CN113013401B - Preparation method and application of positive electrode active material of lithium ion battery - Google Patents

Preparation method and application of positive electrode active material of lithium ion battery Download PDF

Info

Publication number
CN113013401B
CN113013401B CN202110166932.3A CN202110166932A CN113013401B CN 113013401 B CN113013401 B CN 113013401B CN 202110166932 A CN202110166932 A CN 202110166932A CN 113013401 B CN113013401 B CN 113013401B
Authority
CN
China
Prior art keywords
ion battery
lithium ion
positive electrode
lithium
active material
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Active
Application number
CN202110166932.3A
Other languages
Chinese (zh)
Other versions
CN113013401A (en
Inventor
李建玲
杨哲
钟健健
冯佳萌
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
University of Science and Technology Beijing USTB
Original Assignee
University of Science and Technology Beijing USTB
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by University of Science and Technology Beijing USTB filed Critical University of Science and Technology Beijing USTB
Priority to CN202110166932.3A priority Critical patent/CN113013401B/en
Publication of CN113013401A publication Critical patent/CN113013401A/en
Application granted granted Critical
Publication of CN113013401B publication Critical patent/CN113013401B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

Classifications

    • 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
    • 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
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/05—Accumulators with non-aqueous electrolyte
    • H01M10/058—Construction or manufacture
    • 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
    • H01M4/04—Processes of manufacture in general
    • 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
    • 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
    • H01M4/62—Selection of inactive substances as ingredients for active masses, e.g. binders, fillers
    • H01M4/624—Electric conductive fillers
    • H01M4/625—Carbon or graphite
    • 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
    • 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
    • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
    • Y02P70/00—Climate change mitigation technologies in the production process for final industrial or consumer products
    • Y02P70/50—Manufacturing or production processes characterised by the final manufactured product

Abstract

The invention provides a preparation method and application of a lithium ion battery anode active material, relates to the technical field of lithium ion batteries, and can realize reversible oxidation reduction of anions in the lithium ion battery anode material and effectively inhibit oxygen loss of a lithium-rich manganese-based anode material; the method comprises the following steps: s1, uniformly mixing lithium salt, sodium salt and transition metal oxide according to a preset molar ratio to obtain a mixture; s2, calcining the mixture to obtain a first anode material; s3, mixing the first positive electrode material, a conductive agent and a binder according to a preset mass fraction to prepare a second positive electrode material; and S4, activating the second anode material to obtain the final anode active material of the lithium ion battery. The technical scheme provided by the invention is suitable for the preparation and application processes of the lithium ion battery.

Description

Preparation method and application of positive electrode active material of lithium ion battery
Technical Field
The invention relates to the technical field of lithium ion batteries, in particular to a preparation method and application of a lithium ion battery anode active material.
Background
Lithium ion batteries are currently the most widely used secondary batteries due to their high energy density and good cycling stability. The lithium ion battery anode material becomes a limiting link of the energy density of the lithium ion battery due to the problems of lower specific capacity and the like. Conventional lithium ion battery positive electrode materials, such as LiCoO 2 、LiFePO 4 、LiNi x Co y Mn 1-x-y O 2 And the like, the higher atomic weight and the smaller electron holding capacity of the material fundamentally limit the improvement of the specific capacity by the charge storage and release of the transition metal ions. While the current anion (O) 2- 、S 2- Etc.) the energy storage is gradually concerned by people, more and more research findings and advanced characterization means prove the feasibility and the authenticity of the generation of anion energy storage, which opens up a new world for improving the specific capacity of the anode material and is expected to lead the lithium ion to be expectedThe development of batteries is moving to a new stage.
The lithium-rich manganese-based cathode material, which is a typical material with oxidation and reduction of anions, has no corresponding reduction plateau of oxygen in the discharge stage, but shows a sloped curve, although oxidation of oxygen occurs in the first charge to 4.5V plateau. This phenomenon of inconsistent first charge and discharge behavior can be attributed to the following explanation: the transition metal in the lithium-rich material undergoes irreversible interlayer migration in the first charging process, the honeycomb superlattice structure is damaged, and O is generated 2 Molecules are trapped in the interlayer and during the discharge phase O 2 The molecule is reduced to generate O 2- But cannot be restored to the original crystal structure state. Lithium-rich materials are therefore to some extent not considered to be fully reversible by anionic redox, and new positive electrode materials which are reversible within the category of electrochemical and crystalline structures are sought and studied. Recently, researchers developed a sodium-ion battery positive electrode material Na with a band-shaped superlattice structure and completely reversible in electrochemistry for the first time 0.6 Li 0.2 MnO 2 Therefore, the method can be used as a reference for preparing and developing a novel lithium ion battery cathode material.
The ion exchange method can exchange alkali metal ions without damaging the structural framework of the material, and can utilize the positive electrode material of the sodium ion battery to carry out ion exchange to prepare the novel positive electrode material of the lithium ion battery. Researchers successfully prepare the lithium ion battery anode material with the 02 metastable state structure through a molten salt ion exchange method, the lithium ion battery anode material has ultrahigh specific capacity and good cycle stability, but the preparation method is high in cost, difficult to put into practical production, and inconsistent in first charge and discharge behaviors.
Therefore, there is a need to develop a method for preparing a positive electrode active material of a lithium ion battery and an application thereof, which can implement reversible oxidation reduction of anions of the positive electrode material of the lithium ion battery, so as to overcome the deficiencies of the prior art and solve or alleviate one or more of the above problems.
Disclosure of Invention
In view of this, the invention provides a preparation method and application of a lithium ion battery anode active material, which are simple, convenient and quick, have low cost, can realize reversible oxidation reduction of anions in the lithium ion battery anode material, and effectively inhibit oxygen loss of the lithium-rich manganese-based anode material.
In one aspect, the present invention provides a method for preparing a positive electrode active material for a lithium ion battery, wherein the method comprises the steps of:
s1, uniformly mixing lithium salt, sodium salt and transition metal oxide according to a preset molar ratio to obtain a mixture;
s2, calcining the mixture to obtain a first anode material;
s3, mixing the first positive electrode material, a conductive agent and a binder according to a preset mass fraction to prepare a second positive electrode material;
the mixing preparation process of the step is a pure physical reaction, and does not influence the performance of the first anode material; the binder plays a role in binding, the conductive agent plays a role in enhancing conductivity, and the materials in the original powder form are bound into a solid state, such as a block, a rod, a sheet and the like;
and S4, activating the second anode material to obtain the final anode active material of the lithium ion battery.
The above aspect and any possible implementation manner further provide an implementation manner that a molar ratio of the lithium salt, the sodium salt, and the transition metal oxide is (0.1 to 0.4): (0.5-1): (0.6-0.9).
The above aspect and any possible implementation manner further provide an implementation manner, wherein an organic solvent (acetone or alcohol) is added to the mixture of the lithium salt, the sodium salt and the transition metal oxide, and the mixture is ground or stirred uniformly until the organic solvent is completely volatilized, so as to obtain a final mixture.
The above aspects and any possible implementations further provide an implementation where the mixture is placed in a crucible, and the crucible is placed in a muffle furnace for calcination.
The above aspect and any possible implementation manner further provide an implementation manner, wherein the lithium salt is lithium hydroxide, lithium oxide, or lithium carbonate; the sodium salt is sodium hydroxide, sodium oxide or sodium carbonate; the transition metal oxide is any one or more of manganese oxide, nickel oxide and cobalt oxide.
The above aspects and any possible implementations further provide an implementation, and the calcining includes: firstly calcining for 4-8 h at the temperature of 450-600 ℃, then heating to 750-950 ℃, calcining for 10-18 h, and then cooling.
The above aspects and any possible implementation manners further provide an implementation manner, wherein the temperature rising rate in the calcining process is 2-10 ℃/min, and the cooling rate is 1-10 ℃/min.
The above aspect and any possible implementation manner further provide an implementation manner that the mass fractions of the first cathode material, the conductive agent, and the binder are 70 to 85%, 10 to 20%, and 5 to 15% in this order.
The above aspects and any possible implementations further provide an implementation, in which the conductive agent is super carbon black, acetylene black, or carbon nanotubes; the binder is polyvinylidene fluoride (PVDF) or Polytetrafluoroethylene (PTFE).
The above-described aspect and any possible implementation manner further provide an implementation manner, and the process activated in step S4 includes: and performing electrochemical charge and discharge under the action of an electrolyte by taking the second anode material as an anode and metallic lithium as a cathode to realize ion exchange, thereby obtaining the lithium ion battery anode active material with reversible anion redox activity.
The above aspects and any possible implementation manners further provide an implementation manner, and the activation device is placed still for 8 to 48 hours after being assembled, and then is subjected to electrochemical charging and discharging.
In accordance with one aspect and any possible implementation manner of the above aspect, there is further provided an implementation manner of the electrochemical charging and discharging, wherein the current density is 5 to 20mA/g, the upper voltage cut-off limit is 4.5 to 4.8V, and the lower voltage cut-off limit is 2 to 3.5V.
The aspects and any possible implementation described above are further directed toProviding an implementation mode, wherein the electrolyte comprises the following components: liPF with solute of 0.5-3 mol/L 6 Or LiClO 4 The organic solvent is a mixed solvent of any two or more of ethylene carbonate, propylene carbonate, dimethyl carbonate, diethyl carbonate and ethyl methyl carbonate.
On the other hand, the invention provides a lithium ion battery, which is characterized in that the lithium ion battery adopts the lithium ion battery positive electrode active material prepared by any one of the methods as a positive electrode.
Compared with the prior art, the invention can obtain the following technical effects: the method assembles the anode material for the sodium ion battery into the lithium ion battery, charges and discharges with small current in a certain voltage interval, and realizes Na through an electrochemical mode + And Li + The structural skeleton of the material body is kept unchanged, so that oxygen is subjected to reversible redox; compared with the traditional molten salt ion exchange, the method is simple, convenient and quick, has low cost, and can realize reversible oxidation reduction of anions in the lithium ion battery anode material;
the Li/Na exchange is realized by a simple and quick electrochemical ion exchange method, so that the integrity of a banded superlattice structure of the material is maintained, the interlayer migration of transition metal elements is inhibited, the structural stability of the anode material in the charge-discharge process is enhanced, the reversible redox reaction of anions is realized, and a foundation is laid for an anion energy storage and electrochemical preparation method.
Of course, it is not necessary for any one product in which the invention is practiced to achieve all of the above-described technical effects simultaneously.
Drawings
In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings needed to be used in the embodiments will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without creative efforts.
Fig. 1 is a flowchart of a method for preparing a positive active material for a lithium ion battery according to an embodiment of the present invention;
FIG. 2 is an electron microscope (SEM) image and an energy spectrum (EDS) image of an initial cathode material prepared by the method of the invention provided by one embodiment of the invention; wherein, fig. 2a is an SEM image of the material, fig. 2b to d are mapping images of element distribution of Na, O, mn, respectively, and fig. 2e is an EDS spectrum of the whole material;
FIG. 3 is a test chart of the first three cycles of charging and discharging of a lithium ion battery by an electrochemical ion exchange method according to an embodiment of the present invention;
FIG. 4 is a first three-cycle capacity differential plot of a lithium ion battery obtained by electrochemical ion exchange according to one embodiment of the present invention;
fig. 5 is an ex-situ XRD pattern of the positive electrode material provided by one embodiment of the present invention under different states of charge of the first two circles;
fig. 6 is a graph of the first ten cycles of specific discharge capacity data for a positive electrode material provided in accordance with an embodiment of the present invention.
Detailed Description
In order to better understand the technical scheme of the invention, the following detailed description of the embodiments of the invention is made with reference to the accompanying drawings.
It should be understood that the described embodiments are only some embodiments of the invention, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
The terminology used in the embodiments of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used in the examples of the present invention and the appended claims, the singular forms "a," "an," and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise.
In view of the shortcomings of the prior art, the alkali metal ion (Li) is generated by taking the alkali ion battery as a rocking chair type battery + /Na + ) Is inserted and released from the bodyIf the material is not changed, na can be electrochemically removed + First of all, then Li is extracted + Back intercalation, electrochemical ion exchange is achieved? The answer is affirmative. The invention uses the positive electrode material of the sodium-ion battery as a precursor by an electrochemical means to complete Na + /Li + Exchange and realize reversible oxidation reduction of anions, and provides a new idea for multi-electron energy storage and electrochemical basic scientific research.
A preparation method of a positive electrode active material of a lithium ion battery comprises the following steps:
(1) Putting lithium salt, sodium salt and transition metal oxide in a certain molar ratio into a mortar, adding a proper amount of acetone or alcohol, and uniformly grinding until the organic solvent is completely volatilized;
the lithium salt is lithium hydroxide, lithium oxide or lithium carbonate and the like; the sodium salt is sodium hydroxide, sodium oxide or sodium carbonate; the transition metal oxide is one or more of manganese oxide, nickel oxide and cobalt oxide; the molar ratio of the lithium salt to the sodium salt to the transition metal oxide is (0.1-0.4): (0.5-1): (0.6-0.9);
(2) Collecting the uniformly ground mixture in a crucible, calcining the uniformly ground mixture in a muffle furnace according to a certain sintering system, and cooling the calcined mixture to room temperature to obtain a final product;
the sintering system is specifically that the raw materials are calcined for 4 to 8 hours at the temperature of 450 to 600 ℃ and then calcined for 10 to 18 hours at the temperature of 750 to 950 ℃; the heating rate of all heating programs in the sintering process is 2-10 ℃/min, and the cooling rate is 1-10 ℃/min;
(3) Preparing a positive pole piece of a lithium ion battery from a positive pole material, and assembling the positive pole piece into a button battery, wherein the electrolyte is the lithium ion battery electrolyte, and the negative pole is metal lithium;
the positive pole piece comprises a positive active material, a conductive agent and a binder, wherein the mass fractions of the positive active material, the conductive agent and the binder are respectively 70-85%, 10-20% and 5-15%; the conductive agent is Super carbon black (Super P), acetylene black or carbon nano tube. The binder is PVDF or PTFE and the like.
The lithium ion battery electrolyte comprises the following components: liPF with solute of 0.5-3 mol/L 6 Or LiClO 4 Etc. are as followsThe organic solvent is formed by mixing two or more solvents with different proportions, such as ethylene carbonate, propylene carbonate, dimethyl carbonate, diethyl carbonate, methyl ethyl carbonate and the like;
(4) Standing the assembled battery for a period of time, and then testing in a certain charging and discharging mode to enable the battery to generate electrochemical Li/Na exchange, so that the reversible redox reaction of the positive electrode material anions can be realized;
the standing time of the assembled battery is 8-48 h; the current density of electrochemical charge and discharge is 5-20 mA/g, the upper limit of voltage cut-off is 4.5-4.8V, and the lower limit is 2-3.5V.
The mechanism of the invention is as follows: na is electrochemically added to a positive electrode material of a sodium ion battery having a band-shaped superlattice structure and reversible anion redox activity + Firstly, the Li is extracted from the anode material + Back-embedded with Na + The vacancy does not damage the material lattice framework, the Li/Na exchange is realized, the lithium ion battery anode material with a special superlattice structure is obtained, and the completely reversible redox reaction of the lithium ion battery anode material anions is realized for the first time.
Example 1: a method for realizing reversible redox of anions of a lithium ion battery cathode material comprises the following steps:
(1) Placing lithium hydroxide, sodium carbonate and manganese dioxide with a molar ratio of 0.2.6;
(2) The uniformly ground mixture was collected in a crucible, heated in a muffle furnace first for 5h at 450 ℃ and then calcined at 800 ℃ for 12h, and then cooled to room temperature.
(3) The positive electrode material, super P and PVDF are mixed according to the mass fraction of 75%:15%: preparing the positive pole piece of the lithium ion battery with the proportion of 10 percent, and assembling the positive pole piece into the button cell, wherein the electrolyte is lithium ion battery electrolyte (LiPF of 1 mol/L) 6 Dissolved in EC/DMC solution with the volume ratio of 1;
(4) And standing the assembled battery for 8 hours, and activating the battery at a current density of 10mA/g in a voltage range of 2-4.5V to generate electrochemical Li/Na exchange so as to realize the reversible redox reaction of the anions of the anode material.
Example 2: a method for realizing reversible redox of negative ions of a lithium ion battery positive electrode material comprises the following steps:
(1) Placing lithium hydroxide, sodium carbonate and manganese dioxide in a molar ratio of 0.33;
(2) The uniformly ground mixture was collected in a crucible, heated in a muffle furnace first at 450 ℃ for 5h, then calcined at 850 ℃ for 12h, and then cooled to room temperature.
(3) The positive electrode material, super P and PVDF are mixed according to the mass fraction of 75%:15%: preparing a lithium ion battery anode plate by a proportion of 10 percent, and assembling the lithium ion battery anode plate into a button cell, wherein the electrolyte is lithium ion battery electrolyte (1 mol/L LiPF) 6 Dissolving in EC/DMC solution with volume ratio of 1;
(4) And (3) standing the assembled battery for 8 hours, and activating the battery at a current density of 10mA/g and a voltage range of 2-4.5V to generate electrochemical Li/Na exchange so as to realize the reversible redox reaction of the positive electrode material anions.
Example 3: a method for realizing reversible redox of anions of a lithium ion battery cathode material comprises the following steps:
(1) Placing lithium hydroxide, sodium carbonate and manganese dioxide in a molar ratio of 0.2;
(2) The uniformly ground mixture was collected in a crucible, heated in a muffle furnace first at 450 ℃ for 5h, then calcined at 800 ℃ for 12h, and then cooled to room temperature.
(3) The positive electrode material, super P and PVDF are mixed according to the mass fraction of 75%:15%: preparing the positive pole piece of the lithium ion battery with the proportion of 10 percent, and assembling the positive pole piece into the button cell, wherein the electrolyte is lithium ion battery electrolyte (LiPF of 2 mol/L) 6 Dissolved in EC/DMC solution with the volume ratio of 1;
(4) And standing the assembled battery for 8 hours, and activating the battery at a current density of 10mA/g in a voltage range of 2-4.8V to generate electrochemical Li/Na exchange so as to realize the reversible redox reaction of the anions of the anode material.
Example 4: a method for realizing reversible redox of negative ions of a lithium ion battery positive electrode material comprises the following steps:
(1) Placing lithium hydroxide, sodium carbonate and manganese dioxide with a molar ratio of 0.25 to 0.6;
(2) The uniformly ground mixture was collected in a crucible, heated in a muffle furnace first at 500 ℃ for 5h, then calcined at 800 ℃ for 12h, and then cooled to room temperature.
(3) The positive electrode material, super P and PVDF are mixed according to the mass fraction of 75%:15%: preparing the positive pole piece of the lithium ion battery with the proportion of 10 percent, and assembling the positive pole piece into the button cell, wherein the electrolyte is lithium ion battery electrolyte (LiPF of 1 mol/L) 6 Dissolved in EC/DMC solution with the volume ratio of 1;
(4) And standing the assembled battery for 24 hours, and activating the battery at a current density of 10mA/g in a voltage range of 2-4.8V to generate electrochemical Li/Na exchange so as to realize the reversible redox reaction of the anions of the anode material.
FIG. 2 is SEM image and EDS image of the scanning electron microscope of example 1, and it can be seen that the material is in the form of irregular polyhedron with size of about 500 nm-1 μm, sharp edges and corners, smooth surface, good crystallinity and no significant agglomeration. And Na, mn and O elements are uniformly distributed in the material, which shows that the material phase is uniformly distributed, the elements are fully migrated in the preparation process, and the reaction is complete.
Fig. 3 shows the results of the first three-cycle charge and discharge tests of electrochemical activation, and it is found that the material shows a voltage plateau around a 4.5V high-voltage region during the first charge process, and shows a high voltage plateau opposite to the first high-voltage region during the discharge process, and shows good reversibility. And an additional voltage plateau appears below the first-discharged low-voltage region of 3.0V, which plateau persists during subsequent charging and discharging. The capacity differential curve of fig. 4 corresponds to a reversible electrochemical behavior.
In order to study the crystal structure evolution rule of the cathode material in the electrochemical ion exchange process, ex-situ XRD tests under different charge states were performed on the cathode material, as shown in fig. 5. The material is found to be subjected to first electrochemical Na removal + Thereafter, the (002) interplanar spacing between the metal ion layers shrinks dramatically and does not return to the original position during subsequent cycles, and the surface electrochemical ion exchange is completed after the first activation. And the other diffraction peaks (010), (012), (120), (122) and the like all show good reversibility in the circulation process, which indicates that electrochemical ion exchange causes the material to narrow the interlayer distance along the c-axis direction, and other structures all keep good stability and reversibility, so that the electrochemical behavior of the cathode material keeps good reversibility.
FIG. 6 shows the specific discharge capacity of the material in the first ten cycles, wherein the first three cycles are electrochemical activation process of 2-4.5V, and then the charge and discharge test is performed in the high voltage interval of 2-4.7V. It is found that the specific capacity of the material is gradually increased in the electrochemical activation process, and after the upper voltage limit is increased to 4.7V, the specific discharge capacity of the material can reach 230mAh/g, the high specific capacity of the material exceeds that of the current commercial cathode material, and the good cycle performance is shown, which can be attributed to a great contribution of anions in the material to charge compensation. Therefore, the electrochemical ion exchange can realize reversible redox reaction of anions in the lithium ion battery anode material.
The method for realizing reversible redox of the negative ions of the lithium ion battery positive electrode material provided by the embodiment of the application is described in detail above. The above description of the embodiments is only for the purpose of helping to understand the method of the present application and its core idea; meanwhile, for a person skilled in the art, according to the idea of the present application, there may be variations in the specific embodiments and the application scope, and in summary, the content of the present specification should not be construed as a limitation to the present application.
As used in the specification and claims, certain terms are used to refer to particular components. As one skilled in the art will appreciate, manufacturers may refer to a component by different names. The present specification and claims do not intend to distinguish between components that differ in name but not function. In the following description and in the claims, the terms "include" and "comprise" are used in an open-ended fashion, and thus should be interpreted to mean "include, but not limited to. "substantially" means within an acceptable error range, and a person skilled in the art can solve the technical problem within a certain error range to substantially achieve the technical effect. The description which follows is a preferred embodiment of the present application, but is made for the purpose of illustrating the general principles of the application and not for the purpose of limiting the scope of the application. The scope of the present application is to be construed in accordance with the substance defined by the following claims.
It is also noted that the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a good or system that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such good or system. Without further limitation, an element defined by the phrases "comprising one of \8230;" does not exclude the presence of additional like elements in an article or system comprising the element.
It should be understood that the term "and/or" as used herein is merely a relationship that describes an associated object, meaning that three relationships may exist, e.g., a and/or B, may represent: a exists alone, A and B exist simultaneously, and B exists alone. In addition, the character "/" herein generally indicates that the former and latter associated objects are in an "or" relationship.
The foregoing description shows and describes several preferred embodiments of the present application, but as aforementioned, it is to be understood that the application is not limited to the forms disclosed herein, but is not to be construed as excluding other embodiments and is capable of use in various other combinations, modifications, and environments and is capable of changes within the scope of the application as described herein, commensurate with the above teachings, or the skill or knowledge of the relevant art. And that modifications and variations may be effected by those skilled in the art without departing from the spirit and scope of the application, which is to be protected by the claims appended hereto.

Claims (5)

1. A method for preparing a positive active material of a lithium ion battery is characterized by comprising the following steps:
s1, uniformly mixing lithium salt, sodium salt and transition metal oxide according to a preset molar ratio to obtain a mixture;
s2, calcining the mixture to obtain a first positive electrode material with a band-shaped superlattice structure and reversible anion redox activity;
s3, mixing the first positive electrode material, a conductive agent and a binder according to a preset mass fraction to prepare a second positive electrode material;
s4, activating the second positive electrode material to obtain a final positive electrode active material of the lithium ion battery;
the molar ratio of the lithium salt, the sodium salt and the transition metal oxide is (0.1-0.4): (0.5-1): (0.6 to 0.9);
the lithium salt is lithium hydroxide, lithium oxide or lithium carbonate; the sodium salt is sodium hydroxide, sodium oxide or sodium carbonate; the transition metal oxide is manganese dioxide;
the process activated in step S4 includes: performing electrochemical charge and discharge under the action of electrolyte by taking the second positive electrode material as a positive electrode and taking metal lithium as a negative electrode to realize ion exchange, thereby obtaining the lithium ion battery positive electrode active material with reversible anion redox activity;
the current density of electrochemical charging and discharging is 5-20 mA/g, the upper limit of the cut-off voltage is 4.5-4.8V, and the lower limit of the cut-off voltage is 2-3.5V;
by means of electrochemistry, na is realized + Firstly, li is extracted from the anode material + Back embedded with Na + And the crystal lattice framework of the material body is kept unchanged;
the calcination process comprises: firstly calcining for 4-8 h at the temperature of 450-600 ℃, then heating to 750-950 ℃, calcining for 10-18 h, and then cooling.
2. The method for preparing the positive electrode active material of the lithium ion battery according to claim 1, wherein the mass fractions of the first positive electrode material, the conductive agent, and the binder are 70 to 85%, 10 to 20%, and 5 to 15%, respectively.
3. The method for preparing the positive active material of the lithium ion battery according to claim 1, wherein the conductive agent is super carbon black, acetylene black or carbon nanotubes; the binder is polyvinylidene fluoride or polytetrafluoroethylene.
4. The method for preparing the positive active material of the lithium ion battery according to claim 1, wherein the electrolyte comprises the following components: liPF with solute of 0.5-3 mol/L 6 Or LiClO 4 The organic solvent is a mixed solvent of any two or more of ethylene carbonate, propylene carbonate, dimethyl carbonate, diethyl carbonate and ethyl methyl carbonate.
5. A lithium ion battery, characterized in that the battery employs the positive electrode active material for a lithium ion battery prepared by the method of any one of claims 1 to 4 as a positive electrode.
CN202110166932.3A 2021-02-04 2021-02-04 Preparation method and application of positive electrode active material of lithium ion battery Active CN113013401B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202110166932.3A CN113013401B (en) 2021-02-04 2021-02-04 Preparation method and application of positive electrode active material of lithium ion battery

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202110166932.3A CN113013401B (en) 2021-02-04 2021-02-04 Preparation method and application of positive electrode active material of lithium ion battery

Publications (2)

Publication Number Publication Date
CN113013401A CN113013401A (en) 2021-06-22
CN113013401B true CN113013401B (en) 2022-11-04

Family

ID=76384350

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202110166932.3A Active CN113013401B (en) 2021-02-04 2021-02-04 Preparation method and application of positive electrode active material of lithium ion battery

Country Status (1)

Country Link
CN (1) CN113013401B (en)

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN114368736B (en) * 2022-01-28 2023-03-31 中南大学 Preparation method of olivine type sodium iron phosphate cathode material

Family Cites Families (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN103119761B (en) * 2010-09-22 2016-04-13 株式会社杰士汤浅国际 Active material for lithium secondary battery, electrode of lithium secondary cell and lithium secondary battery
US20160351901A1 (en) * 2014-01-31 2016-12-01 Sanyo Electric Co., Ltd. Nonaqueous-electrolyte secondary battery
JP6395051B2 (en) * 2014-09-18 2018-09-26 本田技研工業株式会社 Lithium composite oxide, method for producing lithium composite oxide, positive electrode active material for lithium secondary battery, and lithium secondary battery
CN110010886A (en) * 2019-04-09 2019-07-12 上海卡耐新能源有限公司 A kind of lithium-rich manganese-based anode material, preparation method, anode pole piece and lithium ion secondary battery

Also Published As

Publication number Publication date
CN113013401A (en) 2021-06-22

Similar Documents

Publication Publication Date Title
CN108780884A (en) Prelithiation electrode material and use its battery
Hu et al. Improved cycling performance of CeO2-inlaid Li-rich cathode materials for lithium-ion battery
CN109560265B (en) Coating method for effectively inhibiting oxygen loss of lithium-rich manganese-based positive electrode material
WO2014022986A1 (en) Composite cathode materials with controlled irreversible capacity loss for lithium ion batteries
CN113044891B (en) Preparation method of surface grafting type high-voltage lithium cobaltate, surface grafting type high-voltage lithium cobaltate and application thereof
CN111403729A (en) Sodium ion battery positive electrode material, preparation method thereof and sodium ion battery
CN113690414A (en) Mixed lithium-rich cathode material and preparation method and application thereof
CN111106331A (en) Layered-spinel phase composite positive electrode material and preparation method thereof
ES2954791A2 (en) Positive electrode material precursor, preparation method therefor and application thereof
CN113571679A (en) Spinel oxide coated lithium-rich manganese-based positive electrode material
CN114597532A (en) Method for directly regenerating failed lithium cobaltate positive electrode into high-voltage lithium cobaltate positive electrode and product
Wang et al. Gradient-regeneration of Li (Ni0. 9Co0. 05Mn0. 05) O2 from spent LiCoO2 lithium-ion battery
CN113113586B (en) Positive electrode for lithium ion battery and preparation method and application thereof
Sun et al. Preparation and characterization of lithium-rich ternary cathode materials using novel chelating agent and solvent
CN113013401B (en) Preparation method and application of positive electrode active material of lithium ion battery
Yi et al. Advanced electrochemical performance of LiMn1. 4Cr0. 2Ni0. 4O4 as 5 V cathode material by citric-acid-assisted method
KR101600476B1 (en) Solid electrolyte coated cathode materials for lithium ion battery
Ren et al. Effects of different carbonate precipitators on LiNi1/3Co1/3Mn1/3O2 morphology and electrochemical performance
CN112186166A (en) Molybdenum/cobalt oxide-carbon composite material and preparation method thereof, lithium ion battery negative electrode piece and lithium ion battery
JP2002260722A (en) Lithium secondary battery
KR101542838B1 (en) Manufacturing method of Cathode material for Mg rechargeable batteries, and Cathode material for Mg rechargeable batteries made by the same
CN114864894A (en) High-pressure-resistant coating-layer-modified lithium-rich manganese-based positive electrode material and preparation method and application thereof
KR20160076037A (en) Process for the production of lithium complex oxide and lithium complex oxide made by the same, and lithium ion batteries comprising the same
CN115148970A (en) Olivine NaMPO 4 High-nickel-coated ternary or lithium-rich manganese-based positive electrode material and preparation method thereof
CN113437285B (en) Positive electrode material of potassium ion secondary battery and preparation method and application thereof

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination
GR01 Patent grant
GR01 Patent grant