CN115036449A - Preparation method of dry-method composite electrode, dry-method composite electrode and battery - Google Patents

Preparation method of dry-method composite electrode, dry-method composite electrode and battery Download PDF

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CN115036449A
CN115036449A CN202210964814.1A CN202210964814A CN115036449A CN 115036449 A CN115036449 A CN 115036449A CN 202210964814 A CN202210964814 A CN 202210964814A CN 115036449 A CN115036449 A CN 115036449A
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dry
electrode
electrode active
substrate
carbon
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何姿颖
魏飞
张晨曦
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Tsinghua University
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Tsinghua University
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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
    • H01M4/04—Processes of manufacture in general
    • H01M4/0402—Methods of deposition of the material
    • H01M4/0404—Methods of deposition of the material by coating on electrode collectors
    • 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
    • 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
    • H01M4/62—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

Abstract

The invention provides a preparation method of a dry-method composite electrode, the dry-method composite electrode and a battery, wherein the preparation method of the dry-method composite electrode comprises the following steps: placing the carbon nano material and the electrode active substance in a crushing chamber together, introducing compressed gas into the crushing chamber, and carrying out airflow crushing treatment on the carbon nano material and the electrode active substance to respectively form carbon nano powder and electrode active powder; the crushing chamber is provided with a latticed substrate, the substrate is arranged on a flow path of gas, and the carbon nano powder and the electrode active powder are driven to be attached to the substrate by the gas. The preparation method of the dry-method composite electrode can prepare the dry-method composite electrode with stable structure and no falling of active substances, and has the advantages of convenient overall preparation process and wider application range.

Description

Preparation method of dry-method composite electrode, dry-method composite electrode and battery
Technical Field
The invention relates to the technical field of batteries, in particular to a preparation method of a dry-method composite electrode, the dry-method composite electrode and a battery.
Background
Electric energy plays a very important role in the daily production and life of human beings. Many portable electronic devices, electric automobiles, and the like require secondary batteries as power sources. With the rapid development of portable electronic devices and electric vehicles, secondary batteries have also received much attention. Among them, the lithium ion battery has the advantages of higher working voltage, no memory effect, small self-discharge, long cycle life, and the like, and thus becomes a secondary battery mainly applied at present.
In the case of a lithium ion battery, the electrodes therein include a current collector and an active material. The conductivity of the active material itself is generally poor, and therefore it is generally necessary to introduce a conductive agent to improve the charge and discharge performance of the active material. And the adhesion between the active material and the conductive agent is poor, and thus it is further necessary to fix both to the surface of the current collector by an adhesive. However, the use of the binder is accompanied by the use of a liquid solvent, which brings about additional material costs, and on the other hand, the use of an organic solvent also pollutes the environment and damages the human body, and on the other hand, the use of the organic solvent also hinders the contact between the active material of the electrode and the conductive agent.
Although there are some methods for preparing an integrated electrode in the conventional art to avoid the use of a binder, these methods usually employ in-situ growth to prepare an electrode active material or a conductive agent on the electrode, and such methods are complicated and have limited applicability, which is not suitable for large-scale industrial application.
Disclosure of Invention
In this respect, the invention is based on the primary object of providing a dry composite electrode which is easy to produce, while being as free as possible from the use of binders.
According to some embodiments of the present disclosure, there is provided a method of preparing a dry-process composite electrode, including the steps of:
placing a carbon nano material and an electrode active substance into a crushing chamber together, introducing compressed gas into the crushing chamber, and carrying out airflow crushing treatment on the carbon nano material and the electrode active substance to form carbon nano powder and electrode active powder;
and the crushing chamber is also internally provided with a latticed substrate, the substrate is arranged on the flow path of the gas, and the carbon nano powder and the electrode active powder are driven by the gas to be attached to the substrate.
In one embodiment, the carbon nanomaterial comprises an array of carbon nanotubes.
In one embodiment, the pressure of the gas introduced into the crushing chamber is controlled to be 0.4-1 MPa.
In one embodiment, a filter is arranged in the crushing chamber and is positioned at the air outlet of the crushing chamber, and the base cover is arranged on the surface of the filter.
In one embodiment, the aperture of the mesh on the substrate is 10-100 μm.
In one embodiment, in the step of placing the carbon nanomaterial and the electrode active substance together in the pulverization chamber, the mass ratio of the carbon nanomaterial in the total of the carbon nanomaterial and the electrode active substance is controlled to be 5% -50%.
In one embodiment, after the carbon nanomaterial and the electrode active substance are attached to the substrate, the method further comprises the step of pressing the carbon nanomaterial and the electrode active substance into a film on the substrate.
In one embodiment, in the step of compressing the carbon nanomaterial and the electrode active substance into a film on the substrate, the thickness of the compressed film is controlled to be less than or equal to 3 mm.
According to still other embodiments of the present disclosure, there is also provided a dry method composite electrode, which includes a carbon nanomaterial, an electrode active substance, and a grid-shaped substrate, wherein the carbon nanomaterial and the electrode active substance are pulverized by an air flow and attached to the surface of the substrate under the driving of the air flow.
According to still further embodiments of the present disclosure, there is also provided a battery including a positive electrode, a negative electrode, and an electrolyte, wherein the positive electrode is disposed opposite to the negative electrode, the electrolyte is disposed between the positive electrode and the negative electrode, and one or both of the positive electrode and the negative electrode are prepared by the method for preparing a dry-process composite electrode according to any one of the embodiments, or are the dry-process composite electrode according to any one of the embodiments.
In the method for preparing the dry-method composite electrode in at least one embodiment, the carbon nanomaterial and the electrode active substance are dispersed in a manner of airflow pulverization treatment without damaging the carbon nanomaterial and the electrode active substance, and the formed carbon nanopowder and the electrode active powder move towards the air outlet under the driving of the compressed airflow and directly adhere to the surface of the latticed substrate without re-agglomeration. The carbon nanopowder and the electrode active powder can be bonded by van der Waals 'force, and bonded to the surface of the substrate by van der Waals' force.
Compared with the mode of combining the electrode material with the binder in the prior art, the preparation method of the dry-method composite electrode can prepare the dry-method composite electrode with stable structure and no falling of the active substance under the condition of not using the binder. The electrode active substance in the dry method composite electrode is attached to the latticed substrate mainly by virtue of Van der Waals force of the carbon nano powder, and the carbon nano material also plays a role in participating in electric conduction among the active substances. The prepared composite electrode can participate in electrochemical reaction and release enough specific capacity like a common electrode. In addition, the electrode active powder and the carbon nano powder in the preparation method of the dry method composite electrode are dispersed and attached to the substrate by physical means, chemical reaction and in-situ preparation of raw materials are not involved in the preparation process, the whole preparation process is convenient, the application range is wider, and the method is more favorable for realizing large-scale production.
The foregoing description is only an overview of the technical solutions of the present invention, and in order to make the technical solutions of the present invention more clearly understood and to implement them in accordance with the contents of the description, the following detailed description is given with reference to the preferred embodiments of the present invention and the accompanying drawings.
Drawings
FIG. 1 shows a schematic diagram of a process for making a dry composite electrode in some embodiments of the present disclosure;
FIG. 2 shows a surface topography photograph of the dry-process composite electrode prepared in example 1;
FIG. 3 shows a surface scanning electron micrograph of the dry composite electrode prepared in example 1;
fig. 4 shows the ac impedance profile of the dry composite electrode prepared in example 1 after activation, 100 cycles, 250 cycles and 500 cycles;
FIG. 5 shows a schematic of the cycling performance of the dry composite electrode prepared in example 1 for the first 50 cycles of cycling;
wherein the reference symbols and their meanings are as follows:
100. compounding the electrode by a dry method; 110. an electrode active material; 111. an electrode active powder; 120. a carbon nanomaterial; 121. carbon nanopowder; 130. a substrate.
Detailed Description
To facilitate an understanding of the invention, the invention will now be described more fully with reference to the accompanying drawings. Preferred embodiments of the present invention are shown in the drawings. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete.
Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used in the description of the invention herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items, and as used herein, a "plurality" includes two or more items.
In the present invention, the sum of the parts of the components in the composition may be 100 parts by weight, unless otherwise specified. The percentages (including weight percentages) of the present invention are based on the total weight of the composition, unless otherwise specified, and as used herein, "wt%" means mass percent and "at%" means atomic percent.
Herein, unless otherwise specified, the individual reaction steps may or may not be performed in the order indicated. For example, other steps may be included between the respective reaction steps, and the order may be appropriately changed between the reaction steps. As can be determined by the skilled person from routine knowledge and experience. Preferably, the reaction processes herein are carried out sequentially.
One embodiment of the present disclosure provides a method for preparing a dry-process composite electrode, including the following steps.
Placing the carbon nano material and the electrode active substance in a crushing chamber together, introducing compressed gas into the crushing chamber, and carrying out airflow crushing treatment on the carbon nano material and the electrode active substance to respectively form carbon nano powder and electrode active powder;
the crushing chamber is also provided with a latticed substrate, the substrate is arranged on a flow path of gas, and the carbon nano material subjected to jet milling treatment and the electrode active substance are attached to the substrate under the driving of the gas.
It is understood that the jet milling treatment means that the material is impacted by high-speed air flow generated by compressed gas, and the material is dispersed by the self-grinding effect of the material. In a milling chamber for carrying out a jet milling process, there are usually provided a gas inlet and a gas outlet, into which compressed gas is introduced and which, by means of a pressure difference, forms a gas flow towards the gas outlet. The inventors of the present disclosure have found that by treating a carbon nanomaterial with a compressed gas, it is possible to temporarily separate particles of the carbon nanomaterial, which are originally in an agglomerated state, into particles having a small particle diameter, thereby increasing the specific surface area thereof and enhancing the van der waals force on the surface of the carbon nanomaterial.
And dispersing the carbon nano material and the electrode active substances in a jet milling treatment mode under the condition of not damaging the carbon nano material and the electrode active substances, wherein the formed carbon nano powder and the electrode active substances move towards an air outlet under the driving of compressed air flow and are directly attached to the surface of the latticed substrate under the condition of not re-agglomerating. The carbon nanopowder and the electrode active powder can be bonded by van der Waals force, and bonded to the surface of the substrate by van der Waals force. Wherein the carbon nano material not only can play a role in conducting electricity, but also can play a role in combining electrode active substances and fixing the electrode active substances on a substrate.
Compared with the mode of combining the electrode material with the binder in the prior art, the preparation method of the dry-method composite electrode can prepare the dry-method composite electrode with stable structure and no falling of the active substance under the condition of not using the binder. The electrode active substance in the dry method composite electrode is attached to the latticed substrate mainly by virtue of Van der Waals force of the carbon nano powder, and the carbon nano powder also plays a role in participating in electric conduction among the active substances. The prepared composite electrode can participate in electrochemical reaction and release enough specific capacity like a common electrode. In addition, the electrode active powder and the carbon nano powder in the preparation method of the dry method composite electrode are dispersed and attached to the substrate by physical means, chemical reaction and in-situ preparation of raw materials are not involved in the preparation process, the whole preparation process is convenient, the application range is wider, and the large-scale production is more favorably realized.
In some of the specific examples of this embodiment, the dry composite electrode has no binder therein. The dry method composite electrode is not provided with a binder, so that the material cost in the actual preparation process can be reduced, the problem of pollution caused by an organic solvent in the wet method electrode preparation process is avoided, and the dispersed carbon nano material is directly contacted with an electrode active substance, so that the conductivity among particles is increased.
It is understood that the carbon nanomaterial may be selected from zero-dimensional, one-dimensional, and two-dimensional carbon nanomaterials such as carbon quantum dots, carbon nanotubes, and graphene. The carbon nanomaterials have high specific surface areas and high van der waals interaction forces with each other, and the carbon nanomaterials are generally in an aggregated state with large particle sizes. The carbon nanomaterial is treated by airflow pulverization, so that the carbon nanomaterial with a large particle size can be pulverized into carbon nanomaterial powder with a small particle size, the specific surface area of the carbon nanomaterial is increased, and the carbon nanomaterial is combined with the electrode active powder material by van der waals acting force.
In some specific examples of the embodiment, the carbon nanomaterial includes a carbon nanotube array, the carbon nanotube array refers to carbon nanotubes grown in an array shape, the carbon nanotubes in the carbon nanotube array have high uniformity in an arrangement direction, and the carbon nanotubes in the carbon nanotube array are mainly bonded by wall contact. The jet milling method is particularly suitable for the carbon nano tube array, the carbon nano tubes can be separated along the wall of the carbon nano tubes, and the milled carbon nano powder has higher length-diameter ratio compared with the carbon nano material before milling. And the carbon nano tube array after the jet milling treatment still takes the shape of a beam. The obvious difference from the granular carbon nanotubes is that when the carbon nanotubes are attached to the substrate, the bundled carbon nanotubes are in contact with each other through the tube wall to form a conductive network. And the particles of the electrode active powder are adhered and fixed by virtue of the carbon nano tubes, and the conductive network formed by the carbon nano tubes is positioned among the particles of the electrode active powder, so that the conductive network can enable the particles of the electrode active powder to fully discharge so as to obtain higher initial specific discharge capacity.
It can be understood that in the dry composite electrode, the substrate is used for the adhesion of the carbon nanopowder and the electrode active powder, and plays a supporting role. In some specific examples of this embodiment, the material of the substrate is selected from conductive materials to simultaneously enhance the conductive action of the conductive network of carbon nanotubes. Alternatively, the material of the substrate may be a metal or a carbon material. Further, the material of the substrate is metal. For example, the mesh-like substrate is a copper mesh.
In some specific examples of this embodiment, the mesh openings on the substrate are 10 μm to 100 μm in size. Optionally, the aperture of the mesh on the substrate is 30-80 μm. For example, the mesh openings on the substrate are 30 μm, 40 μm, 50 μm, 60 μm, 70 μm, 80 μm, or ranges therebetween. The mesh hole on the substrate is controlled to be 30-80 mu m, so that a more compact dry-method composite electrode can be obtained.
In some specific examples of this embodiment, a filter is disposed in the pulverization chamber, the air outlet is opened on the filter, and the substrate covers the surface of the filter. The filter is used for filtering gas passing through the gas outlet, preventing the carbon nano powder and the electrode active powder from being sprayed out of the gas outlet, covering the surface of the filter with the substrate, enabling the carbon nano powder and the electrode active powder to be attached to the substrate, and improving the collection efficiency of the carbon nano material and the electrode active substances after jet milling.
In some specific examples of the embodiment, in the step of performing jet milling treatment on the carbon nanomaterial and the electrode active substance, the pressure of the introduced gas is controlled to be 0.4 to 1 MPa. Optionally, in the step of performing jet milling treatment on the carbon nanomaterial and the electrode active substance, the pressure of the introduced gas is controlled to be 0.4MPa to 0.65MPa, for example, the pressure of the introduced gas is controlled to be 0.4MPa, 0.5MPa, 0.55MPa, 0.6MPa, 0.65MPa, or a range between the pressures of the above gases.
In some specific examples of this embodiment, after the adhering the carbon nanopowder and the electrode active powder material on the substrate, the method further comprises: pressing the carbon nano powder and the electrode active powder on a substrate to form a film. The carbon nano powder and the electrode active powder are further pressed into a film, so that the compactness and the flatness of the carbon nano powder and the electrode active powder on the surface of the substrate can be improved, and a more compact and uniform dry-process composite electrode can be obtained.
In some specific examples of the embodiment, in the step of compressing the carbon nanomaterial and the electrode active substance into a film on the substrate, the thickness of the film obtained by the compression is controlled to be 3mm or less. Optionally, the thickness of the film obtained by pressing is controlled to be 0.01 mm-3 mm. Further, optionally, the thickness of the film layer obtained by pressing can be controlled to be 0.02 mm-1 mm. For example, the thickness of the film layer obtained by pressing may be controlled to 0.02mm, 0.04mm, 0.06mm, 0.08mm, 1mm, or a range between the thicknesses of the above-mentioned respective film layers.
In some specific examples of this embodiment, in the step of pressing the carbon nanopowder and the electrode active powder material onto the substrate to form the film, the carbon nanopowder and the electrode active powder material are pressed onto the substrate to form the film by means of rolling. Optionally, the temperature of the roller is controlled to be 20 ℃ to 100 ℃ in the rolling process.
In some specific examples of the embodiment, in the step of placing the carbon nanomaterial and the electrode active substance together in the pulverization chamber, the mass ratio of the carbon nanomaterial in the total of the carbon nanomaterial and the electrode active substance is controlled to be 5% to 50%. Optionally, the mass ratio of the carbon nano material in the total of the carbon nano material and the electrode active substance is controlled to be 5% -10%. For example, the mass ratio of the carbon nanomaterial in the total of the carbon nanomaterial and the electrode active material is controlled to be 5%, 6%, 7%, 8%, 9%, 10%, or a range between the mass ratios. Compared with the traditional wet coating electrode, the dry composite electrode prepared by the preparation method of the dry composite electrode has the advantages that the carbon nano material is more fully contacted with the electrode active substance, the conductive capacity between the carbon nano material and the particles of the electrode active substance is stronger, and higher conductivity can be obtained under the condition of less using amount of the carbon nano material, so that the mass ratio of the carbon nano material in the electrode can be obviously reduced.
It is understood that the dry-process composite electrode preparation method can be used for preparing electrodes of various battery systems, wherein the battery systems can include but are not limited to lithium ion batteries, lithium sulfur batteries, lithium air batteries, sodium ion batteries and the like. The preparation method of the dry-method composite electrode can be used for preparing the anode and the cathode, and only the used electrode active substances need to be correspondingly changed.
In some specific examples of this embodiment, the electrode active material in the dry composite electrode may include one or both of silicon and silica. Silicon and silicon monoxide can be used as the negative electrode of a lithium ion battery, and therefore the dry composite electrode in this specific example can be used as the negative electrode of a lithium ion battery.
Yet another embodiment of the present disclosure also provides a dry-process composite electrode. The dry method composite electrode comprises a carbon nano material, an electrode active substance and a substrate, wherein the substrate is in a grid shape, and the carbon nano material and the electrode active substance are attached to the surface of the substrate after being pulverized by airflow.
Further, a dry-process composite electrode is prepared by the preparation method of the dry-process composite electrode in the above embodiment.
Still another embodiment of the present disclosure also provides a battery including a positive electrode, a negative electrode, and an electrolyte, the positive electrode being disposed opposite to the negative electrode, the electrolyte being disposed between the positive electrode and the negative electrode, one or both of the positive electrode and the negative electrode being prepared by the method of preparing the dry-process composite electrode in the above-described embodiment, or being the dry-process composite electrode in the above-described embodiment.
In order to facilitate understanding of the method for preparing the dry composite electrode in the above embodiment, please refer to fig. 1, which includes steps S1 to S4.
In step S1, the electrode active material 110 and the carbon nanomaterial 120 are provided.
The carbon nanomaterial 120 is a carbon nanotube array.
Wherein, the mass ratio of the carbon nano material 120 in the whole formed by the electrode active substance 110 and the carbon nano material 120 is 5-10%.
The electrode active material 110 is silicon or silicon oxide.
In step S2, the electrode active material 110 and the carbon nanomaterial 120 are subjected to jet milling.
When the jet milling is performed on the electrode active material 110 and the carbon nanomaterial 120, the carbon nanomaterial 120 and the electrode active material 110 are placed in a milling chamber together, the milling chamber is provided with an air inlet and an air outlet, and compressed air is introduced into the milling chamber through the air inlet to perform jet milling on the carbon nanomaterial 120 and the electrode active material 110.
Wherein the pressure of the compressed gas introduced into the crushing chamber is 0.4 MPa-0.65 MPa. The air pressure outside the air outlet is one atmosphere.
Referring to step S2 in fig. 1, the electrode active material 110 and the carbon nanomaterial 120 are pulverized by the compressed gas, so that the electrode active material 110 and the carbon nanomaterial 120 can be pulverized into an electrode active powder material 111 and a carbon nanomaterial material 121, respectively, having smaller particle diameters. The electrode active material powder 111 and the carbon nano material powder 121 have a higher specific surface area than the electrode active material 110 and the carbon nano material 120, and thus the van der waals force of the mutual bonding is stronger. During the pulverization, preliminary cross-linking bonding may also occur between the electrode active powder 111 and the carbon nanopowder 121, but the overall particle size is small.
In step S3, the electrode active powder 111 and the carbon nano powder 121 are attached to the substrate 130.
The substrate 130 is in a grid shape, and the grid-shaped substrate 130 is disposed in the pulverization chamber and located on a moving path of the gas.
Wherein, the material of the substrate 130 is selected from metals. For example, the substrate is a copper mesh.
Wherein, the aperture of the mesh of the substrate 130 is 10 μm to 100 μm.
Wherein, be provided with the filter in the crushing chamber, the gas outlet is seted up on the filter, and the basement lid is located the filter surface.
The gas passes through the substrate 130 in the process of driving the carbon nanomaterial and the electrode active substance, and the electrode active powder 111 and the carbon nanopowder 121 are attached to the surface of the substrate 130 by van der waals force. In this way, the electrode active material powder 111 and the carbon nanopowder 121 can be bonded and fixed to the substrate surface without relying on a binder.
In step S4, the electrode active powder 111 and the carbon nanopowder 121 are pressed on the substrate 130 to form a film.
Wherein the thickness of the film layer obtained by pressing is less than or equal to 3 mm. Specifically, the thickness of the film layer obtained by pressing is 0.02 mm-1 mm.
Wherein, the electrode active powder 111 and the carbon nano powder 121 are pressed on the substrate 130 by a rolling method to form a film.
Wherein, in the pressing process, the temperature of the pressing roller is controlled to be 20-100 ℃.
Through steps S1-S4, the preparation of the dry composite electrode can be completed.
In order that the invention may be more readily understood and readily carried into effect, the following more specific and detailed test examples and comparative examples are provided below by reference. The embodiments of the present invention and their advantages will also be apparent from the descriptions and performance results of the specific test examples and comparative examples described below. In each of the following test examples and comparative examples,
the raw materials used in the following examples and comparative examples are all commercially available as usual unless otherwise specified.
Example 1
Putting the carbon nano tube array and the composite active material of the silicon monoxide and the carbon into a crushing chamber together according to the proportion of 7:93, and setting the pressure of gas for crushing to be 0.65 MPa;
the filter is arranged at the air outlet, and the copper mesh is taken as a substrate and covers the surface of the filter;
introducing compressed gas for crushing into the crushing chamber, crushing the carbon nanotube array and the composite active material, and driving the crushed material to be attached to the copper mesh;
and taking down the copper mesh attached with the carbon nanotube array and the composite active material, and putting the copper mesh into a hot roller press for rolling, wherein the temperature is set to be 40 ℃, and the rolling thickness is set to be 0.02mm, so as to obtain the dry-method composite electrode.
Example 2
Putting the carbon nanotube array and the silicon-carbon composite active material into a crushing chamber together according to the proportion of 7:93, and setting the gas pressure for crushing to be 0.65 MPa;
the filter is arranged at the air outlet, and the copper mesh is taken as a substrate and covers the surface of the filter;
introducing compressed gas for crushing into the crushing chamber, crushing the carbon nanotube array and the composite active material, and driving the crushed material to be attached to the copper mesh;
and taking down the copper mesh attached with the carbon nanotube array and the composite active material, and putting the copper mesh into a hot roller press for rolling, wherein the temperature is set to be 40 ℃, and the rolling thickness is set to be 0.02mm, so as to obtain the dry-method composite electrode.
Comparative example 1
Putting the carbon nanotube array and the composite active material of the silicon oxide and the carbon into a crushing chamber together according to the proportion of 7:93, and setting the pressure of gas for crushing to be 0.65 MPa;
the crushing chamber is internally provided with a filter which is arranged at the air outlet;
introducing compressed gas for crushing into the crushing chamber, crushing the carbon nanotube array and the composite active material, and collecting the crushed carbon nanotube array and the composite active material at a filter at an air outlet;
covering the crushed carbon nanotube array and the composite active material on the surface of the copper mesh, and putting the copper mesh into a hot roller press for rolling, wherein the temperature is set to be 40 ℃, and the rolling thickness is set to be 0.02 mm.
The carbon nanotube array and the composite active material of comparative example 1 were not stably attached to the copper mesh after roll-forming, and it was difficult to form an electrode suitable for practical use.
Test 1: the surface of the dry-process composite electrode prepared in example 1 was optically photographed and subjected to a scanning electron microscope test. The schematic optical photograph thereof is shown in FIG. 2, and the schematic observation view of the scanning electron microscope is shown in FIG. 3.
Half cells in which a lithium electrode was used as a counter electrode were assembled using the dry composite electrodes prepared in examples 1 and 2 as electrodes. The half cells were tested for their electrochemical impedance spectra and their cycling performance. The first-turn discharge capacities of example 1 and example 2 are shown in table 1, the electrochemical impedance spectrum of example 1 is shown in fig. 4, and the cycle performance diagram of example 1 is shown in fig. 5.
TABLE 1
Figure 216792DEST_PATH_IMAGE002
Referring to fig. 2, on the surface of the dry-method composite electrode, the carbon nanotube array and the electrode active material can be stably attached to the surface of the substrate to form the composite electrode, the surface powder does not fall off when placed obliquely, and the blank area at the edge of the substrate is the area where the powder material is not attached in the preparation process.
Referring to fig. 3, in the dry composite electrode, the particle size of the electrode active material after the pulverization process is generally in the range of 1 to 20 μm, and gaps between the particles of the electrode active material are filled with a fine carbon nanomaterial and are bonded and fixed by the carbon nanomaterial, thereby forming a dry composite electrode having a stable structure.
Referring to fig. 4, wherein "after activation" represents the ac impedance spectrum of the battery after activation, "100C" represents the ac impedance spectrum of the battery after one hundred cycles, "250C" represents the ac impedance spectrum of the battery after 250 cycles, and "500C" represents the ac impedance spectrum of the battery after 500 cycles. Wherein, in the process from activation to circulation of 100 circles, the alternating current impedance spectrum curve has obvious left shift, which mainly corresponds to the obvious reduction of the ohmic internal resistance of the battery, and may correspond to the gradual optimization of the structure of the dry-method composite electrode in the discharging process. During the process from 100 cycles to 500 cycles, the AC impedance spectrum curve has obvious right shift.
Referring to fig. 5, the specific discharge capacity of the prepared battery after activation shows obvious specific decay in the first few cycles, and then gradually becomes stable, which may correspond to the process that the dry-process composite electrode structure gradually becomes stable from the initial state.
As can be seen from fig. 2 to 5, the method for manufacturing a dry composite electrode can manufacture a dry composite electrode having a stable structure and no active material falling off without using a binder. The electrode active substance in the dry method composite electrode is attached to the lattice-like substrate mainly by van der waals force of the dispersed carbon nanomaterial, and the carbon nanomaterial also plays a role of participating in electrical conduction between the active substances. Referring to table 1, the prepared composite electrode can participate in electrochemical reaction and release sufficient specific capacity like a general electrode. In addition, in the preparation method of the dry-method composite electrode, the electrode active substance and the carbon nano material are dispersed and attached to the substrate through physical means, chemical reaction and in-situ preparation of raw materials are not involved in the preparation process, the whole preparation process is convenient, the application range is wider, and the large-scale production is more favorably realized.
The technical features of the above embodiments can be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the above embodiments are not described, but should be considered as the scope of the present specification as long as there is no contradiction between the combinations of the technical features.
The above examples only show some embodiments of the present invention, and the description thereof is more specific and detailed, but not construed as limiting the scope of the invention. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the inventive concept, which falls within the scope of the present invention. Therefore, the protection scope of the present patent should be subject to the appended claims.

Claims (10)

1. The preparation method of the dry-method composite electrode is characterized by comprising the following steps of:
placing a carbon nano material and an electrode active substance in a crushing chamber together, introducing compressed gas into the crushing chamber, and carrying out airflow crushing treatment on the carbon nano material and the electrode active substance to respectively form carbon nano powder and electrode active powder;
the grinding chamber is internally provided with a latticed substrate which is arranged on a flow path of the gas, and the carbon nano powder and the electrode active powder are driven to be attached to the substrate by the gas.
2. The method of claim 1, wherein the carbon nanomaterial comprises an array of carbon nanotubes.
3. The preparation method of the dry-method composite electrode according to claim 1, wherein the pressure of the gas introduced into the crushing chamber is controlled to be 0.4 MPa-1 MPa.
4. The method for preparing a dry-method composite electrode according to claim 1, wherein a filter is arranged in the crushing chamber, the filter is positioned at the air outlet of the crushing chamber, and the substrate is covered on the surface of the filter.
5. The method for preparing the dry-method composite electrode according to claim 1, wherein the aperture of the mesh on the substrate is 10-100 μm.
6. The method for preparing the dry-method composite electrode according to claim 1, wherein in the step of placing the carbon nanomaterial and the electrode active substance together in the pulverization chamber, the mass ratio of the carbon nanomaterial in the total of the carbon nanomaterial and the electrode active substance is controlled to be 5% to 50%.
7. The method for preparing the dry composite electrode according to any one of claims 1 to 6, further comprising a step of pressing the carbon nanomaterial and the electrode active substance on the substrate to form a film after the carbon nanomaterial and the electrode active substance are attached to the substrate.
8. The method for preparing a dry composite electrode according to claim 1, wherein in the step of compressing the carbon nanomaterial and the electrode active substance into a film on the substrate, the thickness of the film obtained by compression is controlled to be less than or equal to 3 mm.
9. The dry-method composite electrode is characterized by comprising a carbon nano material, an electrode active substance and a latticed substrate, wherein the carbon nano material and the electrode active substance are subjected to airflow crushing and are attached to the surface of the substrate under the driving of airflow.
10. A battery comprising a positive electrode, a negative electrode, and an electrolyte, wherein the positive electrode is disposed opposite to the negative electrode, the electrolyte is disposed between the positive electrode and the negative electrode, and one or both of the positive electrode and the negative electrode are prepared by the method for preparing a dry-process composite electrode according to any one of claims 1 to 8, or the dry-process composite electrode according to claim 9.
CN202210964814.1A 2022-08-12 2022-08-12 Preparation method of dry-method composite electrode, dry-method composite electrode and battery Pending CN115036449A (en)

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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN116207383A (en) * 2023-05-05 2023-06-02 四川新能源汽车创新中心有限公司 Dry functional layer for lithium battery, preparation method, composite electrode and preparation method

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN1884058A (en) * 2006-06-23 2006-12-27 清华大学 Aerogel carbon nanotube and its preparation method and application
US20110111279A1 (en) * 2009-11-09 2011-05-12 Florida State University Research Foundation Inc. Binder-free nanocomposite material and method of manufacture
US20120107683A1 (en) * 2010-10-27 2012-05-03 Korea Institute Of Science And Technology Composites of self-assembled electrode active material-carbon nanotube, fabrication method thereof and secondary battery comprising the same
CN109326765A (en) * 2017-07-31 2019-02-12 本田技研工业株式会社 Self-support electrode and its manufacturing method

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN1884058A (en) * 2006-06-23 2006-12-27 清华大学 Aerogel carbon nanotube and its preparation method and application
US20110111279A1 (en) * 2009-11-09 2011-05-12 Florida State University Research Foundation Inc. Binder-free nanocomposite material and method of manufacture
US20120107683A1 (en) * 2010-10-27 2012-05-03 Korea Institute Of Science And Technology Composites of self-assembled electrode active material-carbon nanotube, fabrication method thereof and secondary battery comprising the same
CN109326765A (en) * 2017-07-31 2019-02-12 本田技研工业株式会社 Self-support electrode and its manufacturing method

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN116207383A (en) * 2023-05-05 2023-06-02 四川新能源汽车创新中心有限公司 Dry functional layer for lithium battery, preparation method, composite electrode and preparation method
CN116207383B (en) * 2023-05-05 2023-07-25 四川新能源汽车创新中心有限公司 Dry functional layer for lithium battery, preparation method, composite electrode and preparation method

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