Method for preparing porous electrode by secondary fluid injection and battery
The preparation of porous electrodes by secondary fluid injection method solves the problems of stress concentration and powder loss during winding at high curvature by traditional methods, achieving higher flexibility and charge and discharge dynamics, while reducing costs and equipment complexity Spend.
Patent Information
- Application Number
- CN202411418833.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-10-11
- Publication Date
- 2025-02-14
AI Technical Summary
Traditional lithium-ion battery electrode preparation methods can easily lead to stress concentration and powder loss problems when wound at high curvature, and laser etching or mechanical printing technology can easily damage the structure of the active material and reduce the battery cell capacity.
The porous electrode is prepared by the secondary fluid injection method, and the lithium-ion battery electrode sheet with a porous structure is formed by wet coating, preparing secondary fluid, spraying injection liquid and baking pores.
This method does not damage the active material structure, avoids mechanical fatigue damage of the current collector, improves the flexibility of the electrode and the charging and discharge dynamics of the lithium-ion battery, while reducing costs and equipment complexity.
Smart Images
Figure CN119447187A_ABST
Abstract
Description
Technical Field
[0001] The invention belongs to the technical field of lithium ion batteries, and in particular relates to a method for preparing a porous electrode by injecting a secondary fluid and a battery. Background Art
[0002] The energy density and charge and discharge speed of lithium-ion batteries have become the focus of attention at this stage. In the cell manufacturing process, the cell production and winding require the electrodes to have higher flexibility, while the winding of traditional electrodes at high curvature faces huge challenges, especially the powder loss problem caused by stress concentration. And the increase in charge and discharge rate makes electrode design more important.
[0003] At present, in order to improve the flexibility of the electrode and the charging and discharging speed of the battery, laser etching or mechanical printing technology is generally used to make holes in the electrode. For example: a method for manufacturing an electrode using laser etching and an electrode manufacturing device for executing the method; the electrode hole-making technology by laser ablation of the electrode surface is easy to destroy the structural integrity of the active material and reduce the capacity of the battery cell. A hole-making roller and its method and application for improving the porosity of the electrode. The technical solution is to modify the rolling equipment, introduce evenly arranged hole-making nails on the roller body, and use the hole-making nails to mechanically make holes on the surface of the electrode during rolling.
[0004] Traditional porous electrode preparation methods mainly use laser etching or mechanical printing to make holes, which will damage the structure of the electrode active material and reduce the capacity of the material. On the other hand, it will cause mechanical fatigue damage to the current collector, which will reduce the application life of the current collector. In addition, the development of new laser hole making or mechanical printing equipment requires higher material and R&D costs. Summary of the invention
[0005] The purpose of the present invention is to overcome the above-mentioned defects in the prior art and provide a method and a battery for preparing a porous electrode by injecting a secondary fluid; the secondary fluid is injected into the coating surface to form pores, which will not damage the structure of the active material or cause mechanical fatigue damage to the current collector, and the operation is simple and easy with low cost.
[0006] To achieve the above object, the present invention provides a method for preparing a porous electrode by secondary fluid injection, comprising the following steps:
[0007] Step S1: wet coating: coating the prepared electrode slurry onto the current collector to obtain a wet electrode sheet for a lithium-ion battery;
[0008] Step S2: preparing a secondary fluid: adding a dispersant and a solid substance into a solvent in a preset ratio and in a certain order, and continuously stirring until uniformly mixed to obtain a secondary fluid;
[0009] Step S3: secondary fluid injection: injecting the secondary fluid onto the upper surface of the wet electrode;
[0010] Step S4: Baking and forming holes: Baking is performed according to a program to increase the temperature. The solvent on the secondary fluid evaporates after baking, leaving holes on the electrode.
[0011] Preferably, the baking time in step S4 is determined by the coating speed in step S1, and the heating and baking method is vacuum drying.
[0012] Preferably, the baking temperature is divided into three sections, wherein the first section baking temperature is 50-70°C, the second section baking temperature is 80-100°C, and the third section baking temperature is 120°C. Ventilation in the second and third sections accelerates heat conduction; the coating speed is ≤10m / min.
[0013] Preferably, the spraying in step S3 is controlled by a pressure regulator to spray the secondary fluid onto the upper surface of the electrode slurry, the diameter of the spray end nozzle is between 50 and 200 μm, and the injection volume of the secondary fluid is ≤0.1 μL.
[0014] Preferably, the secondary fluid is injected in a direction perpendicular to the upper surface of the electrode slurry, the nozzle diameter and injection volume can adjust the aperture size and shape, the array arrangement of the injection valves can adjust the channel pattern, and the injection pressure is ≤10MPa.
[0015] Preferably, in step S2, the contents of the components in the secondary fluid are: 90% to 96% solvent, 2% to 5% dispersant, and 2% to 5% solid matter; the solid content of the secondary fluid is 4% to 10%, and the viscosity is 200 MPa·s to 1500 MPa·s.
[0016] Preferably, the solvent is water, methanol, ethanol, acetone, dimethyl carbonate, diethyl carbonate, ethyl methyl carbonate, ethylene carbonate or propylene carbonate; the dispersant is any one of an inorganic dispersant, an organic dispersant or a polymer dispersant; the solid material is a conductive agent, a solid electrolyte with ion conductivity or a mixture of the two.
[0017] Preferably, the inorganic dispersant is a polyphosphate, such as sodium pyrophosphate, sodium tripolyphosphate or sodium hexametaphosphate; the organic dispersant is an alkyl aryl phosphate, alkyl benzene sulfonate, dialkyl sulfosuccinate, trimethyl stearamide chloride, polyoxyethylene alkylphenol ether or sorbitol alkylate; the polymer dispersant is carboxymethyl cellulose, polycarboxylate, poly (meth) acrylic acid derivative, maleic anhydride copolymer, CMC-Li or PAA-Li with ion-conducting effect; the conductive agent is any one or more of conductive carbon black, graphene, carbon nanotubes, vapor-grown carbon fiber, and conductive graphite; the solid electrolyte is poly Any one or more of a polymer solid electrolyte, an oxide solid electrolyte or a sulfide solid electrolyte; the polymer solid electrolyte includes polyethylene oxide PEO, polyacrylonitrile PAN, polyvinylidene fluoride PVDF, polymethyl methacrylate PMMA, polypropylene oxide PPO, polyvinylidene chloride PVDC and a single-ion polymer electrolyte; the oxide solid electrolyte includes a crystalline electrolyte and a glassy (amorphous) electrolyte; the crystalline electrolyte includes a garnet-type solid electrolyte, a perovskite-type solid electrolyte, and a NASICON-type solid electrolyte; the glassy electrolyte includes an antiperovskite-type solid electrolyte and a LiPON thin film solid electrolyte.
[0018] The present invention also provides a lithium-ion battery pole piece with a porous structure prepared by the above-mentioned method of preparing a porous electrode by injecting a secondary fluid, comprising a current collector, an electrode coating provided on the current collector, and a plurality of pore structures uniformly distributed in the electrode coating, wherein the pore structure is obtained by evaporation of a solvent in a secondary fluid; the lithium-ion battery pole piece is used for a porous negative electrode or a porous positive electrode.
[0019] The present invention also provides a battery, comprising the lithium-ion battery pole piece with a porous structure as described above.
[0020] Preferably, the lithium-ion battery pole piece is preferably used as a porous negative electrode.
[0021] Compared with the prior art, the present invention has the following beneficial effects:
[0022] 1. The present invention firstly performs wet coating, and applies the prepared electrode slurry to the current collector to obtain a wet electrode sheet of a lithium-ion battery; secondly, prepares a secondary fluid: adds a dispersant and a solid matter into a solvent according to a preset ratio and a certain order, and continuously stirs until uniformly mixed to obtain a secondary fluid; thirdly, injects the secondary fluid: pressurizes and injects the secondary fluid onto the upper surface of the wet electrode sheet; impacts pits on the electrode slurry on the upper surface of the wet electrode sheet, and fills them with the secondary fluid; finally, bakes and forms holes: bakes according to a program, and the solvent on the secondary fluid evaporates after baking, leaving pores on the electrode sheet; the electrode slurry is filled due to its inability to flow independently, and multiple pores formed by the evaporation of the solvent are formed, thereby preparing a lithium-ion battery electrode sheet with a porous structure.
[0023] 2. The porous electrode in the present invention has higher flexibility and is particularly suitable for wound lithium-ion batteries; the porous electrode can also improve the rate performance of lithium-ion batteries and greatly improve the dynamics of lithium-ion batteries during charging and discharging; the porous electrode is also beneficial to improving the wettability of the electrolyte and ensuring the uniform diffusion of the electrolyte in the electrode.
[0024] 3. The porous electrode preparation method of the present invention is simpler, and the material cost and operating cost during use are lower. The mechanical fatigue damage of the current collector will not be caused during the preparation process, and the performance of the current collector can be guaranteed to be stable. It will not damage the structure of the active main material, and will not cause compensation in the cell capacity design due to the ablation of part of the active material, which is conducive to improving the stability of the electrode in calendar cycle use.
[0025] 4. The porous electrode in the present invention is also beneficial to improving the safety of lithium-ion batteries, especially the safety issues caused by mechanical abuse. BRIEF DESCRIPTION OF THE DRAWINGS
[0026] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.
[0027] Figure 1 It is a schematic flow chart of a method for preparing a porous electrode by secondary fluid injection provided by the present invention;
[0028] Figure 2 It is a partial enlarged plan view of the porous electrode provided by the present invention;
[0029] Figure 3 It is a structural schematic diagram of the secondary fluid injection system provided by the present invention.
[0030] Included in the figure are:
[0031] 11. Pressurized liquid storage tank; 12. Diversion pipe; 13. Injection valve; 14. Stirring device; 15. Pressure regulator; 1. Secondary fluid injection system. DETAILED DESCRIPTION
[0032] The technical scheme in this embodiment of the present invention will be clearly and completely described below in conjunction with the drawings in this embodiment of the present invention. Obviously, the described embodiment is one embodiment of the present invention, not all embodiments of the present invention. Based on this embodiment of the present invention, all other embodiments of the present invention obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.
[0033] Embodiment 1
[0034] Please refer to Figures 1 to 3 The present invention provides a method for preparing a porous electrode by secondary fluid injection; the method comprises the following steps:
[0035] Step S1: wet coating: prepare an electrode slurry and coat it on the current collector. Specifically, the formula of the electrode slurry can use existing technology, add active materials, binders, and conductive agents into a solvent according to a preset ratio and a certain order, and continuously stir until uniformly mixed to obtain electrode slurry. The prepared electrode slurry is coated on the current collector to obtain a wet electrode sheet of a lithium-ion battery;
[0036] Step S2: preparing a secondary fluid: the secondary fluid comprises a solvent, a dispersant dissolved in the solvent and a solid substance dispersed in the solvent; specifically, the dispersant and the solid substance are added to the solvent in a preset ratio and in a certain order, and continuously stirred until uniformly mixed to obtain the secondary fluid;
[0037] In step S2, the contents of the components in the secondary fluid are: 90% to 96% solvent, 2% to 5% dispersant, and 2% to 5% solid matter; the solid content of the secondary fluid is 4% to 10%, and the viscosity is 200 MPa·s to 1500 MPa·s.
[0038] The solvent is any one of water, methanol, ethanol, acetone, dimethyl carbonate, diethyl carbonate, ethyl methyl carbonate, ethylene carbonate or propylene carbonate.
[0039] The dispersant is any one of an inorganic dispersant, an organic dispersant or a polymer dispersant.
[0040] The solid object is a conductive agent, a solid electrolyte having an ion-conducting function, or a mixture of the two.
[0041] The inorganic dispersant is a polyphosphate, such as sodium pyrophosphate, sodium tripolyphosphate or sodium hexametaphosphate.
[0042] The organic dispersant is alkyl aryl phosphate, alkyl benzene sulfonate, dialkyl sulfosuccinate, trimethyl stearamide chloride, polyoxyethylene alkylphenol ether or sorbitol alkylate.
[0043] The polymer dispersant is carboxymethyl cellulose, polycarboxylate, poly(meth)acrylic acid derivative, maleic anhydride copolymer; among the polymer dispersants, CMC-Li and PAA-Li having ion-conducting function are more preferred.
[0044] The conductive agent is any one or more of conductive carbon black, graphene, carbon nanotubes, vapor-grown carbon fibers, and conductive graphite.
[0045] The solid electrolyte is any one or more of a polymer solid electrolyte, an oxide solid electrolyte or a sulfide solid electrolyte.
[0046] The polymer solid electrolyte comprises polyethylene oxide PEO, polyacrylonitrile PAN, polyvinylidene fluoride PVDF, polymethyl methacrylate PMMA, polypropylene oxide PPO, polyvinylidene chloride PVDC and a single ion polymer electrolyte.
[0047] The oxide solid electrolyte includes a crystalline electrolyte and a glassy (amorphous) electrolyte; the crystalline electrolyte includes a garnet-type solid electrolyte, a perovskite-type solid electrolyte, and a NASICON-type solid electrolyte; the glassy electrolyte includes an antiperovskite-type solid electrolyte and a LiPON thin film solid electrolyte.
[0048] Step S3: Secondary fluid injection: The secondary fluid is injected by spraying onto the upper surface of the wet electrode plate; further, when the secondary fluid is injected by spraying, it is preferably injected in a direction perpendicular to the upper surface of the electrode slurry to ensure the regularity and stability of the porous structure.
[0049] Step S4: Baking to form pores: Baking is performed according to a program to increase the temperature. The solvent on the secondary fluid evaporates after baking, leaving pores on the electrode. The electrode slurry cannot flow independently and fills the multiple pores formed by the evaporation of the solvent, thereby preparing a lithium-ion battery electrode with a porous structure.
[0050] The wet electrode of the lithium-ion battery is heated and baked, wherein the baking time is determined by the coating speed in step S1, and the heating and baking method is vacuum drying.
[0051] During the heating and baking process, the side of the lithium-ion battery wet electrode sheet coated with the electrode slurry is placed upward and parallel to the horizontal plane. The solvent completely evaporates during the heating and baking process to generate water vapor, and the gas escapes along the thickness direction of the lithium-ion battery electrode sheet to form channels.
[0052] When the secondary fluid is injected, it impacts the electrode slurry, creates pits, and fills them with the secondary fluid; if the secondary fluid is injected vertically, the lithium-ion battery electrode has multiple pore structures, and the pore structures are arranged vertically and evenly. When lithium ions in the electrolyte are transmitted, they can be efficiently transmitted to the interior of the electrode through the directional straight holes with low tortuosity, and then further penetrate into the active particles through the vertical pore structure on the side, thereby improving the overall transmission efficiency of liquid-phase ions in the porous electrode.
[0053] The preparation method of this embodiment is low-cost, simple in process, and has good compatibility with current industrial methods. Only a small amount of secondary fluid injection system 1 needs to be added to realize large-scale manufacturing of electrodes with this special structure.
[0054] In step S4, the heating and baking must be carried out with the electrode to be dried facing upward, and the drying process parameters (such as temperature and wind speed) should control the solvent evaporation rate. The solvent evaporation to a certain amount means that the solid content of the slurry or the slurry viscosity rises to a certain value, so that the slurry cannot flow independently and fill the formed channels.
[0055] Preferably, the process and equipment can directly adopt the current mainstream baking technology in the industry. In this embodiment, vacuum multi-stage baking is adopted, the baking temperature of the first stage is 50-70°C, the baking temperature of the second stage is 80-100°C, and the baking temperature of the third stage is 120°C; wherein, ventilation in the second and third stages accelerates heat conduction; the coating speed is ≤10m / min.
[0056] like Figure 3 As shown, in the step S3, the secondary fluid is injected by a secondary fluid injection system 1, and the secondary fluid injection system 1 includes a pressurized liquid storage tank 11, a diversion pipe 12 connected to the pressurized liquid storage tank 11, and an injection valve 13 installed at the end of the diversion pipe 12, and the pressurized liquid storage tank 11 is equipped with a stirring device 14 for stirring the secondary fluid.
[0057] Specifically, the dispersant and the solid matter are added to the solvent in a preset proportion and a certain order, and are stirred by a stirring device 14 until they are evenly mixed to obtain a secondary fluid, which is stored in a pressurized liquid storage tank 11 and flows into an injection valve 13 through a diversion pipe 12. The injection valve 13 is equipped with a pressure regulator 15. The injection valve 13 controls the outward injection of the secondary fluid. Under the control of the pressure regulator 15, the injected secondary fluid is sprayed onto the upper surface of the electrode slurry. The injection pressure is ≤10MPa. A circular nozzle is used at the end of the injection valve 13. The diameter of the nozzle is relatively small, the injection pressure is adjustable, and the injection volume is also small, so that a tiny injection pit can be formed on the upper surface of the electrode slurry, which is filled with the secondary fluid before drying; but after drying, the solvent evaporates to form a pore.
[0058] Furthermore, the diameter of the circular nozzle is between 50 and 200 μm, and the injection volume of the secondary fluid is ≤ 0.1 μL; generally, a plurality of injection valves 13 are arranged in transverse and longitudinal arrays so as to cover the entire upper surface of the electrode slurry.
[0059] Furthermore, the diameter of the nozzle at the end of the injection valve 13 is preferably between 100 and 150 μm, the secondary fluid injection is performed in a non-contact manner, and the injection valve 13 is opened and closed by an internal plunger controlled by a piezoelectric trigger pulse; by changing the injection amount of the secondary fluid, directional channels with different shapes and sizes are created, and by adjusting the group arrangement of different injection valves 13, different channel arrangement patterns are formed, such as regular arrangement, chaotic arrangement or intermittent arrangement.
[0060] Embodiment 2
[0061] The present invention provides a lithium-ion battery pole piece with a porous structure prepared by a method for preparing a porous electrode by injecting a secondary fluid as described in Example 1, comprising a current collector, an electrode coating provided on the current collector, and a plurality of pore structures uniformly distributed in the electrode coating, wherein the pore structures are obtained by evaporating a solvent in a secondary fluid; the lithium-ion battery pole piece is used for a porous negative electrode or a porous positive electrode; and is generally preferably used for making a porous negative electrode.
[0062] Embodiment 3
[0063] The present invention provides a battery, comprising a lithium-ion battery pole piece with a porous structure as described in the second embodiment, a diaphragm, an electrolyte and a casing.
[0064] Embodiment 4
[0065] Step S1: coating the negative electrode active material particles on the copper foil current collector by transfer coating.
[0066] Step S2: The secondary fluid is composed of 95% water, 2.5% CMC-Li, and 2.5% conductive carbon black. The solid content of the secondary fluid is 5%, and the viscosity is about 500 MPa·s.
[0067] Step S3: inject the prepared secondary fluid into the pressurized liquid storage tank 11 and inject it onto the upper surface of the coated wet film through a circular nozzle. The diameter of the circular nozzle is 100 μm, and the injection volume of the secondary fluid is about 0.01 μL.
[0068] Step S4: After drying, a porous negative electrode with a standardized arrangement is produced.
[0069] The pore diameter distribution range of the prepared porous electrode is ≤10 μm, and the pore depth range is less than the single-sided coating thickness.
[0070] Embodiment 5
[0071] Step S1: coating the negative electrode active material particles on the aluminum foil current collector by transfer coating.
[0072] Step S2: The secondary fluid is composed of 95% water, 2.5% CMC-Li, and 2.5% oxide solid electrolyte. The solid content of the secondary fluid is 5%, and the viscosity is about 500 MPa·s.
[0073] Step S3: inject the prepared secondary fluid into the pressurized liquid storage tank 11 and inject it onto the upper surface of the coated wet film through a circular nozzle. The diameter of the circular nozzle is 100 μm, and the injection volume of the secondary fluid is about 0.01 μL.
[0074] Step S4: After drying, a porous negative electrode with disordered arrangement is produced.
[0075] The pore diameter of the prepared porous electrode is in the range of ≦10 μm, and the pore depth range is less than the thickness of the single-sided coating.
[0076] Embodiment 6
[0077] Step S1: coating the negative electrode active material particles on the copper foil current collector by transfer coating.
[0078] Step S2: The secondary fluid is composed of 92% dimethyl carbonate, 4% CMC-Li, 2% graphene, and 2% solid electrolyte. The solid content of the secondary fluid is 8%, and the viscosity is about 900 MPa·s.
[0079] Step S3: inject the prepared secondary fluid into the pressurized liquid storage tank 11 and inject it onto the upper surface of the coated wet film through a circular nozzle. The diameter of the circular nozzle is 150 μm, and the injection volume of the secondary fluid is about 0.06 μL.
[0080] Step S4: After drying, a porous negative electrode with a standardized arrangement is produced.
[0081] The pore diameter of the prepared porous electrode is in the range of ≦8 μm, and the pore depth range is less than the thickness of the single-sided coating.
[0082] The above embodiments are preferred implementation modes of the present invention, but the implementation modes of the present invention are not limited to the above embodiments. Any other changes, modifications, substitutions, combinations, and simplifications that do not deviate from the spirit and principles of the present invention should be equivalent replacement methods and are included in the protection scope of the present invention.
Claims
1. A method for preparing a porous electrode by secondary fluid injection, characterized in that: The following steps are involved: Step S1: wet coating: coating the prepared electrode slurry onto the current collector to obtain a wet electrode sheet for a lithium-ion battery; Step S2: preparing a secondary fluid: adding a dispersant and a solid substance into a solvent in a preset ratio and in a certain order, and continuously stirring until uniformly mixed to obtain a secondary fluid; Step S3: secondary fluid injection: injecting the secondary fluid onto the upper surface of the wet electrode; Step S4: Baking and forming holes: Baking is performed according to a program to increase the temperature. The solvent on the secondary fluid evaporates after baking, leaving holes on the electrode.
2. A method for preparing a porous electrode by secondary fluid injection according to claim 1, characterized in that: The baking time in step S4 is determined by the coating speed in step S1, and the heating and baking method is vacuum drying.
3. A method for preparing a porous electrode by secondary fluid injection according to claim 2, characterized in that: The baking temperature is divided into three sections, wherein the first section baking temperature is 50-70°C, the second section baking temperature is 80-100°C, and the third section baking temperature is 120°C. Ventilation in the second and third sections accelerates heat conduction; the coating speed is ≤10m / min.
4. The method for preparing a porous electrode by secondary fluid injection according to claim 1, characterized in that: The spraying in step S3 is controlled by a pressure regulator (15) to spray the secondary fluid onto the upper surface of the electrode slurry. The diameter of the spraying end nozzle is between 50 and 200 μm, and the injection volume of the secondary fluid is ≤ 0.1 μL.
5. A method for preparing a porous electrode by secondary fluid injection according to claim 4, characterized in that: The secondary fluid is injected in a direction perpendicular to the upper surface of the electrode slurry, the nozzle diameter and injection volume can adjust the aperture size and shape, the array arrangement of the injection valve can adjust the channel pattern, and the injection pressure is ≤10MPa.
6. The method for preparing a porous electrode by secondary fluid injection according to claim 1, characterized in that: In step S2, the contents of the components in the secondary fluid are: 90% to 96% solvent, 2% to 5% dispersant, and 2% to 5% solid matter; the solid content of the secondary fluid is 4% to 10%, and the viscosity is 200 MPa·s to 1500 MPa·s.
7. A method for preparing a porous electrode by secondary fluid injection according to claim 6, characterized in that: The solvent is water, methanol, ethanol, acetone, dimethyl carbonate, diethyl carbonate, ethyl methyl carbonate, ethylene carbonate or propylene carbonate; the dispersant is any one of an inorganic dispersant, an organic dispersant or a polymer dispersant; the solid matter is a conductive agent, a solid electrolyte with ion conductivity or a mixture of the two.
8. The method for preparing a porous electrode by secondary fluid injection according to claim 7, characterized in that: The inorganic dispersant is a polyphosphate, such as sodium pyrophosphate, sodium tripolyphosphate or sodium hexametaphosphate; the organic dispersant is an alkyl aryl phosphate, alkyl benzene sulfonate, dialkyl sulfosuccinate, trimethyl stearamide chloride, polyoxyethylene alkylphenol ether or sorbitol alkylate; the polymer dispersant is carboxymethyl cellulose, polycarboxylate, poly (meth) acrylic acid derivative, maleic anhydride copolymer, CMC-Li or PAA-Li with ion-conducting effect; the conductive agent is any one or more of conductive carbon black, graphene, carbon nanotubes, vapor-grown carbon fiber, and conductive graphite; the solid electrolyte is a polymer solid electrolyte. any one or more of a solid electrolyte, an oxide solid electrolyte or a sulfide solid electrolyte; the polymer solid electrolyte comprises polyethylene oxide PEO, polyacrylonitrile PAN, polyvinylidene fluoride PVDF, polymethyl methacrylate PMMA, polypropylene oxide PPO, polyvinylidene chloride PVDC and a single-ion polymer electrolyte; the oxide solid electrolyte comprises a crystalline electrolyte and a glassy (amorphous) electrolyte; the crystalline electrolyte comprises a garnet-type solid electrolyte, a perovskite-type solid electrolyte, and a NASICON-type solid electrolyte; the glassy electrolyte comprises an antiperovskite-type solid electrolyte and a LiPON thin film solid electrolyte.
9. A lithium-ion battery electrode having a porous structure prepared by the method for preparing a porous electrode by injecting a secondary fluid as claimed in any one of claims 1 to 8, characterized in that: It comprises a current collector, an electrode coating arranged on the current collector and a plurality of pore structures uniformly distributed in the electrode coating, wherein the pore structures are obtained by evaporation of a solvent in a secondary fluid; the lithium ion battery pole piece is used for a porous negative electrode or a porous positive electrode.
10. A battery comprising the lithium-ion battery pole piece with a porous structure as claimed in claim 9.