clean in 100L, the temperature of the liquid in the reaction kettle is maintained to be 50 ℃ by heating in a water bath, and stirring is started, wherein the stirring speed is 600 rpm; introducing the prepared complexing agent solution into a reaction kettle, measuring the ammonia value in the kettle to be 0.2mol/L, introducing the strong base solution into the reaction kettle, and adjusting the pH value to be 12.0; during the period, pure nitrogen is introduced below the liquid level of the reaction kettle, and the flow rate of the nitrogen is 0.2m 3 /h；
(5) Continuously introducing mixed metal salt solution, precipitant solution and complexing agent solution through a feed pipe, and performing constant-temperature reaction on the obtained mixed solution, wherein the flow rate of the mixed solution is 0.2m continuously introduced below the liquid level of the reaction kettle in the whole feeding process 3 And (3) pure nitrogen in the reactor, and controlling the oxygen content in the reactor to be below 2%. In the early stage of the precipitation reaction, the feeding flow rate of the mixed metal salt solution is 30 mL/min, the feeding flow rate of the precipitant solution is 25 mL/min, and the feeding flow rate of the complexing agent solution is 5 mL/min; the stirring rate was 400 rpm; the pH was reduced at a rate of 0.02 decreases per hour after the reaction began. After the particle D50 reaches 2 mu m, the ammonia concentration in the kettle is increased by 0.05mol/L per hour by increasing the feeding amount of the complexing agent solution; stopping the introduction of each solution after the particles grow to the D50 of 6 mu m, and aging, filtering, washing and drying the reaction product to obtain a precursor, wherein the D50 of the precursor is 6 mu m.
(6) The precursor and sodium carbonate were uniformly mixed with a mixer at about 4800rpm for 12min in a mixture of transition metal element to sodium ratio of 1:0.45. The mixed materials are in a tube furnaceHeating to 800 ℃ at a speed of 3 ℃/min, calcining at a high temperature of 10h, and naturally cooling in an air atmosphere to obtain Na 0.45 Ni 0.25 Mn 0.75 O 2 Sample powder.
Example 2
This embodiment is substantially the same as embodiment 1, except that: the calcination temperature was 750 ℃.
Example 3
This embodiment is substantially the same as embodiment 1, except that: (1) uniformly mixing the precursor material obtained by synthesis with sodium carbonate according to a ratio of 1:0.6 for 12min by using a mixer at about 4800 rpm; (2) heating to 680 deg.C, calcining at high temperature 8 h.
Example 4
This embodiment is substantially the same as embodiment 1, except that: (1) uniformly mixing the precursor material obtained by synthesis with sodium carbonate according to a ratio of 1:0.66 for 12min by using a mixer at about 4800 rpm; (2) heating to 925 deg.C, calcining at high temperature 12 h.
Example 5
This embodiment is substantially the same as embodiment 4, except that: the calcination temperature was 875 ℃.
Example 6
This embodiment is substantially the same as embodiment 4, except that: the calcination temperature was 800 ℃.
Example 7
This embodiment is substantially the same as embodiment 4, except that: the calcination temperature was 700 ℃.
Example 8
This embodiment is substantially the same as embodiment 1, except that: the solutes in the mixed metal salt solution are nickel sulfate and manganese sulfate, wherein the molar ratio of the nickel to the manganese is 0.5:0.5.
Example 9
This embodiment is substantially the same as embodiment 1, except that: the steps (4) and (5) are as follows:
(4) 70L of deionized water is added into a reaction kettle which is clean in 100L, the temperature of the liquid in the reaction kettle is maintained to be 50 ℃ by heating in a water bath, and stirring is started, wherein the stirring speed is 600 rpm; complexing the preparedIntroducing the reagent solution into a reaction kettle, measuring the ammonia value in the kettle to be 0.4mol/L, introducing the strong base solution into the reaction kettle, and adjusting the pH value to be 11.5; during the period, pure nitrogen is introduced below the liquid level of the reaction kettle, and the flow rate of the nitrogen is 0.2m 3 /h；
(5) Continuously introducing mixed metal salt solution, precipitant solution and complexing agent solution through a feed pipe, and performing constant-temperature reaction on the obtained mixed solution, wherein the flow rate of the mixed solution is 0.2m continuously introduced below the liquid level of the reaction kettle in the whole feeding process 3 And (3) pure nitrogen in the reactor, and controlling the oxygen content in the reactor to be below 2%. In the early stage of the precipitation reaction, the feeding flow rate of the mixed metal salt solution is 30 mL/min, the feeding flow rate of the second solution is 25 mL/min, and the feeding flow rate of the third solution is 5 mL/min; the stirring rate was 400 rpm; the pH was controlled to decrease at a rate of 0.01 decrease per hour after the start of the reaction. After the particle D50 reaches 1 mu m, the ammonia concentration in the kettle is increased by 0.2mol/L per hour by increasing the feeding amount of the complexing agent solution; stopping the introduction of each solution after the particles grow until the particle D50 reaches 4 mu m; and (3) ageing, filtering, washing and drying the reaction product to obtain the precursor.
Comparative example 1
This comparative example is substantially the same as example 1, except that: the calcination temperature was 1000 ℃.
Comparative example 2
This comparative example is substantially the same as example 1, except that: after the precipitation reaction starts, the pH is kept substantially unchanged by adjusting the rate of addition of the precipitant solution.
Comparative example 3
This comparative example is substantially the same as example 1, except that: after the precipitation reaction starts, the ammonia value in the reaction kettle is not raised after the D50 grows to 2 mu m, so that the ammonia value is always kept at about 0.2 mol/L.
Comparative example 4
This comparative example is substantially the same as example 1, except that: after the start of the precipitation reaction, the ammonia value was raised to 0.6 mol/L after the D50 had grown to 2. Mu.m.
Comparative examples 5 to 7
Comparative examples 5 to 7 are basically the same as example 1 except that: the molar ratio of the transition metal element in the precursor to sodium in the sodium carbonate is 1:0.75, 1:0.895 and 1:1.1 respectively; the calcination temperature was 925 ℃.
Experimental example 1
The microscopic morphologies of the precursors prepared in the preparation process of example 1, example 9 and comparative examples 2 to 4 were photographed, as shown in fig. 1 to 5.
As can be seen from fig. 1, the morphology of the prepared precursor is the morphology of spherical secondary particles assembled from primary elongated grains. As can be seen from comparing fig. 3 to 5 with fig. 1, the precursors prepared in comparative examples 2 to 4 are fine primary particles agglomerated, and have no clear primary long-sized crystal grains, which means that the precursor with the morphology described above cannot be prepared without adjusting the ammonia value and the pH value in the reaction process in the manner required by the present invention.
Experimental example 2
The morphology of the positive electrode materials prepared in each of examples and comparative examples was photographed, as shown in fig. 6 to 21, fig. 6 to 14 are SEM images of the positive electrode materials prepared in examples 1 to 9, respectively, and fig. 15 to 21 are SEM images of the positive electrode materials prepared in comparative examples 1 to 7, respectively. As can be seen from fig. 6 to 14, the positive electrode material prepared in each embodiment of the present invention has a micron-sized secondary particle morphology assembled from primary flaky grains, which continuously penetrate from the inside to the outside of the particle. The secondary particle aggregate granularity D10 of the positive electrode materials is more than or equal to 3 mu m, D50=5-10 mu m, and D90 is less than or equal to 11 mu m; the length of the primary flaky grains is 1.5-6 mu m.
And the morphology of the positive electrode materials prepared by different precursors in comparative examples 2-4 is obviously different from that of the examples. The positive electrode materials prepared in comparative examples 1 and 5 to 7 were micron-sized secondary particles assembled from primary flaky grains that became large and thick, and some of the grains were agglomerated.
Experimental example 3
XRD patterns of the positive electrode materials prepared in examples 1 to 7 and comparative examples 5 to 7 were prepared as shown in FIGS. 22 to 25; XRD patterns of the positive electrode materials prepared in comparative examples 1 and 2 were prepared as shown in fig. 26.
Fig. 22 shows XRD patterns of the two positive electrode materials of examples 1 and 2; FIG. 23 is an XRD pattern of the positive electrode material obtained in example 3; FIG. 24 is an XRD pattern of the positive electrode materials prepared in examples 4 to 7; FIG. 25 is an XRD pattern of the positive electrode materials prepared in comparative examples 5 to 7; fig. 26 is an XRD pattern of the positive electrode material prepared in comparative examples 1 and 2.
As can be seen from fig. 22 to 25, at low sodium and low temperature, the material is pure P3 phase, and the P2 phase gradually forms with increasing calcination temperature and sodium content.
As can be seen from fig. 26, the material is a P2 phase with higher crystallinity when the calcination temperature exceeds the range required by the present invention.
Experimental example 4
The electrochemical properties of the positive electrode materials prepared in each of the examples and comparative examples were tested. The specific test method comprises the following steps: and (3) preparing the positive electrode material into a CR2025 button cell, and performing charge-discharge cycle test on the half cell in a blue electric test system under the conditions of 30 ℃ and the voltage range of 2-4.3V, wherein the nominal specific capacity is 1C =120 mAh/g, and performing long cycle test on the activated cell at the multiplying power of 1C. The test results are recorded in table 1.
Table 1 electrochemical properties of each of examples and comparative examples
As can be seen from the table above, the positive electrode material prepared by each embodiment of the invention has higher specific discharge capacity. Comparing example 1 with comparative examples 5-7, the discharge specific capacity of comparative example 1 is significantly lower, which indicates that the calcination temperature defined by the invention is more suitable, and the positive electrode material prepared by too high calcination temperature cannot be used as the positive electrode material with ultra-high capacity; comparing comparative examples 2-4 with example 1, the discharge specific capacity is significantly lower, which indicates that the capacity of the prepared positive electrode material is slightly worse when the pH value and the ammonia value are not regulated according to the requirement of the invention in the precursor preparation process; by comparing comparative example 7 with example 1, increasing the sodium content beyond the range required by the present invention, the specific discharge capacity of the positive electrode material obtained was significantly reduced. Comparing comparative examples 5 to 7 with example 1, comparative examples 5 to 7 are sodium compounds and sintering modes of the conventional positive electrode materials at present, and as can be seen from the comparison example results, the positive electrode material of example 1 has significantly higher specific discharge volume, which indicates that the sodium compounds and sintering modes provided by the examples of the present invention can prepare positive electrode materials with high capacity.
Comparing examples 1-7, it was found that Ni 0.25 Mn 0.75 The electrochemical performance of the system is related to different phases, sodium content and calcination temperature. In the voltage range of 2-4.3V, the sodium-lean low-nickel manganese-rich sodium electric positive electrode has ultrahigh discharge specific capacity at 0.1C.
In summary, the high-capacity positive electrode material provided by the invention has a relatively low sodium proportion, so that the positive electrode material has relatively high capacity, and the primary flaky grains of the positive electrode material continuously penetrate from the inside of the particles to the outer surface, thereby being beneficial to sodium ion deintercalation in the charge and discharge process; the higher P3 phase content is distributed in the inner core region, and the content exceeds 50%, so that the charge-discharge capacity of the positive electrode material can be further improved.
The preparation method provided by the invention adopts the precursor with the morphology of the secondary particles assembled by the primary strip-shaped grains as the raw material, and the precursor with the morphology has better porosity, thereby being beneficial to completing the precursor sodium embedding reaction in a larger temperature interval; the precursor with the morphology also has longer primary grain size, and the mixed sintering of the precursor and a sodium source is beneficial to the penetration of the primary grain of the anode from the center to the surface, thereby being beneficial to the sodium ion deintercalation in the charge and discharge process. And sintering is carried out at a low temperature of 600-950 ℃ for a short time, so that the generated P3 phase is ensured to be concentrated in the crystal of the positive electrode material, and the positive electrode material with proper P3 phase content is obtained, thereby ensuring that the sodium ion battery with ultra-high discharge capacity is obtained. In addition, compared with the prior art, the preparation method of the layered positive electrode material for the high-capacity sodium-poor sodium ion battery has the advantages of simple and easy realization of the material preparation process, abundant and wide raw material sources and low cost.
In a preferred scheme, the preparation method of the precursor is specifically disclosed, and the precursor of the secondary particles assembled by the primary long-strip grains can be prepared by adjusting the pH value and the ammonia value in the preparation process of the precursor, and the precursor has better porosity and is beneficial to completing the sodium intercalation reaction of the precursor in a larger temperature range.
The above is only a preferred embodiment of the present invention, and is not intended to limit the present invention, but various modifications and variations can be made to the present invention by those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims (10)

1. The layered oxide positive electrode material of the sodium ion battery with the ultrahigh capacity is characterized by comprising the following chemical formula: na (Na) x Ni y Mn z M 1-y-z O 2 Wherein M is at least one of Co, fe or Mg, x is more than or equal to 0.3 and less than or equal to 0.7,0.25, y is more than or equal to 0.5, z is more than or equal to 0.5 and less than or equal to 0.75,1-y-z is more than or equal to 0.05;
the positive electrode material phase composition is provided with a P3 phase with a space group R3m, and the P3 phase in the positive electrode material is distributed in a crystal grain inner core area, and the content of the P3 phase is more than or equal to 50%; the positive electrode material has a micron-sized secondary particle morphology assembled from primary platelet-shaped grains that continuously penetrate from the interior to the exterior of the particle.
2. The positive electrode material according to claim 1, wherein the secondary particle agglomerate particle size d10 is not less than 3 μm, d50=5 to 10 μm, d90 is not more than 11 μm; the length of the primary flaky grains is 1.5-6 mu m.
3. A method for producing the positive electrode material according to any one of claims 1 to 2, comprising:
mixing and sintering a precursor and a sodium source according to the molar ratio of transition metal element to sodium of 1:0.3-0.7, wherein the chemical formula of the precursor is as follows:
Ni y Mn z M 1-y-z (OH) 2 wherein M is at least one of Co, fe and Mg, y is more than or equal to 0.25 and less than or equal to 0.5, z is more than or equal to 0.5 and less than or equal to 0.75,1-y-z is more than or equal to 0.05;
the morphology of the precursor is a secondary particle morphology assembled by strip-shaped primary grains;
the sintering temperature is 600-950 ℃ and the sintering time is 8-15 h.
4. A method of preparing according to claim 3, further comprising preparing a precursor prior to sintering, the method of preparing a precursor comprising:
controlling the temperature of liquid in the reaction kettle to be 45-55 ℃, the initial ammonia value to be 0.2-0.4 mol/L and the pH to be 10-12;
continuously introducing mixed metal salt solution, precipitant solution and ammonia liquor into the reaction kettle to carry out precipitation reaction; and reducing the pH value at a rate of 0.01-0.03 per hour after the precipitation reaction starts, increasing the ammonia value in the reaction kettle to 0.05-0.2 mol/L per hour after the particles D50 grow to 1/3-1/2 of the final target particle size, forming for 1-3 hours after the particles grow to the target particle size, and aging, solid-liquid separation, washing and drying the obtained precipitate to obtain the precursor.
5. The preparation method of claim 4, further comprising introducing water into the reaction kettle in an amount of 30-80% of the volume of the reaction kettle before the precipitation reaction.
6. The method of claim 4, wherein the precipitant solution is sodium hydroxide solution; the metal salt solution is a salt solution in which Ni and Mn ions are dissolved, or a salt solution in which Ni, mn and M ions are dissolved.
7. The method according to claim 4, wherein the stirring speed in the reaction vessel is 200-400 rpm during the precipitation reaction.
8. The method according to claim 4, wherein inert gas is introduced under the liquid surface of the reaction vessel during the precipitation reaction.
9. A positive electrode prepared by the positive electrode material according to claim 1 or 2 or the positive electrode material prepared by the preparation method according to any one of claims 3 to 8.
10. A sodium ion battery comprising the positive electrode of claim 9.
CN202311280150.8A 2023-10-07 2023-10-07 Ultra-high-capacity positive electrode material, preparation method thereof, positive electrode and sodium ion battery Pending CN117038964A (en)

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Citations (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2017045600A (en) * 2015-08-26 2017-03-02 日産自動車株式会社 Control method of sodium ion secondary battery, controller for sodium ion secondary battery, and sodium ion secondary battery for use in control method or controller for sodium ion secondary battery
CN109686969A (en) * 2018-12-14 2019-04-26 北京化工大学 A kind of sodium-ion battery of the preparation and application of stratiform transition metal oxide the material material
CN113651369A (en) * 2021-08-18 2021-11-16 宁波容百新能源科技股份有限公司 Spherical high-nickel ternary precursor material, preparation method thereof and high-nickel ternary cathode material
CN113651370A (en) * 2021-08-18 2021-11-16 宁波容百新能源科技股份有限公司 NCMA precursor material, preparation method and NCMA positive electrode material
CN114122382A (en) * 2021-11-24 2022-03-01 西安交通大学 Layered positive electrode material of P3 type sodium-ion battery and preparation method and application thereof
CN115072805A (en) * 2022-07-21 2022-09-20 多氟多新材料股份有限公司 Sodium-ion battery positive electrode material precursor, preparation method thereof and preparation method of sodium-ion battery positive electrode material
CN115432748A (en) * 2022-10-09 2022-12-06 济南大学 Preparation method of nickel-manganese-based precursor and monocrystal layered positive electrode material of lithium/sodium ion battery
US20230122382A1 (en) * 2020-12-23 2023-04-20 Beijing Easpring Material Technology Co., Ltd. Positive electrode material for lithium ion battery and preparation method therefor, and lithium ion battery
CN116375111A (en) * 2023-06-06 2023-07-04 宜宾锂宝新材料有限公司 Sodium ion battery, positive electrode material and precursor thereof and preparation method
CN116759525A (en) * 2023-07-31 2023-09-15 中伟新材料股份有限公司 Sodium ion battery positive electrode material precursor, preparation method thereof, sodium ion battery positive electrode material, sodium ion battery and electric equipment

Patent Citations (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2017045600A (en) * 2015-08-26 2017-03-02 日産自動車株式会社 Control method of sodium ion secondary battery, controller for sodium ion secondary battery, and sodium ion secondary battery for use in control method or controller for sodium ion secondary battery
CN109686969A (en) * 2018-12-14 2019-04-26 北京化工大学 A kind of sodium-ion battery of the preparation and application of stratiform transition metal oxide the material material
US20230122382A1 (en) * 2020-12-23 2023-04-20 Beijing Easpring Material Technology Co., Ltd. Positive electrode material for lithium ion battery and preparation method therefor, and lithium ion battery
CN113651369A (en) * 2021-08-18 2021-11-16 宁波容百新能源科技股份有限公司 Spherical high-nickel ternary precursor material, preparation method thereof and high-nickel ternary cathode material
CN113651370A (en) * 2021-08-18 2021-11-16 宁波容百新能源科技股份有限公司 NCMA precursor material, preparation method and NCMA positive electrode material
CN114122382A (en) * 2021-11-24 2022-03-01 西安交通大学 Layered positive electrode material of P3 type sodium-ion battery and preparation method and application thereof
CN115072805A (en) * 2022-07-21 2022-09-20 多氟多新材料股份有限公司 Sodium-ion battery positive electrode material precursor, preparation method thereof and preparation method of sodium-ion battery positive electrode material
CN115432748A (en) * 2022-10-09 2022-12-06 济南大学 Preparation method of nickel-manganese-based precursor and monocrystal layered positive electrode material of lithium/sodium ion battery
CN116375111A (en) * 2023-06-06 2023-07-04 宜宾锂宝新材料有限公司 Sodium ion battery, positive electrode material and precursor thereof and preparation method
CN116759525A (en) * 2023-07-31 2023-09-15 中伟新材料股份有限公司 Sodium ion battery positive electrode material precursor, preparation method thereof, sodium ion battery positive electrode material, sodium ion battery and electric equipment

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
LI ZHANG 等: ""Preferential occupation of Na in P3-type layered cathode material for sodium ion batteries"", 《NANO ENERGY》, vol. 70 *

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