Silicon negative pole piece, sodium ion solid-state battery and preparation method of sodium ion solid-state battery

Abstract

The invention relates to the technical field of batteries, and provides a silicon negative pole piece, a sodium ion solid-state battery and a preparation method thereof, the silicon negative pole piece comprises a current collector and an active material layer arranged on the current collector; the active material layer comprises a binder and an active material; the binder comprises a polymer and a carboxylic acid compound forming gradient hydrogen bonds with a main chain of the polymer; the polymer contains a conductive polymer. A coating layer is formed on the surface of a silicon particle by introducing a proper functional group into a binding agent of a silicon negative electrode plate, and the coating layer can generate dipole moment interaction with fluorides in an electrolyte when being applied to a sodium ion solid-state battery, so that the fluorides are promoted to be reduced, and a lithium fluoride-rich SEI (Solid Electrolyte Interphase) film is generated; the stability of the silicon negative electrode plate is improved, and the cycling stability of the sodium ion solid-state battery is finally improved.

Description

Technical Field

[0001] The present invention relates to the field of battery technology, and in particular to a silicon negative electrode sheet, a sodium ion solid-state battery and a preparation method thereof. Background Art

[0002] Traditional liquid batteries have poor safety because they use organic solvents as electrolytes. Solid-state batteries are batteries that use solid electrodes and solid electrolytes. In recent years, solid-state batteries may inherit the status of liquid batteries.

[0003] Sodium is more abundant in the Earth's crust than lithium and is relatively cheap, making sodium-ion solid-state batteries relatively affordable to manufacture and attracting considerable attention. Sodium-ion batteries are also less prone to overheating or explosion during use and charging and discharging, making them highly safe. They have undergone short-circuit, needle penetration, and extrusion tests without catching fire or exploding. They operate normally in temperatures ranging from -40°C to 80°C, performing particularly well at low temperatures and maintaining a high capacity.

[0004] Regarding the anodes used in sodium-ion solid-state batteries, silicon anode sheets offer significant advantages in all-solid-state batteries. Their theoretical capacity is over ten times that of graphite-based anode materials. This means they can store more energy for the same volume or weight, thereby improving the battery's energy density and battery life. Furthermore, silicon anode sheets charge faster, significantly reducing charging time. However, during the charge and discharge process, silicon undergoes significant volume changes, leading to particle breakage and pulverization, which in turn affects the efficient transfer of sodium ions. This volume change also leads to poor electrical contact, creating an "islanding effect," which in turn affects battery performance and significantly reduces cycle life. Common methods for improving silicon anode sheets include optimizing silicon particle structure, surface modification, and electrolyte and binder modification. Binders suitable for silicon anode sheets require high mechanical properties and recoverability. Most binders are improved primarily by constructing cross-linked conductive networks or designing layered structures. However, these methods aim to improve the binder's tolerance to silicon expansion, reduce internal stress, and thus stabilize the electrode structure, but their impact on battery cycling stability and rate performance is limited. Summary of the Invention

[0005] In order to overcome the above-mentioned deficiencies in the prior art, the present inventors conducted a large number of research experiments. During the research, it was found that when the binder and the active material form an active material layer, the components of the binder participate in electrochemical reduction, which contributes to the formation of SEI. The binder usually contains many polar groups. These polar groups interact with the electrolyte molecules and significantly affect the distribution and decomposition of the electrolyte on the silicon surface. Therefore, through in-depth research, the structure of the binder was redesigned, and the mechanical properties of the binder and the influence of the binder on the chemical composition of SEI (solid electrolyte interface) were fully considered.

[0006] Specifically, in the first aspect, the present invention provides a silicon negative electrode sheet, a sodium ion solid-state battery and a preparation method thereof. Specifically, by introducing suitable functional groups into the binder of the silicon negative electrode sheet, a coating layer is formed on the surface of the silicon particles. When applied to the sodium ion solid-state battery, it can produce a dipole moment interaction with the fluorides in the electrolyte, promote the reduction of these fluorides, generate a lithium fluoride-rich SEI film, improve the stability of the silicon negative electrode sheet, and ultimately improve the cycle stability of the sodium ion solid-state battery.

[0007] In a first aspect, the present invention provides a silicon negative electrode plate, comprising a current collector, and further comprising: an active material layer provided on the current collector; The active material layer includes a binder and an active material; The binder comprises a polymer and a carboxylic acid compound which forms a gradient hydrogen bond with the main chain of the polymer; and the polymer comprises a conductive polymer.

[0008] The present invention optimizes the structure of a binder, which includes a polymer and a carboxylic acid compound that forms gradient hydrogen bonds with the polymer backbone. The polymer also contains a conductive polymer. This binder, on the one hand, creates a "rigid yet flexible" polymer network backbone formed by gradient hydrogen bonding and covalent bonding. Specifically, the carboxylic acid compound forms gradient hydrogen bonds between the polymers, endowing the binder with the ability to dissipate stress. Furthermore, the carboxylic acid compound, on the surface of the active material, also generates dipole interactions with fluorides in the electrolyte, preferentially attracting them to the surface. Furthermore, the electronically conductive conductive polymer (such as polypyrrole) within the polymer provides abundant electrons, promoting the reduction of these fluorides and forming a lithium fluoride-rich SEI, which protects the active material. Ultimately, this achieves macroscopic and mesoscopic stability of the silicon negative electrode.

[0009] According to the silicon negative electrode plate provided by the present invention, the carboxylic acid compound is selected from one or a combination of two or more of citric acid, propane tricarboxylic acid and butane tetracarboxylic acid. Preferably, the carboxylic acid compound can be selected from one or a combination of two or more of CAS: 77-92-9, CAS: 125139-13-1 and CAS: 16922-05-7.

[0010] In the experiment, it was found that the above-mentioned carboxylic acid compounds have good compatibility with polymers, which is more conducive to the formation of the above-mentioned gradient hydrogen bonds and the construction of covalent bonds between polymers to form a "rigid but flexible" polymer network main chain.

[0011] According to the silicon negative electrode plate provided by the present invention, the active material includes a silicon-based material, and the silicon-based material is silicon particles, preferably micron silicon particles; Preferably, the active material further comprises a carbon-based material; Further preferably, the carbon-based material is selected from one or a combination of two or more of hard carbon, soft carbon, and graphite; preferably hard carbon; Most preferably, the active material contains silicon particles and hard carbon in a mass ratio of (4-7):(1-4.5).

[0012] The mass ratio of silicon particles to hard carbon in the present invention may be any value or a range consisting of any values ​​selected from 4:1, 4.5:1, 5:1, 5.5:1.5, 6:2, 6.5:2.5, 6.5:3.5, 6.5:4 and 7:4.5.

[0013] By using silicon particles and hard carbon as the active materials of the silicon negative electrode plate of the present invention and optimizing the ratio of the two within the above range, the structural performance advantages of silicon particles and hard carbon can be fully utilized, thereby making the energy density, cycle stability and rate performance of the silicon negative electrode plate better.

[0014] According to the silicon negative electrode plate provided by the present invention, the polymer includes an acrylic acid reagent, an enol reagent and polypyrrole; Preferably, different types of polymers are at least partially bonded to each other by covalent bonds.

[0015] In a second aspect, the present invention further provides a method for preparing the silicon negative electrode sheet as described above, comprising: Mixing a polymer raw material, a carboxylic acid compound, and an oxidant to obtain a mixture having a viscosity of 100 to 20,000 mPa·s; preferably, the viscosity is 500 to 3,500 mPa·s; mixing the mixture with an active material to obtain a slurry; The slurry is formed into an active material layer on a current collector.

[0016] The method for preparing the silicon negative electrode sheet provided by the present invention comprises: mixing an acrylic acid reagent and a carboxylic acid compound to obtain a first mixture; mixing the first mixture with an enol reagent to obtain a second mixture; mixing the second mixture with a pyrrole reagent and an oxidant to obtain the mixture; The acrylic acid reagent is selected from polyacrylic acid and / or acrylic acid; preferably, the acrylic acid reagent is selected from one or a combination of two or more of CAS: 9003-01-4, CAS: 79-10-7, CAS: 38071-32-8 and CAS: 9007-20-9; The enol reagent is selected from one or a combination of two or more of polyvinyl alcohol, vinyl alcohol and propenol; preferably, the enol reagent is selected from one or a combination of two or more of CAS: 9002-89-5, CAS: 557-75-5, CAS: 107-18-6 and CAS: 98002-49-4; The pyrrole reagent is selected from polypyrrole and / or pyrrole; preferably, the pyrrole reagent is selected from CAS: 109-97-7 and / or CAS: 30604-81-0; The oxidant is selected from peroxodisulfuric acid and / or ammonium persulfate; preferably, the oxidant is selected from one or a combination of two or more of CAS: 7727-54-0, CAS: 52900-28-4 and CAS: 13445-49-3.

[0017] The present invention uses the above-mentioned specific materials and combines them with the above-mentioned mixing order to achieve the construction of gradient hydrogen bonds and polymer network main chains based on the thorough mixing of the raw materials. Among them, the acrylic acid reagent and the enol reagent can be made of either polymers or monomers. The purpose of the present invention is to utilize the functional groups of the raw materials to form the "rigid but flexible" polymer network main chain formed by the gradient hydrogen bonds and covalent bonds. Different types of raw materials can be adjusted by adjusting the mixing temperature and time after the addition of each material to adjust the material system. As long as the viscosity of the formed material system is within the range controlled by the present invention, the structural construction of the gradient hydrogen bonds and the "rigid but flexible" polymer network main chain of the present invention can be achieved.

[0018] The method for preparing the silicon negative electrode sheet provided by the present invention comprises: Mixing the acrylic acid reagent and the carboxylic acid compound aqueous solution for H1 time to obtain a first mixture; wherein H1 is 2 to 8 hours; Stirring the first mixture and the aqueous solution of the enol reagent at 15-35° C. for H2 for 3-10 h to obtain a second mixture; The second mixture is placed in a H3 condition at 0-4°C for 10-60 minutes, and then a pyrrole reagent and an oxidant are added and mixed to obtain the mixture; wherein the H3 is 10-60 minutes; An ice bath can be used at 0~4℃.

[0019] mixing the mixture with an active material to obtain a slurry; The slurry is coated on the current collector, first treated at a first temperature for H4 time, and then treated at a second temperature for H5 time to form an active material layer; preferably, the first temperature is 50~80℃, the second temperature is 120~150℃, H4 is 8~15h, and H5 is 30~180min.

[0020] On the one hand, the present invention optimizes the mixing degree of each raw material by adjusting the mixing order of each raw material. On the other hand, by controlling the temperature and time of the above mixing, especially combining the oxidant and the heat treatment process after coating, the reaction degree of the mixture at different stages is further optimized. In this way, while ensuring that the slurry is easy to coat, a more rationally structured "rigid but flexible" polymer network main chain formed by gradient hydrogen bonds and covalent bonds can be obtained.

[0021] In the present invention, H1 may be any value of 2h, 3h, 4h, 5h, 6h, 7h and 8h, or a range of any values.

[0022] H2 in the present invention can be any value among 3h, 4h, 5h, 6h, 7h, 8h, 9h and 10h, or a range consisting of any values.

[0023] In the present invention, H3 may be any value or a range of any values.

[0024] The first temperature in the present invention may be any value of 50° C., 60° C., 70° C., and 80° C., or a range consisting of any values.

[0025] The second temperature in the present invention may be any value among 120° C., 130° C., 140° C. and 150° C., or a range consisting of any values.

[0026] In the present invention, H4 may be any value among 8h, 9h, 10h, 11h, 12h, 13h, 14h and 15h, or a range consisting of any values.

[0027] H5 in the present invention can be any value of 30min, 40min, 50min, 60min, 70min, 80min, 90min, 100min, 110min, 120min, 130min, 140min, 150min, 160min, 170min and 180min, or a range consisting of any values.

[0028] Experiments have found that introducing carboxylic acid compounds in the form of an aqueous solution helps to construct gradient hydrogen bonds between the carboxylic acid compounds and the polymer. Preferably, the mass concentration of the aqueous solution of the carboxylic acid compound is 1~15%; specifically, the mass concentration of the aqueous solution of the carboxylic acid compound in the present invention can be any value of 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14% and 15%, or a range consisting of any values.

[0029] The amount of acrylic acid reagent and carboxylic acid compound is mainly controlled to achieve a balance between gradient hydrogen bonding and the main chain of the polymer network. If the content of the carboxylic acid compound is too high or too low, it is not conducive to obtaining gradient hydrogen bonding. Preferably, the molar ratio of the acrylic acid reagent to the carboxylic acid compound is (0.5-2):(0.5-2). Specifically, the molar ratio of the acrylic acid reagent to the carboxylic acid compound in the present invention can be any value selected from 0.5:1, 0.5:2, 1:1, 1:0.5 and 2:0.5, or a range consisting of any values.

[0030] Experiments have found that introducing the enol reagent in the form of an aqueous solution is beneficial to mixing it with the premixed mixture to construct a gradient hydrogen bond and a "rigid yet flexible" polymer network backbone with better performance; preferably, the mass concentration of the enol reagent aqueous solution is 1~15%; specifically, the mass concentration of the enol reagent aqueous solution in the present invention can be any value of 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14% and 15%, or a range of any values.

[0031] Preferably, the mass ratio of the acrylic acid reagent to the enol reagent is (5-15):1; The amount of the oxidant in the present invention is determined based on the desired degree of reaction. If the amount of the oxidant is too high, the viscosity of the slurry will be too high and it cannot be used for coating. If the amount of the oxidant is too low, it will be detrimental to the formation of the above-mentioned gradient hydrogen bonds and effective polymer network. Preferably, the mass ratio of the pyrrole reagent to the oxidant is (1~2.5): (0.1~1); specifically, the mass ratio of the pyrrole reagent to the oxidant in the present invention can be any value of 1:1, 1:0.5, 1:0.1, 2:0.1 and 2.5:0.1, or a range consisting of any values.

[0032] If the content of the pyrrole reagent is too low, it is not conducive to the formation of lithium fluoride-rich SEI, and if the content is too high, on the one hand, it will lead to a decrease in mechanical properties and destroy the structure of the "rigid but flexible" polymer network main chain; on the other hand, it will also lead to an increase in interfacial impedance and affect the charge transfer efficiency; preferably, the content of the pyrrole reagent is 0.1~0.5wt% of the total mass of the acrylic reagent; specifically, the ratio of the content of the pyrrole reagent to the total mass of the acrylic reagent in the present invention can be any value among 0.1wt%, 0.2wt%, 0.3wt%, 0.4wt% and 0.5wt% or a range consisting of any values.

[0033] Preferably, the mass ratio of the silicon-based material in the active material to the mixture is (5-7):(0.5-3.5). Specifically, the mass ratio of the silicon-based material in the active material to the mixture in the present invention can be any value or a range consisting of 5:3.5, 5:2, 5:1, 5:0.5, 6:3, 6:2, 6:1, 7:3.5, 7:2, 7:1, and 7:0.5.

[0034] Specifically, when the acrylic acid reagent, the enol reagent, and the pyrrole reagent are all polymers, the method for preparing the silicon negative electrode sheet includes: (1) Mixing an acrylic acid reagent and a carboxylic acid compound aqueous solution for H1 time to obtain a first mixture; wherein H1 is 4 to 6 hours; the mass concentration of the carboxylic acid compound aqueous solution is 1 to 5%; and the molar ratio of the acrylic acid reagent to the carboxylic acid compound is (1 to 1.5): (1 to 1.5); (2) The first mixture and the aqueous solution of the enol reagent are stirred at 25-30° C. for H2 for 6-8 hours to obtain a second mixture; wherein the H2 is 6-8 hours; the mass concentration of the aqueous solution of the enol reagent is 5-8%; and the mass ratio of the enol reagent to the acrylic acid reagent is (8-10):1; (3) After the second mixture is placed in an ice bath for H3 time, a pyrrole reagent and an oxidant are added and mixed to obtain a mixture of the viscosity; wherein H3 is 30-45 min; the mass ratio of the pyrrole reagent to the oxidant is (1.5-2.5): (0.5-1); the content of the pyrrole reagent is 0.25-0.5 wt% of the total mass of the acrylic acid reagent.

[0035] (4) The mixture is mixed with an active material to obtain a slurry; the active material is a mixture of micron silicon and hard carbon in a mass ratio of (4-7): (2-3); the mass ratio of the silicon-based material in the active material to the mixture is (5-7): (1.5-2.5).

[0036] (5) The slurry is coated on the current collector, first treated at a first temperature for H4 hours, and then treated at a second temperature for H5 hours to form an active material layer; preferably, the first temperature is 50-80°C, the second temperature is 120-150°C, H4 is 8-11 hours, and H5 is 90-110 minutes.

[0037] When the acrylic acid reagent, the enol reagent, and the pyrrole reagent are all monomers, the method for preparing the silicon negative electrode plate includes: (1) Mixing an acrylic acid reagent and a carboxylic acid compound aqueous solution for H1 time to obtain a uniform first mixture; wherein H1 is 6.5 to 8 hours; the mass concentration of the carboxylic acid compound aqueous solution is 12 to 14%; and the molar ratio of the acrylic acid reagent to the carboxylic acid compound is (0.5 to 1): (1 to 2); (2) The first mixture and the aqueous solution of the enol reagent are stirred at 15-30° C. for H2 for 8-10 h to obtain a second mixture; wherein the mass concentration of the aqueous solution of the enol reagent is 11-14%; and the mass ratio of the enol reagent to the acrylic acid reagent is (5-6):1; (3) After the second mixture is placed in an ice bath for H3 time, a pyrrole reagent and an oxidant are added and mixed to obtain a mixture of the viscosity; wherein H3 is 45-60 min; the mass ratio of the pyrrole reagent to the oxidant is (2-2.5):(0.5-1); and the content of the pyrrole reagent is 0.35-0.5 wt% of the total mass of the acrylic acid reagent.

[0038] (4) The mixture is mixed with an active material to obtain a slurry; the active material is a mixture of micron silicon and hard carbon in a mass ratio of (5.5-6): (1.5-2); the mass ratio of the silicon-based material in the active material to the mixture is (5-7): (0.5-3).

[0039] (5) The slurry is coated on the current collector, first treated at a first temperature for H4 hours, and then treated at a second temperature for H5 hours to form an active material layer; preferably, the first temperature is 50-80°C, the second temperature is 140-150°C, H4 is 13-15 hours, and H5 is 165-180 minutes.

[0040] In a third aspect, the present invention further provides a sodium ion solid-state battery, comprising: a positive electrode sheet, a negative electrode sheet, and an electrolyte; The electrolyte element facing the negative electrode plate contains F; The negative electrode plate is the silicon negative electrode plate as described above or the silicon negative electrode plate prepared by the preparation method as described above; Preferably, the electrolyte elements facing the positive electrode plate contain Na, P, S and X; and X is Cl and / or Br.

[0041] According to the sodium ion solid-state battery provided by the present invention, the positive electrode plate contains a sodium ion positive electrode material with a P2 type structure; Preferably, the sodium ion positive electrode material is a high entropy positive electrode material formed by mixing more than 7 elements; the more than 7 elements include Na, Ni, Cu, O and other metal elements; the types of the other metal elements are more than 3.

[0042] Studies have found that compared with other types of positive electrode materials, the negative electrode plate of the present invention is used in combination with the above-mentioned type of positive electrode material, and the cycle stability and rate performance of the resulting solid-state battery are more significantly improved.

[0043] The present invention provides a silicon negative electrode plate, a sodium-ion solid-state battery, and a preparation method thereof. By optimizing the structure of a binder comprising a polymer and a carboxylic acid compound that forms gradient hydrogen bonds with the polymer backbone, the polymer containing a conductive polymer. The binder, on the one hand, constructs a "rigid yet flexible" polymer network backbone formed by gradient hydrogen bonding and covalent bonding. On the other hand, the carboxylic acid compound, on the surface of the active material, also generates dipole interactions with fluorides in the electrolyte, preferentially attracting the fluorides to the active material surface. Simultaneously, the electronically conductive conductive polymer (such as polypyrrole) in the polymer provides abundant electrons, promoting the reduction of these fluorides, forming a lithium fluoride-rich SEI, and protecting the active material. Ultimately, the silicon negative electrode plate is stabilized at both macro and meso scales.

[0044] Furthermore, the silicon anode electrode of the present invention is assembled with a high-entropy sodium-ion cathode material to produce an all-solid-state battery. The high-entropy sodium-ion cathode material is co-doped with at least three metal elements to strengthen the metal layer, effectively preventing cracks and the formation of O2 phases during the sodium removal process. This suppresses the phase transition of the cathode material under high pressure, enhances structural stability, and improves the diffusion performance of sodium ions. This ultimately results in an assembled high-entropy sodium-ion cathode material / silicon-carbon anode all-solid-state battery with excellent cycling stability and rate performance. DETAILED DESCRIPTION

[0045] To make the objectives, technical solutions, and advantages of the present invention more clear, the technical solutions of the present invention are described clearly and completely below. Obviously, the embodiments described are only some of the embodiments of the present invention, not all of them. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0046] If no specific techniques or conditions are specified in the examples, the experiments were carried out according to the techniques or conditions described in the literature in the field or according to the product instructions. If no manufacturer is specified for the reagents or instruments used, they are all conventional products that can be purchased through regular channels.

[0047] The silicon particles in the present invention can be selected from manufacturers such as Beiterry, Tianmu Xiandao, and Shanshan.

[0048] The hard carbon in the present invention can be selected from manufacturers such as Sumitomo, BTR, and Shanshan of Japan.

[0049] Example 1 A silicon negative electrode plate comprises a current collector and an active material layer provided on the current collector; The active material layer includes a binder and an active material; The binder includes a polymer containing polypyrrole and a carboxylic acid compound which forms a gradient hydrogen bond with the main chain of the polymer.

[0050] The polymers include acrylic polymers, enol polymers and polypyrroles; different types of polymers are partially bonded to each other by covalent bonds.

[0051] This embodiment also provides a method for preparing the above silicon negative electrode sheet, including: (1) Mixing polyacrylic acid (CAS: 9003-01-4) and citric acid (CAS: 77-92-9) in an aqueous solution for H1 time to obtain a first mixture; wherein H1 is 5 hours; the mass concentration of the carboxylic acid compound aqueous solution is 1%; and the molar ratio of the acrylic acid reagent to the carboxylic acid compound is 1:1; (2) The first mixture and a polyvinyl alcohol (CAS: 9002-89-5) aqueous solution are stirred at 25° C. for H2 for 6 hours to obtain a second mixture; wherein the H2 is 6 hours; the mass concentration of the enol reagent aqueous solution is 5.5%; and the mass ratio of the acrylic acid reagent to the enol reagent is 8:1; (3) After the second mixture is placed in an ice bath under H3 conditions, polypyrrole and peroxodisulfuric acid are added and mixed to obtain a mixture with a viscosity of 1500 mPa·s; wherein H3 is 45 min; the mass ratio of the pyrrole reagent to the oxidant is 2:1; and the content of the pyrrole reagent is 0.25 wt% of the total mass of the acrylic acid reagent.

[0052] (4) The mixture is mixed with an active material to obtain a slurry; the active material is a mixture of micron silicon and hard carbon in a mass ratio of 5.5:3; the mass ratio of the silicon-based material in the active material to the mixture is 5.5:1.5.

[0053] (5) The slurry is coated on the current collector and treated at a first temperature for H4 time and then at a second temperature for H5 time to form an active material layer; preferably, the first temperature is 75°C, the second temperature is 125°C, H4 is 8.5h, and H5 is 90min.

[0054] Example 2 A silicon negative electrode plate comprises a current collector and an active material layer provided on the current collector; The active material layer includes a binder and an active material; The binder includes a polymer containing polypyrrole and a carboxylic acid compound which forms a gradient hydrogen bond with the main chain of the polymer.

[0055] The polymers include acrylic polymers, enol polymers and polypyrroles; different types of polymers are partially bonded to each other by covalent bonds.

[0056] This embodiment also provides a method for preparing the above silicon negative electrode sheet, including: (1) An acrylic acid reagent (CAS: 38071-32-8) and a propane tricarboxylic acid aqueous solution are mixed for H1 time to obtain a first mixture; wherein H1 is 4.5 hours; the mass concentration of the carboxylic acid compound aqueous solution is 3%; and the molar ratio of the acrylic acid reagent to the carboxylic acid compound is 1.5:1; (2) The first mixture and the polyvinyl alcohol 2099 aqueous solution are stirred at 27° C. for H2 time to obtain a second mixture; wherein H2 is 7h; the mass concentration of the enol reagent aqueous solution is 6.5%; and the mass ratio of the acrylic acid reagent to the enol reagent is 9:1; (3) After the second mixture is placed in an ice bath under H3 conditions, polypyrrole and ammonium persulfate are added and mixed to obtain a mixture with a viscosity of 2500 mPa·s; wherein H3 is 40 min; the mass ratio of the pyrrole reagent to the oxidant is 1.5:0.5; and the content of the pyrrole reagent is 0.35 wt% of the total mass of the acrylic acid reagent.

[0057] (4) The mixture is mixed with an active material to obtain a slurry; the active material is a mixture of micron silicon and hard carbon in a mass ratio of 6:2; the mass ratio of the silicon-based material in the active material to the mixture is 6:2.

[0058] (5) The slurry is coated on the current collector, first treated at a first temperature for H4 time, and then treated at a second temperature for H5 time to form an active material layer; preferably, the first temperature is 65°C, the second temperature is 130°C, H4 is 10 hours, and H5 is 100 minutes.

[0059] Example 3 A silicon negative electrode plate comprises a current collector and an active material layer provided on the current collector; The active material layer includes a binder and an active material; The binder includes a polymer containing polypyrrole and a carboxylic acid compound which forms a gradient hydrogen bond with the main chain of the polymer.

[0060] The polymers include acrylic polymers, enol polymers and polypyrroles; different types of polymers are partially bonded to each other by covalent bonds.

[0061] This embodiment also provides a method for preparing the above silicon negative electrode sheet, including: (1) Mixing polyacrylic acid (CAS: 9007-20-9) and citric acid (CAS: 125139-13-1) in an aqueous solution for H1 time to obtain a uniform first mixture; wherein H1 is 5.5h; the mass concentration of the carboxylic acid compound aqueous solution is 4%; and the molar ratio of the acrylic acid reagent to the carboxylic acid compound is 1:1.5; (2) The first mixture and a polyvinyl alcohol (CAS: 98002-49-4) aqueous solution are stirred at 30° C. for 8 hours under H2 to obtain a second mixture; wherein the H2 is 8 hours; the mass concentration of the enol reagent aqueous solution is 7.5%; and the mass ratio of the acrylic acid reagent to the enol reagent is 10:1; (3) After the second mixture is placed in an ice bath under H3 conditions, polypyrrole and peroxydisulfuric acid are added and mixed to obtain a mixture with a viscosity of 2000 mPa·s; wherein H3 is 35 min; the mass ratio of the pyrrole reagent to the oxidant is 2.5:1; and the content of the pyrrole reagent is 0.45 wt% of the total mass of the acrylic acid reagent.

[0062] (4) The mixture is mixed with an active material to obtain a slurry; the active material is a mixture of micron silicon and hard carbon in a mass ratio of 6.5:2.5; the mass ratio of the silicon-based material in the active material to the mixture is 6.5:2.5.

[0063] (5) The slurry is coated on the current collector and treated at a first temperature for H4 time and then at a second temperature for H5 time to form an active material layer; preferably, the first temperature is 70°C, the second temperature is 135°C, H4 is 11 hours, and H5 is 110 minutes.

[0064] Example 4 A silicon negative electrode plate comprises a current collector and an active material layer provided on the current collector; The active material layer includes a binder and an active material; The binder includes a polymer containing polypyrrole and a carboxylic acid compound which forms a gradient hydrogen bond with the main chain of the polymer.

[0065] The polymers include acrylic polymers, enol polymers and polypyrroles; different types of polymers are partially bonded to each other by covalent bonds.

[0066] This embodiment also provides a method for preparing the above silicon negative electrode sheet, including: (1) Acrylic acid and citric acid (CAS: 77-92-9) aqueous solution are mixed for H1 time to obtain a first mixture; wherein H1 is 8 hours; the mass concentration of the carboxylic acid compound aqueous solution is 13%; and the molar ratio of the acrylic acid reagent to the carboxylic acid compound is 0.5:1.5; (2) The first mixture and the ethylene alcohol aqueous solution are stirred at 15° C. for H2 for 8 hours to obtain a second mixture; wherein the H2 is 8 hours; the mass concentration of the aqueous solution of the enol reagent is 11%; and the mass ratio of the acrylic acid reagent to the enol reagent is 5:1; (3) After the second mixture is placed in an ice bath under H3 conditions, pyrrole and peroxydisulfuric acid are added and mixed to obtain a mixture with a viscosity of 1000 mPa·s; wherein H3 is 60 min; the mass ratio of the pyrrole reagent to the oxidant is 2.5:1; and the content of the pyrrole reagent is 0.35 wt% of the total mass of the acrylic acid reagent.

[0067] (4) The mixture is mixed with an active material to obtain a slurry; the active material is a mixture of micron silicon and hard carbon in a mass ratio of 6:2; the mass ratio of the silicon-based material in the active material to the mixture is 7:1.5.

[0068] (5) The slurry is coated on the current collector, first treated at a first temperature for H4 time, and then treated at a second temperature for H5 time to form an active material layer; preferably, the first temperature is 65°C, the second temperature is 150°C, H4 is 15h, and H5 is 170min.

[0069] Example 5 A silicon negative electrode plate comprises a current collector and an active material layer provided on the current collector; The active material layer includes a binder and an active material; The binder includes a polymer containing polypyrrole and a carboxylic acid compound which forms a gradient hydrogen bond with the main chain of the polymer.

[0070] The polymers include acrylic polymers, enol polymers and polypyrroles; different types of polymers are partially bonded to each other by covalent bonds.

[0071] This embodiment also provides a method for preparing the above silicon negative electrode sheet, including: (1) mixing acrylic acid and propane tricarboxylic acid aqueous solution for H1 time to make them uniform to obtain a first mixture; wherein H1 is 6.5h; the mass concentration of the carboxylic acid compound aqueous solution is 14%; and the molar ratio of acrylic acid reagent to carboxylic acid compound is 1:2; (2) The first mixture and the aqueous solution of propylene alcohol are stirred at 20° C. for H2 for 8.5 h to obtain a second mixture; wherein the H2 is 8.5 h; the mass concentration of the aqueous solution of the enol reagent is 12.5%; and the mass ratio of the acrylic acid reagent to the enol reagent is 6:1; (3) After the second mixture is placed in an ice bath under H3 conditions, pyrrole and ammonium persulfate are added and mixed to obtain a mixture with a viscosity of 1500 mPa·s; wherein H3 is 50 min; the mass ratio of the pyrrole reagent to the oxidant is 2:0.7; and the content of the pyrrole reagent is 0.4 wt% of the total mass of the acrylic acid reagent.

[0072] (4) The mixture is mixed with an active material to obtain a slurry; the active material is a mixture of micron silicon and hard carbon in a mass ratio of 5.5:1.5; the mass ratio of the silicon-based material in the active material to the mixture is 6.5:0.5.

[0073] (5) The slurry is coated on the current collector, first treated at a first temperature for H4 time, and then treated at a second temperature for H5 time to form an active material layer; preferably, the first temperature is 70°C, the second temperature is 145°C, H4 is 14 hours, and H5 is 180 minutes.

[0074] Example 6 A silicon negative electrode plate comprises a current collector and an active material layer provided on the current collector; The active material layer includes a binder and an active material; The binder includes a polymer containing polypyrrole and a carboxylic acid compound which forms a gradient hydrogen bond with the main chain of the polymer.

[0075] The polymers include acrylic polymers, enol polymers and polypyrroles; different types of polymers are partially bonded to each other by covalent bonds.

[0076] This embodiment also provides a method for preparing the above silicon negative electrode sheet, including: (1) Acrylic acid and citric acid (CAS: 125139-13-1) aqueous solution are mixed for H1 time to obtain a first mixture; wherein H1 is 7.5h; the mass concentration of the carboxylic acid compound aqueous solution is 12%; and the molar ratio of the acrylic acid reagent to the carboxylic acid compound is 1.5:1; (2) The first mixture and the ethylene alcohol aqueous solution are stirred at 35° C. for H2 for 9.5 h to obtain a second mixture; wherein the H2 is 9.5 h; the mass concentration of the enol reagent aqueous solution is 14%; and the mass ratio of the acrylic acid reagent to the enol reagent is 5.5:1; (3) After the second mixture is placed in an ice bath under H3 conditions for 45 min, pyrrole and peroxodisulfuric acid are added and mixed to obtain a mixture with a viscosity of 2000 mPa·s; wherein H3 is 45 min; the mass ratio of the pyrrole reagent to the oxidant is 2:1; and the content of the pyrrole reagent is 0.5 wt% of the total mass of the acrylic acid reagent.

[0077] (4) The mixture is mixed with an active material to obtain a slurry; the active material is a mixture of micron silicon and hard carbon in a mass ratio of 6.5:1.75; the mass ratio of the silicon-based material in the active material to the mixture is 5:3.

[0078] (5) The slurry is coated on the current collector and treated at a first temperature for H4 time and then at a second temperature for H5 time to form an active material layer; preferably, the first temperature is 75°C, the second temperature is 140°C, H4 is 13h, and H5 is 165min.

[0079] Example 7 A silicon negative electrode plate comprises a current collector and an active material layer provided on the current collector; The active material layer includes a binder and an active material; The binder includes a polymer containing polypyrrole and a carboxylic acid compound which forms a gradient hydrogen bond with the main chain of the polymer.

[0080] The polymers include acrylic polymers, enol polymers and polypyrroles; different types of polymers are partially bonded to each other by covalent bonds.

[0081] This embodiment also provides a method for preparing the above silicon negative electrode sheet, including: (1) Polyacrylic acid (CAS: 9003-01-4) and citric acid aqueous solution were mixed for H1 time to obtain a first mixture; wherein H1 was 8 hours; the mass concentration of the carboxylic acid compound aqueous solution was 8%; and the molar ratio of the acrylic acid reagent to the carboxylic acid compound was 1.5:1; (2) The first mixture and the ethylene alcohol aqueous solution are stirred at 30° C. for H2 for 3.5 hours to obtain a second mixture; wherein the H2 is 3.5 hours; the mass concentration of the enol reagent aqueous solution is 8.5%; and the mass ratio of the acrylic acid reagent to the enol reagent is 9.5:1; (3) After the second mixture is placed in an ice bath under H3 conditions, polypyrrole and peroxodisulfuric acid are added and mixed to obtain a mixture with a viscosity of 500 mPa·s; wherein H3 is 40 min; the mass ratio of the pyrrole reagent to the oxidant is 2.5:0.5; and the content of the pyrrole reagent is 0.15 wt% of the total mass of the acrylic acid reagent.

[0082] (4) The mixture is mixed with an active material to obtain a slurry; the active material is a mixture of micron silicon and hard carbon in a mass ratio of 4.5:1; the mass ratio of the silicon-based material in the active material to the mixture is 6:2.

[0083] (5) The slurry is coated on the current collector and treated at a first temperature for H4 time and then at a second temperature for H5 time to form an active material layer; preferably, the first temperature is 50°C, the second temperature is 150°C, H4 is 8.5h, and H5 is 120min.

[0084] Example 8 A silicon negative electrode plate comprises a current collector and an active material layer provided on the current collector; The active material layer includes a binder and an active material; The binder includes a polymer containing polypyrrole and a carboxylic acid compound which forms a gradient hydrogen bond with the main chain of the polymer.

[0085] The polymers include acrylic polymers, enol polymers and polypyrroles; different types of polymers are partially bonded to each other by covalent bonds.

[0086] This embodiment also provides a method for preparing the above silicon negative electrode sheet, including: (1) Mixing polyacrylic acid (CAS: 9003-01-4) and citric acid (CAS: 77-92-9) in an aqueous solution for H1 time to obtain a first mixture; wherein H1 is 5 hours; the mass concentration of the carboxylic acid compound aqueous solution is 9%; and the molar ratio of the acrylic acid reagent to the carboxylic acid compound is 0.5:2; (2) The first mixture and the ethylene alcohol aqueous solution are stirred at 15° C. for H2 for 5 h to obtain a second mixture; wherein the H2 is 5 h; the mass concentration of the ethylene alcohol aqueous solution is 10%; and the mass ratio of the acrylic acid reagent to the ethylene alcohol reagent is 11:1; (3) After the second mixture is placed in an ice bath under H3 conditions, pyrrole and ammonium persulfate are added and mixed to obtain a mixture with a viscosity of 750 mPa·s; wherein H3 is 50 min; the mass ratio of the pyrrole reagent to the oxidant is 1.5:0.8; and the content of the pyrrole reagent is 0.2 wt% of the total mass of the acrylic acid reagent.

[0087] (4) The mixture is mixed with an active material to obtain a slurry; the active material is a mixture of micron silicon and hard carbon in a mass ratio of 4.5:1; the mass ratio of the silicon-based material in the active material to the mixture is 6.5:2.5.

[0088] (5) The slurry is coated on the current collector, first treated at a first temperature for H4 hours, and then treated at a second temperature for H5 hours to form an active material layer; preferably, the first temperature is 80°C, the second temperature is 125°C, H4 is 12.5 hours, and H5 is 150 minutes.

[0089] Example 9 A silicon negative electrode plate comprises a current collector and an active material layer provided on the current collector; The active material layer includes a binder and an active material; The binder includes a polymer containing polypyrrole and a carboxylic acid compound which forms a gradient hydrogen bond with the main chain of the polymer.

[0090] The polymers include acrylic polymers, enol polymers and polypyrroles; different types of polymers are partially bonded to each other by covalent bonds.

[0091] This embodiment also provides a method for preparing the above silicon negative electrode sheet, including: (1) mixing acrylic acid and butane tetracarboxylic acid aqueous solution for H1 time to make them uniform to obtain a first mixture; wherein H1 is 6.5h; the mass concentration of the carboxylic acid compound aqueous solution is 10%; and the molar ratio of acrylic acid reagent to carboxylic acid compound is 2:1.5; (2) The first mixture and the aqueous solution of propylene alcohol are stirred at 20° C. for H2 for 7 hours to obtain a second mixture; wherein the mass concentration of the aqueous solution of the enol reagent is 9%; and the mass ratio of the acrylic acid reagent to the enol reagent is 5:1; (3) After the second mixture is placed in an ice bath under H3 conditions, polypyrrole and peroxodisulfuric acid are added and mixed to obtain a mixture with a viscosity of 1250 mPa·s; wherein H3 is 55 min; the mass ratio of the pyrrole reagent to the oxidant is 2.5:0.25; and the content of the pyrrole reagent is 0.35 wt% of the total mass of the acrylic acid reagent.

[0092] (4) The mixture is mixed with an active material to obtain a slurry; the active material is a mixture of micron silicon and hard carbon in a mass ratio of 7:2.5; the mass ratio of the silicon-based material in the active material to the mixture is 7:1.5.

[0093] (5) The slurry is coated on the current collector, first treated at a first temperature for H4 time, and then treated at a second temperature for H5 time to form an active material layer; preferably, the first temperature is 65°C, the second temperature is 130°C, H4 is 10 hours, and H5 is 130 minutes.

[0094] Example 10 A silicon negative electrode plate comprises a current collector and an active material layer provided on the current collector; The active material layer includes a binder and an active material; The binder includes a polymer containing polypyrrole and a carboxylic acid compound which forms a gradient hydrogen bond with the main chain of the polymer.

[0095] The polymers include acrylic polymers, enol polymers and polypyrroles; different types of polymers are partially bonded to each other by covalent bonds.

[0096] This embodiment also provides a method for preparing the above silicon negative electrode sheet, including: (1) mixing acrylic acid and propane tricarboxylic acid aqueous solution for H1 time to obtain a first mixture; wherein H1 is 7.5h; the mass concentration of the carboxylic acid compound aqueous solution is 7%; and the molar ratio of the acrylic acid reagent to the carboxylic acid compound is 1.5:1; (2) The first mixture and the polyvinyl alcohol 2099 aqueous solution are stirred at 25° C. for H2 time to obtain a second mixture; wherein H2 is 7.5 hours; the mass concentration of the enol reagent aqueous solution is 6.5%; and the mass ratio of the acrylic acid reagent to the enol reagent is 6.5:1; (3) After the second mixture was placed in an ice bath under H3 conditions for 60 min, pyrrole and an oxidant (CAS: 52900-28-4) were added and mixed to obtain a mixture with a viscosity of 1000 mPa·s; wherein, H3 was 60 min; the mass ratio of the pyrrole reagent to the oxidant was 1.75:0.45; and the content of the pyrrole reagent was 0.25 wt% of the total mass of the acrylic acid reagent.

[0097] (4) The mixture is mixed with an active material to obtain a slurry; the active material is a mixture of micron silicon and hard carbon in a mass ratio of 6:3.5; the mass ratio of the silicon-based material in the active material to the mixture is 5.5:1.75.

[0098] (5) The slurry is coated on the current collector and treated at a first temperature for H4 time and then at a second temperature for H5 time to form an active material layer; preferably, the first temperature is 75°C, the second temperature is 135°C, H4 is 11.5h, and H5 is 155min.

[0099] Example 11 A silicon negative electrode plate comprises a current collector and an active material layer provided on the current collector; The active material layer includes a binder and an active material; The binder includes a polymer containing polypyrrole and a carboxylic acid compound which forms a gradient hydrogen bond with the main chain of the polymer.

[0100] The polymers include acrylic polymers, enol polymers and polypyrroles; different types of polymers are partially bonded to each other by covalent bonds.

[0101] This embodiment also provides a method for preparing the above silicon negative electrode sheet, including: (1) Acrylic acid and citric acid (CAS: 125139-13-1) aqueous solution are mixed for H1 time to obtain a first mixture; wherein H1 is 7 hours; the mass concentration of the carboxylic acid compound aqueous solution is 6%; and the molar ratio of the acrylic acid reagent to the carboxylic acid compound is 2:0.5; (2) The first mixture and the polyvinyl alcohol 2099 aqueous solution are stirred at 25° C. for H2 time to obtain a second mixture; wherein H2 is 8 hours; the mass concentration of the enol reagent aqueous solution is 5.5%; and the mass ratio of the acrylic acid reagent to the enol reagent is 7.5:1; (3) After the second mixture is placed in an ice bath under H3 conditions, polypyrrole and ammonium persulfate are added and mixed to obtain a mixture with a viscosity of 3500 mPa·s; wherein H3 is 35 min; the mass ratio of the pyrrole reagent to the oxidant is 2:0.35; and the content of the pyrrole reagent is 0.5 wt% of the total mass of the acrylic acid reagent.

[0102] (4) The mixture is mixed with an active material to obtain a slurry; the active material is a mixture of micron silicon and hard carbon in a mass ratio of 5:1; the mass ratio of the silicon-based material in the active material to the mixture is 6.75:2.25.

[0103] (5) The slurry is coated on the current collector and treated at a first temperature for H4 hours and then at a second temperature for H5 hours to form an active material layer; preferably, the first temperature is 80°C, the second temperature is 145°C, H4 is 12.5 hours, and H5 is 165 minutes.

[0104] Application Example 1 This application example provides a sodium ion solid-state battery, including a positive electrode sheet, a negative electrode sheet and an electrolyte; The electrolyte I facing the positive electrode is Na6PS5Cl 0.5 Br 0.5 ; The electrolyte II facing the negative electrode is Na6PS5Cl 0.5 Br 0.5 F 0.5 ; The mass ratio of electrolyte I to electrolyte II is 1:1.

[0105] The negative electrode plate is the silicon negative electrode plate of the above embodiment 1. The specific corresponding relationship is shown in Table 1 below.

[0106] The positive electrode material on the positive electrode sheet is Na2 phase structure. 0.75 Ni 0.24 Cu 0.07 Zn 0.03 Mn 0.62 Mg 0.05O2, NaNbOCl4 and conductive carbon black SP are mixed and stirred in a mass ratio of 60:30:10.

[0107] This embodiment also provides an assembly process of a sodium ion solid-state battery, which is as follows: (1) Weigh 60 mg of Na6PS5Cl 0.5 Br 0.5 Place the powder in the inner liner of an alumina ceramic mold (10 mm in diameter), rotate the stainless steel electrode indenter to the bottom of the mold, rotate the indenter to flatten the powder, and then add 60 mg of Na6PS5Cl 0.5 Br 0.5 F 0.5 , press it into electrolyte sheets with the help of a press (parameters: 100MPa, 30s), and use an ear cleansing bulb to remove excess electrolyte powder.

[0108] (2) Place the positive electrode sheet facing the Na6PS5Cl 0.5 Br 0.5 The electrolyte is placed on one side and the negative electrode is placed on the other side of the electrolyte sheet.

[0109] (3) Fasten the mold and the pressure head and tighten the nut to obtain a solid-state mold battery; use blue electricity test. During the test, when the battery's cycle test capacity retention rate is lower than 80% and the coulomb efficiency is lower than 98%, the battery test is stopped.

[0110] Application Examples 2~11 It is basically the same as Application Example 1, except that the silicon negative electrode piece of Example 1 is replaced by the silicon negative electrode pieces of Examples 2 to 11. The specific corresponding relationship is shown in Table 1 below.

[0111] Comparative Example 1 The process is basically the same as Application Example 1, except that the binder used in the process of preparing the negative electrode sheet is PAA.

[0112] Comparative Example 2 It is basically the same as Application Example 1, except that the electrolyte is Na6PS5Cl 0.5 Br.

[0113] Table 1

[0114] It can be seen from the above test results that by optimizing the adhesive mixed with the active material on the silicon negative electrode sheet, the cycle stability and rate performance of the silicon negative electrode sheet in the above-mentioned specific solid-state battery can be significantly improved.

[0115] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A silicon negative electrode plate, comprising a current collector, characterized in that: Also includes: an active material layer disposed on the current collector; The active material layer includes a binder and an active material; The binder comprises a polymer and a carboxylic acid compound which forms a gradient hydrogen bond with the main chain of the polymer; and the polymer comprises a conductive polymer.

2. The silicon negative electrode plate according to claim 1, characterized in that: The carboxylic acid compound is selected from one or a combination of two or more of citric acid, propane tricarboxylic acid and butane tetracarboxylic acid.

3. The silicon negative electrode plate according to claim 1, characterized in that: The active material includes a silicon-based material and a carbon-based material in a mass ratio of (4-7): (1-4.5), and the silicon-based material is silicon particles.

4. The silicon negative electrode sheet according to any one of claims 1 to 3, characterized in that: The polymers include acrylic polymers, enol polymers and polypyrroles.

5. The method for preparing the silicon negative electrode sheet according to any one of claims 1 to 4, characterized in that: include: The polymer raw material, the carboxylic acid compound and the oxidant are mixed to obtain a mixture having a viscosity of 100 to 20,000 mPa·s; The mixture is mixed with an active material to obtain a slurry; The slurry forms an active material layer on a current collector.

6. The method for preparing a silicon negative electrode sheet according to claim 5, characterized in that: include: mixing an acrylic acid reagent and a carboxylic acid compound to obtain a first mixture; mixing the first mixture with an enol reagent to obtain a second mixture; mixing the second mixture with a pyrrole reagent and an oxidant to obtain the mixture; The acrylic agent is selected from polyacrylic acid and / or acrylic acid; The enol reagent is selected from one or a combination of two or more of polyvinyl alcohol, vinyl alcohol and propenol; The pyrrole reagent is selected from polypyrrole and / or pyrrole; The oxidizing agent is selected from peroxodisulfuric acid and / or ammonium persulfate.

7. The method for preparing a silicon negative electrode sheet according to claim 5 or 6, characterized in that: include: Mixing the acrylic acid reagent and the carboxylic acid compound aqueous solution for H1 time to obtain a first mixture; wherein H1 is 2 to 8 hours; Stirring the first mixture and the aqueous solution of the enol reagent at 15-35° C. for H2 for 3-10 h to obtain a second mixture; The second mixture is placed in a H3 condition at 0-4°C for 10-60 minutes, and then a pyrrole reagent and an oxidant are added and mixed to obtain the mixture; wherein the H3 is 10-60 minutes; mixing the mixture with an active material to obtain a slurry; The slurry is coated on a current collector, first treated at a first temperature for H4 time, and then treated at a second temperature for H5 time to form an active material layer; the first temperature is 50-80°C, the second temperature is 120-150°C, H4 is 8-15h, and H5 is 30-180min.

8. The method for preparing a silicon negative electrode sheet according to claim 7, characterized in that: The mass concentration of the carboxylic acid compound aqueous solution is 1-15%; the molar ratio of the acrylic acid reagent to the carboxylic acid compound is (0.5-2): (0.5-2); The mass concentration of the aqueous solution of the enol reagent is 1-15%; the mass ratio of the acrylic acid reagent to the enol reagent is (5-15):1; The mass ratio of the pyrrole reagent to the oxidant is (1-2.5): (0.1-1); the content of the pyrrole reagent is 0.1-0.5wt% of the total mass of the acrylic acid reagent; The mass ratio of the silicon-based material in the active material to the mixture is (5-7): (0.5-3.5).

9. A sodium ion solid-state battery, characterized in that: Including positive electrode sheet, negative electrode sheet and electrolyte; The electrolyte element facing the negative electrode plate contains F; The negative electrode plate is the silicon negative electrode plate described in any one of claims 1 to 4 or the silicon negative electrode plate prepared by the preparation method described in any one of claims 5 to 8.

10. The sodium ion solid-state battery according to claim 9, characterized in that: The positive electrode plate contains a sodium ion positive electrode material with a P2 type structure.

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