CN114551818A - Nano silicon composite particle, negative plate and solid lithium battery - Google Patents
Nano silicon composite particle, negative plate and solid lithium battery Download PDFInfo
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Abstract
The invention relates to the technical field of battery materials, and discloses a nano silicon composite particle, a negative plate and a solid lithium battery, wherein the nano silicon composite particle is an N-P-COF-GO modified nano silicon composite particle, COF and GO are loaded on the surface of a silicon nanoparticle, and N and P are codoped in COF and GO; dispersing silicon nanoparticles, a phosphorus source material, a nitrogen source material and graphene oxide in an organic solvent, and synthesizing N-P-COF-GO modified nano silicon composite particles by adopting a solvothermal method; the negative plate and the solid lithium battery are prepared by utilizing the nano silicon composite particles. The invention overcomes the defects of obvious volume expansion and continuous increase of a surface SEI layer of a silicon material in continuous charge and discharge, realizes the rapid transmission and storage of lithium ions, and the negative plate and the solid lithium battery prepared by the nano silicon composite particles have lower alternating current impedance, higher discharge capacity and cycle performance.
Description
Technical Field
The invention relates to the technical field of battery materials, in particular to a nano silicon composite particle, a negative plate and a solid lithium battery.
Background
Silicon (Si) has very high theoretical capacity (3579mAh/g), is considered to be one of the most promising negative electrode materials of the solid lithium battery, and the solid lithium battery has high energy density and is the preferred choice for the development of next-generation lithium battery products. The energy density of the all-solid-state lithium battery using the silicon-based cathode is far higher than that of the conventional liquid lithium ion secondary battery, so that the generation of lithium dendrite can be avoided, and the safety performance is good. However, significant volume expansion of the silicon material and continuous increase of the surface solid electrolyte membrane (SEI) in continuous charge and discharge consume free lithium ions, resulting in rapid degradation of battery performance.
Due to its high porosity and adjustable physicochemical properties, in recent years, the combination of COFs with lithium batteries has attracted a great deal of attention from the chemical and material sciences, because of the high mechanical strength of the ordered porous frameworks, rapid transport and storage of lithium ions can be achieved without large volume changes. Chinese patent publication No. CN112736245A discloses a lithium ion battery negative electrode material, a preparation method and an application thereof, the lithium ion battery negative electrode material is formed by uniformly forming a film on the surface of a current collector through a dispersion liquid containing a covalent organic framework material, and the lithium ion battery negative electrode is obtained by electrochemically depositing metal lithium on the lithium ion battery negative electrode material. The method has the disadvantages that the covalent metal framework layer is directly used as the battery cathode material, compared with a silicon-based cathode material, the theoretical capacity is low, the energy density of the obtained lithium ion battery is low, and the comprehensive electrochemical performance of the lithium ion battery is poor.
Disclosure of Invention
The invention aims to provide nano silicon composite particles, a negative plate and a solid lithium battery, which overcome the defects of obvious volume expansion and continuous increase of a surface SEI layer of a silicon material in continuous charge and discharge on the premise of keeping the advantages of high theoretical capacity and energy density of the silicon-based negative material, and realize the rapid transmission and storage of lithium ions.
The purpose of the invention is realized by the following technical scheme.
The invention provides a nano silicon composite particle used as a lithium battery cathode material, wherein the nano silicon composite particle is a N-P-COF-GO modified nano silicon composite particle, COF and GO are loaded on the surface of a silicon nanoparticle, and N and P are codoped in COF and GO.
The Covalent Organic Framework (COF) has a stable and ordered porous framework structure, after being compounded with the nano silicon particles, the Covalent Organic Framework (COF) relieves and inhibits the violent volume change of the nano silicon particles, reduces the generation of a surface SEI film, and simultaneously has a large number of redox active centers and long-range ordered open channels in the COF, so that the diffusion path of lithium ions is more convenient, and the electrochemical performance of the battery is more excellent.
Meanwhile, Graphene Oxide (GO) has excellent lithium ion transmission performance, and the conductivity of silicon particles can be increased by adding graphene oxide. COF possesses high mechanical strength because of its orderly porous skeleton, and GO mechanical strength is lower, and COF and GO's complex has formed the lithium ion transmission channel of just gentle combination, can realize the quick transmission and the storage of lithium ion under the condition that does not have the bulky change. The addition of COF and GO can also buffer particle pulverization and SEI film continuous growth brought by volume expansion of silicon particles, so that the service life is prolonged, and the structure and chemical stability of the material are improved.
The doping of the nitrogen source material (N) and the phosphorus source material (P) endows COF and GO with more topological defects and larger interlayer spacing, and further enhances the transmission performance of electrons and ions. Therefore, the solid lithium battery corresponding to the N-P-COF-GO modified nano silicon particles has lower alternating current impedance, higher discharge capacity and cycle performance.
Preferably, the method for preparing the nano silicon composite particle comprises the following steps:
dispersing silicon nano particles, a phosphorus source material, a nitrogen source material and graphene oxide in an organic solvent, and performing ultrasonic treatment at normal temperature; adding the obtained mixed solution into a Pyrex tube, adjusting the pH value to 5-6, then performing ultrasonic mixing at normal temperature, quickly freezing in liquid nitrogen, and degassing through unfreezing circulation; heating a Pyrex tube, filtering, washing the precipitate, removing impurities on the surface, and then performing vacuum drying and sintering; and after cooling to room temperature, performing ball milling on the obtained powder to obtain the nano-silicon composite particles.
Preferably, the particle size of the silicon nano-particles is 50-500 nm; the mass ratio of the silicon nanoparticles to the phosphorus source material to the nitrogen source material to the graphene oxide is (30-40): (0.001-0.003): (0.001-0.003): (0.5 to 2.0); the organic solvent comprises a solvent a and a solvent b, and the volume ratio of the solvent a to the solvent b is (2-3): 0.5 to 1; the ultrasonic time at normal temperature is 40-60 minutes; the solvent for adjusting the pH value to 5-6 is one of acetic acid, citric acid, tartaric acid and malic acid; after the pH is adjusted, the ultrasonic mixing time at normal temperature is 20-40 minutes; the heating temperature in the Pyrex tube is 80-120 ℃, and the heating time is 24-60 hours; the filtered washing solvent is deionized water and ethanol; the vacuum drying temperature is 60 ℃, the vacuum drying time is 4-6 hours, the vacuum sintering temperature is 300-400 ℃, and the vacuum sintering time is 8-12 hours; the ball milling time is 10-30 minutes.
Preferably, the phosphorus source material is one or more phosphate esters; the nitrogen source material is one of acrylamide, polyacrylamide, N-p-hydroxyphenyl acrylamide, isopropyl acrylamide and N- (3-aminopropyl) methacrylamide; the solvent a is one of dioxane and dimethylformamide, and is preferably dioxane; the solvent b is one of trimethylbenzene, toluene, xylene, tetramethylbenzene and pentamethylene, and trimethylbenzene is preferable.
Preferably, the phosphorus source material is phosphoketene pyruvic acid, and the nitrogen source material is acrylamide.
Acrylamide reacts in a high-temperature Pyrex tube for a long time (heated at the temperature of 80-120 ℃ for 24-60 hours) to generate a COF microcrystal aggregate, and the acrylamide can form a COF and can also be used as a nitrogen source to be doped in the COF and the GO. Acrylamide is used as a nitrogen source, phosphoketene pyruvic acid is used as a phosphorus source, and a COF porous structure and a GO layered structure are doped in a vacuum sintering process at the temperature of 300-400 ℃ to form a structure in which N and P are codoped in the COF and GO.
The invention also provides a negative plate comprising the nano silicon composite particles.
Preferably, the negative plate is a double-layer silicon-based composite negative plate, and the preparation method comprises the following steps of performing ball milling on a mixture of nano silicon composite particles and LATP, and pressing the mixed powder into a film to obtain a silicon-based film layer; stirring the polymer electrolyte and chlorate electrolyte in an organic solvent until the polymer electrolyte and chlorate electrolyte are fully dissolved, and uniformly coating the obtained mixed solution on one side of a silicon-based membrane layer to form a polymer solid electrolyte layer; and finally, after vacuum drying, obtaining the double-layer silicon-based composite negative plate.
Compared with a single-layer silicon-based composite negative plate, the double-layer silicon-based composite negative plate avoids direct contact of a silicon-based film layer and an electrode, is not easy to fall off from the electrode in the charging and discharging processes, and prolongs the service life. And the energy density and the cycle life of the solid lithium battery can be obviously improved, so that the preparation method is a more stable preparation method of the silicon-based composite negative plate.
Preferably, the mass ratio of the nano silicon composite particles to the LATP is 8-10: 1.0 to 2.0; the ball milling time is 10-20 minutes; the pressing condition is that the pressing is carried out under 50-200 standard atmospheric pressures; the thickness of the silicon-based film layer is 50-150 mu m; the molar ratio of the polymer electrolyte to the chlorate electrolyte is 7-10: 1-3; the temperature of the polymer electrolyte and chlorate electrolyte when dissolved in an organic solvent is 45-55 ℃, the stirring time is 3-5 hours, and the organic solvent is one of acetonitrile, methanol, tetrahydrofuran, N-dimethylformamide, dimethyl sulfoxide, diethyl ether and carbon tetrachloride; the thickness of the polymer solid electrolyte layer is 10-15 mu m; the temperature of the vacuum drying is 30-40 ℃, and the time is 12-20 hours.
Preferably, the polymer electrolyte is one of polyethylene oxide, polymethacrylic acid, polyurethane, polyvinylidene fluoride, polyacrylonitrile and polymethyl methacrylate, and is preferably polyethylene oxide; the chlorate electrolyte is one of cesium perchlorate, lithium perchlorate, sodium perchlorate, potassium perchlorate and rubidium perchlorate, and is preferably cesium perchlorate.
The polyethylene oxide (PEO) is a flexible semi-crystalline polymer, has high lithium ion transmission capacity in an amorphous region and good interface compatibility, and can solve the problem of interface incompatibility between the LATP solid electrolyte and solid silicon-based particles. Cesium perchlorate forms a salt bridge on the surface of LATP, repairs the surface grain boundary and reduces the interface resistance. The polymer solid electrolyte layer composed of PEO and cesium perchlorate is used as a buffer layer between the LATP and the silicon-based negative electrode, so that the interface compatibility between the LATP solid particles and the nano-silicon composite particles is improved, the deposition of lithium ions on the negative electrode sheet is more uniform, and the electrochemical performance of the battery is improved.
The invention also provides a solid lithium battery which comprises the negative plate.
Compared with the prior art, the invention has the following beneficial effects:
(1) on the premise of keeping the advantages of high theoretical capacity and energy density of the silicon-based negative electrode material, the nano silicon composite particles overcome the defects of remarkable volume expansion and continuous increase of a surface SEI (solid electrolyte interphase) layer of the silicon material in continuous charge and discharge, and realize the rapid transmission and storage of lithium ions;
(2) the double-layer silicon-based composite negative plate avoids the direct contact of the silicon-based film layer with the electrode, is not easy to fall off from the electrode in the charging and discharging process, prolongs the service life, improves the deposition uniformity of lithium ions on the negative plate and finally ensures that the performance of the negative plate is more stable;
(3) The negative plate and the solid lithium battery prepared by the nano-silicon composite particles have lower alternating current impedance, higher discharge capacity and cycle performance and more excellent comprehensive electrochemical performance.
Detailed Description
The technical solution of the present invention is illustrated by the following specific examples, but the scope of the present invention is not limited thereto:
example 1
1. Preparation of nano-silicon composite particles
The nano silicon composite particles are modified by N-P-COF-GO and are a structure that COF and GO are alternatively loaded on the surfaces of silicon nanoparticles and N and P are codoped in COF and GO.
The preparation method of the nano silicon composite particle comprises the following steps:
dispersing silicon nanoparticles, phosphoketene pyruvic acid, acrylamide and graphene oxide in an organic solvent, wherein the particle size of the silicon nanoparticles is 50nm (the purity is more than 99%), and the mass ratio of the silicon nanoparticles to the phosphoketene pyruvic acid to the acrylamide to the graphene oxide is 33: 0.002: 0.002: 1.5, the volume ratio of the organic solvent dioxane to the trimethylbenzene is 3: 1.
And (3) performing ultrasonic treatment on the mixture at normal temperature for 60 minutes, adding the obtained mixed solution into a Pyrex tube, and adjusting the pH to 5-6 by using acetic acid, wherein the concentration of the acetic acid is 5mol/L, and the molar ratio of the acetic acid to silicon is 20: 3. Then ultrasonically mixed at room temperature for 40 minutes, rapidly frozen in liquid nitrogen, and degassed by a freeze pump thaw cycle. Heating the Pyrex tube at 90 ℃ for 45 hours, filtering, washing the precipitate with deionized water and ethanol, and removing impurities on the surface. Vacuum drying at 60 deg.C for 6 hr, and vacuum sintering at 300 deg.C for 12 hr. And after sintering, cooling to room temperature, putting the obtained powder into a high-energy vibration ball mill, and ball-milling for 30 minutes at the room temperature to obtain the nano-silicon composite particles.
2. Preparation of double-layer silicon-based composite negative plate
Adding the N-P-COF-GO modified nano silicon particles prepared in the step 1 and LATP into a ball mill according to the mass ratio of 8:1.0, ball-milling for 10 minutes at normal temperature, transferring the mixed powder to a molybdenum alloy die, and pressing into a film under 100 standard atmospheric pressures to obtain a silicon-based film layer with the thickness of 100 micrometers. And then dissolving the polymer electrolyte and chlorate electrolyte in acetonitrile at 45 ℃, wherein the polymer electrolyte is PEO, the chlorate electrolyte is cesium perchlorate, and the molar ratio of the PEO to the cesium perchlorate is 8: 1.5, stirring for 5 hours until fully dissolved. The mixed solution was uniformly coated on one side of a silicon-based film layer as a polymer solid electrolyte layer with a thickness of 13 μm. And (3) carrying out vacuum drying at the temperature of 40 ℃ for 19 hours to finally prepare the double-layer silicon-based composite negative plate.
3. Solid lithium battery assembly and performance evaluation
Mixing a positive electrode active material, a LATP solid electrolyte and a conductive agent according to the proportion of 70:25:4, compressing the mixed material into granules under 200 standard atmospheric pressures, then grinding for 25 minutes, repeating for 4 times to obtain a uniformly mixed composite positive electrode material, and compressing and combining the composite positive electrode material with indium foil with the thickness of 40 microns under 200 standard atmospheric pressures to obtain a solid lithium battery positive electrode plate, wherein the thickness of the plate is 100 microns, and the used positive electrode material is lithium iron phosphate LFP. And (3) respectively pressing the double-layer silicon-based composite negative electrode and the positive electrode plate prepared in the step (2) on two sides of the LATP solid electrolyte under 100 standard atmospheric pressures, wherein the side of the PEO and cesium perchlorate coating layer faces to one side of the LATP solid electrolyte, so as to prepare the button solid full cell.
And carrying out constant-current and constant-voltage charge-discharge circulation on the assembled solid battery at room temperature within the range of 4.1-2.5V at the rate of 0.4C. The internal resistance of the cell was measured by electrochemical ac impedance spectroscopy with a frequency range of 0.1HZ to 1MHZ and an applied voltage amplitude of 5 mV.
Example 2
Compared with the embodiment 1, the particle size of the silicon nanoparticles in the preparation process of the nano-silicon composite particles in the embodiment 2 is 200nm, and the mass ratio of the silicon nanoparticles to the phosphoketene pyruvic acid to the acrylamide to the graphene oxide is 40:0.003: 0.001: 0.5; the volume ratio of dioxane to trimethylbenzene is 2: 0.7; ultrasonic mixing at normal temperature for 40 min, quickly freezing in liquid nitrogen, degassing by a freeze pump-thawing cycle, and heating a Pyrex tube at 120 deg.C for 60 hr; vacuum drying at 60 deg.C for 4 hr, and vacuum sintering at 400 deg.C for 8 hr; the ball milling time was 10 minutes. The remaining conditions were the same as in example 1.
Example 3
Compared with example 1, acrylamide in the preparation process of the nano-silicon composite particle in example 3 is replaced by aliphatic n, n-methylene bisacrylamide, the particle size of the silicon nanoparticle is 500nm, and the mass ratio of the silicon nanoparticle, phosphoketene pyruvic acid, n-methylene bisacrylamide and graphene oxide is 30:0.001: 0.003: 2.0, the volume ratio of dioxane to trimethylbenzene is 2.5: 0.5; ultrasonically mixing for 20 minutes at normal temperature, quickly freezing in liquid nitrogen, degassing through a freeze pump-unfreezing cycle, and heating a Pyrex tube at the temperature of 80 ℃ for 24 hours; vacuum drying at 60 deg.C for 5 hr, and vacuum sintering at 350 deg.C for 10 hr; the ball milling time was 20 minutes. The remaining conditions were the same as in example 1.
Example 4
In comparison with example 1, the phosphoketene pyruvic acid used in example 4 was replaced by dialkyl phosphate, the positive electrode active material was lithium manganate LMO, and the rest of the conditions were the same as in example 1.
Example 5
Compared with the embodiment 1, the thickness of the silicon-based film layer in the embodiment 5 is 150 μm, the thickness of the PEO and cesium perchlorate coating layer is 15 μm, and the double-layer silicon-based composite negative plate is dried at 30 ℃ for 20 hours; the thickness of the positive plate was 200. mu.m. The remaining conditions were the same as in example 1.
Example 6
Compared with the embodiment 1, the thickness of the silicon-based film layer in the embodiment 6 is 50 μm, the thickness of the PEO and cesium perchlorate coating layer is 10 μm, and the double-layer silicon-based composite negative plate is dried at 35 ℃ for 12 hours; the thickness of the positive electrode sheet was 50 μm. The remaining conditions were the same as in example 1.
Example 7
Compared with the example 1, the mass ratio of the N-P-COF-GO modified nano silicon particles to the LATP in the example 7 is 10.0: 2.0; the ball milling time is 20 minutes; pressing the silicon-based film layer under 200 atmospheric pressures; PEO to cesium perchlorate molar ratio of 7: 1, stirred in acetonitrile at 55 ℃ for 4 hours. The remaining conditions were the same as in example 1.
Example 8
Compared with the example 1, the mass ratio of the N-P-COF-GO modified nano silicon particles to the LATP in the example 8 is 9.0: 1.5; the ball milling time is 15 minutes; pressing the silicon-based film layer under 100 atmospheric pressures; PEO to cesium perchlorate molar ratio of 10: 3, stir in acetonitrile at 50 ℃ for 3 hours. The remaining conditions were the same as in example 1.
Comparative example 1
In comparison with example 1, the nano-silicon composite particle in comparative example 1 did not contain COF modification, and the rest of the conditions were the same as in example 1.
Comparative example 2
In comparison with example 1, the nano-silicon composite particles in comparative example 2 did not contain GO modification, and the rest of the conditions were the same as in example 1.
Comparative example 3
In comparison with example 1, the nano-silicon composite particles in comparative example 3 were not doped with N, P, and the remaining conditions were the same as in example 1.
Comparative example 4
Comparative example 4 uses pure nano-silicon particles as compared with example 1, and the rest of the conditions are the same as example 1.
Comparative example 5
Compared with the example 1, the composite silicon-based negative plate of the comparative example 5 has a single-layer structure and does not contain a PEO and cesium perchlorate coating layer, and the rest conditions are the same as those of the example 1.
Comparative example 6
Compared with the example 1, the composite silicon-based negative electrode plate coating layer of the comparative example 5 does not contain cesium perchlorate, only contains PEO, and the rest conditions are the same as the example 1.
TABLE 1 comparison of the Performance of solid lithium batteries prepared under different conditions
Specific results are shown in table 1, and it can be seen from examples 1 to 8 that the solid-state battery performance is significantly improved within the technical requirements of the present invention, and the results of example 1 are the best. By combining the embodiment 1 and the comparative examples 1 to 4, the N-P-COF-GO modified nano silicon particle negative electrode prepared by the invention is found to reduce the internal resistance and the cycle life of a solid battery, and the main reason is that graphene with excellent lithium ion transmission performance and COFs form a rigid-flexible combined rapid lithium ion transmission channel, so that the volume change of silicon particles in the charging and discharging process is effectively reduced, the structure and the chemical stability of the material are improved, N and P doping endow more structural defects to the N-P-COF-GO modified nano silicon particle negative electrode, and the transmission performance of electrons and ions is further enhanced. By combining example 1 with comparative examples 5 to 6, it can be found that after the surface of the silicon-based negative electrode is coated with the polymer solid electrolyte layer, the transmission speed of lithium ions at the interface between the LATP solid electrolyte layer and the silicon-based negative electrode can be significantly improved, thereby improving the electrochemical performance of the solid lithium battery.
The results show that the method provided by the invention can obviously improve the stability of the silicon-based negative electrode, prolong the service life of the solid lithium battery and provide technical reference for researching the high-performance solid lithium battery.
The above description is only a preferred embodiment of the present invention, and not intended to limit the scope of the present invention, and all modifications of equivalent structures and equivalent processes, which are made by the present specification, or directly or indirectly applied to other related technical fields, are included in the scope of the present invention.
Claims (10)
1. The nano silicon composite particle used as the negative electrode material of the lithium battery is characterized in that the nano silicon composite particle is a N-P-COF-GO modified nano silicon composite particle, COF and GO are loaded on the surface of a silicon nanoparticle, and N and P are codoped in COF and GO.
2. The nano-silicon composite particle for a negative electrode material of a lithium battery as claimed in claim 1, wherein the preparation method comprises the steps of:
dispersing silicon nano particles, a phosphorus source material, a nitrogen source material and graphene oxide in an organic solvent, and performing ultrasonic treatment at normal temperature; adding the obtained mixed solution into a Pyrex tube, adjusting the pH value to 5-6, performing ultrasonic mixing again at normal temperature, then quickly freezing in liquid nitrogen, and performing degassing through unfreezing circulation; heating a Pyrex tube, filtering, washing the precipitate, removing impurities on the surface, and then performing vacuum drying and vacuum sintering; and after cooling to room temperature, performing ball milling on the obtained powder to obtain the nano-silicon composite particles.
3. The nano-silicon composite particle for a negative electrode material of a lithium battery according to claim 2,
the particle size of the silicon nano particles is 50-500 nm;
the mass ratio of the silicon nanoparticles to the phosphorus source material to the nitrogen source material to the graphene oxide is (30-40): (0.001-0.003): (0.001-0.003): (0.5 to 2.0);
the organic solvent comprises a solvent a and a solvent b, and the volume ratio of the solvent a to the solvent b is (2-3): 0.5 to 1;
the ultrasonic time at normal temperature is 40-60 minutes;
the solvent for adjusting the pH value to 5-6 is one of acetic acid, citric acid, tartaric acid and malic acid;
after the pH is adjusted, the ultrasonic mixing time at normal temperature is 20-40 minutes;
the heating temperature in the Pyrex tube is 80-120 ℃, and the heating time is 24-60 hours;
the filtered washing solvent is deionized water and ethanol;
the vacuum drying temperature is 60 ℃, the vacuum drying time is 4-6 hours, the vacuum sintering temperature is 300-400 ℃, and the vacuum sintering time is 8-12 hours;
the ball milling time is 10-30 minutes.
4. The nano-silicon composite particle for a negative electrode material of a lithium battery as claimed in claim 3,
The phosphorus source material is one or more phosphate esters;
the nitrogen source material is one of acrylamide, polyacrylamide, N-p-hydroxyphenyl acrylamide, isopropyl acrylamide and N- (3-aminopropyl) methacrylamide;
the solvent a is one of dioxane and dimethylformamide, and the solvent b is one of trimethylbenzene, toluene, xylene, tetramethylbenzene and pentamethylene.
5. The nano-silicon composite particle as claimed in claim 4, wherein the phosphorus source material is phosphoketene pyruvic acid and the nitrogen source material is acrylamide.
6. A negative electrode sheet comprising the nano-silicon composite particles according to any one of claims 1 to 5.
7. The negative plate according to claim 6, wherein the negative plate is a double-layer silicon-based composite negative plate, and the preparation method comprises the following steps,
ball-milling the mixture of the nano-silicon composite particles and the LATP, and pressing the mixed powder into a film to obtain a silicon-based film layer; stirring the polymer electrolyte and chlorate electrolyte in an organic solvent until the polymer electrolyte and chlorate electrolyte are fully dissolved, and uniformly coating the obtained mixed solution on one side of a silicon-based membrane layer to form a polymer solid electrolyte layer; and finally, after vacuum drying, obtaining the double-layer silicon-based composite negative plate.
8. A negative electrode sheet according to claim 7,
the mass ratio of the nano silicon composite particles to the LATP is 8-10: 1.0 to 2.0;
the ball milling time is 10-20 minutes;
the pressing condition is that the pressing is carried out under 50-200 standard atmospheric pressures;
the thickness of the silicon-based film layer is 50-150 mu m;
the molar ratio of the polymer electrolyte to the chlorate electrolyte is 7-10: 1-3;
the temperature of the polymer electrolyte and chlorate electrolyte when dissolved in an organic solvent is 45-55 ℃, the stirring time is 3-5 hours, and the organic solvent is one of acetonitrile, methanol, tetrahydrofuran, N-dimethylformamide, dimethyl sulfoxide, diethyl ether and carbon tetrachloride;
the thickness of the polymer solid electrolyte layer is 10-15 mu m;
the temperature of the vacuum drying is 30-40 ℃, and the time is 12-20 hours.
9. A negative electrode sheet according to claim 7,
the polymer electrolyte is one of polyethylene oxide, polymethacrylic acid, polyurethane, polyvinylidene fluoride, polyacrylonitrile and polymethyl methacrylate;
the chlorate electrolyte is one of cesium perchlorate, lithium perchlorate, sodium perchlorate, potassium perchlorate and rubidium perchlorate.
10. A solid lithium battery comprising the negative electrode sheet according to any one of claims 6 to 9.
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| Application Number | Priority Date | Filing Date | Title |
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| CN202110772171.6A CN114551818B (en) | 2021-07-08 | 2021-07-08 | Nano silicon composite particles, negative plate and solid lithium battery |
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| CN202110772171.6A CN114551818B (en) | 2021-07-08 | 2021-07-08 | Nano silicon composite particles, negative plate and solid lithium battery |
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