CN116314598A - Dry electrode slice and preparation method and application thereof - Google Patents

Dry electrode slice and preparation method and application thereof Download PDF

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Publication number
CN116314598A
CN116314598A CN202310607206.XA CN202310607206A CN116314598A CN 116314598 A CN116314598 A CN 116314598A CN 202310607206 A CN202310607206 A CN 202310607206A CN 116314598 A CN116314598 A CN 116314598A
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electrode
dry
active material
conductive
material layer
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CN116314598B (en
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王翔翔
江柯成
蒋绮雯
李慧茹
陈以蒙
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Jiangsu Zenio New Energy Battery Technologies Co Ltd
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Jiangsu Zenergy Battery Technologies Co Ltd
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    • 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
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/05—Accumulators with non-aqueous electrolyte
    • H01M10/054—Accumulators with insertion or intercalation of metals other than lithium, e.g. with magnesium or aluminium
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
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    • H—ELECTRICITY
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    • H01M4/00—Electrodes
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    • H01M4/13—Electrodes for accumulators with non-aqueous electrolyte, e.g. for lithium-accumulators; Processes of manufacture thereof
    • H01M4/131—Electrodes based on mixed oxides or hydroxides, or on mixtures of oxides or hydroxides, e.g. LiCoOx
    • H—ELECTRICITY
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    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
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    • H01M4/13—Electrodes for accumulators with non-aqueous electrolyte, e.g. for lithium-accumulators; Processes of manufacture thereof
    • H01M4/133—Electrodes based on carbonaceous material, e.g. graphite-intercalation compounds or CFx
    • H—ELECTRICITY
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    • 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
    • H01M4/136—Electrodes based on inorganic compounds other than oxides or hydroxides, e.g. sulfides, selenides, tellurides, halogenides or LiCoFy
    • H—ELECTRICITY
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    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
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    • 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
    • H01M4/13—Electrodes for accumulators with non-aqueous electrolyte, e.g. for lithium-accumulators; Processes of manufacture thereof
    • H01M4/139—Processes of manufacture
    • H01M4/1391—Processes of manufacture of electrodes based on mixed oxides or hydroxides, or on mixtures of oxides or hydroxides, e.g. LiCoOx
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/13—Electrodes for accumulators with non-aqueous electrolyte, e.g. for lithium-accumulators; Processes of manufacture thereof
    • H01M4/139—Processes of manufacture
    • H01M4/1393—Processes of manufacture of electrodes based on carbonaceous material, e.g. graphite-intercalation compounds or CFx
    • H—ELECTRICITY
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    • 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
    • H01M4/1397—Processes of manufacture of electrodes based on inorganic compounds other than oxides or hydroxides, e.g. sulfides, selenides, tellurides, halogenides or LiCoFy
    • H—ELECTRICITY
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    • 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
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    • H01M4/62—Selection of inactive substances as ingredients for active masses, e.g. binders, fillers
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    • H01M4/00—Electrodes
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    • H01M4/64—Carriers or collectors
    • H01M4/70—Carriers or collectors characterised by shape or form
    • H01M4/72—Grids
    • H01M4/74—Meshes or woven material; Expanded metal
    • H01M4/745—Expanded metal
    • 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
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    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
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Abstract

The invention discloses a dry electrode slice, a preparation method and application thereof, wherein the dry electrode slice comprises two or more layers of electrode membranes which are mutually adhered, the electrode membrane comprises a conductive metal net and an active substance layer arranged on the surface of the metal net, and the active substance layer at least comprises an anode/cathode active material, a conductive agent and a binder. The invention prepares an electrode membrane by compounding an electrode active material layer with a metal net-shaped current collector in a film forming process, and rolls and bonds a plurality of layers of electrode membranes to obtain a dry electrode plate; the conductive metal net in the pole piece not only has a current collecting function, but also provides a contact point for welding the electrode lugs of the battery core, and the conductive performance of the pole piece can be optimized in the pole piece due to the high conductivity of the metal net, so that the prepared pole piece not only has high surface density but also has lower resistance, and therefore, the sodium ion battery comprising the dry electrode piece has high energy density and good multiplying power performance.

Description

Dry electrode slice and preparation method and application thereof
Technical Field
The invention relates to the technical field of sodium ion batteries, in particular to a dry electrode slice, a preparation method and application thereof.
Background
The positive electrode material of the sodium ion battery is mainly used as a main body rich in sodium, enough sodium ions are provided for transmission in electrolyte in the charging process, and until the present, the sodium-electricity positive electrode material which is focused by a great deal of researchers mainly comprises layered transition metal oxides, prussian blue compounds, polyanion compounds and the like. However, the gram capacity of the sodium-electricity positive electrode material is obviously lower than that of the lithium ion battery positive electrode material, so that the energy density of the prepared full battery is lower, and the improvement of the positive and negative electrode surface density is an important means for improving the energy density of the full battery. However, if the positive/negative electrode sheet with high surface density is prepared by a wet method, coating is difficult, and the thickness of the active material layer is too thick, and the active material layer is easy to crack due to different volatilization rates of the surface and the internal solvent in the baking process, and the problems of powder falling during rolling, lower peeling strength, larger sheet resistance and the like also exist. Compared with the preparation of a wet electrode, the dry electrode plate does not need solvents and baking procedures in the preparation process, so that the baking and drying cracking problem can be avoided, and the production cost of the sodium ion battery can be further reduced.
However, the dry pole piece with high surface density prepared at present still has the defects of small stripping force and large membrane resistance, so that the direct current impedance of the whole battery is increased, and the multiplying power performance of the battery is influenced. Therefore, in order to solve the problems of low stripping force and high pole piece resistance of the high-surface-density dry electrode, a novel dry electrode pole piece and a preparation method thereof are provided, and the resistance of the dry electrode can be effectively reduced, the stripping force can be improved, and the energy density and the multiplying power performance of the sodium ion battery can be effectively improved.
Disclosure of Invention
The invention aims to provide a dry electrode slice, a preparation method and application thereof. The electrode active material layer is compounded with a metal net-shaped current collector in the film forming process to prepare an electrode film, and the electrode film is rolled and bonded to obtain a dry electrode plate. The dry pole piece has higher stripping force and lower pole piece resistance, and can effectively improve the energy density and the multiplying power performance of the sodium ion battery.
In order to solve the technical problems, the invention provides the following technical scheme:
the invention provides a dry electrode slice, which comprises two or more layers of electrode membranes adhered to each other, wherein the electrode membrane comprises a conductive metal net and an active material layer arranged on the surface of the conductive metal net, and the active material layer at least comprises a positive electrode active material/negative electrode active material, a conductive agent and a binder.
Further, the positive electrode active material is preferably Na x M y M’ z O 2 、Na x’ A[Fe(CN) 6 ] y’ · z’H 2 O, sodium iron phosphate, sodium vanadium fluorophosphate, sodium pyrophosphate, sodium oxalate, sodium carbonate, wherein M is one or more of Fe, co, ni, cr, mn, cu, M' is one or more of Li, mg, ca, al, B, A is a transition metal element selected from one or more of Fe, co, ni, mn, 0.5.ltoreq.x.ltoreq.1.1, 0.ltoreq.y, z.ltoreq.1, y+z=1, 0<x'<2，0<y'<1，z'≥0。
Further, the anode active material is preferably one or more of hard carbon, doped or coated modified hard carbon, soft carbon, doped or coated modified soft carbon.
Further, the conductive agent is selected from one or more of conductive carbon black, graphite micropowder, carbon nanotubes and graphene.
Further, the mass ratio of the positive electrode active material/negative electrode active material, the conductive agent and the binder is preferably 80-97:0.5-20:0.5-20.
Further, the active material layer further comprises one or more of a one-dimensional conductive material, a two-dimensional conductive material and a sodium ion conductor material.
Further, the one-dimensional conductive material is preferably one or more of single-walled carbon nanotubes, multi-walled carbon nanotubes and metal nanofibers; the two-dimensional conductive material is preferably graphene.
Further, the sodium ion conductor material is preferably beta' -Al 2 O 3 And/or conductivity of 10 -7 -10 -2 S/cm of a sodium-containing compound; the sodium-containing compound is preferably Na 3 Zr 2 Si 2 PO 12 And/or Na 3 PS 4 。
Further, when the one-dimensional conductive material and/or the two-dimensional conductive material is contained in the active material layer, the content of the one-dimensional conductive material and/or the two-dimensional conductive material accounts for 0.5% -10% of the mass of the active material layer.
Further, when the sodium ion conductor material is contained in the active material layer, the content of the sodium ion conductor material is 0.5% -10% of the mass of the active material layer.
Further, the conductive metal mesh is preferably a copper mesh, an aluminum mesh or a stainless steel mesh, and the conductive metal mesh may be replaced by other conductive materials having a mesh structure.
Further, the mesh number of the conductive metal mesh is 200-1000 mesh.
Further, the thickness of the conductive metal net is 0.05-1 mm.
Further, the thickness of the electrode membrane is 0.05-1 mm.
Further, the thickness of the dry electrode sheet is 0.1-1.5. 1.5 mm.
Further, each layer of electrode membrane in the dry electrode slice is the same or different electrode membrane;
when the dry electrode slice is obtained by mutually bonding two or three layers of same electrode films, the active material layer of the electrode film contains one-dimensional and/or two-dimensional conductive materials and sodium ion conductor materials;
when the dry electrode plate is obtained by mutually bonding two or three electrode films, wherein at least two electrode films are different, at least one active material layer of the electrode films in the dry electrode plate contains one-dimensional and/or two-dimensional conductive materials, and at least one active material layer of the electrode films contains sodium ion conductive materials.
The second aspect of the invention provides a method for preparing the dry electrode slice according to the first aspect, comprising the following steps:
(1) Weighing the raw materials according to the composition ratio of the active material layer, and uniformly mixing at 0-25 ℃ to obtain a mixture;
(2) The mixture is sheared and mixed and then calendared into a film to obtain a dry membrane;
(3) Respectively attaching dry-method diaphragms to the upper and lower surfaces of a conductive metal net, and preparing an electrode diaphragm in a rolling manner;
(4) And stacking the electrode films prepared by the steps according to a preset sequencing mode, and rolling to obtain the dry electrode plate.
The third aspect of the invention provides a sodium ion battery, which is prepared from a positive pole piece, a negative pole piece and a diaphragm by lamination or winding; the positive electrode plate and/or the negative electrode plate are/is the dry electrode plate in the first aspect or the dry electrode plate prepared by the preparation method in the second aspect.
Compared with the prior art, the invention has the beneficial effects that:
the invention prepares the electrode membrane by compounding the membrane prepared by the electrode active material layer with the conductive metal net-shaped current collector, and the dry electrode sheet is obtained by rolling and bonding a plurality of layers of electrode membranes. The dry film of the electrode active material layer is adhered to the upper surface and the lower surface of the conductive metal net with more holes, and the dry film of the upper surface and the lower surface are mutually adhered through the meshes of the conductive metal net after rolling, so that the stripping force of the active material layer and the conductive metal net is greatly improved; in addition, the conductive metal net in each layer of electrode membrane plays a role in collecting current and provides a contact point for welding the electrode lugs of the battery core, and the conductive metal net has high conductivity, so that the conductivity of the electrode plate is further optimized, and the prepared dry electrode has low resistance while having high surface density, so that the sodium ion battery comprising the dry electrode plate has high energy density and excellent multiplying power performance.
In addition, on the basis of the multi-layer electrode membrane, the invention can further optimize the conductivity and ion conducting capacity of the dry electrode sheet, namely, one-dimensional and/or two-dimensional conductive materials and sodium ion conductor materials are introduced into the dry electrode sheet, so that the one-dimensional and/or two-dimensional conductive materials and the sodium ion conductor materials can form uniform high-conductivity and ion conducting networks in the fiberization process of the binder, thereby providing more and stable electron and sodium ion transmission channels in the electrode with high surface density, further reducing the internal resistance of the battery, and enabling the battery to have high-rate performance while having high energy density.
Detailed Description
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 herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and/or" as used herein includes any and all combinations of one or more of the associated listed items. The term "comprising" or "comprises" as used herein means that it may include or comprise other components in addition to the components described. The term "comprising" or "comprising" as used herein may also be replaced by "being" or "consisting of" closed.
As described in the background art, the dry pole piece with high surface density prepared at present still has the defects of small stripping force and large membrane resistance, so that the direct current impedance of the whole battery is increased, and the multiplying power performance of the battery is influenced.
In order to solve the above technical problems, an embodiment of the present invention provides a dry electrode sheet, which includes two or more electrode sheets bonded to each other, the electrode sheet includes a conductive metal mesh and an active material layer disposed on a surface of the conductive metal mesh, where the active material layer includes at least a positive electrode active material/a negative electrode active material, a conductive agent, and a binder.
According to the invention, the membrane prepared by the electrode active material layer is compounded with the conductive metal net-shaped current collector to prepare the electrode membrane, and the dry membrane of the electrode active material layer is attached to the upper surface and the lower surface of the conductive metal net with more holes, so that the stripping force of the active material layer and the conductive metal net is greatly improved through mutual adhesion of the meshes of the conductive metal net; and then bonding the multi-layer electrode films to obtain a dry electrode plate, thereby obtaining the dry electrode plate with high surface density and high stripping force. In addition, the conductive metal net in each layer of electrode membrane plays a role in current collection, a contact point is provided for welding the electrode lugs of the battery core, and the conductive metal net has high conductivity, so that the conductivity of the electrode plate is further optimized, the prepared dry electrode has low resistance while having high surface density, and the sodium ion battery comprising the dry electrode plate has high energy density and high rate performance.
In some preferred embodiments, the positive electrode active material is preferably Na x M y M’ z O 2 、Na x’ A[Fe(CN) 6 ] y’ · z’H 2 O, sodium iron phosphate, sodium vanadium fluorophosphate, sodium pyrophosphate, sodium oxalate, sodium carbonate, wherein M is one or more of Fe, co, ni, cr, mn, cu, M' is one or more of Li, mg, ca, al, B, A is a transition metal element selected from one or more of Fe, co, ni, mn,0.5≤x≤1.1，0≤y、z≤1，y+z=1，0<x'<2，0<y'<1, z'. Gtoreq.0. Illustratively, the positive electrode active material is a layered oxide NaNi 1/3 Fe 1/3 Mn 1/3 O 2 。
In some preferred embodiments, the anode active material may be selected from one or more of hard carbon, doped or clad modified hard carbon, soft carbon, doped or clad modified soft carbon; the conductive agent can be one or more selected from conductive carbon black, graphite micropowder, carbon nanotube and graphene;
in some preferred embodiments, the mass ratio of the positive/negative electrode active material, the conductive agent, and the binder is preferably 80-97:0.5-20:0.5-20; illustratively, the mass ratio of positive electrode active material, conductive agent to binder in the positive/negative active material layer is 96:2:2.
In some preferred embodiments, the active material layer further comprises one or more of a one-dimensional conductive material, a two-dimensional conductive material, a sodium ion conductor material; the one-dimensional conductive material is preferably one or more of single-walled carbon nanotubes, multi-walled carbon nanotubes and metal nanofibers; the two-dimensional conductive material is preferably graphene; the sodium ion conductor material is preferably beta' -Al 2 O 3 And/or conductivity of 10 -7 -10 -2 S/cm sodium-containing compound, where the sodium-containing compound may be selected from Na 3 Zr 2 Si 2 PO 12 、Na 3 PS 4 Etc.
In order to further optimize the conductivity and the ion conducting capacity of the dry electrode plate, the one-dimensional and/or two-dimensional conductive material and the sodium ion conductive material are introduced into the dry electrode plate, so that the one-dimensional and/or two-dimensional conductive material and the sodium ion conductive material can form a uniform high-conductivity network in the fiberization process of the binder, thereby providing stable electron and sodium ion transmission channels in the electrode with high surface density, further reducing the internal resistance of the battery, and enabling the battery to have high-rate performance while having high energy density.
In some preferred embodiments, when the one-dimensional conductive material and/or the two-dimensional conductive material is contained in the active material layer, the content of the one-dimensional conductive material and/or the two-dimensional conductive material is 0.5% -10% of the mass of the active material layer; when the active material layer contains a sodium ion conductor material, the content of the sodium ion conductor material is 0.5% -10% of the mass of the active material layer.
In some preferred embodiments, the conductive metal mesh is preferably a copper mesh, an aluminum mesh, or a stainless steel mesh, but the conductive metal mesh may be replaced with other conductive materials having a mesh structure.
In some preferred embodiments, the mesh number of the conductive metal mesh is 200-1000 mesh, e.g., 200 mesh, 300 mesh, 400 mesh, 500 mesh, 600 mesh, 700 mesh, 800 mesh, 900 mesh, 1000 mesh, etc., including but not limited to the mesh numbers recited above, as well as other values within the ranges recited above.
In some preferred embodiments, the conductive metal mesh has a thickness of 0.05-1 mm, such as 0.05 mm, 0.008 mm, 0.1 mm, 0.2 mm, 0.3 mm, 0.4 mm, 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, 1 mm, etc., including but not limited to the thicknesses recited above, as well as other values within the ranges recited above.
In some preferred embodiments, the electrode membrane has a thickness of 0.05-1 mm, such as 0.1 mm, 0.2 mm, 0.3 mm, 0.4 mm, 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, 1 mm, etc., including but not limited to the thicknesses listed above, and other values within the ranges listed above; the thickness of the electrode membrane is more preferably 0.1-mm-0.5-mm.
In some preferred embodiments, the dry electrode sheet has a thickness of 0.1-1.5 a mm, e.g., 0.1 mm, 0.2 mm, 0.25 mm, 0.3 mm, 0.4 mm, 0.45 mm, 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, 1 mm, etc.
In some preferred embodiments, each layer of electrode membrane in the dry electrode sheet is the same or different electrode membrane; when the dry electrode slice is obtained by bonding two or three layers of same electrode membranes, the active material layer of the electrode membrane comprises one-dimensional and/or two-dimensional conductive materials and sodium ion conductor materials; when the dry electrode sheet is obtained by mutually bonding two or three electrode films, wherein at least two electrode films are different, at least one active substance layer of the electrode film in the dry electrode sheet contains one-dimensional and/or two-dimensional conductive materials, and at least one active substance layer of the electrode film contains sodium ion conductor materials. The dry electrode slice simultaneously containing one-dimensional and/or two-dimensional conductive materials and sodium ion conductor materials is obtained by designing the materials in each electrode membrane.
The dry electrode sheet is obtained by bonding two or three layers of the same electrode films a to each other, or by bonding two films of different electrode films A, B, C in ABA, ACA, BAB, BCB, CAC or CBC arrangement, or by bonding different electrode films A, B, C in ABC, ACB, BAC, BCA, CAB or CBA arrangement, for example. The structure and the composition of the dry electrode slice prepared by the invention can be adjusted according to the performance requirements.
The embodiment of the invention also provides a preparation method of the dry electrode slice, which comprises the following steps:
(1) Weighing the raw materials according to the composition ratio of the active material layer, and uniformly mixing at 0-25 ℃ to obtain a mixture;
(2) The mixture is sheared and mixed and then calendared into a film to obtain a dry membrane;
(3) Attaching dry-method diaphragms to two sides of a conductive metal net, and preparing electrode diaphragms by a rolling mode;
(4) And stacking the electrode films prepared by the steps according to a preset sequencing mode, and rolling to obtain the dry electrode plate.
Wherein in some preferred embodiments, in step (1), the mixing temperature can be controlled between 0 and 25 ℃ by means of circulating cooling or water bath cooling.
In some preferred embodiments, in the step (2), the mixture is placed in a stirring tank, stirring speed and temperature are set, shearing and mixing are performed, and then the mixed mixture is placed in a roll press with the pressure of 5-15 t and the roll gap of 0.2-0.5 mm for calendaring to form a film, so as to obtain the dry film with the target thickness.
In some preferred embodiments, the specific process of roll pressing the electrode membrane in step (3) is: firstly, a single dry membrane is closely attached to one side of a copper net, parameters of pressure and roll gaps are set for rolling, a membrane with target thickness is obtained, then, a dry membrane is closely attached to the other side of the copper net, and parameters of pressure and roll gaps are set for rolling, so that an electrode membrane with target thickness is obtained. In the process of preparing the electrode membrane by rolling, parameters of pressure and roll gap can be adjusted according to requirements.
In some preferred embodiments, the specific process of preparing the dry electrode slice in the roll bonding in the step (4) is as follows: and stacking the electrode films, and setting parameters of pressure and roll gap for rolling to obtain the electrode film with the target thickness. In the process of preparing the electrode membrane by rolling, parameters of pressure and roll gap can be adjusted according to requirements.
The embodiment of the invention also provides a sodium ion battery which is prepared from the positive pole piece, the negative pole piece and the diaphragm by lamination or winding; the positive electrode plate and/or the negative electrode plate are/is the dry electrode plate or the dry electrode plate prepared by the preparation method.
The sodium ion battery can be used for preparing aluminum shells, cylinders and soft package batteries.
The present invention will be further described with reference to specific examples, which are not intended to be limiting, so that those skilled in the art will better understand the present invention and practice it.
Example 1
The embodiment relates to a dry method positive plate which is obtained by rolling and bonding 3 layers of same electrode films, wherein an active material layer in each layer of electrode film contains an active positive electrode active material NaNi 1/3 Fe 1/3 Mn 1/ 3 O 2 The specific preparation process of the conductive carbon black super P and the adhesive PTFE is as follows:
(1) 96 parts of positive electrode active material NaNi is calculated in parts by mass 1/3 Fe 1/3 Mn 1/3 O 2 Mixing 2 parts of conductive carbon black super P with 2 parts of adhesive PTFE, and placing into a stirrer to stir and mix under the action of circulating cooling water, wherein the rotation speed of the stirrer is 600r/min, revolution speed is 20 r/min, stirring and mixing for 90 min to obtain a mixture;
(2) Placing the mixture into a stirring tank for shearing and stirring and mixing, wherein the speed of shearing and stirring is 5000 r/min, the stirring temperature is 75 ℃, and the mixture is calendered to form a film under the conditions of 10 t of pressure and 0.2 mm of roll gap, so as to obtain a dry film with the film thickness of 0.2 mm;
(3) Taking one side of a copper mesh (0.08 mm thick and 200 mesh copper mesh) attached to a dry membrane prepared in the step (2), rolling under the conditions of 10 t of pressure and 0.2 mm of roll gap to enable the copper mesh and the dry membrane to be tightly attached to each other to obtain a membrane with the thickness of 0.2 mm, then taking one piece of dry membrane prepared in the step (2) to attach to the other side of the copper mesh, and rolling under the conditions of 10 t of pressure and 0.3 mm of roll gap until the thickness is 0.25 mm to obtain an electrode membrane;
(4) Three electrode films are stacked, and rolled under the conditions of 60. 60 t pressure and 0.25 mm roll gap, so as to obtain the dry positive plate with the thickness of 0.25 mm.
Example 2
This example relates to the preparation of a dry positive plate obtained by roll bonding 3 layers of the same electrode sheets, differing from example 1 only in that: the active material layer in each electrode membrane also contains 3 parts of Na ion conductor material 3 Zr 2 Si 2 PO 12 The remaining parameters are unchanged.
Example 3
This example relates to the preparation of a dry positive plate obtained by roll bonding 3 layers of the same electrode sheets, differing from example 1 only in that: the active material layer in each electrode membrane also comprises 5 parts of Na ion conductor material 3 Zr 2 Si 2 PO 12 The remaining parameters are unchanged.
Example 4
This example relates to the preparation of a dry positive plate obtained by roll bonding 3 layers of the same electrode sheets, differing from example 1 only in that: the active material layer in each electrode membrane also comprises 3 parts of one-dimensional conductive nano material carbon nano tubes, and the rest parameters are unchanged.
Example 5
This example relates to the preparation of a dry positive plate obtained by roll bonding 3 layers of the same electrode sheets, differing from example 2 only in that: the active material layer in each electrode membrane also comprises 5 parts of one-dimensional conductive nano material carbon nano tubes, and the rest parameters are unchanged.
Example 6
The embodiment relates to a dry method positive plate which is obtained by roll bonding 2 layers of the same electrode films, wherein the active material layer in each layer of electrode film contains an active positive electrode active material NaNi 1/3 Fe 1/3 Mn 1/ 3 O 2 Conductive carbon black super P, adhesive PTFE and sodium ion conductor material Na 3 Zr 2 Si 2 PO 12 The preparation process comprises the following steps:
(1) 96 parts of positive electrode active material NaNi is calculated in parts by mass 1/3 Fe 1/3 Mn 1/3 O 2 2 parts of conductive carbon black super P, 2 parts of adhesive PTFE and 3 parts of sodium ion conductor material Na 3 Zr 2 Si 2 PO 12 Mixing, stirring and mixing in a stirrer under the action of circulating cooling water, wherein the rotation speed of the stirrer is 600 r/min, the revolution speed of the stirrer is 20 r/min, and stirring and mixing for 90 min to obtain a mixture;
(2) Placing the mixture into a stirring tank for shearing and stirring and mixing, wherein the speed of shearing and stirring is 5000 r/min, the stirring temperature is 75 ℃, and the mixture is calendered to form a film under the conditions of 5 t of pressure and 0.4 mm of roll gap, so as to obtain a dry film with the film thickness of 0.4 mm;
(3) Taking one side of a copper mesh (0.08 mm thick and 200 mesh copper mesh) attached to a dry membrane prepared in the step (2), rolling under the conditions of 5. 5 t of pressure and 0.4 mm of roll gap to enable the copper mesh and the dry membrane to be tightly attached to each other to obtain a membrane with the thickness of 0.2 mm, then taking one piece of dry membrane prepared in the step (2) to attach to the other side of the copper mesh, and rolling under the conditions of 25 t of pressure and 0.4 mm of roll gap until the thickness is 0.25 mm to obtain an electrode membrane;
(4) Two electrode films are stacked, and rolled under the conditions of pressure of 60 t and roll gap of 0.25 mm, so as to obtain the dry positive plate with thickness of 0.25 mm.
Example 7
The embodiment relates to a dry method positive plate which is obtained by roll bonding 2 layers of different electrode films, wherein an active material layer in the electrode film A contains an active positive electrode active material NaNi 1/3 Fe 1/3 Mn 1/3 O 2 Conductive carbon black super P, adhesive PTFE and sodium ion conductor material Na 3 Zr 2 Si 2 PO 12 The active material layer in the electrode membrane B contains active positive electrode active material NaNi 1/3 Fe 1/3 Mn 1/3 O 2 The preparation method comprises the following steps of:
preparation of electrode membrane a:
(1) 96 parts of positive electrode active material NaNi is calculated in parts by mass 1/3 Fe 1/3 Mn 1/3 O 2 2 parts of conductive carbon black super P, 2 parts of adhesive PTFE and 3 parts of sodium ion conductor material Na 3 Zr 2 Si 2 PO 12 Mixing, stirring and mixing in a stirrer under the action of circulating cooling water, wherein the rotation speed of the stirrer is 600 r/min, the revolution speed of the stirrer is 20 r/min, and stirring and mixing for 90 min to obtain a mixture;
(2) Placing the mixture into a stirring tank for shearing and stirring and mixing, wherein the speed of shearing and stirring is 5000 r/min, the stirring temperature is 75 ℃, and the mixture is calendered to form a film under the conditions of 10 t of pressure and 0.2 mm of roll gap, so as to obtain a dry film with the film thickness of 0.2 mm;
(3) Taking one side of a copper mesh (0.08 mm thick and 200 mesh copper mesh) attached to a dry membrane prepared in the step (2), rolling under the conditions of 10 t of pressure and 0.2 mm of roll gap to enable the copper mesh and the dry membrane to be tightly attached to each other to obtain a membrane with the thickness of 0.2 mm, then taking one piece of dry membrane prepared in the step (2) to attach to the other side of the copper mesh, and rolling under the conditions of 25 t of pressure and 0.3 mm of roll gap until the thickness is 0.3 mm to obtain an electrode membrane A;
preparation of electrode membrane B:
(1) 96 parts of positive electrode active material NaNi is calculated in parts by mass 1/3 Fe 1/3 Mn 1/3 O 2 Mixing 2 parts of conductive carbon black super P, 2 parts of adhesive PTFE and 3 parts of one-dimensional conductive nano material carbon nano tubes, placing the mixture into a stirrer, stirring and mixing under the action of circulating cooling water, wherein the rotation speed of the stirrer is 600 r/min, the revolution speed of the stirrer is 20 r/min, and stirring and mixing for 90 min to obtain a mixture;
(2) Placing the mixture into a stirring tank for shearing and stirring and mixing, wherein the speed of shearing and stirring is 5000 r/min, the stirring temperature is 75 ℃, and the mixture is calendered to form a film under the conditions of 10 t of pressure and 0.2 mm of roll gap, so as to obtain a dry film with the film thickness of 0.2 mm;
(3) Taking one side of a copper mesh (0.08 mm thick and 200 mesh copper mesh) attached to a dry membrane prepared in the step (2), rolling under the conditions of 10 t of pressure and 0.2 mm of roll gap to enable the copper mesh and the dry membrane to be tightly attached to each other to obtain a membrane with the thickness of 0.2 mm, then taking one piece of dry membrane prepared in the step (2) to attach to the other side of the copper mesh, and rolling under the conditions of 25 t of pressure and 0.3 mm of roll gap until the thickness is 0.3 mm to obtain an electrode membrane B;
the electrode film a and the electrode film B prepared above were stacked and rolled under a pressure of 60 t and a roll gap of 0.25 mm to obtain a dry positive electrode sheet having a thickness of 0.3 mm.
Example 8
This example relates to the preparation of a dry positive plate, in which an electrode membrane a and an electrode membrane B prepared in example 7 are stacked in an ABA manner, and rolled and bonded to obtain a dry electrode of 0.3 mm, and the remaining parameters are the same as those in example 7.
Example 9
This example relates to the preparation of a dry positive plate obtained by roll bonding 3 layers of the same electrode sheets, differing from example 1 only in that: simultaneously adding 3 parts of Na ion conductor material to the active material layer 3 Zr 2 Si 2 PO 12 3 parts of one-dimensionalThe conductive nano material carbon nano tube has the same rest parameters.
Example 10
This example relates to the preparation of a dry negative electrode sheet obtained by roll bonding 3 layers of the same electrode sheets, differing from example 1 only in that: naNi as positive electrode active material in active material layer 1/3 Fe 1/3 Mn 1/3 O 2 The anode active material hard carbon is replaced, and the rest parameters are unchanged.
Example 11
This example relates to the preparation of a dry negative electrode sheet obtained by roll bonding 3 layers of the same electrode sheets, differing from example 10 only in that: 3 parts of one-dimensional conductive nano material carbon nano tube is added into the active material layer, and the rest parameters are unchanged.
Comparative example 1
This comparative example relates to the preparation of a dry positive electrode sheet having only a single layer electrode sheet, wherein the active material layer in the electrode sheet contains the active positive electrode active material NaNi 1/3 Fe 1/3 Mn 1/3 O 2 The preparation method comprises the following steps of:
(1) 96 parts of positive electrode active material NaNi is calculated in parts by mass 1/3 Fe 1/3 Mn 1/3 O 2 Mixing 2 parts of conductive carbon black super P, 2 parts of adhesive PTFE and 5 parts of one-dimensional conductive nano material carbon nano tubes, placing the mixture into a stirrer, stirring and mixing under the action of circulating cooling water, wherein the rotation speed of the stirrer is 600 r/min, the revolution speed of the stirrer is 20 r/min, and stirring and mixing for 90 min to obtain a mixture;
(2) Placing the mixture into a stirring tank for shearing and stirring and mixing, wherein the speed of shearing and stirring is 5000 r/min, the stirring temperature is 75 ℃, and the mixture is calendered to form a film under the conditions of 25 t of pressure and 0.3 mm of roll gap, so as to obtain a dry film with the film thickness of 0.3 mm;
(3) And (3) taking one side of a copper mesh (0.08 mm thick and 200 mesh copper mesh) bonded with the dry film prepared in the step (2), rolling under the conditions of 25 t and 0.2 mm roll gap to enable the copper mesh and the dry film to be tightly bonded to obtain a film with the thickness of 0.2 mm, taking one piece of the dry film prepared in the step (2), bonding the dry film with the other side of the copper mesh, and rolling under the conditions of 40 t and 0.2 mm roll gap until the thickness is 0.25 mm to obtain the electrode film.
Comparative example 2
The comparative example relates to the preparation of a wet positive plate, wherein the active material layer in the wet positive plate comprises an active positive active material NaNi 1/3 Fe 1/3 Mn 1/3 O 2 The preparation method comprises the following steps of:
(1) 96 parts of positive electrode active material NaNi is calculated in parts by mass 1/3 Fe 1/3 Mn 1/3 O 2 Mixing 2 parts of conductive carbon black super P, 2 parts of binder PVDF and 3 parts of one-dimensional conductive nano material carbon nanotubes according to the mass ratio of 96:2:2:3, placing the mixture into a stirrer, stirring and mixing under the action of circulating cooling water, wherein the rotation speed of the stirrer is 1800 r/min, the revolution speed of the stirrer is 20 r/min, and stirring and mixing for 90 min to obtain a mixture;
(2) NMP is added into the mixture to adjust the mixture to proper viscosity, the mixture is coated on the upper surface and the lower surface of the aluminum foil, and the wet positive plate is obtained after drying.
Comparative example 3
This comparative example relates to the preparation of a wet positive plate, which differs from comparative example 2 only in that: the active material layer of the wet positive plate does not contain one-dimensional conductive nano material carbon nano tubes.
Comparative example 4
This comparative example relates to the preparation of a wet cathode sheet, which differs from comparative example 2 only in that: naNi as positive electrode active material in active material layer 1/3 Fe 1/3 Mn 1/3 O 2 The anode active material hard carbon is replaced, and the rest parameters are unchanged.
Application and performance characterization
1. Pole piece performance test
The preparation method of the reference positive electrode plate comprises the following steps:
this comparative example relates toThe dry positive plate is prepared by rolling a dry film and an aluminum foil, wherein an active material layer in the electrode film contains an active positive electrode active material NaNi 1/3 Fe 1/3 Mn 1/3 O 2 The preparation method comprises the following steps of:
96 parts of positive electrode active material NaNi is calculated in parts by mass 1/3 Fe 1/3 Mn 1/3 O 2 Mixing 2 parts of conductive carbon black super P, 2 parts of adhesive PTFE and 5 parts of one-dimensional conductive nano material carbon nano tubes, placing the mixture into a stirrer, stirring and mixing under the action of circulating cooling water, wherein the rotation speed of the stirrer is 600 r/min, the revolution speed of the stirrer is 20 r/min, and stirring and mixing for 90 min to obtain a mixture;
placing the mixture into a stirring tank for shearing and stirring and mixing, wherein the speed of shearing and stirring is 5000 r/min, the stirring temperature is 75 ℃, and the mixture is calendered to form a film under the conditions of 25 t of pressure and 0.3 mm of roll gap, so as to obtain a dry film with the film thickness of 0.3 mm;
two dry films are respectively attached to the upper and lower surfaces of an aluminum foil, wherein the aluminum foil is 0.013 and mm thick, and then an electrode film with the film thickness of 0.25 and mm is prepared by a rolling mode.
The preparation method of the reference negative electrode plate comprises the following steps:
the embodiment relates to preparation of a dry-method negative plate, which is obtained by roll bonding a dry-method membrane and an aluminum foil material, wherein an active material layer in each electrode membrane comprises active negative active material hard carbon, conductive carbon black super P and a bonding agent PTFE, and the preparation process comprises the following steps:
mixing 96 parts by mass of anode active material hard carbon, 2 parts by mass of conductive carbon black super P and 2 parts by mass of binder PTFE, placing the mixture into a stirrer, stirring and mixing under the action of circulating cooling water, wherein the rotation speed of the stirrer is 600 r/min, the revolution speed of the stirrer is 20 r/min, and stirring and mixing for 90 min to obtain a mixture;
placing the mixture into a stirring tank for shearing and stirring and mixing, wherein the speed of shearing and stirring is 5000 r/min, the stirring temperature is 75 ℃, and the mixture is calendered to form a film under the conditions of 10 t of pressure and 0.2 mm of roll gap, so as to obtain a dry film with the film thickness of 0.2 mm;
two dry films are respectively attached to the upper surface and the lower surface of an aluminum foil, wherein the aluminum foil is 0.013 and mm thick, and then the electrode film with the film thickness of 0.25 mm is prepared by a rolling mode.
The positive electrode sheet or the negative electrode sheet prepared in the above examples and comparative examples were tested for the surface density, the peel force, and the sheet resistance of the reference positive/negative electrode sheet, and the specific test method was as follows:
surface Density test: cutting copper wires with a cutting machine, wherein the cutting area is 1540.25 mm 2 Cutting 10 pieces, calculating average value, and obtaining copper net mass m 1 The method comprises the steps of carrying out a first treatment on the surface of the The electrode slice prepared by the method is cut by a cutting machine, and the area of the cut is 1540.25 mm 2 Cutting 10 pieces, calculating average value, and obtaining the mass m of the pole piece 2 The method comprises the steps of carrying out a first treatment on the surface of the Surface Density= (m) according to formula 2 -m 1 ) And/1540.25, calculating the surface density.
Peel force test: taking electrode slices, carrying out vacuum baking at 60 ℃ for 24 h, then naturally cooling, and cutting the electrode slices into strips of 2.5 multiplied by 25 cm for later use; pasting NITTOTAPE double-sided adhesive tape on the stripping steel plate, and enabling the roller to reciprocate for 4 times to enable the adhesive tape and the stripping steel plate to be tightly adhered together; the strip is overlapped with the adhesive tape, the roller moves back and forth for 6 times, then the steel plate is fixed on the stripping equipment, the stripping direction of the pole piece is always controlled at 90 degrees, and the stripping force is obtained by reading the equipment data.
And (3) pole piece resistance test: taking electrode slices, carrying out vacuum baking at 60 ℃ for 24 h, then naturally cooling, and cutting the electrode slices into strips of 2.5 multiplied by 15 cm for later use; regulating the pressure of the pole piece resistance equipment to a stable value, testing the pole piece resistance, testing a blank sample for 6 times before testing, selecting ten points for testing the pole piece resistance, taking an average value, and subtracting the blank sample average value from the pole piece resistance average value to obtain pole piece resistance data;
the test results are shown in Table 1 below:
TABLE 1
Figure SMS_1
As can be seen from table 1, the electrode sheets prepared in examples 1 to 9 and comparative examples 1 and reference positive electrode sheets have a large difference in peel force and sheet resistance under the same surface density, and compared with the electrode sheets prepared in comparative examples 1 to 9 having a single-layer structure, the electrode sheets prepared in examples 1 to 9 having a multi-layer structure have a large peel force and low sheet resistance, and the dry positive electrode sheets (examples 1 to 5 and examples 8 and 9) including three-layer electrode sheets have a larger peel force than the dry positive electrode sheets (examples 6 and 7) including two-layer electrode sheets prepared by roll pressing. In addition, the difference in the surface density, the stripping force and the pole piece resistance between the dry negative pole piece obtained by rolling the three-layer electrode membrane and the reference negative pole piece (the dry negative pole piece obtained by preparing the electrode membrane with a single-layer structure) can further illustrate that the design of the multi-layer structure in the dry electrode piece and the existence of the conductive metal net can improve or maintain the high surface density of the pole piece, and simultaneously greatly improve the stripping force of the active substance layer and the current collector in the pole piece and reduce the pole piece resistance.
In addition, as can be seen from examples 1 to 11, the sodium ion conductor material is introduced into the active material layer of the electrode sheet, the electrode sheet resistance is increased to a certain extent, and the electrode sheet resistance is increased along with the increase of the addition amount of the sodium ion conductor material, but after the one-dimensional conductive nanomaterial is introduced, the electrode sheet resistance is obviously reduced, and the dry electrode sheet with high conductivity and ion conductivity can be obtained under the condition that the one-dimensional conductive nanomaterial and the sodium ion conductor material exist at the same time.
Comparative examples 2-4 are pole pieces prepared by a wet process, and compared with pole pieces prepared by a dry process, the pole pieces have small stripping force and high resistance.
2. Preparation and performance test of soft package battery
The positive electrode plate or the negative electrode plate prepared in the above examples and comparative examples are respectively adopted to prepare corresponding soft package batteries;
the positive pole piece, the negative pole piece and the diaphragm are assembled, and the soft package battery is prepared through liquid injection, encapsulation and formation, and the DC internal resistance, the energy density and the multiplying power performance of the prepared soft package battery are tested, and the specific operation is as follows:
and D.C. internal resistance test: the batteries were tested for capacity in a 25+ -2deg.C incubator as follows: dormancy is performed for 60 min; the cell was discharged to 2.0V with a current of 1C; dormancy is carried out for 5 min; constant current and constant voltage charging the battery to 4.0V with a current of 1C; repeating the steps, and taking the capacity of the second time as the actual capacity of the battery; 1C constant-current and constant-voltage charging to 4.0V; the battery was adjusted to 50% SOC using a current of 1C; sleep for 30 min, recording the voltage V0 at this time as the OCV of the SOC; recording the voltage V1 of the Ts by using the discharge current I1 and the discharge time Ts; the discharge direct current internal resistance calculation formula: DCIR release= (V0-V1)/I1.
And (3) multiplying power performance test: record 0.1C constant current constant voltage charge to 4.0V; 0.1C was discharged to 2.0V, resulting in a capacity of C1; record 0.1C constant current constant voltage charge to 4.0V; 5C to 2.0V, resulting in a capacity of C2; the rate performance of the battery was measured by a calculated value of C2/c1×100%, and the larger this value, the better the rate performance was explained.
The results of the above test are shown in table 2 below:
TABLE 2
Figure SMS_2
As can be seen from the performance of the soft-pack battery corresponding to samples 1 to 3 in table 2, as the content of the sodium ion conductor material increases, the direct current internal resistance of the battery decreases and the rate performance increases, because the introduction of the sodium ion conductor material is beneficial to the ion transmission of the battery in the charge and discharge processes, thereby optimizing the rate performance of the battery; in addition, as can be seen from the sample 1, the sample 4 and the sample 5, the introduction of the one-dimensional conductive nanomaterial can also reduce the internal resistance of direct current and the improvement of the rate capability.
Sample 2, sample 6 and sample 12 are soft-packed batteries prepared by adopting the dry-method positive electrode plate and the reference negative electrode plate prepared in the embodiment 2, the embodiment 6 and the comparative example 1 respectively, and under the condition of the same surface density, the number of metal mesh layers is increased, so that the reduction of direct current internal resistance and the improvement of rate capability are facilitated; in addition, by simultaneously introducing the sodium ion conductor material and the one-dimensional conductive nano material into the dry positive plate, the multiplying power performance can be obviously improved, the direct current internal resistance can be reduced, and the multiplying power performance of the sample 7 with the two-layer metal mesh structure is superior to that of the sample 1 with the three-layer metal mesh structure.
As can be seen from samples 7-9, the film sheet only containing the sodium ion conductor material and the film sheet only containing the one-dimensional conductive nano material are cross-compounded, so that the sodium ion conductor material and the one-dimensional conductive material are contained in the pole piece at the same time, and the performance of the battery cell (sample 8) can be effectively improved; in addition, the positive electrode material is directly compounded with the sodium ion conductor material and the one-dimensional conductive nano material, and then rolled with a multi-layer copper mesh to prepare the pole piece, so that the performance of the battery cell is improved (sample 9). In addition, as can be seen from the performance differences of samples 10, 11 and 16 comprising different negative electrode sheets, the electrode sheets comprising the multi-layer copper mesh and/or the one-dimensional conductive nanomaterial are more beneficial to the performance improvement of the battery cell.
In summary, under the condition that the positive electrode material and the negative electrode material have similar surface densities, the rate performance of the battery can be effectively improved by introducing the multilayer copper mesh, and on the basis, the rate performance of the battery can be further optimized by introducing the sodium ion conductor material and/or the one-dimensional conductive nano material; in addition, the introduction of the multilayer copper mesh can improve the surface density of the electrode slice on the premise of ensuring the stripping force between the active layer and the current collector, thereby being beneficial to the preparation of the battery with high surface density and high rate performance.
The above-described embodiments are merely preferred embodiments for fully explaining the present invention, and the scope of the present invention is not limited thereto. Equivalent substitutions and modifications will occur to those skilled in the art based on the present invention, and are intended to be within the scope of the present invention. The protection scope of the invention is subject to the claims.

Claims (11)

1. The dry electrode slice is characterized by comprising two or more layers of electrode membranes which are mutually adhered, wherein the electrode membrane comprises a conductive metal net and an active material layer arranged on the surface of the conductive metal net, and the active material layer at least comprises a positive electrode active material/negative electrode active material, a conductive agent and a binder.
2. The dry electrode tab according to claim 1, wherein the positive electrode active material is Na x M y M’ z O 2 、Na x’ A[Fe(CN) 6 ] y’ · z’H 2 O, sodium iron phosphate, sodium vanadium fluorophosphate, sodium pyrophosphate, sodium oxalate, sodium carbonate, wherein M is one or more of Fe, co, ni, cr, mn, cu, M' is one or more of Li, mg, ca, al, B, A is one or more of Fe, co, ni, mn, 0.5.ltoreq.x.ltoreq.1.1, 0.ltoreq.y, z.ltoreq.1, y+z=1, 0<x’<2，0<y’<1，z’≥0；
The negative electrode active material is one or more of hard carbon, doped or coated modified hard carbon, soft carbon and doped or coated modified soft carbon;
the conductive agent is selected from one or more of conductive carbon black, graphite micropowder, carbon nano tube and graphene;
the mass ratio of the positive electrode active material to the negative electrode active material to the conductive agent to the binder is 80-97:0.5-20:0.5-20.
3. The dry electrode tab of claim 1, wherein the active material layer further comprises one or more of a one-dimensional conductive material, a two-dimensional conductive material, and a sodium ion conductor material.
4. The dry electrode sheet according to claim 3, wherein the one-dimensional conductive material is one or more of single-walled carbon nanotubes, multi-walled carbon nanotubes, metal nanofibers; the two-dimensional conductive material is graphene;
the sodium ion conductor material is beta' -Al 2 O 3 And/or conductivity of 10 -7 -10 -2 S/cm sodium-containing compound.
5. The dry electrode sheet according to claim 4, wherein the sodium-containing compound is Na 3 Zr 2 Si 2 PO 12 And/or Na 3 PS 4 。
6. A dry electrode sheet according to claim 3, wherein when the one-dimensional conductive material and/or the two-dimensional conductive material is contained in the active material layer, the content of the one-dimensional conductive material and/or the two-dimensional conductive material is 0.5% -10% of the mass of the active material layer;
when the sodium ion conductor material is contained in the active material layer, the content of the sodium ion conductor material is 0.5% -10% of the mass of the active material layer.
7. The dry electrode tab of claim 1, wherein the conductive metal mesh is a copper mesh, an aluminum mesh, or a stainless steel mesh; the mesh number of the conductive metal net is 200-1000 meshes, and the thickness of the conductive metal net is 0.05-1 mm.
8. The dry electrode tab of claim 1, wherein the dry electrode tab has a thickness of 0.1-1.5 a mm a.
9. The dry electrode sheet according to claim 1, wherein each layer of electrode membrane in the dry electrode sheet is the same or different electrode membrane;
when the dry electrode slice is obtained by mutually bonding two or three layers of same electrode films, the active material layer of the electrode film contains one-dimensional and/or two-dimensional conductive materials and sodium ion conductor materials;
when the dry electrode plate is obtained by mutually bonding two or three electrode films, wherein at least two electrode films are different, at least one active material layer of the electrode films in the dry electrode plate contains one-dimensional and/or two-dimensional conductive materials, and at least one active material layer of the electrode films contains sodium ion conductive materials.
10. A method for preparing the dry electrode sheet according to any one of claims 1 to 9, comprising the steps of:
(1) Weighing the raw materials according to the composition ratio of the active material layer, and uniformly mixing at 0-25 ℃ to obtain a mixture;
(2) The mixture is sheared and mixed and then calendared into a film to obtain a dry membrane;
(3) Respectively attaching dry-method diaphragms to the upper and lower surfaces of a conductive metal net, and preparing an electrode diaphragm in a rolling manner;
(4) And stacking the electrode films prepared by the steps according to a preset sequencing mode, and rolling to obtain the dry electrode plate.
11. The sodium ion battery is characterized in that the sodium ion battery is prepared from a positive pole piece, a negative pole piece and a diaphragm in a lamination or winding mode; the positive electrode plate and/or the negative electrode plate is the dry electrode plate according to any one of claims 1-9, or the dry electrode plate prepared by the preparation method according to claim 10.
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CN113178557A (en) * 2021-04-26 2021-07-27 昆山宝创新能源科技有限公司 Battery material, battery pole piece, preparation method of battery pole piece and battery
CN113054155A (en) * 2021-04-27 2021-06-29 昆山宝创新能源科技有限公司 Preparation method of pole piece and lithium ion battery
CN218274694U (en) * 2022-02-28 2023-01-10 上海桔晟科技有限公司 Dry method composite electrode pole piece and lithium battery
CN114759158A (en) * 2022-04-13 2022-07-15 合肥国轩高科动力能源有限公司 Preparation method of dry-method electrode pole piece and secondary battery
CN115132961A (en) * 2022-06-27 2022-09-30 蜂巢能源科技(无锡)有限公司 Positive pole piece of sodium-ion battery and preparation method and application thereof
CN115425173A (en) * 2022-09-29 2022-12-02 浙江大象新能源科技有限公司 Sodium ion positive electrode plate, preparation method thereof and sodium ion battery
CN115621410A (en) * 2022-11-14 2023-01-17 楚能新能源股份有限公司 Preparation method of dry electrode pole piece, electrode pole piece and application thereof

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN117253988A (en) * 2023-11-17 2023-12-19 江苏中兴派能电池有限公司 Positive plate and preparation method thereof, battery cell and battery and preparation method thereof
CN117253988B (en) * 2023-11-17 2024-01-30 江苏中兴派能电池有限公司 Positive plate and preparation method thereof, battery cell and battery and preparation method thereof

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