CN110048081B - All-solid-state lithium secondary battery positive electrode composite material and preparation method thereof - Google Patents

All-solid-state lithium secondary battery positive electrode composite material and preparation method thereof Download PDF

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CN110048081B
CN110048081B CN201910295271.7A CN201910295271A CN110048081B CN 110048081 B CN110048081 B CN 110048081B CN 201910295271 A CN201910295271 A CN 201910295271A CN 110048081 B CN110048081 B CN 110048081B
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lithium
secondary battery
polymer
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CN110048081A (en
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胡宏玖
陶波
贺耀龙
朱作权
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University of Shanghai for Science and Technology
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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
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/05—Accumulators with non-aqueous electrolyte
    • H01M10/052—Li-accumulators
    • H01M10/0525—Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/13—Electrodes for accumulators with non-aqueous electrolyte, e.g. for lithium-accumulators; Processes of manufacture thereof
    • H01M4/139—Processes of 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
    • H01M4/36—Selection of substances as active materials, active masses, active liquids
    • 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
    • H01M4/621—Binders
    • H01M4/622—Binders being polymers
    • 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
    • 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
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    • Y02E60/10—Energy storage using batteries

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Abstract

The invention discloses an all-solid-state lithium secondary battery anode composite material and a preparation method thereof, and the all-solid-state lithium secondary battery anode composite material comprises an anode composite material and is characterized in that the anode composite material is formed by combining electrode active particles, a polar polymer, lithium salt and a conductive additive, wherein the raw material components are as follows according to the dry mass percentage: 5.0-10.0 wt% of polar polymer; 2.0-6.0 wt% of lithium salt; 3.0-9.0 wt% of conductive additive; 75.0-90.0 wt% of active particles. The polymer adhesive in the anode composite material prepared by the method is distributed more uniformly, and the electrode has higher bonding mechanical property and good normal-temperature electrochemical performance.

Description

All-solid-state lithium secondary battery positive electrode composite material and preparation method thereof
Technical Field
The invention relates to the technical field of new energy materials and forming processes, in particular to an all-solid-state lithium secondary battery positive electrode composite material and a preparation method thereof.
Background
Because of the advantages of low self-discharge rate, no memory effect, good cycle life, higher energy density and operating voltage, and the like, the application fields of lithium ion batteries have been extended from consumer electronics, pure Electric Vehicles (EV) and hybrid electric vehicles to energy conversion and storage systems of aviation and aerospace equipment. In particular, the development of EVs has been identified as one of the national strategies to address energy crisis, environmental pollution, and climate change. However, the endurance mileage, cycle performance and use cost of the most advanced EV at present still cannot be compared with those of fuel vehicles, and one of the main reasons is that the battery system contains a large amount of volatile and leaky carbonate organic solvent, so that the battery system cannot be matched with a high-energy-density negative electrode material, and has potential safety risks of fire, explosion and the like, especially severe under abuse conditions of thermal shock, over-discharge, short circuit and the like. Therefore, the research and development of the solid electrolyte which has no leakage, low flammability, good compatibility with electrode materials and excellent thermal stability and mechanical property to replace the electrolyte or gel polymer electrolyte is a first choice for realizing the leap of the specific capacity, service life and safety performance of the secondary battery of the new generation. Solid electrolyte materials are classified into two categories, inorganic and polymer, in which although inorganic solid electrolytes have high ionic conductivity, occurrence of side reactions can be effectively suppressed during charge and discharge, but interface resistance is large and electrochemical window is narrow when they are in contact with an electrode active material. The polymer electrolyte (SPE) has excellent processing performance, good flexibility and wide electrochemical window, thereby presenting wider application prospect.
Since SPE has low room temperature ionic conductivity, and an electrode material composed of active particles, a conductive agent and a polymer binder lacks the wetting of an electrolyte in the service environment of an all-solid-state battery, and the diffusion and transportation rates of ions are low, the electrochemical performance of a polymer electrolyte all-solid-state lithium secondary battery has not been able to meet the commercial requirement so far.
Disclosure of Invention
The invention aims to solve the defects in the prior art and provides a positive electrode composite material of an all-solid-state lithium secondary battery and a preparation method thereof.
In order to achieve the purpose, the invention adopts the following technical scheme:
the positive composite material of the all-solid-state lithium secondary battery comprises a positive composite material and is characterized in that the positive composite material is formed by combining electrode active particles, a polar polymer, lithium salt and a conductive additive, wherein the raw material components are as follows according to the dry mass percentage:
Figure GDA0002855518730000021
preferably, the polar polymer is any one polymer or a mixture of any several polymers of polyvinyl alcohol, waterborne polyurethane, polyvinylpyrrolidone, polyacrylic acid and sodium alginate.
Preferably, the lithium salt is any one or a mixture of any several of lithium perchlorate, lithium tetrafluoroborate, lithium hexafluorophosphate and lithium trifluoromethanesulfonate.
Preferably, the conductive auxiliary agent is any one of conductive carbon black and acetylene black or a mixture thereof.
Preferably, the lithium salt is dispersed in the polar polymer to form a complex, the complex serves as a bonding matrix, and the bonding matrix, the active particles and the conductive auxiliary agent form the all-solid-state battery positive electrode composite material.
A preparation method of a positive electrode composite material of an all-solid-state lithium secondary battery comprises the following steps:
a. adding the polar polymer and the solvent into a reaction kettle according to the mass ratio of (2-5) to 100, and mechanically stirring for 1-5 hours at the temperature of 40-90 ℃ to fully dissolve the polymer;
b. cooling to 40 ℃, slowly adding lithium salt into the polymer solution prepared in the step a, and mechanically stirring for 1-3 hours to uniformly dissolve the lithium salt in the polymer solution;
c. gradually adding a conductive aid into the polymer electrolyte solution prepared in the step b, and mixing for 2-3 hours under the combined action of ultrasonic waves and mechanical stirring to uniformly disperse the conductive aid;
d. adding electrode active particles into the mixed solution prepared in the step c, and mechanically stirring for 1-2 hours to disperse the active particles into the mixed solution to obtain electrode composite material slurry;
e. and d, coating the slurry prepared in the step d on a metal current collector with the thickness of 10-50 microns, evaporating the solvent in the hot air at the temperature of 40-80 ℃, gradually reducing the thickness of the coating, linearly decreasing the evaporation rate of the solvent in the slurry along with the change of time by controlling the flow of drying gas until the thickness of the coating is stable, continuously drying at a constant rate, and completely removing residual solvent in the electrode slurry to obtain the anode composite material with the thickness of 10-50 microns.
Compared with the prior art, the invention has the beneficial effects that:
1. the prepared electrode composite material bonding matrix is polymer electrolyte, and lithium ions contained in the electrode composite material bonding matrix are beneficial to improving the reaction rate of lithium intercalation and lithium deintercalation of electrode particles in the charging and discharging processes, so that the rate capability of the all-solid-state battery is better improved.
2. In order to increase the production efficiency of the electrode, a common solution is to increase the drying rate of the electrode coating and shorten the forming time, but this leads to an increased capillary effect during the evaporation of the solvent, so that the polymer binder is unevenly distributed in the electrode material, particularly in a lower amount near the current collector side, resulting in delamination failure of the electrode active material from the substrate. Based on the dynamic characteristics of the evaporation process of the solvent in the composite material during electrode forming and the law of the influence of the dynamic characteristics on the mechanical property of the electrode coating, the invention adopts a two-stage forming method which is characterized in that the drying rate is linearly decreased to the constant thickness of the coating and then the residual solvent is removed according to a higher constant speed. The polymer adhesive is uniformly distributed in the electrode composite material, and the electrochemical cycle performance of the battery and the stability of a pole piece structure are improved.
3. The proper amount of lithium salt has a typical plasticizing effect on the polymer, and can reduce the elastic modulus of the composite material, thereby obviously reducing the stress level of the active particles and a bonding system and further enhancing the charge and discharge life of a battery system.
4. Compared with the existing preparation method of the lithium secondary battery electrode, the method of the invention not only has more excellent product performance, but also has lower energy consumption.
Drawings
FIG. 1 is a diagram showing the distribution of the binder content by mass in the positive electrode material of all-solid batteries according to examples of the present invention and comparative examples;
fig. 2 is a table comparing the main physical and mechanical properties of the positive electrode composite materials prepared in the examples of the present invention and the comparative examples.
Detailed Description
The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments.
In the description of the present invention, it is to be understood that the terms "upper", "lower", "front", "rear", "left", "right", "top", "bottom", "inner", "outer", and the like, indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, are merely for convenience in describing the present invention and simplifying the description, and do not indicate or imply that the device or element being referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus, should not be construed as limiting the present invention.
Referring to fig. 1-2, an all-solid-state lithium secondary battery positive electrode composite material comprises a positive electrode composite material, wherein the positive electrode composite material is formed by combining electrode active particles, a polar polymer, lithium salt and a conductive additive, and the raw material components are as follows according to the dry mass percentage ratio of the components:
Figure GDA0002855518730000051
the polar polymer is preferably any one polymer or a mixture of any several polymers of polyvinyl alcohol, waterborne polyurethane, polyvinylpyrrolidone, polyacrylic acid and sodium alginate.
The lithium salt is preferably any one or a mixture of any more of lithium perchlorate, lithium tetrafluoroborate, lithium hexafluorophosphate and lithium trifluoromethanesulfonate.
The conductive auxiliary agent is preferably any one of conductive carbon black and acetylene black or a mixture thereof.
The lithium salt is dispersed in the polar polymer to form a complex, the complex is used as a bonding matrix, and the bonding matrix, the active particles and the conductive auxiliary agent form the all-solid-state battery positive electrode composite material.
A preparation method of a positive electrode composite material of an all-solid-state lithium secondary battery comprises the following steps:
a. adding the polar polymer and the solvent into a reaction kettle according to the mass ratio of (2-5) to 100, and mechanically stirring for 1-5 hours at the temperature of 40-90 ℃ to fully dissolve the polymer;
b. cooling to 40 ℃, slowly adding lithium salt into the polymer solution prepared in the step a, and mechanically stirring for 1-3 hours to uniformly dissolve the lithium salt in the polymer solution;
c. gradually adding a conductive aid into the polymer electrolyte solution prepared in the step b, and mixing for 2-3 hours under the combined action of ultrasonic waves and mechanical stirring to uniformly disperse the conductive aid;
d. adding electrode active particles into the mixed solution prepared in the step c, and mechanically stirring for 1-2 hours to disperse the active particles into the mixed solution to obtain electrode composite material slurry;
e. and d, coating the slurry prepared in the step d on a metal current collector with the thickness of 10-50 microns, evaporating the solvent in the hot air at the temperature of 40-80 ℃, gradually reducing the thickness of the coating, linearly decreasing the evaporation rate of the solvent in the slurry along with the change of time by controlling the flow of the drying gas until the thickness of the coating is stable, continuously drying at a constant rate, and completely removing the residual solvent in the electrode slurry to obtain the anode composite material with the thickness of 10-50 microns.
Example one
In this embodiment, a preparation method of an all-solid-state lithium secondary battery cathode composite material is based on a solution mixing and coating method, and adopts raw material components of sodium alginate, lithium perchlorate, Super-P conductive carbon black and lithium iron phosphate according to a proportion of 8:2:5:85 in parts by dry mass, and includes the following steps:
a. adding sodium alginate and deionized water into a reaction kettle according to the mass ratio of 2:100, slowly heating to 70 ℃ at the heating speed of 10 ℃/min, and mechanically stirring for 1.5 hours to obtain a uniformly distributed sodium alginate solution;
b. cooling to 40 ℃, slowly adding lithium perchlorate into the sodium alginate solution prepared in the step a, and mechanically stirring for 2.0 hours to uniformly dissolve the lithium perchlorate into the sodium alginate glue solution;
c. gradually adding Super-P conductive carbon black into the sodium alginate-lithium perchlorate electrolyte solution prepared in the step b, and mixing for 3.0 hours under the combined action of ultrasonic waves and mechanical stirring to uniformly disperse the Super-P conductive carbon black;
d. adding lithium iron phosphate active particles into the mixed solution prepared in the step c, mechanically stirring for 2.0 hours to disperse the lithium iron phosphate active particles into the mixed solution to obtain electrode composite material slurry;
e. and d, coating the slurry prepared in the step d on an aluminum foil current collector with the thickness of 10 microns, and evaporating the solvent in hot air at the temperature of 50 ℃ to gradually reduce the thickness of the coating. Controlling the flow of the drying gas to volatilize water in the electrode slurry in a linear decreasing mode with the initial speed of 0.1 mu m/s until the thickness of the coating is stable (10 microns); thereafter, the drying was continued with a constant evaporation rate of 0.15 μm/s. And after the residual solvent in the electrode slurry is completely removed, obtaining the lithium iron phosphate anode composite material with the coating thickness of 10 microns.
Example two
This embodiment is substantially the same as the first embodiment, and is characterized in that:
in this embodiment, a preparation method of an all-solid-state secondary battery composite positive electrode is based on a solution mixing and coating method, and adopts raw material components of polyvinyl alcohol, lithium perchlorate, acetylene black and lithium iron phosphate according to a proportion of 7:2:3:88 in parts by dry mass, and includes the following steps:
a. adding polyvinyl alcohol and deionized water into a reaction kettle according to the mass ratio of 3:100, slowly heating to 85 ℃ at the heating speed of 10 ℃/min, and mechanically stirring for 2.0 hours to obtain uniformly distributed polyvinyl alcohol solution;
b. cooling to 40 ℃, slowly adding lithium perchlorate into the polyvinyl alcohol solution prepared in the step a, and mechanically stirring for 2.0 hours to uniformly dissolve the lithium perchlorate into the polyvinyl alcohol glue solution;
c. gradually adding acetylene black into the polyvinyl alcohol-lithium perchlorate electrolyte solution prepared in the step b, and mixing for 2.0 hours under the combined action of ultrasonic waves and mechanical stirring to uniformly disperse the acetylene black;
d. adding lithium iron phosphate active particles into the mixed solution prepared in the step c, mechanically stirring for 2.0 hours to disperse the lithium iron phosphate active particles into the mixed solution to obtain electrode composite material slurry;
e. and d, coating the slurry prepared in the step d on an aluminum foil current collector with the thickness of 15 microns, and evaporating the solvent in hot air at the temperature of 55 ℃ to gradually reduce the thickness of the coating. Controlling the flow of the drying gas to volatilize water in the electrode slurry in a linear decreasing mode with the initial speed of 0.15 mu m/s until the thickness of the coating is stable (15 microns); thereafter, drying was continued with a constant evaporation rate of 0.25 μm/s. And after the residual solvent in the electrode slurry is completely removed, obtaining the lithium iron phosphate anode composite material with the coating thickness of 15 microns.
Comparative example one:
in the comparative example, the preparation method of the all-solid-state lithium secondary battery anode composite material is based on a solution mixing and coating method, adopts the raw material components of sodium alginate, Super-P conductive carbon black and lithium iron phosphate according to the proportion of the components in parts by dry mass of 8:7:85, and comprises the following steps:
a. adding sodium alginate and deionized water into a reaction kettle according to the mass ratio of 2:100, slowly heating to 70 ℃ at the heating speed of 10 ℃/min, and mechanically stirring for 1.5 hours to obtain a uniformly distributed sodium alginate solution;
b. cooling to 40 ℃, gradually adding Super-P conductive carbon black into the sodium alginate solution prepared in the step a, and mixing for 2.0 hours under the combined action of ultrasonic waves and mechanical stirring to uniformly disperse the Super-P conductive carbon black;
c. adding lithium iron phosphate active particles into the mixed solution prepared in the step c, mechanically stirring for 2.0 hours to disperse the lithium iron phosphate active particles into the mixed solution to obtain electrode composite material slurry;
d. and c, coating the slurry prepared in the step c on an aluminum foil current collector with the thickness of 10 microns, and evaporating the solvent in hot air at the temperature of 50 ℃ to gradually reduce the thickness of the coating. Controlling the flow of the drying gas to volatilize water in the electrode slurry in a linear decreasing mode with the initial speed of 0.1 mu m/s until the thickness of the coating is stable (10 microns); thereafter, the drying was continued with a constant evaporation rate of 0.15 μm/s. And after the residual solvent in the electrode slurry is completely removed, obtaining the lithium iron phosphate anode composite material with the coating thickness of 10 microns.
Comparative example two:
in this embodiment, a preparation method of an all-solid-state lithium secondary battery cathode composite material is based on a solution mixing and coating method, and adopts raw material components of sodium alginate, lithium perchlorate, Super-P conductive carbon black and lithium iron phosphate according to a proportion of 8:2:5:85 in parts by dry mass, and includes the following steps:
a. adding sodium alginate and deionized water into a reaction kettle according to the mass ratio of 2:100, slowly heating to 70 ℃ at the heating speed of 10 ℃/min, and mechanically stirring for 1.5 hours to obtain a uniformly distributed sodium alginate solution;
b. cooling to 40 ℃, slowly adding lithium perchlorate into the sodium alginate solution prepared in the step a, and mechanically stirring for 2.0 hours to uniformly dissolve the lithium perchlorate into the sodium alginate glue solution;
c. gradually adding Super-P conductive carbon black into the sodium alginate-lithium perchlorate electrolyte solution prepared in the step b, and mixing for 3.0 hours under the combined action of ultrasonic waves and mechanical stirring to uniformly disperse the Super-P conductive carbon black;
d. adding lithium iron phosphate active particles into the mixed solution prepared in the step c, mechanically stirring for 2.0 hours to disperse the lithium iron phosphate active particles into the mixed solution to obtain electrode composite material slurry;
e. and d, coating the slurry prepared in the step d on an aluminum foil current collector with the thickness of 15 microns, and then carrying out a three-section drying and forming process. Firstly drying for 30 minutes at 50 ℃ to carry out primary section drying treatment; then drying at 110 ℃ for 20 minutes for intermediate stage drying treatment; and then carrying out vacuum drying for 40 minutes at 30 ℃ for final stage drying treatment to obtain the lithium iron phosphate anode composite material with the coating thickness of 15 micrometers.
Experimental test analysis:
the all-solid-state secondary battery anode based on the polymer electrolyte bonding system prepared in the embodiment is subjected to relevant experimental detection. Wherein the variation of the mass content of the polymer binder along the thickness direction of the coating in the electrode composite material obtained according to an energy spectrometer is shown in fig. 1. The adhesion strength and electrochemical performance of the positive electrode material were compared by a peel test and an electrochemical charge/discharge test, respectively, and the results are shown in fig. 2.
The adhesion strength of the electrode sheet after electrolyte modification (example one) was also at least 10% higher than that of the composite before modification (comparative example one) under the same adhesive and curing conditions. It can be readily seen from fig. 1 that the polymer binder in the electrode materials according to the invention (example one, example two and comparative example one) obtained by the "two-stage" shaping process with a linear decrease in drying rate to a constant thickness of the coating, followed by a higher constant rate of removal of residual solvent, is distributed more uniformly along the coating. The composite material obtained by the three-stage drying method (comparative example) shows a typical gradient effect, which leads to significant degradation of the adhesive property, especially the peel strength of the interface with the current collector is reduced by nearly 40%, thus leading to rapid degradation of the normal-temperature electrochemical cycle performance of the all-solid battery (see fig. 2).
As can be seen from fig. 2, the specific capacity of the positive electrode composite material (example one, example two and comparative example two) prepared based on the polymer electrolyte bonding system of the present invention at normal temperature is significantly better than that of the electrode modified without the electrolyte (comparative example one).
The above description is only for the preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art should be considered to be within the technical scope of the present invention, and the technical solutions and the inventive concepts thereof according to the present invention should be equivalent or changed within the scope of the present invention.

Claims (5)

1. The positive composite material of the all-solid-state lithium secondary battery comprises a positive composite material and is characterized in that the positive composite material is formed by combining electrode active particles, a polar polymer, lithium salt and a conductive additive, and the raw material components are as follows according to the dry mass percentage of the components:
Figure FDA0002855518720000011
the preparation method of the positive electrode composite material comprises the following steps:
a. adding the polar polymer and the solvent into a reaction kettle according to the mass ratio of (2-5) to 100, and mechanically stirring for 1-5 hours at the temperature of 40-90 ℃ to fully dissolve the polymer;
b. cooling to 40 ℃, slowly adding lithium salt into the polymer solution prepared in the step a, and mechanically stirring for 1-3 hours to uniformly dissolve the lithium salt in the polymer solution;
c. gradually adding a conductive aid into the polymer electrolyte solution prepared in the step b, and mixing for 2-3 hours under the combined action of ultrasonic waves and mechanical stirring to uniformly disperse the conductive aid;
d. adding electrode active particles into the mixed solution prepared in the step c, and mechanically stirring for 1-2 hours to disperse the active particles into the mixed solution to obtain electrode composite material slurry;
e. and d, coating the slurry prepared in the step d on a metal current collector with the thickness of 10-50 microns, evaporating the solvent in the hot air at the temperature of 40-80 ℃, gradually reducing the thickness of the coating, linearly decreasing the evaporation rate of the solvent in the slurry along with the change of time by controlling the flow of drying gas until the thickness of the coating is stable, continuously drying at a constant rate, and completely removing residual solvent in the electrode slurry to obtain the anode composite material with the thickness of 10-50 microns.
2. The positive electrode composite material for an all-solid-state lithium secondary battery according to claim 1, characterized in that: the polar polymer is any one polymer or a mixture of any several polymers of polyvinyl alcohol, waterborne polyurethane, polyvinylpyrrolidone, polyacrylic acid and sodium alginate.
3. The positive electrode composite material for an all-solid-state lithium secondary battery according to claim 1, characterized in that: the lithium salt is any one or a mixture of any more of lithium perchlorate, lithium tetrafluoroborate, lithium hexafluorophosphate and lithium trifluoromethanesulfonate.
4. The positive electrode composite material for an all-solid-state lithium secondary battery according to claim 1, characterized in that: the conductive auxiliary agent adopts any one or a mixture of conductive carbon black and acetylene black.
5. The positive electrode composite material for an all-solid-state lithium secondary battery according to claim 1, characterized in that: the lithium salt is dispersed in the polar polymer to form a complex, the complex is used as an adhesive matrix, and the adhesive matrix, the active particles and the conductive auxiliary agent form the all-solid-state battery positive electrode composite material.
CN201910295271.7A 2019-04-12 2019-04-12 All-solid-state lithium secondary battery positive electrode composite material and preparation method thereof Active CN110048081B (en)

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