CN116230908A - Lithium supplementing agent, positive electrode plate, electrochemical device and preparation method of lithium supplementing agent - Google Patents

Lithium supplementing agent, positive electrode plate, electrochemical device and preparation method of lithium supplementing agent Download PDF

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Publication number
CN116230908A
CN116230908A CN202310453479.3A CN202310453479A CN116230908A CN 116230908 A CN116230908 A CN 116230908A CN 202310453479 A CN202310453479 A CN 202310453479A CN 116230908 A CN116230908 A CN 116230908A
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lithium
positive electrode
carbon
supplementing agent
copper oxide
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伍文
齐士博
刘祥哲
郭永兴
易四勇
涂操
张涵
王凯
盛鹏飞
陈建鹏
詹孝军
于晟
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Jiangsu Yaoning New Energy Innovation Technology 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
    • H01M4/362—Composites
    • H01M4/366—Composites as layered products
    • 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
    • H01M10/42—Methods or arrangements for servicing or maintenance of secondary cells or secondary half-cells
    • H01M10/4235—Safety or regulating additives or arrangements in electrodes, separators or electrolyte
    • 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
    • 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
    • H01M4/485—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides of mixed oxides or hydroxides for inserting or intercalating light metals, e.g. LiTi2O4 or LiTi2OxFy
    • 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
    • H01M4/58—Selection of substances as active materials, active masses, active liquids of inorganic compounds other than oxides or hydroxides, e.g. sulfides, selenides, tellurides, halogenides or LiCoFy; of polyanionic structures, e.g. phosphates, silicates or borates
    • H01M4/583—Carbonaceous material, e.g. graphite-intercalation compounds or CFx
    • 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 provides a lithium supplementing agent, a positive electrode plate, an electrochemical device and a preparation method of the lithium supplementing agent, and belongs to the technical field of secondary batteries. Wherein, metal elements are doped in the lithium cuprate; the coating layer is coated on the surface of the lithium copper oxide particles, and the coating layer is made of carbon materials. The lithium supplementing agent, the positive electrode plate, the electrochemical device and the preparation method of the lithium supplementing agent have the advantages of low production cost and good material stability, and the material is insensitive to air humidity, can stably exist in an air environment and is convenient for practical application in battery production and manufacturing.

Description

Lithium supplementing agent, positive electrode plate, electrochemical device and preparation method of lithium supplementing agent
Technical Field
The invention relates to the technical field of secondary batteries, in particular to a lithium supplementing agent, a positive electrode plate, an electrochemical device and a preparation method of the lithium supplementing agent.
Background
In the first cycle charging process of lithium ion batteries, a solid electrolyte interface (SolidElectrolyte Interface, SEI for short) is formed on the surface of the negative electrode, which consumes active lithium in the positive electrode, resulting in irreversible capacity loss of up to 10% for the currently most widely used graphite negative electrodes, and even up to 30% or more for silicon-based and tin-based negative electrodes with high specific capacities, which means Li extracted from the positive electrode material + Part of the lithium is irreversibly consumed, and lithium loss causes a decrease in battery capacity, a decrease in coulombic efficiency, and a deterioration in cycle performance. The irreversible capacity loss of the part can be recovered by using a lithium supplementing method, and the lithium supplementing method can be divided into positive electrode lithium supplementing and negative electrode lithium supplementing. The positive electrode lithium supplement has the advantages of simple process, low cost, high safety, etcAdvantages have received a great deal of attention in recent years.
Currently, conventional positive electrode lithium supplements include, in Li 2 O、Li 2 O 2 、Li 2 S、Li 3 Binary lithium-containing compound represented by N, li 2 NiO 2 、Li 5 FeO 4 、Li 6 CoO 4 Ternary lithium-containing compounds represented by, and Li 2 DHBN、Li 2 C 2 O 4 Is a representative organic lithium-containing compound. Wherein Li is used as 2 NiO 2 And Li (lithium) 5 FeO 4 At most, the two materials Li are applied to actual production and manufacture 2 NiO 2 、Li 5 FeO 4 The environment adaptability is very poor, the water is very easy to absorb and wet in the air environment to deteriorate, and the requirement on the battery manufacturing environment is very high in practical application.
Therefore, there is a need to design a lithium-supplementing agent, a positive electrode sheet, an electrochemical device, and a method for preparing the lithium-supplementing agent, so as to solve the above-mentioned problems.
Disclosure of Invention
In view of the defects in the prior art, the invention provides a lithium supplementing agent, a positive electrode plate, an electrochemical device and a preparation method of the lithium supplementing agent, which can give consideration to both stable material performance and production cost, thereby solving the technical problems that the common positive electrode lithium supplementing agent in the prior art is unstable in material performance, easy to damp and deteriorate in an air environment and has severe requirements on battery manufacturing process environment.
To achieve the above and other related objects, the present invention provides a positive electrode lithium supplementing agent including lithium cuprate and a coating layer.
Wherein, metal elements are doped in the lithium cuprate; the coating layer is coated on the surface of the lithium copper oxide particles, and the coating layer is made of carbon materials.
In one example of the present invention, the lithium cuprate has the chemical formula Li 2 Cu 1-x M x O 2 X is more than or equal to 0.01 and less than or equal to 0.5, wherein M comprises one or more of Fe, ni, mn, co, al, ti, mg, V, cr.
In an example of the present invention, the carbon material is 3% to 6% by mass in the positive electrode lithium supplementing agent; the carbon material comprises one or more of carbon nano tube, graphene, graphite alkyne, carbon fiber, acetylene black, conductive carbon black, soft carbon and hard carbon.
In another aspect, the present invention provides a method for preparing a positive electrode lithium-supplementing agent, the method comprising the steps of: uniformly mixing a lithium source, a copper source and a doped metal source, and performing primary sintering to obtain lithium copper oxide doped with metal elements; and uniformly mixing the lithium copper oxide with a carbon material, and performing secondary sintering to coat the carbon material on the surface of the lithium copper oxide to obtain the positive electrode lithium supplementing agent.
In one example of the invention, the molar ratio of the lithium source to the copper source to the doped metal source is 40 (10-20): 1-10; the mass ratio of the lithium cuprate to the carbon material is (94-97) to (3-6).
In one example of the present invention, the lithium source comprises LiF, li 2 O、LiOH、Li 2 CO 3 、LiNO 3 、Li 2 C 2 O 4 、LiCH 3 At least one of COO. At least one of them.
In an example of the present invention, the doped metal element source is a metal powder, an oxide, a hydroxide, an inorganic salt, or an organic salt containing at least one metal element of Fe, ni, mn, co, al, ti, mg, V, cr.
In an example of the present invention, the temperature of the primary sintering is 500 ℃ to 950 ℃, and the time of the primary sintering is 18 to 24 hours; the secondary sintering temperature is 80-100 ℃, and the secondary sintering time is 18-24 hours.
The invention also provides a positive electrode plate, which comprises a positive electrode current collector and a positive electrode active material layer, wherein the positive electrode active material layer comprises a positive electrode active material and the positive electrode lithium supplementing agent described in any one example, or the positive electrode lithium supplementing agent prepared by the preparation method described in any one example.
The invention also provides an electrochemical device comprising a negative electrode plate, a diaphragm, an electrolyte and the positive electrode plate according to any one of the examples.
According to the lithium supplementing agent, the positive electrode plate, the electrochemical device and the preparation method of the lithium supplementing agent, lithium cuprate is adopted as a positive electrode lithium supplementing agent material, the theoretical gram capacity of the lithium cuprate material is up to 490mAh/g, the first charging platform is 3.0V-3.5V, the discharging platform is lower than 3V, lithium ions can be released on the positive electrode plate before the positive electrode active material when the battery is charged for the first time, so that loss of SEI film formed on the surface of the negative electrode plate is compensated, and the lithium supplementing effect is achieved.
In summary, compared with three types of positive electrode lithium supplementing agents commonly used at present: li (Li) 2 NiO 2 、Li 5 FeO 4 、Li 6 CoO 4 The lithium cuprate is used as a lithium supplementing agent material of the anode, and has the advantages of low production cost and good material stability, and the material is insensitive to air humidity, can stably exist in an air environment, and is convenient for practical application in battery production and manufacturing. Therefore, the invention effectively overcomes some practical problems in the prior art, thereby having high utilization value and use significance.
Drawings
In order to more clearly illustrate the embodiments of the invention or the technical solutions in the prior art, the drawings that are required in the embodiments or the description of the prior art will be briefly described, it being obvious that the drawings in the following description are only some embodiments of the invention, and that other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.
FIG. 1 is a scanning electron microscope test chart of a positive electrode lithium-replenishing material according to an embodiment of the present invention.
FIG. 2 is a scanning electron microscope test chart of the positive electrode lithium-replenishing material according to an embodiment of the present invention.
FIG. 3 is a scanning electron microscope test chart of the positive electrode lithium-replenishing material according to an embodiment of the present invention.
FIG. 4 is a scanning electron microscope test chart of the positive electrode lithium-replenishing material according to an embodiment of the present invention.
FIG. 5 is a scanning electron microscope test chart of the positive electrode lithium-replenishing material according to an embodiment of the present invention.
Fig. 6 is a schematic flow chart of a preparation method of the positive electrode lithium supplementing agent.
Detailed Description
Other advantages and effects of the present invention will become apparent to those skilled in the art from the following disclosure, which describes the embodiments of the present invention with reference to specific examples. The invention may be practiced or carried out in other embodiments that depart from the specific details, and the details of the present description may be modified or varied from the spirit and scope of the present invention. It should be noted that the following embodiments and features in the embodiments may be combined with each other without conflict. It is also to be understood that the terminology used in the examples of the invention is for the purpose of describing particular embodiments only, and is not intended to limit the scope of the invention. The test methods in the following examples, in which specific conditions are not noted, are generally conducted under conventional conditions or under conditions recommended by the respective manufacturers.
It should be understood that the terms such as "upper," "lower," "left," "right," "middle," and "a" and the like are used in this specification for descriptive purposes only and not for purposes of limitation, and that the invention may be practiced without materially departing from the novel teachings and without departing from the scope of the invention.
The invention provides a positive electrode lithium supplementing agent which is used for manufacturing a positive electrode plate of an electrochemical device. Electrochemical devices typically include a positive electrode material, a negative electrode material, an electrolyte, a separator, and corresponding communication aids and circuits. The positive electrode material and the negative electrode material can be used for removing and inserting lithium ions to realize energy storage and release, the electrolyte is a carrier for transmitting lithium ions between the positive electrode and the negative electrode, and the diaphragm can penetrate lithium ions but is not conductive so as to separate the positive electrode from the negative electrode to prevent short circuit.
The positive electrode lithium supplementing agent and the positive electrode material are used for manufacturing a positive electrode active material layer of the positive electrode material in the electrochemical device, and when the electrochemical device is charged for the first time, the positive electrode lithium supplementing agent can release lithium ions before the positive electrode material on the positive electrode plate, so that lithium ions consumed by SEI (solid electrolyte interface) formed on the surface of the negative electrode material during the first charging are compensated, coulomb efficiency loss of the positive electrode and the negative electrode during the first charging is compensated, and the electric energy capacity of the electrochemical device is further effectively maintained.
Referring to fig. 1 to 5, the positive electrode lithium supplementing agent provided by the present invention includes lithium cuprate and a coating layer. In the positive electrode lithium supplementing agent, metal elements are doped in the lithium copper oxide, and the lithium copper oxide exists in a particle form, such as spherical secondary particles formed by aggregation of primary particles; the coating layer is coated on the surface of the lithium copper oxide particles, and the coating layer is made of carbon materials.
Wherein the chemical formula of the lithium cuprate is Li 2 Cu 1-x M x O 2 Wherein x is more than or equal to 0.01 and less than or equal to 0.5, and the M element is a doped metal element in lithium cuprate. The invention provides a carbon-coated lithium copper oxide material (Li 2 Cu 1-x M x O 2 and/C composite material), the theoretical gram capacity is up to 490mAh/g, and the composite material can be mixed with the positive electrode active material to prepare a positive electrode active material layer of a positive electrode plate in an electrochemical device. The first charging platform of the carbon-coated lithium copper oxide material is 3.0V-3.5V, and the discharging platform is lower than 3V, so that lithium ions can be extracted from the positive electrode active material in advance in the positive electrode plate in the first charging of the electrochemical device, so that lithium ions consumed by SEI (solid electrolyte interface) formation on the surface of the negative electrode material can be compensated, and the discharging platform is lower than the positive electrode material, so that the lithium-inserting reaction of the positive electrode material is not participated in the discharging process of the electrochemical device, the lithium-supplementing effect is achieved in the electrochemical device, and the effects of compensating the coulomb efficiency loss of the first circulation of the positive electrode plate and the negative electrode plate and maintaining the capacity of the electrochemical device are achieved.
And the carbon-coated lithium copper oxide material has the advantages of low production cost and good material stability. Since the carbon-coated lithium cuprate material is insensitive to air humidity and can exist stably in an air environment, compared with Li 2 NiO 2 、Li 5 FeO 4 Such as the severe requirements of common lithium supplementing agent materials on the preparation environment, and electrochemical device preparation by using carbon-coated lithium cuprate materialsThe preparation process is simple. And the synthesis cost of the carbon-coated lithium copper oxide material is lower than that of common Li 6 CoO 4 The lithium supplementing agent material has the advantage of cost.
In some embodiments, the M element is selected from any one or more combinations of Fe, ni, mn, co, al, ti, mg, V, cr. That is, the M element may be any one of the above-listed element types, for example Fe, ni, mn, co, al, ti, mg, V or Cr or the like, and the M element may be any two or more of the above-listed element types, for example, the M element is a combination of Fe and V, or a combination of Fe and Ti, or a combination of Ti and Mn, or a combination of Fe and Co, or a combination of Fe, V and Ti, or a combination of Co, ti and Al, or a combination of Co, al, ti and Mg, or a combination of Fe, V, ti, co, or the like, which are not listed herein one by one. In addition, when the M element is a combination of two or more kinds, the proportion of each element in the combination is not limited, and may be mixed in an arbitrary proportion, and the like. In other embodiments, the M element may also be a non-enumerated element species as described above.
In some embodiments, the carbon material used for the cladding layer includes any one or more of carbon nanotubes, graphene, graphite alkyne, carbon fiber, acetylene black, conductive carbon black, soft carbon, hard carbon, or a combination thereof. That is, the carbon material may be any one of the materials listed above, for example, carbon nanotube, graphene, graphite alkyne, carbon fiber, acetylene black, conductive carbon black, soft carbon, hard carbon, or the like; the carbon material may also be any two or more combinations of the above-listed materials, for example, the carbon material is a combination of carbon nanotubes and graphene, or acetylene black and graphene, or a combination of conductive carbon black and graphene, or a combination of carbon fibers and graphene, or a combination of carbon nanotubes and acetylene black, or a combination of conductive carbon black and acetylene black, or a combination of graphene, graphite alkyne, and hard carbon, etc., which are not listed herein one by one. When the carbon material is a combination of two or more materials, the ratio of each material in the combination is not limited, and may be mixed in any ratio, and the like. In other embodiments, the carbon material may also be a material not listed above.
In some embodiments, the carbon material in the positive electrode lithium supplement is 3% to 6% by mass, for example 3%, 4%, 5% or 6%.
Referring to fig. 6, the present invention provides a method for preparing a positive electrode lithium-supplementing agent, comprising the following steps:
s1, uniformly mixing a lithium source, a copper source and a doped metal source, and performing primary sintering to obtain lithium copper oxide doped with metal elements;
and S2, uniformly mixing the lithium copper oxide with a carbon material, and performing secondary sintering to coat the carbon material on the surface of the lithium copper oxide to obtain the positive electrode lithium supplementing agent.
The step S1 specifically comprises the following steps: uniformly mixing a lithium source, a copper source and a doped metal source according to the molar ratio of (10-20) to (1-10), and heating and sintering to synthesize the lithium copper oxide.
For example, respectively putting lithium sources into 100ml deionized water for dissolution according to the molar ratio to prepare solution A; simultaneously placing a copper source and a doped metal source into 100ml deionized water for dissolution to prepare a solution B; after the solution a and the solution B are mixed and stirred uniformly, the mixed solution is heated to 500 ℃ to 950 ℃ in an oven under an oxygen atmosphere, for example, 650 ℃, 750 ℃, 800 ℃, 850 ℃, 900 ℃ or 950 ℃ for 18 to 24 hours at constant temperature for primary sintering, for example, for 18 hours, 21 hours or 24 hours, to obtain lithium cuprate.
The chemical formula of the lithium cuprate is Li 2 Cu 1-x M x O 2 Wherein x is more than or equal to 0.01 and less than or equal to 0.5, M is a doped metal element in lithium cuprate, and M is selected from any one or a plurality of combinations in Fe, ni, mn, co, al, ti, mg, V, cr.
The lithium source employed in step S1 is a lithium ion loaded inorganic/organic metal salt, in some embodiments selected from LiF, li 2 O、LiOH、Li 2 CO 3 、LiNO 3 、Li 2 C 2 O 4 And LiCH 3 COO, and any one or more of COO. Further, is selected from LiOH and Li 2 CO 3 In (a) and (b)One or both, for example LiOH.
The copper source used in step S1 is one or a combination of inorganic/organic metal salts loaded with monovalent or divalent copper ions. In some embodiments, the copper source is selected from CuO, cu 2 O、CuCl、CuCl 2 、CuNO 3 、Cu(NO 3 ) 2 And CuSO 4 、Cu(acac) 2 Any one or more combinations thereof. Further, is selected from CuO and Cu 2 One or both of O, e.g. Cu 2 O。
The doping metal source used in step S1 is a metal powder, oxide, hydroxide, inorganic salt or organic salt containing at least one metal element of Fe, ni, mn, co, al, ti, mg, V, cr. In some embodiments, the dopant metal source may be selected from any one or more of iron oxide, nickel oxide, manganese oxide, cobalt oxide, aluminum oxide, titanium oxide, magnesium oxide, vanadium oxide, and chromium oxide.
In some embodiments, step S2 specifically includes the steps of: mixing the lithium copper oxide obtained in the step S1 with a carbon material according to the mass ratio of (94-97) (3-6), adding the mixture into a ball mill, stirring and mixing at a high speed of 400-500 rpm for 5-10 hours, placing the mixture of the lithium copper oxide and the carbon material into an oven, heating the mixture to 80-100 ℃, for example, 80 ℃, 85 ℃, 90 ℃, 95 ℃ or 100 ℃ in a protective atmosphere, heating the mixture at a constant temperature for 18-24 hours, and performing secondary sintering, for example, heating for 18 hours, 21 hours or 24 hours, so that the carbon material is coated on the surfaces of the lithium copper oxide particles, thereby obtaining the positive electrode lithium supplement agent.
In some embodiments, the carbon material employed in step S2 includes any one or more combinations of carbon nanotubes, graphene, graphite alkyne, carbon fiber, acetylene black, conductive carbon black, soft carbon, hard carbon. That is, the carbon material may be any one of the materials listed above, for example, carbon nanotube, graphene, graphite alkyne, carbon fiber, acetylene black, conductive carbon black, soft carbon, hard carbon, or the like; the carbon material may also be any two or more combinations of the above-listed materials, for example, the carbon material is a combination of carbon nanotubes and graphene, or acetylene black and graphene, or a combination of conductive carbon black and graphene, or a combination of carbon fibers and graphene, or a combination of carbon nanotubes and acetylene black, or a combination of conductive carbon black and acetylene black, or a combination of graphene, graphite alkyne, and hard carbon, etc., which are not listed herein one by one. When the carbon material is a combination of two or more materials, the ratio of each material in the combination is not limited, and may be mixed in any ratio, and the like. In other embodiments, the carbon material may also be a material not listed above.
The invention also provides a positive electrode plate, which comprises a positive electrode current collector and a positive electrode active material layer arranged on the current collector, wherein the positive electrode active material layer comprises a positive electrode active material and the positive electrode lithium supplementing agent according to any one of the above embodiments or the positive electrode lithium supplementing agent prepared by the preparation method according to any one of the above embodiments.
The preparation process of the positive electrode plate comprises the following steps: mixing the positive electrode material, the conductive agent, the binder and the prepared positive electrode lithium supplementing agent according to the mass ratio (88-92) of 3:2 (3-7), adding solvent N-methyl pyrrolidone (NMP), and fully stirring and mixing to obtain positive electrode slurry; and coating the positive electrode slurry on a positive electrode current collector aluminum foil, and performing procedures such as drying, cold pressing, cutting and the like to prepare the positive electrode plate. Wherein, the conductive agent can be selected from the following: at least one of conductive materials such as SP (carbon black), acetylene black, CNT (carbon nano tube), graphene, VGCF, etc., for example, the conductive agent is SP and CNT, and the mass ratio of SP to CNT is 1:0.5; the binder may be selected from: at least one of PVDF, PTFE, and the like. The positive electrode material may be selected from ternary materials conventional in the art, such as LiNi 0.8 Co 0.1 Mn 0.1 O 2 Or LiNi 0.97 Co 0.02 Mn 0.01 O 2 。
The present invention also provides an electrochemical device, which may be a solid lithium ion battery or a liquid lithium ion battery. Taking a liquid lithium ion battery as an example, the electrochemical device comprises a positive electrode plate, a negative electrode plate, a diaphragm and electrolyte, wherein the diaphragm and the electrolyte are arranged between the positive electrode plate and the negative electrode plate, and the positive electrode plate comprises the positive electrode lithium supplementing agent. The positive electrode material and the negative electrode material can be used for removing and inserting lithium ions to realize energy storage and release, the electrolyte is a carrier for transmitting lithium ions between the positive electrode and the negative electrode, the diaphragm can penetrate the lithium ions but is not conductive to separate the positive electrode from the negative electrode so as to prevent short circuit, and the positive electrode lithium supplementing agent can be used for removing and inserting lithium ions before the positive electrode active material in the first charging process of the electrochemical device so as to be used for compensating lithium ions consumed by SEI formed on the surface of the negative electrode material when the negative electrode plate is charged for the first time, thereby playing a role of compensating coulomb efficiency loss of the first cycle of the positive electrode plate and the negative electrode plate and maintaining the capacity of the electrochemical device.
Wherein, the positive plate is prepared by adopting the preparation method disclosed by the invention;
preparing a negative electrode sheet: mixing a negative electrode material such as graphite, a conductive agent SP, a thickener CMC ((sodium carboxymethyl cellulose)) and a binder SBR (styrene butadiene rubber) in a mass ratio of (90 to 99): 1:1.5:2, adding deionized water, and fully stirring and mixing to obtain a negative electrode slurry; uniformly coating the negative electrode slurry on a negative electrode current collector copper foil, and preparing a negative electrode plate through procedures of drying, cold pressing, slitting and the like;
a diaphragm: the PE and PP porous films are made of a diaphragm, and the thickness of the diaphragm is 9 mu m to 18 mu m, such as 9 mu m, 12 mu m, 16 mu m or 18 mu m; the air permeability is 180s/100mL to 380s/100mL, such as 180s/100mL, 280s/100mL or 380s/100mL; the porosity is 30% to 50%, for example 30%, 40% or 50%.
Preparing an electrolyte: EC (ethylene carbonate), EMC (methyl ethyl carbonate), DMC (dimethyl carbonate) and PC (polycarbonate) were mixed in mass ratio (2 to 4): (3 to 5): (2 to 4): (0 to 1) and then dissolving the fully dried lithium salt LiPF6 in the mixed organic solvent to prepare the electrolyte with the concentration of 4 to 24 weight percent. When the mass ratio is (2 to 4): (3 to 5): (2 to 4): 0, it means that the solvent does not contain PC.
Assembling a battery: and laminating the prepared positive pole piece, the diaphragm and the negative pole piece in sequence, so that the diaphragm is positioned between the positive pole piece and the negative pole piece to play a role in isolation. And then coating an aluminum plastic film, drying, injecting the prepared electrolyte, and finally preparing the soft-packaged battery (namely the lithium ion battery) with the capacity of 1Ah through the procedures of packaging, standing, forming and the like.
The technical scheme of the present invention will be described in detail by means of several specific examples and comparative examples, and the raw materials and reagents used in the following examples are commercially available or can be prepared by conventional methods in the art unless otherwise specified.
Example 1
The embodiment provides a secondary lithium ion battery, and the preparation method comprises the following steps:
(1) Preparing a positive electrode plate:
adopts nickel-cobalt-manganese ternary material as positive electrode active material, in particular to LiNi 0.8 Co 0.1 Mn 0.1 O 2 The method comprises the steps of carrying out a first treatment on the surface of the Mixing a positive electrode material, acetylene black, polyvinylidene fluoride and a positive electrode lithium supplementing agent according to a mass ratio of 92:3:2:3, adding a solvent N-methylpyrrolidone (NMP), and fully stirring and mixing to obtain a positive electrode slurry; and coating the positive electrode slurry on a positive electrode current collector aluminum foil, and performing procedures such as drying, cold pressing, cutting and the like to prepare the positive electrode plate.
Wherein the positive electrode lithium supplementing agent adopts Li 2 Cu 0.8 M 0.2 O 2 and/C (lithium copper oxide coated with carbon material), wherein M is Fe.
The preparation process of the positive electrode lithium supplementing agent comprises the following steps:
s1, liOH and Cu 2 O and FeO are mixed according to the mole ratio of Li to Cu to Fe of 10:8:1, specifically, liOH is respectively put into 100ml deionized water for dissolution according to the mole ratio, and solution A is prepared; cu is added with 2 O and FeO are simultaneously put into 100ml of deionized water for dissolution, so as to prepare solution B; mixing and stirring the solution A and the solution B uniformly; then placing the mixed solution in an oven, heating to 750 ℃ in an oxygen atmosphere, heating for 18 hours at constant temperature, and sintering to obtain Li 2 Cu 0.8 Fe 0.2 O 2 ；
S2, li is 2 Cu 0.8 Fe 0.2 O 2 Mixing with carbon nanotube at a mass ratio of 95:5, adding into ball mill, stirring at 500rpm for 5 hr, and mixing at 80deg.CBaking and drying in an oven for 24 hours, performing secondary sintering, crushing and grading to obtain lithium copper oxide/carbon (Li) 2 Cu 0.8 Fe 0.2 O 2 and/C) a composite material.
(2) Preparing a negative electrode plate: mixing graphite and SP, CMC, SBR according to a mass ratio of 97:1:1.5:2, adding deionized water serving as a solvent, and fully stirring and mixing to obtain negative electrode slurry; and uniformly coating the negative electrode slurry on a negative electrode current collector copper foil, and performing procedures such as drying, cold pressing, slitting and the like to prepare the negative electrode plate.
(3) Preparation of electrolyte: EC, EMC, DEC and PC are mixed according to the mass ratio of 3:4:3:1 to obtain an organic solvent, and then the lithium salt LiPF which is fully dried is obtained 6 Dissolving in the mixed organic solvent to prepare the electrolyte with the lithium salt content of 12 wt%.
(4) Preparation of the separator: PE is selected, and the thickness is 15 mu m; the air permeability is 280s/100mL; the porosity was 40%.
(5) Preparation of the battery: and laminating the prepared positive pole piece, the diaphragm and the negative pole piece in sequence, so that the diaphragm is positioned between the positive pole piece and the negative pole piece to play a role in isolation. And then coating an aluminum plastic film, transferring the aluminum plastic film into a vacuum oven, drying at 120 ℃, injecting electrolyte at 3.0g/Ah, sealing, and finally preparing the soft-packaged battery (namely the lithium ion battery) with the capacity of 1Ah after the procedures of standing, hot-cold pressing, formation, clamping, capacity division and the like.
Example 2
Unlike the embodiment 1 in that,
in the preparation of the positive electrode lithium supplementing agent: liOH, cu 2 O and NiO are mixed according to the proportion solution of Li to Cu to Ni element mol ratio of 20:7:3, and heated for 24 hours in the oxygen atmosphere at 800 ℃ to synthesize lithium copper oxide Li 2 Cu 0.7 Ni 0.3 O 2 The method comprises the steps of carrying out a first treatment on the surface of the Lithium cuprate Li 2 Cu 0.7 Ni 0.3 O 2 Mixing with graphene material according to the mass ratio of 94:6, adding into a ball mill, stirring at a high speed of 500rpm for 6 hours, baking and drying in a 90 ℃ oven for 18 hours, crushing and grading to obtain lithium/carbon (Li) cuprate 2 Cu 0.7 Ni 0.3 O 2 and/C) a composite material.
In the preparation of the positive electrode plate: mixing the anode material, acetylene black, polyvinylidene fluoride and an anode lithium supplementing agent according to the mass ratio of 92:3:2:3.
Example 3
Unlike the embodiment 1 in that,
in the preparation of the positive electrode lithium supplementing agent: liOH, cu 2 O and MnO are mixed according to the proportion of the mol ratio of Li to Cu to Mn of 20:8.5:1.5, and heated for 21 hours in the oxygen atmosphere at 650 ℃ to synthesize the lithium copper oxide Li 2 Cu 0.85 Mn 0.15 O 2 The method comprises the steps of carrying out a first treatment on the surface of the Lithium cuprate Li 2 Cu 0.85 Mn 0.15 O 2 Mixing with acetylene black material at a mass ratio of 95:5, adding into a ball mill, stirring at a high speed of 450rpm for 7 hours, baking and drying in a 100 ℃ oven for 21 hours, crushing and grading to obtain lithium/carbon (Li) cuprate 2 Cu 0.85 Mn 0.15 O 2 and/C) a composite material.
In the preparation of the positive electrode plate: mixing the anode material, acetylene black, polyvinylidene fluoride and an anode lithium supplementing agent according to the mass ratio of 89:3:2:6.
Example 4
Unlike the embodiment 1 in that,
in the preparation of the positive electrode lithium supplementing agent: li is mixed with 2 C 2 O 4 、Cu 2 O and CoO are mixed according to the proportion solution of Li to Cu to Co element mol ratio of 20:9:1, and heated for 24 hours in the oxygen atmosphere at 850 ℃ to synthesize lithium copper oxide Li 2 Cu 0.9 Co 0.1 O 2 The method comprises the steps of carrying out a first treatment on the surface of the Lithium cuprate Li 2 Cu 0.9 Mn 0.1 O 2 Mixing with conductive carbon black material according to the mass ratio of 97:3, adding into a ball mill, stirring at a high speed of 500rpm for 4 hours, baking and drying in an oven at 85 ℃ for 24 hours, crushing and grading to obtain lithium/carbon (Li) cuprate 2 Cu 0.9 Co 0.1 O 2 and/C) a composite material.
In the preparation of the positive electrode plate: mixing the anode material, acetylene black, polyvinylidene fluoride and an anode lithium supplementing agent according to the mass ratio of 90:3:2:5.
Example 5
Unlike the embodiment 1 in that,
in the preparation of the positive electrode lithium supplementing agent: liF, cu 2 O and Al 2 O 3 Mixing the solutions according to the molar ratio of Li to Cu to Al of 20:9.5:0.5, and heating for 18 hours in the oxygen atmosphere at 750 ℃ to synthesize the lithium copper lithium carbonate Li 2 Cu 0.95 Al 0.05 O 2 The method comprises the steps of carrying out a first treatment on the surface of the Lithium cuprate Li 2 Cu 0.95 Al 0.05 O 2 Mixing with carbon fiber material according to the mass ratio of 96:4, adding into a ball mill, stirring at 400rpm for mixing at high speed for 6 hours, baking and drying in a 95 ℃ oven for 21 hours, crushing and grading to obtain lithium/carbon (Li) cuprate 2 Cu 0.95 Al 0.05 O 2 and/C) a composite material.
In the preparation of the positive electrode plate: mixing the anode material, acetylene black, polyvinylidene fluoride and an anode lithium supplementing agent according to the mass ratio of 90:3:2:5.
Example 6
Unlike the embodiment 1 in that,
in the preparation of the positive electrode lithium supplementing agent: liNO is to be carried out 3 、Cu 2 O and TiO 2 Mixing the solutions according to the mole ratio of Li to Cu to Ti of 20:7.5:2.5, and heating for 24 hours in the oxygen atmosphere at 900 ℃ to synthesize the lithium copper oxide Li 2 Cu 0.75 Ti 0.25 O 2 The method comprises the steps of carrying out a first treatment on the surface of the Mixing carbon nano tube and graphene in a ratio of 1:1, and then mixing with the prepared lithium copper oxide Li 2 Cu 0.75 Ti 0.25 O 2 Mixing the materials, adding into a ball mill at a ratio of 6:94, stirring at high speed for 7h and at speed of 450rpm, baking and drying in an oven at 80deg.C for 24h, crushing, and grading to obtain lithium/carbon (Li) copper oxide 2 Cu 0.75 Ti 0.25 O 2 and/C) a composite material.
In the preparation of the positive electrode plate: mixing the positive electrode material, acetylene black, polyvinylidene fluoride and a positive electrode lithium supplementing agent according to the mass ratio of 91:3:2:4.
Example 7
Unlike the embodiment 1 in that,
in the preparation of the positive electrode lithium supplementing agent: liCH is subjected to 3 COO 3 、Cu 2 O and VO are as followsMixing the solution according to the mole ratio of Li to Cu to V element of 20:6.5:3.5, heating for 21 hours in the oxygen atmosphere at 600 ℃ to synthesize the lithium copper oxide Li 2 Cu 0.65 V 0.35 O 2 The method comprises the steps of carrying out a first treatment on the surface of the Mixing acetylene black and graphene in a ratio of 2:1, and then mixing with the prepared lithium copper oxide Li 2 Cu 0.65 V 0.35 O 2 Mixing the materials, adding into a ball mill at a ratio of 5.5:94.5, stirring at high speed for 5h and 500rpm, baking and drying in a 90 deg.C oven for 24h, crushing and grading to obtain lithium/carbon (Li) cuprate 2 Cu 0.65 V 0.35 O 2 and/C) a composite material.
In the preparation of the positive electrode plate: mixing the positive electrode material, acetylene black, polyvinylidene fluoride and a positive electrode lithium supplementing agent according to the mass ratio of 91:3:2:4.
Example 8
Unlike the embodiment 1 in that,
in the preparation of the positive electrode lithium supplementing agent: liOH, cu 2 O and MgO are mixed according to the proportion solution of Li to Cu to Mg element mol ratio of 20:7:3, and heated for 18 hours in oxygen atmosphere at 750 ℃ to synthesize lithium copper oxide Li 2 Cu 0.7 Mg 0.3 O 2 The method comprises the steps of carrying out a first treatment on the surface of the Mixing conductive carbon black and graphene in a ratio of 3:1, and then mixing with the prepared lithium copper oxide Li 2 Cu 0.7 Mg 0.3 O 2 Mixing the materials, adding into a ball mill at a ratio of 5:95, stirring at high speed of 400rpm for 6h, baking and drying in a 100 ℃ oven for 21h, crushing and grading to obtain lithium copper oxide/carbon (Li) 2 Cu 0.7 Mg 0.3 O 2 and/C) a composite material.
In the preparation of the positive electrode plate: mixing the anode material, acetylene black, polyvinylidene fluoride and an anode lithium supplementing agent according to a mass ratio of 88:3:2:7.
Example 9
Unlike the embodiment 1 in that,
in the preparation of the positive electrode lithium supplementing agent: liOH, cu 2 O and Cr 2 O 3 Mixing the solutions according to the mole ratio of Li to Cu to Cr of 20:6:4, and heating for 18 hours in an oxygen atmosphere at 800 ℃ to synthesize lithium copper oxide Li 2 Cu 0.6 Cr 0.4 O 2 The method comprises the steps of carrying out a first treatment on the surface of the Carbon is added toMixing the fiber and the graphene in a ratio of 1:1, and then mixing with the prepared lithium copper oxide Li 2 Cu 0.6 Cr 0.4 O 2 Mixing the materials, adding into a ball mill at a ratio of 5:95, stirring at high speed for 8h at a speed of 450rpm, baking and drying in an oven at 95deg.C for 18h, crushing, and grading to obtain lithium/carbon (Li) copper oxide 2 Cu 0.6 Cr 0.4 O 2 and/C) a composite material.
In the preparation of the positive electrode plate: mixing the anode material, acetylene black, polyvinylidene fluoride and an anode lithium supplementing agent according to the mass ratio of 89:3:2:6.
Example 10
Unlike the embodiment 1 in that,
in the preparation of the positive electrode lithium supplementing agent: liOH, cu 2 O, feO and VO are mixed according to the proportion solution of Li to Cu to Fe to V element mol ratio of 20:8:1:1, and heated for 24 hours in the oxygen atmosphere at 800 ℃ to synthesize lithium copper oxide Li 2 Cu 0.8 Fe 0.1 V 0.1 O 2 The method comprises the steps of carrying out a first treatment on the surface of the Carbon nanotubes and prepared lithium copper oxide Li 2 Cu 0.8 Fe 0.1 V 0.1 O 2 Mixing the materials, adding into ball mill at a ratio of 4:96, stirring at high speed for 10 hr at 500rpm, baking at 85deg.C in oven for 18 hr, crushing, and grading to obtain lithium/carbon (Li) copper oxide 2 Cu 0.8 Fe 0.1 V 0.1 O 2 and/C) a composite material.
In the preparation of the positive electrode plate: mixing the anode material, acetylene black, polyvinylidene fluoride and an anode lithium supplementing agent according to the mass ratio of 92:3:2:3.
Example 11
Unlike the embodiment 1 in that,
in the preparation of the positive electrode lithium supplementing agent: liOH, cu 2 O、FeO、VO、TiO 2 Mixing the solution according to the mole ratio of Li to Cu to Fe to V to Ti of 20:7:1:1:1, and heating for 24 hours in the oxygen atmosphere at 850 ℃ to synthesize the lithium copper oxide Li 2 Cu 0.7 Fe 0.1 V 0.1 Ti 0.1 O 2 The method comprises the steps of carrying out a first treatment on the surface of the Graphene and prepared lithium copper oxide Li 2 Cu 0.7 Fe 0.1 V 0.1 Ti 0.1 O 2 Mixing and adding materialsBall mill, mixing at a ratio of 3:97, stirring at high speed for 9h at 400rpm, baking and drying in a 90 deg.C oven for 24h, crushing and grading to obtain lithium/carbon (Li) cuprate 2 Cu 0.7 Fe 0.1 V 0.1 Ti 0.1 O 2 and/C) a composite material.
In the preparation of the positive electrode plate: mixing the anode material, acetylene black, polyvinylidene fluoride and an anode lithium supplementing agent according to the mass ratio of 90:3:2:5.
Example 12
Unlike the embodiment 1 in that,
in the preparation of the positive electrode lithium supplementing agent: li is mixed with 2 CO 3 、Cu 2 O、FeO、VO、TiO 2 Mixing the solution of CoO according to the mole ratio of Li to Cu to Fe to V to Ti to Co of 20:6.5:1:1:1:0.5, and heating for 21 hours in the oxygen atmosphere at 900 ℃ to synthesize lithium copper oxide Li 2 Cu 0.65 Fe 0.1 V 0.1 Ti 0.1 Co 0.05 O 2 ；
Acetylene black and the prepared lithium copper oxide Li 2 Cu 0.65 Fe 0.1 V 0.1 Ti 0.1 Co 0.05 O 2 Mixing the materials, adding into ball mill at a ratio of 6:94, stirring at high speed for 5 hr at speed of 450rpm, baking at 80deg.C in oven for drying for 21 hr, crushing, and grading to obtain lithium copper oxide/carbon (Li) 2 Cu 0.65 Fe 0.1 V 0.1 Ti 0.1 Co 0.05 O 2 and/C) a composite material.
In the preparation of the positive electrode plate: mixing the positive electrode material, acetylene black, polyvinylidene fluoride and a positive electrode lithium supplementing agent according to the mass ratio of 91:3:2:4.
Example 13
Unlike the embodiment 1 in that,
in the preparation of the positive electrode lithium supplementing agent: li is mixed with 2 CO 3 、Cu 2 O、CoO、TiO 2 、Al 2 O 3 Mixing the solutions according to the mole ratio of Li to Cu to Co to Ti to Al of 20:8:1:0.5:0.5, and heating for 21 hours in an oxygen atmosphere at 900 ℃ to synthesize the lithium copper oxide Li 2 Cu 0.8 Co 0.1 Ti 0.05 Al 0.05 O 2 The method comprises the steps of carrying out a first treatment on the surface of the Mixing conductive carbon black with the prepared lithium copper oxide Li 2 Cu 0.8 Co 0.1 Ti 0.05 Al 0.05 O 2 Mixing the materials, adding into a ball mill at a ratio of 5:95, stirring at high speed of 500rpm for 7h, baking at 100deg.C in an oven for 24h, crushing, and grading to obtain lithium/carbon (Li) copper oxide 2 Cu 0.8 Co 0.1 Ti 0.05 Al 0.05 O 2 and/C) a composite material.
In the preparation of the positive electrode plate: mixing the anode material, acetylene black, polyvinylidene fluoride and an anode lithium supplementing agent according to a mass ratio of 88:3:2:7.
Example 14
Unlike the embodiment 1 in that,
in the preparation of the positive electrode lithium supplementing agent: li is mixed with 2 CO 3 、Cu 2 O、TiO 2 、MnO 2 Mixing the solution according to the mole ratio of Li to Cu to Ti to Mn of 20:8.5:0.5:1, and heating for 18 hours in the oxygen atmosphere at 850 ℃ to synthesize the lithium copper oxide Li 2 Cu 0.85 Ti 0.05 Mn 0.1 O 2 The method comprises the steps of carrying out a first treatment on the surface of the Mixing carbon nano tube and acetylene black in a ratio of 1:2, and then mixing with the prepared lithium copper oxide Li 2 Cu 0.85 Ti 0.05 Mn 0.1 O 2 Mixing the materials, adding into a ball mill at a ratio of 3:97, stirring at high speed of 400rpm for 6h, baking and drying in an oven at 95deg.C for 18h, crushing, and grading to obtain lithium/carbon (Li) copper oxide 2 Cu 0.85 Ti 0.05 Mn 0.1 O 2 and/C) a composite material.
In the preparation of the positive electrode plate: mixing the anode material, acetylene black, polyvinylidene fluoride and an anode lithium supplementing agent according to the mass ratio of 90:3:2:5.
Example 15
Unlike the embodiment 1 in that,
in the preparation of the positive electrode lithium supplementing agent: li is mixed with 2 CO 3 、Cu 2 O、FeO、TiO 2 Mixing the solutions according to the mole ratio of Li to Cu to Fe to Ti of 20:6:2:2, and heating for 18 hours in an oxygen atmosphere at 800 ℃ to synthesize the lithium copper oxide Li 2 Cu 0.6 Fe 0.2 Ti 0.2 O 2 The method comprises the steps of carrying out a first treatment on the surface of the Mixing conductive carbon black and acetylene black in a ratio of 1:1, and then mixing with the prepared lithium copper oxide Li 2 Cu 0.6 Fe 0.2 Ti 0.2 O 2 Mixing the materials, adding into ball mill at a ratio of 4:96, stirring at high speed for 8 hr at speed of 450rpm, baking at 80deg.C in oven for 18 hr, crushing, and grading to obtain lithium copper oxide/carbon (Li) 2 Cu 0.6 Fe 0.2 Ti 0.2 O 2 and/C) a composite material.
In the preparation of the positive electrode plate: mixing the anode material, acetylene black, polyvinylidene fluoride and an anode lithium supplementing agent according to the mass ratio of 92:3:2:3.
First effect tests were performed on lithium batteries including the lithium-compensating agents prepared in examples 1 to 15 to verify the improvement of charge and discharge performance of the electrochemical devices by the lithium-compensating agents in the different examples.
The battery was placed in a voltage range of 2.0 to 3.8V and tested for its first charge-discharge gram capacity at 0.3C rate, with test results shown in table 2.
Table 1: examples 1 to 15 preparation of specific surface area of lithium supplement
Figure BDA0004198316020000161
Figure BDA0004198316020000171
Table 1: examples 1 to 15 preparation of first discharge gram Capacity of lithium batteries
Figure BDA0004198316020000172
Figure BDA0004198316020000181
From the test results of the above examples, it can be known that lithium batteries employ Li 2 Cu 1-x M x O 2 the/C composite material isThe positive electrode lithium supplementing agent can ensure that the gram capacity of the battery for the first discharge is 207-223 mAh/g. Compared with the method adopting a positive electrode lithium supplementing agent Li 2 NiO 2 160mAh/g of initial discharge gram capacity of battery and positive electrode lithium supplementing agent Li 5 FeO 4 When the battery discharges 180mAh/g of gram capacity for the first time, the lithium copper acid/carbon composite material of the positive electrode lithium supplementing agent has better material stability and higher discharge gram capacity, and the service life of the battery can be effectively prolonged.
The above embodiments are merely illustrative of the principles of the present invention and its effectiveness, and are not intended to limit the invention. Modifications and variations may be made to the above-described embodiments by those skilled in the art without departing from the spirit and scope of the invention. Accordingly, it is intended that all equivalent modifications and variations of the invention be covered by the claims, which are within the ordinary skill of the art, be within the spirit and scope of the present disclosure.

Claims (10)

1. A positive electrode lithium supplementing agent, characterized by comprising:
a lithium copper oxide doped with a metal element;
and the coating layer is coated on the surface of the lithium copper oxide particles, and the coating layer is made of carbon material.
2. The positive electrode lithium-supplementing agent according to claim 1, wherein the chemical formula of the lithium cuprate is Li 2 Cu 1-x M x O 2 X is more than or equal to 0.01 and less than or equal to 0.5, wherein M comprises one or more of Fe, ni, mn, co, al, ti, mg, V, cr.
3. The positive electrode lithium-supplementing agent according to claim 1, wherein a mass percentage of the carbon material in the positive electrode lithium-supplementing agent is 3% to 6%;
and/or the number of the groups of groups,
the carbon material comprises one or more of carbon nano tube, graphene, graphite alkyne, carbon fiber, acetylene black, conductive carbon black, soft carbon and hard carbon.
4. A method of producing the positive electrode lithium-compensating agent according to any one of claims 1 to 3, comprising:
uniformly mixing a lithium source, a copper source and a doped metal source, and performing primary sintering to obtain lithium copper oxide doped with metal elements;
and uniformly mixing the lithium copper oxide with a carbon material, and performing secondary sintering to coat the carbon material on the surface of the lithium copper oxide to obtain the positive electrode lithium supplementing agent.
5. The method for preparing the positive electrode lithium supplementing agent according to claim 4, wherein the molar ratio of the lithium source to the copper source to the doped metal source is 40 (10-20): 1-10;
and/or the number of the groups of groups,
the mass ratio of the lithium cuprate to the carbon material is (94-97) to (3-6).
6. The method for producing a positive electrode lithium-compensating agent according to claim 4, wherein the lithium source comprises LiF, li 2 O、LiOH、Li 2 CO 3 、LiNO 3 、Li 2 C 2 O 4 、LiCH 3 At least one of COO.
7. The method according to claim 4, wherein the source of the doped metal element is a metal powder, an oxide, a hydroxide, an inorganic salt, or an organic salt containing at least one metal element of Fe, ni, mn, co, al, ti, mg, V, cr.
8. The method for producing a positive electrode lithium-compensating agent according to claim 4, wherein the temperature of the primary sintering is 500 ℃ to 950 ℃, and the time of the primary sintering is 18 to 24 hours; the secondary sintering temperature is 80-100 ℃, and the secondary sintering time is 18-24 hours.
9. A positive electrode sheet, characterized by comprising: a positive electrode current collector and a positive electrode active material layer comprising a positive electrode active material and the positive electrode lithium-supplementing agent according to any one of claims 1 to 3 or the positive electrode lithium-supplementing agent prepared by the preparation method according to any one of claims 4 to 8.
10. An electrochemical device comprising a negative electrode sheet, a separator, an electrolyte, and the positive electrode sheet of claim 9.
CN202310453479.3A 2023-04-24 2023-04-24 Lithium supplementing agent, positive electrode plate, electrochemical device and preparation method of lithium supplementing agent Pending CN116230908A (en)

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Publication number Priority date Publication date Assignee Title
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* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
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