CN115050925B - Electrode material, preparation method, electrode plate and battery - Google Patents

Electrode material, preparation method, electrode plate and battery Download PDF

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Publication number
CN115050925B
CN115050925B CN202210774823.4A CN202210774823A CN115050925B CN 115050925 B CN115050925 B CN 115050925B CN 202210774823 A CN202210774823 A CN 202210774823A CN 115050925 B CN115050925 B CN 115050925B
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electrode material
ions
carbon
carbon paper
ion
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CN115050925A (en
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宋佃凤
方帅男
吴立群
徐汝义
王燕
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Shandong Renfeng Speical Materials Co ltd
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Shandong Renfeng Speical Materials Co ltd
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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/13—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
    • 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
    • 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
    • H01M4/134—Electrodes based on metals, Si or alloys
    • 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
    • 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
    • H01M4/1395—Processes of manufacture of electrodes based on metals, Si or alloys
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/36—Selection of substances as active materials, active masses, active liquids
    • H01M4/38—Selection of substances as active materials, active masses, active liquids of elements or alloys
    • H01M4/386—Silicon or alloys based on silicon
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/36—Selection of substances as active materials, active masses, active liquids
    • H01M4/58—Selection of substances as active materials, active masses, active liquids of inorganic compounds other than oxides or hydroxides, e.g. sulfides, selenides, tellurides, halogenides or LiCoFy; of polyanionic structures, e.g. phosphates, silicates or borates
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/36—Selection of substances as active materials, active masses, active liquids
    • H01M4/58—Selection of substances as active materials, active masses, active liquids of inorganic compounds other than oxides or hydroxides, e.g. sulfides, selenides, tellurides, halogenides or LiCoFy; of polyanionic structures, e.g. phosphates, silicates or borates
    • H01M4/583—Carbonaceous material, e.g. graphite-intercalation compounds or CFx
    • H01M4/587—Carbonaceous material, e.g. graphite-intercalation compounds or CFx for inserting or intercalating light metals
    • 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
    • H01M4/64—Carriers or collectors
    • H01M4/66—Selection of materials
    • H01M4/663—Selection of materials containing carbon or carbonaceous materials as conductive part, e.g. graphite, carbon fibres
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M2004/021—Physical characteristics, e.g. porosity, surface area
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M2004/026—Electrodes composed of, or comprising, active material characterised by the polarity
    • H01M2004/027—Negative electrodes
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02E60/10—Energy storage using batteries

Abstract

The invention discloses an electrode material, a preparation method thereof, an electrode plate and a battery, which relate to the technical field of batteries and are used for solving the problems of low specific capacity and poor cycle stability of the existing electrode material. The electrode material comprises a carbon paper matrix and a composite layer formed on the surface of the carbon paper matrix, wherein the composite layer contains porous SiC and metal ions which are crosslinked together, and a silicon simple substance contained in the porous SiC is dispersed in a carbon simple substance contained in the porous SiC. The preparation method is used for preparing the electrode material, the electrode sheet uses the electrode material, and the battery uses the electrode material. The electrode material, the preparation method, the electrode plate and the battery are used for improving the specific capacity and the cycling stability of the battery.

Description

Electrode material, preparation method, electrode plate and battery
Technical Field
The invention relates to the technical field of batteries, in particular to an electrode material, a preparation method, an electrode plate and a battery.
Background
In recent years, with the development of technology, secondary batteries are widely used in various fields. The research on key materials of secondary batteries tends to be white-heated, and among them, the research on negative electrode materials of ion batteries is receiving high attention, and silicon-based materials and metal oxide composite materials belong to research hotspots of negative electrode materials of ion batteries. However, because the cost of the silicon-based material and the metal oxide composite material is high, the charge-discharge platform is unstable, and the capacity of the negative electrode is obviously attenuated after a plurality of cycles of circulation, so that the application of the negative electrode in practice is limited.
Therefore, carbon-based materials are used as a negative electrode material of an ion battery into the human field of view. The carbon-based material is nontoxic and relatively stable in air when in a discharge state. However, when the carbon-based material is used as a negative electrode material of an ion battery, since the spacing between graphite layers is too small, larger-radius sodium ions are embedded between graphite layers to require larger energy, reversible deintercalation cannot be performed in an effective potential window, and energy attenuation is fast, so that the cycle stability of the ion battery is poor. Therefore, it is required to develop a carbon-based negative electrode material having a high specific capacity and good cycle stability.
Disclosure of Invention
The invention aims to provide an electrode material, a preparation method, an electrode plate and a battery, and the specific capacity and the cycling stability of the electrode material of the ion battery are improved, so that the safety of the battery is improved.
In a first aspect, the present invention provides a negative electrode material comprising: the carbon paper matrix comprises a carbon paper matrix and a composite layer formed on the surface of the carbon paper matrix, wherein the composite layer contains porous SiC and metal ions which are crosslinked together, and a silicon element contained in the porous SiC is dispersed in a carbon element contained in the porous SiC.
Compared with the prior art, the electrode material provided by the invention has the following advantages:
In the electrode material provided by the application, the composite layer is formed on the surface of the carbon paper-based skeleton, and contains porous SiC and metal ions which are crosslinked together, so that the porous SiC and the metal ions form an alloy with a three-dimensional network structure, and the specific capacity of the electrode material can be improved. Moreover, because the three-dimensional network structure has small pores and low porosity, the moving channels of metal ions are reduced, so that on one hand, the electrolyte is not easy to directly contact with the metal ions, and on the other hand, if free metal ions exist, the electrolyte is not easy to enter the electrolyte through the moving channels. Therefore, in the electrode material provided by the application, metal ions are difficult to react with the electrolyte, so that the decomposition of the metal ions to the electrolyte and the precipitation of metal are reduced, the gas expansion of the electrolyte is avoided, and the cycle stability and safety of the battery are improved. Meanwhile, when the silicon simple substance contained in the porous SiC is dispersed in the carbon simple substance contained in the porous SiC, the volume change of the simple substance carbon in the charging and discharging process is small, so that the volume expansion of silicon in the discharging process can be buffered by utilizing the carbon simple substance, the silicon-based electrode material is prevented from generating cracks until the silicon-based electrode material is powdered, the contact property of the electrode material and a current collector is enhanced, the energy attenuation of a metal electrode plate is slowed down, and the battery capacity is improved. And extrusion of the electrode plate caused by internal stress of the battery due to volume expansion can be avoided, and the risk of breakage of the electrode plate is reduced. In addition, the carbon simple substance provided by the embodiment of the application has better conductivity, and can improve the electronic conductivity of the electrode material, thereby improving the cycle stability of the battery.
From the above, the electrode material provided by the invention can form a composite layer on the surface of the carbon paper-based skeleton, and the specific capacity and the cycling stability of the anode material of the ion battery are improved, so that the safety of the battery is improved.
In a second aspect, the present invention also provides a method for preparing an electrode material, including:
mixing the porous SiC nano material with metal ions by using an initiator to obtain a composite material;
preparing a carbon paper-based skeleton by using chopped carbon fibers;
and forming the composite material on the surface of the carbon paper-based skeleton, so that a composite layer is formed on the surface of the carbon paper-based skeleton, and an electrode material is obtained.
Compared with the prior art, the preparation method of the electrode material has the same beneficial effects as those of the electrode material provided in the first aspect, and the description is omitted here.
In a third aspect, the present invention also provides an electrode sheet comprising the electrode material provided in the first aspect.
Compared with the prior art, the electrode plate has the same beneficial effects as the electrode material of the first aspect, and the description is omitted here.
In a fourth aspect, the present invention also provides a battery comprising the electrode material provided in the first aspect.
Compared with the prior art, the beneficial effects of the battery provided by the invention are the same as those of the electrode material of the first aspect, and the description is omitted here.
Drawings
The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the invention and do not constitute a limitation on the invention. In the drawings:
fig. 1 is a schematic view of a battery according to an embodiment of the present invention;
FIG. 2 is a schematic diagram of an electrode material according to an embodiment of the present invention;
FIG. 3 is a flow chart of the preparation of an electrode material according to an embodiment of the present invention;
FIG. 4 is a flow chart of the preparation of porous SiC nanomaterials according to an embodiment of the present invention;
fig. 5 is a flowchart of the preparation of a carbon paper-based skeleton according to an embodiment of the present invention.
Reference numerals:
100-battery, 101-separator, 102 a-first current collector, 102 b-second current collector, 103-positive electrode material, 104-negative electrode material, 200-electrode material, 201-carbon paper matrix, 202-composite layer.
Detailed Description
In order to make the technical problems, technical schemes and beneficial effects to be solved more clear, the invention is further described in detail below with reference to the embodiments. It should be understood that the specific embodiments described herein are for purposes of illustration only and are not intended to limit the scope of the invention.
Furthermore, the terms "first," "second," and the like, are used for descriptive purposes only and are not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include one or more such feature. In the description of the present invention, the meaning of "a plurality" is two or more, unless explicitly defined otherwise. The meaning of "a number" is one or more than one unless specifically defined otherwise.
With the rapid growth of new energy automobiles in the market, related fields such as upstream materials and the like are rapidly developed. The requirements of people on the cruising ability of new energy automobiles are higher and higher, the energy density of batteries is dependent, and along with the continuous improvement of the requirements of consumers on the cruising mileage of the automobiles, the high energy density becomes the future development direction of power batteries.
Silicon-based materials, having a high theoretical lithium storage capacity (4200 mAh/g), are considered to be the next-generation negative electrode materials most promising for replacing graphite. However, in the charge and discharge process of the sodium ion battery, repeated deintercalation of sodium ions can cause huge volume expansion of the silicon-based material, and the volume expansion rate can even reach 300%, so that the damage and mechanical pulverization of the silicon-based material structure are easily caused, the electrode structure is collapsed and the electrode material is peeled off, and the cycle performance of the electrode material is seriously reduced. Meanwhile, when the silicon-based material is applied to the negative electrode, the volume effect of the silicon-based material in the charging and discharging process also causes that silicon is exposed to the electrolyte continuously, so that a stable solid electrolyte film (SEI film for short) is difficult to form on the surface of the negative electrode, and therefore sodium ions contained in the electrolyte are consumed greatly, and the first charging and discharging efficiency of the silicon-based material is reduced and the capacity is rapidly attenuated. In addition, silicon is a semiconductor material having low conductivity, and the use of a silicon-based material as a negative electrode also reduces the transmission rate of sodium ions, thereby reducing the specific capacity of the battery.
In view of the above problems, embodiments of the present invention provide a battery, which may include the electrode material of the embodiments of the present invention, to improve the specific capacity, the cycling stability, and the safety of the electrode material of the ion battery. It is understood that the electrode material may be defined as a negative electrode material, and the ion battery may further include a positive electrode material, a current collector, a separator, and an electrolyte. The separator may be defined to have opposing first and second surfaces with the positive electrode material between the first current collector and the first surface and the negative electrode material between the second current collector and the second surface. Fig. 1 shows a schematic structural view of a battery according to an embodiment of the present invention, and as shown in fig. 1, a battery 100 according to an embodiment of the present invention includes a separator 101, a first current collector 102a, a positive electrode material 103, a negative electrode material 104, and a second current collector 102b distributed on both sides of the separator 101.
In practical applications, the battery of the embodiment of the present invention may be a sodium ion battery, a lithium ion battery, an aluminum ion battery, or other ion batteries, which are not described in detail herein.
The electrode material provided by the embodiment of the invention can be applied to the battery. Fig. 2 shows a schematic structural view of an electrode material according to an embodiment of the present invention. As shown in fig. 2, an electrode material 200 according to an embodiment of the present invention includes a carbon paper-based skeleton 201 and a composite layer 202 formed on the surface of the carbon paper-based skeleton, wherein the composite layer 202 contains porous SiC and metal ions that are crosslinked together, and a silicon element contained in the porous SiC is dispersed in a carbon element contained in the porous SiC.
In the electrode material provided by the application, the composite layer is formed on the surface of the carbon paper-based skeleton, and contains porous SiC and metal ions which are crosslinked together, so that the porous SiC and the metal ions form an alloy with a three-dimensional network structure, and the specific capacity of the electrode material can be improved. Moreover, because the three-dimensional network structure has small pores and low porosity, the moving channels of metal ions are reduced, so that on one hand, the electrolyte is not easy to directly contact with the metal ions, and on the other hand, if free metal ions exist, the electrolyte is not easy to enter the electrolyte through the moving channels. Therefore, in the electrode material provided by the application, metal ions are difficult to react with the electrolyte, so that the decomposition of the metal ions to the electrolyte and the precipitation of metal are reduced, the gas expansion of the electrolyte is avoided, and the cycle stability and safety of the battery are improved. Meanwhile, according to the electrode material provided by the embodiment of the application, when the silicon simple substance contained in the porous SiC is dispersed in the carbon simple substance contained in the porous SiC, the volume change is small in the process of charging and discharging the simple substance carbon, so that the volume expansion of silicon in the process of discharging can be buffered by utilizing the carbon simple substance, the silicon-based electrode material is prevented from generating cracks until the silicon-based electrode material is powdered, the contact property of the electrode material and a current collector is enhanced, the energy attenuation of a metal electrode plate is slowed down, and the battery capacity is improved. And extrusion of the electrode plate caused by internal stress of the battery due to volume expansion can be avoided, and the risk of breakage of the electrode plate is reduced. In addition, the carbon simple substance provided by the embodiment of the application has better conductivity, and can improve the electronic conductivity of the electrode material, thereby improving the cycle stability of the battery.
From the above, the electrode material provided by the invention can form a composite layer on the surface of the carbon paper-based skeleton, and the specific capacity and the cycling stability of the anode material of the ion battery are improved, so that the safety of the battery is improved.
In one implementation manner, the porous SiC of the embodiment of the present invention has a nano porous network structure, and the mass ratio of the porous SiC to the metal ion is (20-50): (40-75). Therefore, the porous SiC has a plurality of pores and is nano-scale, so that the contact area between metal ions and the surface of the porous SiC is increased, and the contact area when the metal ions and the porous SiC undergo a crosslinking reaction is promoted under the action of an initiator under the condition of the mass ratio, so that the porous SiC and the metal ions are more densely combined together. Meanwhile, because the specific surface area of the porous SiC is large, a small amount of porous SiC can load a large amount of metal ions, so that the use amount of the metal ions can be reduced, and the production cost is saved.
In practical applications, the metal ions of the embodiments of the present invention may include at least one of P-region metal ions and transition metal ions. It is understood that the metal ions may be present in the form of metal salts and that the P-block metal may include metal elements from the P-block elements, including elements from group IVA and group VA of the periodic table. The group IVA elements are also called carbon group elements, including C, si, ge, sn, pb, etc.; the VA group element is also called nitrogen group element, and comprises nitrogen N, phosphorus P, arsenic As, antimony Sb, bismuth Bi and the like.
Illustratively, the P-region metal ions include at least one of germanium ions, tin ions, lead ions, antimony ions, and bismuth ions, or other P-region metal elements. The transition metal ion includes at least one of chromium ion, manganese ion, iron ion, cobalt ion, nickel ion, copper ion, zinc ion, palladium ion, silver ion, platinum ion, gold ion, and mercury ion.
In an alternative mode, the carbon paper-based skeleton of the embodiment of the invention is a carbide formed by chopped carbon fibers comprising carbon fibers and water soluble fibers, and thermosetting phenolic resin is formed on the surface of the carbon paper-based skeleton. The chopped carbon fiber comprises, by mass, 85-100 parts of carbon fiber and 0-15 parts of water-soluble carbon fiber. The diameter of the carbon fiber is 5 um-10 um, the length of the carbon fiber is 5 mm-10 mm, the diameter of the water-soluble fiber is 7 um-15 um, and the length of the water-soluble fiber is 5 mm-10 mm. The carbon paper matrix skeleton of the embodiment of the invention is a carbide formed by carbon fibers and chopped carbon fibers of water-soluble fibers, and the carbon fibers and the water-soluble fibers have small diameters and short lengths, so that the carbon paper matrix skeleton has high porosity and is more beneficial to storing sodium ions. Meanwhile, a certain amount of water-soluble fiber is added into the carbon fiber to increase certain strength when the carbon paper is off-net. The mechanical properties of the carbon paper base paper manufactured by using the charred matter formed by the chopped carbon fibers of the carbon fibers and the water soluble fibers are poor, and the carbon paper base paper is soaked in thermosetting phenolic resin to improve the mechanical strength, heat resistance and electrical properties of the carbon paper base paper.
Illustratively, the carbon paper-based skeleton further comprises polyethylene oxide and polyvinyl alcohol, wherein the mass ratio of the chopped carbon fiber to the polyethylene oxide to the polyvinyl alcohol is (1-2): (0.1 to 0.5) and (0.1 to 0.3). According to the embodiment of the invention, the polyethylene oxide and the polyvinyl alcohol are added into the water containing the chopped carbon fibers, so that the adhesive force and the film forming property of the fibers can be improved. Meanwhile, the polyethylene oxide can be used as a dispersing agent in the slurry, carbon fibers and water-soluble fibers are uniformly dispersed, and the polyvinyl alcohol is also used as a surface sizing agent, so that the wear resistance, folding resistance and tearing resistance of the carbon paper can be improved, and the glossiness, smoothness and printing adaptability of the carbon paper can be improved. Therefore, the carbon paper with uniform fiber dispersion and good glossiness can be prepared by adding the polyethylene oxide and the polyvinyl alcohol into the chopped carbon fibers in the embodiment of the invention.
The embodiment of the invention also provides a preparation method of the electrode material, which can be used for preparing the electrode material of the embodiment of the invention. Fig. 3 shows a schematic flow chart of a method for preparing an electrode material according to an embodiment of the present invention. As shown in fig. 3, the preparation method of the electrode material according to the embodiment of the invention includes:
step 301: and mixing the porous SiC nano material with metal ions by using an initiator to obtain the composite material.
For example, the porous SiC nanomaterial may be mixed with a metal salt solution, an initiator, and then the PH of the mixed solution is adjusted to neutral with HCl solution or NaOH solution. At this time, porous SiC and metal ions can be made to form an alloy of a three-dimensional network structure under the action of an initiator, so that the specific capacity of the electrode material can be improved. Moreover, because the three-dimensional network structure has small pores and low porosity, the moving channels of metal ions are reduced, so that on one hand, the electrolyte is not easy to directly contact with the metal ions, and on the other hand, if free metal ions exist, the electrolyte is not easy to enter the electrolyte through the moving channels. Therefore, the decomposition of metal ions to the electrolyte and the precipitation of metal are reduced, the gas expansion of the electrolyte is avoided, and the cycling stability and the safety of the battery are improved.
For example: the above metal salt solution may include at least one of a Ge salt, a Sn salt, a Pb salt, an Sb salt, a Bi salt, and a transition metal salt. The initiator may include at least one of monoammonium phosphate, monoammonium carbonate, ammonium bicarbonate. The molar concentration of the metal salt solution is 10mol/L to 60mol/L. The mass percentages of the porous SiC nano material, the metal salt solution and the initiator are respectively 20% -50%, 40% -75% and 20% -50%.
Step 302: and preparing a carbon paper-based skeleton by using the chopped carbon fibers.
The embodiment of the invention prepares the carbon paper-based skeleton by using the chopped carbon fiber, and the chopped carbon fiber has high porosity due to small diameter and short length, thereby being more beneficial to storing sodium ions.
Step 303: and forming the composite material on the surface of the carbon paper matrix so that a composite layer is formed on the surface of the carbon paper matrix to obtain the electrode material.
Illustratively, the above carbon paper-based skeleton is immersed in a dispersion of the composite material, and then subjected to a hydrothermal reaction, so that the composite material is formed on the surface of the carbon paper-based skeleton, so that the surface of the carbon paper-based skeleton forms a composite layer, and then taken out and dried to obtain the electrode material. Wherein the reaction time of the hydrothermal reaction can be 30 min-60 min, and the reaction temperature can be 180-400 ℃. According to the electrode material provided by the invention, the carbon paper matrix is immersed in the dispersion liquid of the composite material, and then the hydrothermal reaction is carried out, so that the composite material is uniformly and densely formed on the surface of the carbon paper matrix, and the specific capacity of the electrode material can be improved.
In an alternative manner, fig. 4 shows a flowchart of preparation of a porous SiC nanomaterial in an embodiment of the present invention, and as shown in fig. 4, before the porous SiC nanomaterial is mixed with metal ions by using an initiator to obtain a composite material, a preparation method of the porous SiC nanomaterial in the embodiment of the present invention includes:
Step 401: the silicon source and the carbon source are mixed and the obtained mixture is ground into nano-sized powder.
The pulping and papermaking industry is one of important industries of national economy in China, and papermaking black liquor is used as a byproduct in the pulping and papermaking process, and contains abundant lignin, cellulose and hemicellulose, trace metal elements, si, S and other elements. The discharge of black liquor can cause serious environmental pollution problems.
The silicon source and the carbon source can be derived from papermaking black liquor by evaporating and concentrating the papermaking black liquor in an oven at 70-120 ℃, evaporating water and other volatile impurities in the papermaking black liquor to obtain concentrated black liquor, and freeze-drying the concentrated black liquor. The freeze drying is carried out when the concentration is high, so that the deterioration of each component in the concentrated black liquor can be avoided. The silicon source and the carbon source of the embodiment of the invention can ensure that the dried materials keep the original chemical composition and physical properties (such as porous structure, colloid property and the like) through freeze drying, and the freeze drying is different from the common heating drying, the water in the materials is basically sublimated and dried on the frozen solid surface below 0 ℃, and the materials themselves are remained in the frozen ice frame. Therefore, the dried product has unchanged volume, is loose and porous, can keep the original properties unchanged, and can be ground into nano-scale powder more conveniently.
Step 402: heating the nano-scale powder from room temperature to 400-600 ℃ at a heating rate of 1-5 ℃/min under a positive pressure argon environment, preserving heat for 0.5-1.5 h, heating to 900-1000 ℃ at 1-5 ℃/min, preserving heat for 1-2 h, continuously heating to 1200-1400 ℃ at 3-10 ℃/min, and preserving heat for 1-2 h to obtain the porous SiC nano-material.
In the embodiment of the application, organic matters such as lignin and cellulose in the papermaking black liquor contain a large amount of carbon elements, and the direct carbonization method (namely a pyrolysis method) is used, so that chemical bonds of a large amount of carbon elements contained in the papermaking black liquor are destroyed by utilizing heat energy under the anaerobic condition, and the porous carbon material is prepared through thermal decomposition. Meanwhile, the nanoscale powder is heated and insulated for three times, so that papermaking black liquor is carbonized more fully. At this time, the silicon simple substance is dispersed in the carbon simple substance, and the volume change is small in the process of charging and discharging the simple substance carbon, so that the volume expansion of the silicon in the process of discharging can be buffered by utilizing the carbon simple substance, thereby avoiding the crack of the silicon-based electrode material until the silicon-based electrode material is powdered, enhancing the contact property of the electrode material and the current collector, slowing down the energy attenuation of the metal electrode plate and improving the battery capacity. And extrusion of the electrode plate caused by internal stress of the battery due to volume expansion can be avoided, and the risk of breakage of the electrode plate is reduced. In addition, the carbon simple substance provided by the embodiment of the application has better conductivity, and can improve the electronic conductivity of the electrode material, thereby improving the cycle stability of the battery.
In an alternative manner, fig. 5 shows a flowchart of the preparation of the carbon paper-based skeleton in the embodiment of the present invention, and as shown in fig. 5, the preparation method of the carbon paper-based skeleton in the embodiment of the present invention includes:
step 501: polyethylene oxide and polyvinyl alcohol are added to the chopped carbon fibers to form a first mixed slurry.
Illustratively, chopped carbon fibers including carbon fibers and water-soluble fibers are mixed with water, and then polyethylene oxide (PEO) and polyvinyl alcohol (PVA) are sequentially added to obtain a first mixed slurry. According to the embodiment of the invention, the polyethylene oxide and the polyvinyl alcohol are added into the water containing the chopped carbon fibers, so that the adhesive force and the film forming property of the fibers can be improved. Meanwhile, the polyethylene oxide can be used as a dispersing agent in the slurry, carbon fibers and water-soluble fibers are uniformly dispersed, and the polyvinyl alcohol is also used as a surface sizing agent, so that the wear resistance, folding resistance and tearing resistance of the carbon paper can be improved, and the glossiness, smoothness and printing adaptability of the carbon paper can be improved. Therefore, the carbon paper with uniform fiber dispersion and good glossiness can be prepared by adding the polyethylene oxide and the polyvinyl alcohol into the chopped carbon fibers in the embodiment of the invention.
The chopped carbon fiber accounts for 1 to 2 percent of the mass of the first mixed slurry, the PEO addition amount is 0.1 to 0.5 percent of the mass of the mixed slurry, and the PVA addition amount is 0.1 to 0.3 percent of the mass of the mixed slurry.
Step 502: the first mixed slurry is made into carbon paper.
For example: and (3) making the first mixed slurry into a wet paper web, and then drying to obtain the carbon paper.
Step 503: and (3) immersing the carbon paper in thermosetting phenolic resin added with a toughening agent, and then carrying out hot press curing to obtain the carbon paper matrix skeleton.
Illustratively, the carbon paper is immersed in thermosetting phenolic resin added with a toughening agent, and then subjected to hot press curing, wherein the curing temperature can be 120-180 ℃, the curing time can be 3-8 min, and the curing pressure can be 1-6 MPa. The toughening agent can comprise at least one of carboxylated nitrile rubber, liquid nitrile rubber, polyvinyl butyral, polyethersulfone and polyphenylene oxide ketone. According to the embodiment of the invention, the toughening agent is added into the thermosetting phenolic resin, so that the elongation and brittleness of the thermosetting phenolic resin can be improved, and cracks are not easy to generate when the bonding part bears external force, so that the thermosetting phenolic resin is prevented from cracking, and the carbon paper-based skeleton with better mechanical strength is prepared. Meanwhile, the phenolic resin has good bonding effect, can be compatible with various organic and inorganic fillers, and has strong interface bonding capability. Furthermore, the composite layer in the embodiments of the present invention contains porous SiC and metal ions crosslinked together. Therefore, the thermosetting phenolic resin on the surface of the carbon paper matrix skeleton can have good bonding effect and strong interface bonding capability with the composite layer, so that the structure of the electrode material is more stable.
In an alternative mode, the electrode material of the embodiment of the application is soaked in polytetrafluoroethylene containing a conductive agent, and then the polytetrafluoroethylene is placed into a sintering furnace for sintering, wherein the sintering temperature is 300-400 ℃, and the electrode plate of the ion battery is obtained. The conductive agent can comprise at least one of carbon nano tube, acetylene black, carbon black or graphene, and the mass content of the conductive agent is 10-30%.
From the above, in the electrode material provided by the application, the composite layer is formed on the surface of the carbon paper matrix skeleton, and contains porous SiC and metal ions which are crosslinked together, so that the porous SiC and the metal ions form an alloy with a three-dimensional network structure, and the specific capacity of the electrode material can be improved. Meanwhile, when the silicon simple substance contained in the porous SiC is dispersed in the carbon simple substance contained in the porous SiC, the volume change of the simple substance carbon in the charging and discharging process is small, so that the volume expansion of silicon in the discharging process can be buffered by utilizing the carbon simple substance, the silicon-based electrode material is prevented from generating cracks until the silicon-based electrode material is powdered, the contact property of the electrode material and a current collector is enhanced, the energy attenuation of a metal electrode plate is slowed down, and the battery capacity is improved. And extrusion of the electrode plate caused by internal stress of the battery due to volume expansion can be avoided, and the risk of breakage of the electrode plate is reduced. In addition, the carbon simple substance provided by the embodiment of the application has better conductivity, and can improve the electronic conductivity of the electrode material, thereby improving the cycle stability of the battery.
In order to verify the effect of the electrode material provided in the examples of the present invention, the examples of the present invention were demonstrated by comparing the examples with comparative examples.
Example 1
The embodiment of the invention provides an electrode material, which comprises a carbon paper matrix and a composite layer formed on the surface of the carbon paper matrix.
The preparation method of the electrode material provided by the embodiment of the invention comprises the following steps:
firstly, preparing a porous SiC nano material: the papermaking black liquor is evaporated and concentrated in an oven at 90 ℃ to thick black liquor, and then freeze-dried. Grinding the freeze-dried solid into nanoscale powder, heating the nanoscale powder to 400 ℃ at a heating rate of 3 ℃/min under a positive pressure argon environment, preserving heat for 1h, and then heating to 900 ℃ at a heating rate of 3 ℃/min, and preserving heat for 1.5h; and finally, continuously heating to 1200 ℃ at a speed of 5 ℃/min, and preserving heat for 2 hours to obtain the porous SiC nano material.
Secondly, preparing a composite material dispersion liquid: according to mass percentage, 40 percent of porous SiC nano material and 55 percent of Ge (SO) 2 ) 2 Mixing and stirring the solution and 5% ammonium carbonate to obtain a mixed solution, and regulating the pH value to be neutral by using a NaOH solution to obtain a composite material dispersion liquid.
Thirdly, preparing a carbon paper matrix: adding water into 85% of carbon fibers and 15% of water-soluble fibers according to mass percentage, uniformly mixing, and then sequentially adding polyethylene oxide and polyvinyl alcohol to obtain mixed slurry. Wherein, the mass percent of the mixed slurry is calculated, the carbon fiber and the water-soluble fiber account for 1 percent of the mixed slurry, the polyethylene oxide accounts for 0.2 percent of the mixed slurry, and the polyvinyl alcohol accounts for 0.2 percent of the mixed slurry. And then the mixed slurry is made into a wet paper web, the wet paper web is dried to obtain carbon paper base paper, and the carbon paper base paper is immersed in thermosetting phenolic resin added with 1% polyether sulfone and then subjected to hot press curing to obtain the carbon paper base skeleton. Wherein the temperature of the hot press solidification is 120 ℃, the time of the hot press solidification is 5min, and the pressure of the hot press solidification is 2MPa.
Fourth, preparing electrode materials: immersing the carbon paper matrix in the composite layer dispersion liquid, placing the composite layer dispersion liquid into a reaction container for hydrothermal reaction for 30min at the reaction temperature of 200 ℃, and taking out and drying to obtain the SiC-Ge alloy layer electrode material.
Fifth, preparing electrode plates: and immersing the SiC-Ge alloy layer electrode material into polytetrafluoroethylene containing 10% of carbon nano tubes, and then placing the polytetrafluoroethylene into a sintering furnace for sintering at the temperature of 350 ℃ to obtain the electrode slice of the ion battery.
Example two
The embodiment of the invention provides an electrode material, which comprises a carbon paper matrix and a composite layer formed on the surface of the carbon paper matrix.
The preparation method of the electrode material provided by the second embodiment of the invention comprises the following steps:
firstly, preparing a porous SiC nano material: the papermaking black liquor is evaporated and concentrated in an oven at 105 ℃ to thick black liquor, and then freeze-dried. Grinding the freeze-dried solid into nanoscale powder, heating the nanoscale powder to 450 ℃ at a heating rate of 3 ℃/min under a positive pressure argon environment, preserving heat for 1h, and then heating to 950 ℃ at a heating rate of 3 ℃/min, and preserving heat for 1.5h; and finally, continuously heating to 1200 ℃ at a speed of 5 ℃/min, and preserving heat for 2 hours to obtain the porous SiC nano material.
Secondly, preparing a composite material dispersion liquid: according to mass percent, 45 percent of porous SiC nano material and 50 percent of SnCl 2 Mixing and stirring the solution and 5% ammonium bicarbonate to obtain a mixed solution, and regulating the pH value to be neutral by using an HCl solution to obtain a composite material dispersion liquid.
Thirdly, preparing a carbon paper matrix: adding water into 85% of carbon fibers and 15% of water-soluble fibers according to mass percentage, uniformly mixing, and then sequentially adding polyethylene oxide and polyvinyl alcohol to obtain mixed slurry. Wherein, the mass percent of the mixed slurry is calculated, the carbon fiber and the water-soluble fiber account for 1 percent of the mixed slurry, the polyethylene oxide accounts for 0.2 percent of the mixed slurry, and the polyvinyl alcohol accounts for 0.2 percent of the mixed slurry. And then the mixed slurry is made into a wet paper web, the wet paper web is dried to obtain carbon paper base paper, and the carbon paper base paper is immersed in thermosetting phenolic resin added with 1% of polyphenyl ether ketone and then subjected to hot press curing to obtain the carbon paper base skeleton. Wherein the temperature of the hot press solidification is 120 ℃, the time of the hot press solidification is 5min, and the pressure of the hot press solidification is 3MPa.
Fourth, preparing electrode materials: immersing the carbon paper matrix in the composite layer dispersion liquid, placing the composite layer dispersion liquid into a reaction container for hydrothermal reaction for 30min at the reaction temperature of 250 ℃, and taking out and drying to obtain the SiC-Sn alloy layer electrode material.
Fifth, preparing electrode plates: and immersing the SiC-Sn alloy layer electrode material in polytetrafluoroethylene containing 10% of carbon nano tubes, and then placing the electrode material in a sintering furnace for sintering at the sintering temperature of 350 ℃ to obtain the electrode plate of the ion battery.
Example III
The embodiment of the invention provides an electrode material, which comprises a carbon paper matrix and a composite layer formed on the surface of the carbon paper matrix.
The preparation method of the electrode material provided by the third embodiment of the invention comprises the following steps:
firstly, preparing a porous SiC nano material: the papermaking black liquor is evaporated and concentrated in an oven at 105 ℃ to thick black liquor, and then freeze-dried. Grinding the freeze-dried solid into nanoscale powder, heating the nanoscale powder to 450 ℃ at a heating rate of 3 ℃/min under a positive pressure argon environment, preserving heat for 1h, and then heating to 950 ℃ at a heating rate of 3 ℃/min, and preserving heat for 1.5h; and finally, continuously heating to 1300 ℃ at a speed of 5 ℃/min, and preserving heat for 1.5 hours to obtain the porous SiC nano material.
Secondly, preparing a composite material dispersion liquid: 45% of porous SiC nano material and 50% of PbCl in percentage by mass 2 Mixing and stirring the solution and 5% ammonium dihydrogen phosphate to obtain a mixed solution, and regulating the pH value to be neutral by using an HCl solution to obtain a composite material dispersion liquid.
Thirdly, preparing a carbon paper matrix: adding water into 80% of carbon fibers and 20% of water-soluble fibers according to mass percentage, uniformly mixing, and then sequentially adding polyethylene oxide and polyvinyl alcohol to obtain mixed slurry. Wherein, the mass percent of the mixed slurry is calculated, the carbon fiber and the water-soluble fiber account for 1 percent of the mixed slurry, the polyethylene oxide accounts for 0.2 percent of the mixed slurry, and the polyvinyl alcohol accounts for 0.3 percent of the mixed slurry. And then the mixed slurry is made into a wet paper web, the wet paper web is dried to obtain carbon paper base paper, the carbon paper base paper is immersed in thermosetting phenolic resin added with 1% of liquid nitrile rubber, and then hot pressing solidification is carried out to obtain the carbon paper base skeleton. Wherein the temperature of the hot press solidification is 120 ℃, the time of the hot press solidification is 5min, and the pressure of the hot press solidification is 3MPa.
Fourth, preparing electrode materials: immersing the carbon paper matrix in the composite layer dispersion liquid, placing the composite layer dispersion liquid into a reaction container for hydrothermal reaction, wherein the reaction time is 30min, the reaction temperature is 300 ℃, and then taking out and drying to obtain the SiC-Pb alloy layer electrode material.
Fifth, preparing electrode plates: and immersing the SiC-Pb alloy layer electrode material into polytetrafluoroethylene containing 10% of acetylene black, and then placing the electrode material into a sintering furnace for sintering at the temperature of 350 ℃ to obtain the electrode plate of the ion battery.
Example IV
The embodiment of the invention provides an electrode material, which comprises a carbon paper matrix and a composite layer formed on the surface of the carbon paper matrix.
The preparation method of the electrode material provided by the fourth embodiment of the invention comprises the following steps:
firstly, preparing a porous SiC nano material: the papermaking black liquor is evaporated and concentrated in an oven at 105 ℃ to thick black liquor, and then freeze-dried. Grinding the freeze-dried solid into nanoscale powder, heating the nanoscale powder to 450 ℃ at a heating rate of 3 ℃/min under a positive pressure argon environment, preserving heat for 1h, and then heating to 950 ℃ at a heating rate of 3 ℃/min, and preserving heat for 1.5h; and finally, continuously heating to 1300 ℃ at a speed of 5 ℃/min, and preserving heat for 1.5 hours to obtain the porous SiC nano material.
Secondly, preparing a composite material dispersion liquid: according to the mass percentage, 50 percent of porous SiC nano material and 45 percent of SbCl are mixed 2 Mixing and stirring the solution and 5% ammonium bicarbonate to obtain a mixed solution, and regulating the pH value to be neutral by using an HCl solution to obtain a composite material dispersion liquid.
Thirdly, preparing a carbon paper matrix: adding water into 90% of carbon fibers and 10% of water-soluble fibers according to mass percentage, uniformly mixing, and then sequentially adding polyethylene oxide and polyvinyl alcohol to obtain mixed slurry. Wherein, the mass percent of the mixed slurry is calculated, the carbon fiber and the water-soluble fiber account for 1 percent of the mixed slurry, the polyethylene oxide accounts for 0.2 percent of the mixed slurry, and the polyvinyl alcohol accounts for 0.3 percent of the mixed slurry. And then the mixed slurry is made into a wet paper web, the wet paper web is dried to obtain carbon paper base paper, and the carbon paper base paper is immersed in thermosetting phenolic resin added with 1% polyvinyl butyral and then subjected to hot press curing to obtain the carbon paper base skeleton. Wherein the temperature of the hot press solidification is 120 ℃, the time of the hot press solidification is 6min, and the pressure of the hot press solidification is 2MPa.
Fourth, preparing electrode materials: and immersing the carbon paper matrix in the composite layer dispersion liquid, placing the composite layer dispersion liquid into a reaction container for hydrothermal reaction for 30min at the reaction temperature of 300 ℃, and taking out and drying to obtain the SiC-Sb alloy layer electrode material.
Fifth, preparing electrode plates: and immersing the SiC-Sb alloy layer electrode material in polytetrafluoroethylene containing 12% of carbon black, and then placing the electrode material in a sintering furnace for sintering at the temperature of 350 ℃ to obtain the electrode plate of the ion battery.
Example five
The embodiment of the invention provides an electrode material, which comprises a carbon paper matrix and a composite layer formed on the surface of the carbon paper matrix.
The preparation method of the electrode material provided by the fifth embodiment of the invention comprises the following steps:
firstly, preparing a porous SiC nano material: the papermaking black liquor is evaporated and concentrated in an oven at 105 ℃ to thick black liquor, and then freeze-dried. Grinding the freeze-dried solid into nanoscale powder, heating the nanoscale powder to 450 ℃ at a heating rate of 3 ℃/min under a positive pressure argon environment, preserving heat for 1h, and then heating to 950 ℃ at a heating rate of 3 ℃/min, and preserving heat for 1.5h; and finally, continuously heating to 1300 ℃ at a speed of 5 ℃/min, and preserving heat for 1.5 hours to obtain the porous SiC nano material.
Secondly, preparing a composite material dispersion liquid: according to mass percentBy ratio, 50% of porous SiC nano material and 20% of BiCl 3 20% SbCl 2 Mixing and stirring the solution, 5% of ammonium bicarbonate and 5% of ammonium carbonate to obtain a mixed solution, and regulating the pH value to be neutral by using an HCl solution to obtain a composite material dispersion liquid.
Thirdly, preparing a carbon paper matrix: adding water into 100% of carbon fibers according to the mass percentage, uniformly mixing, and then sequentially adding polyethylene oxide and polyvinyl alcohol to obtain mixed slurry. Wherein, the mass percent of the mixed slurry is calculated, the carbon fiber and the water-soluble fiber account for 2 percent of the mixed slurry, the polyethylene oxide accounts for 0.5 percent of the mixed slurry, and the polyvinyl alcohol accounts for 0.3 percent of the mixed slurry. And then the mixed slurry is made into a wet paper web, the wet paper web is dried to obtain carbon paper base paper, and the carbon paper base paper is immersed in thermosetting phenolic resin added with 0.5 percent of polyvinyl butyral and 0.5 percent of liquid nitrile rubber, and then hot-pressed and cured to obtain the carbon paper base skeleton. Wherein the temperature of the hot press solidification is 120 ℃, the time of the hot press solidification is 6min, and the pressure of the hot press solidification is 2MPa.
Fourth, preparing electrode materials: immersing the carbon paper matrix in the composite layer dispersion liquid, placing the composite layer dispersion liquid into a reaction container for hydrothermal reaction, wherein the reaction time is 30min, the reaction temperature is 300 ℃, and then taking out and drying to obtain the SiC-Bi alloy layer electrode material.
Fifth, preparing electrode plates: the SiC-Bi alloy layer electrode material is immersed in polytetrafluoroethylene containing 12% of carbon black, and then is placed into a sintering furnace for sintering at the sintering temperature of 350 ℃ to obtain the electrode plate of the ion battery.
Example six
The embodiment of the invention provides an electrode material, which comprises a carbon paper matrix and a composite layer formed on the surface of the carbon paper matrix.
The preparation method of the electrode material provided by the fifth embodiment of the invention comprises the following steps:
firstly, preparing a porous SiC nano material: the papermaking black liquor is evaporated and concentrated in an oven at 105 ℃ to thick black liquor, and then freeze-dried. Grinding the freeze-dried solid into nanoscale powder, heating the nanoscale powder to 450 ℃ at a heating rate of 3 ℃/min under a positive pressure argon environment, preserving heat for 1h, and then heating to 950 ℃ at a heating rate of 3 ℃/min, and preserving heat for 1.5h; and finally, continuously heating to 1300 ℃ at a speed of 5 ℃/min, and preserving heat for 1.5 hours to obtain the porous SiC nano material.
Secondly, preparing a composite material dispersion liquid: according to mass percent, 20 percent of porous SiC nano material and 75 percent of FeCl are mixed 3 Mixing and stirring the solution and 5% ammonium bicarbonate to obtain a mixed solution, and regulating the pH value to be neutral by using an HCl solution to obtain a composite material dispersion liquid.
Thirdly, preparing a carbon paper matrix: adding water into 85% of carbon fibers and 15% of water-soluble fibers according to mass percentage, uniformly mixing, and then sequentially adding polyethylene oxide and polyvinyl alcohol to obtain mixed slurry. Wherein, the mass percent of the mixed slurry is calculated, the carbon fiber and the water-soluble fiber account for 1 percent of the mixed slurry, the polyethylene oxide accounts for 0.1 percent of the mixed slurry, and the polyvinyl alcohol accounts for 0.1 percent of the mixed slurry. And then the mixed slurry is made into a wet paper web, the wet paper web is dried to obtain carbon paper base paper, and the carbon paper base paper is immersed in thermosetting phenolic resin added with 1% polyvinyl butyral and then subjected to hot press curing to obtain the carbon paper base skeleton. Wherein the temperature of the hot press solidification is 120 ℃, the time of the hot press solidification is 6min, and the pressure of the hot press solidification is 2MPa.
Fourth, preparing electrode materials: immersing the carbon paper matrix in the composite layer dispersion liquid, placing the composite layer dispersion liquid into a reaction container for hydrothermal reaction, wherein the reaction time is 30min, the reaction temperature is 300 ℃, and then taking out and drying to obtain the SiC-Fe alloy layer electrode material.
Fifth, preparing electrode plates: the SiC-Fe alloy layer electrode material is immersed in polytetrafluoroethylene containing 12% of carbon black, and then is placed into a sintering furnace for sintering, wherein the sintering temperature is 350 ℃, and the electrode plate of the ion battery is obtained.
Comparative example one
Comparative example one of the present invention provides an electrode material that does not contain the composite layer of the embodiments of the present invention.
The preparation method of the electrode material provided by the first comparative example of the invention comprises the following steps:
firstly, preparing a porous SiC nano material: the papermaking black liquor is evaporated and concentrated in an oven at 105 ℃ to thick black liquor, and then freeze-dried. Grinding the freeze-dried solid into nano-scale powder, heating the nano-scale powder to 500 ℃ at a heating rate of 3 ℃/min under a positive pressure argon environment, preserving heat for 1h, and then heating to 950 ℃ at a heating rate of 3 ℃/min, preserving heat for 1.5h; and finally, continuously heating to 1300 ℃ at a speed of 5 ℃/min, and preserving heat for 1.5 hours to obtain the porous SiC nano material.
Secondly, preparing a carbon paper matrix: adding water into 90% of carbon fibers and 10% of water-soluble fibers according to mass percentage, uniformly mixing, and then sequentially adding polyethylene oxide and polyvinyl alcohol to obtain mixed slurry. Wherein, the mass percent of the mixed slurry is calculated, the carbon fiber and the water-soluble fiber account for 1 percent of the mixed slurry, the polyethylene oxide accounts for 0.2 percent of the mixed slurry, and the polyvinyl alcohol accounts for 0.3 percent of the mixed slurry. And then the mixed slurry is made into a wet paper web, and the wet paper web is dried to obtain the carbon paper base paper.
Thirdly, preparing a load SiC layer: mixing the porous SiC nano material into a mixed solution of thermosetting phenolic resin added with 1% polyethersulfone, then immersing the carbon paper base paper into the mixed solution, and carrying out hot press solidification to obtain the SiC layer-loaded carbon paper electrode material. Wherein the temperature of the hot press solidification is 120 ℃, the time of the hot press solidification is 6min, and the pressure of the hot press solidification is 2MPa.
Fourth, preparing electrode plates: and (3) immersing the SiC-layer-loaded carbon paper electrode material into polytetrafluoroethylene containing 12% of carbon nano tubes, and then placing the polytetrafluoroethylene into a sintering furnace for sintering at the sintering temperature of 350 ℃ to obtain the electrode plate of the ion battery.
Comparative example two
The second comparative example of the present invention provides an electrode material that does not contain the composite layer and the carbon paper-based skeleton of the embodiment of the present invention.
The preparation method of the electrode material provided by the second comparative example comprises the following steps:
firstly, preparing a porous SiC nano material: the papermaking black liquor is evaporated and concentrated in an oven at 105 ℃ to thick black liquor, and then freeze-dried. Grinding the freeze-dried solid into nano-scale powder, heating the nano-scale powder to 500 ℃ at a heating rate of 3 ℃/min under a positive pressure argon environment, preserving heat for 1h, and then heating to 950 ℃ at a heating rate of 3 ℃/min, preserving heat for 1.5h; and finally, continuously heating to 1300 ℃ at a speed of 5 ℃/min, and preserving heat for 1.5 hours to obtain the porous SiC nano material.
Secondly, preparing an electrode plate: according to the mass percentage, 55% of porous SiC nano material, 25% of carbon fiber, 10% of carbon nano tube and 10% of thermosetting resin are mixed, uniformly stirred mechanically and then pressed into a sheet by a press roller, and the negative plate of the ion battery is obtained.
The invention tests the data related to the electrode materials prepared in the examples and the comparative examples, wherein the electrode materials comprising the carbon paper-based skeleton and the composite layer formed on the surface of the carbon paper-based skeleton are used in the first example and the sixth example, and the composite layer in the example of the invention is not contained in the first comparative example compared with the example of the invention, and the composite layer in the example of the invention is not contained in the second comparative example, and the carbon paper-based skeleton in the example of the invention is not contained in the second comparative example. The test results of examples and comparative examples are shown in the following table:
specific capacity (mAh/g) First time efficiency (%) 2C/0.2C retention (%) Charge and discharge cycle performance (500 times)
Example 1 231 84 49 Good cycle performance
Example 2 240 85 50 Good cycle performance
Example 3 228 84 48 Good cycle performance
Example 4 237 83 47 Good cycle performance
Example 5 238 84 50 Good cycle performance
Example 6 235 85 51 Good cycle performance
Comparative example 1 198 76 22 Poor cycle performance
Comparative example 2 212 69 27 Poor cycle performance
As can be seen from the above table, the electrode materials prepared in the first to sixth embodiments of the present invention use a carbon paper-based skeleton and a composite layer formed on the surface of the carbon paper-based skeleton, and the electrode material prepared in the first comparative example does not contain the composite layer in the embodiment of the present invention, contains only the carbon paper base paper, and in the second comparative example neither the carbon paper base paper nor the composite layer. The specific capacity and the charging cycle times of the electrode material are obviously larger than those of the first comparative example and the second comparative example, so that the electrode material prepared in the first to sixth examples of the invention adopts the carbon paper-based skeleton and the composite layer formed on the surface of the carbon paper-based skeleton, and under the combined action of the carbon paper-based skeleton and the composite layer, the specific capacity of the anode material of the ion battery is improved, the cycling stability of the ion battery is also improved, and the safety of the battery is further improved.
The foregoing is merely a specific embodiment of the invention, and it will be apparent that various modifications and combinations thereof can be made without departing from the spirit and scope of the invention. Accordingly, the specification and drawings are merely exemplary illustrations of the present invention as defined in the appended claims and are considered to cover any and all modifications, variations, combinations, or equivalents that fall within the scope of the invention. It will be apparent to those skilled in the art that various modifications and variations can be made to the present invention without departing from the spirit or scope of the invention. Thus, it is intended that the present invention cover the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents. Any person skilled in the art can easily think of changes or substitutions within the technical scope of the present disclosure, and the present disclosure is intended to be covered by the present disclosure. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.

Claims (11)

1. A method for preparing an electrode material, comprising:
mixing a silicon source and a carbon source to obtain a mixture, and grinding the obtained mixture into nanoscale powder;
heating the nanoscale powder from room temperature to 400-600 ℃ at a heating rate of 1-5 ℃ per minute under a positive pressure argon environment, preserving heat for 0.5-1.5 h, heating to 900-1000 ℃ at 1-5 ℃ per minute, preserving heat for 1-2 h, continuously heating to 1200-1400 ℃ at 3-10 ℃ per minute, and preserving heat for 1-2 h to obtain a porous SiC nanomaterial;
mixing the porous SiC nanomaterial with metal ions by using an initiator to obtain a composite material, wherein the metal ions comprise at least one of P-region metal ions and transition metal ions, the P-region metal ions comprise at least one of germanium ions, tin ions, lead ions, antimony ions and bismuth ions, and the transition metal ions comprise at least one of chromium ions, manganese ions, iron ions, cobalt ions, nickel ions, copper ions, zinc ions, palladium ions, silver ions, platinum ions, gold ions and mercury ions;
preparing a carbon paper-based skeleton by using chopped carbon fibers;
and forming the composite material on the surface of the carbon paper-based skeleton, so that a composite layer is formed on the surface of the carbon paper-based skeleton, and an electrode material is obtained, wherein the composite layer contains porous SiC and metal ions which are crosslinked together, and a silicon simple substance contained in the porous SiC is dispersed in a carbon simple substance contained in the porous SiC.
2. The method for preparing an electrode material according to claim 1, wherein the preparing a carbon paper-based skeleton using chopped carbon fibers comprises:
adding polyethylene oxide and polyvinyl alcohol into the chopped carbon fibers to form first mixed slurry;
copying the first mixed slurry into carbon paper;
and immersing the carbon paper in thermosetting phenolic resin added with a toughening agent, and then carrying out hot press curing to obtain the carbon paper matrix skeleton.
3. The method for preparing an electrode material according to claim 1, wherein the forming the composite material on the surface of the carbon paper-based skeleton so that the surface of the carbon paper-based skeleton forms a composite layer, the electrode material is obtained, comprising:
and immersing the carbon paper-based skeleton in the dispersion liquid of the composite material, and then performing hydrothermal reaction to form the composite material on the surface of the carbon paper-based skeleton, so that a composite layer is formed on the surface of the carbon paper-based skeleton, thereby obtaining the electrode material.
4. An electrode material, characterized in that the electrode material is prepared by the preparation method of the electrode material according to any one of claims 1 to 3, and the electrode material comprises: the carbon paper matrix comprises a carbon paper matrix and a composite layer formed on the surface of the carbon paper matrix, wherein the composite layer contains porous SiC and metal ions which are crosslinked together, and a silicon element contained in the porous SiC is dispersed in a carbon element contained in the porous SiC.
5. The electrode material according to claim 4, wherein the porous SiC has a nanoporous network structure.
6. The electrode material according to claim 4, wherein the mass ratio of the porous SiC to the metal ions is (20 to 50): (40-75).
7. The electrode material of claim 4, wherein the metal ions comprise at least one of P-region metal ions and transition metal ions;
the P region metal ions comprise at least one of germanium ions, tin ions, lead ions, antimony ions and bismuth ions;
the transition metal ion includes at least one of chromium ion, manganese ion, iron ion, cobalt ion, nickel ion, copper ion, zinc ion, palladium ion, silver ion, platinum ion, gold ion, and mercury ion.
8. The electrode material according to any one of claims 4 to 7, wherein the carbon paper-based skeleton is a char formed of chopped carbon fibers including carbon fibers and water-soluble fibers, the surface of the carbon paper-based skeleton is formed with thermosetting phenolic resin, and the chopped carbon fibers include, in parts by mass, 85 to 100 parts of carbon fibers and 0 to 15 parts of water-soluble carbon fibers;
The diameter of the carbon fiber is 5 um-10 um, the length of the carbon fiber is 5 mm-10 mm, the diameter of the water-soluble fiber is 7 um-15 um, and the length of the water-soluble fiber is 5 mm-10 mm.
9. The electrode material according to claim 8, wherein the carbon paper-based skeleton further comprises polyethylene oxide and polyvinyl alcohol, and the mass ratio of the chopped carbon fiber, the polyethylene oxide and the polyvinyl alcohol is (1-2): (0.1 to 0.5) and (0.1 to 0.3).
10. An electrode sheet, characterized in that the electrode sheet comprises the electrode material according to any one of claims 4 to 9.
11. A battery comprising the electrode material according to any one of claims 4 to 9.
CN202210774823.4A 2022-07-01 2022-07-01 Electrode material, preparation method, electrode plate and battery Active CN115050925B (en)

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