Method for modifying composite solid electrolyte by plasma

Abstract

The invention discloses a preparation method of a plasma modified composite solid electrolyte, and belongs to the technical field of electrolyte preparation, and the preparation method comprises the following steps: preparing a material, pretreating the material, and detecting the material; according to the method, the plasma treatment technology is adopted, the plasma treatment reduces the interface impedance between the electrolyte and an electrode and improves the overall quality of the prepared electrolyte by etching surface impurities (such as organic residues) and introducing a lithium-loving functional group, and an oxygen-containing group introduced by oxygen plasma promotes uniform wetting of lithium metal, so that the lithium ion battery is more stable in performance. The method solves the bottleneck problems of low ionic conductivity, large interface positive resistance, easy dendritic crystal growth and the like of the traditional solid electrolyte, has the advantages of environment-friendly process and controllable cost, provides a key technical path for industrialization of high-energy-density and high-safety solid-state batteries, and has wide application prospects. The whole method is good in practical application effect.

Description

Technical Field

[0001] The present invention belongs to the technical field of electrolyte preparation, and in particular relates to a method for preparing a plasma-modified composite solid electrolyte. Background Art

[0002] Electrolytes are compounds that conduct electricity in aqueous solutions or in a molten state. These compounds dissociate into freely moving ions in aqueous solutions, or in a molten state, allowing the flow of current. Electrolyte preparation methods are essential for preparing these compounds.

[0003] A Chinese patent discloses (CN103159890B) a method for preparing a solid electrolyte, which includes the following steps: providing a first monomer, a second monomer, an initiator and a lithium salt, wherein the first monomer is, the second monomer is, and R1, R2 and R3 all contain a group -C=C- or a group -C≡C-, R4 is an alkyl group or a hydrogen atom, m and n are integers, and the molecular weight of the first monomer and the molecular weight of the second monomer are respectively greater than or equal to 100 and less than or equal to 800; mixing the first monomer, the second monomer, the initiator and the lithium salt to form a mixture, and the mass ratio of the first monomer to the second monomer is less than or equal to 50%; and causing the first monomer, the second monomer and the initiator to undergo a polymerization reaction to generate an interpenetrating network polymer, and the lithium salt forms a solid solution in the dispersed interpenetrating network polymer, thereby obtaining the fixed electrolyte. Although current electrolyte preparation methods can also complete the preparation of electrolytes, they do not carry out a plasma modification process, resulting in the quality of the prepared electrolyte being unable to be guaranteed. There is an urgent need for a preparation method for plasma-modified composite solid electrolytes. Summary of the Invention

[0004] The purpose of the present invention is to solve the problem that although the current roadbed construction method can be used to construct the roadbed and has no significant negative impact under general soil conditions, when it is constructed in the strong alkaline saline area of ​​the plateau cold and arid region, the stability of the roadbed cannot be guaranteed, the overall construction scope is limited, and the actual application effect and comprehensiveness of the overall construction method are poor. A preparation method of a plasma-modified composite solid electrolyte is proposed.

[0005] In order to achieve the above object, the present invention adopts the following technical solution: a method for preparing a plasma-modified composite solid electrolyte, comprising the following steps:

[0006] S1. Prepare materials and pre-process them;

[0007] S2. Precursor preparation using composite electrolyte;

[0008] S3, performing plasma modification treatment;

[0009] S4, post-processing of materials;

[0010] S5. Take the finished product and conduct key performance tests.

[0011] As a further description of the above technical solution:

[0012] In S1, materials are prepared and pretreated. The materials include an electrolyte matrix, additives, and target modified materials. The electrolyte matrix is ​​LLZO (lithium lanthanum zirconium oxide), LATP (lithium aluminum titanium phosphorus oxide), and PEO (polyethylene oxide). The additives include conductive fillers, plasticizers, and binders. The target modified material is one of nano-ceramic particles or polymer coating materials.

[0013] As a further description of the above technical solution:

[0014] In S1, the pretreatment process is specifically as follows: placing the raw materials in a vacuum drying device, raising the temperature in the device to 60-70°C, drying for 10-12 hours to remove moisture from the raw materials, and placing them in a ball milling device, controlling the speed to 300-500 r / min, ball milling for 8-12 hours to make the material into powder, and passing through a 200-260 mesh sieve.

[0015] As a further description of the above technical solution:

[0016] In the above-mentioned S2, a composite electrolyte is used to prepare a precursor, and the preparation method adopts one of a solvent preparation method and a dry pressing method.

[0017] As a further description of the above technical solution:

[0018] In the S2, a solvent preparation method is adopted, specifically, PEO and lithium salt are dissolved in acetonitrile or THF, stirred for 12-16 hours, and then ceramic filler is added thereto, ultrasonically treated for 1-2 hours, the filler is LLZO nanoparticles, the filler amount accounts for 10-30wt%, and dry pressing is performed, specifically, LLZO is mixed with a polymer binder, 150-200Mpa is provided, and cold pressing is performed.

[0019] As a further description of the above technical solution:

[0020] In S3, plasma modification treatment is performed, wherein a radio frequency (RF) low-temperature plasma system equipment is used, the treated gas is an Ar / O2 mixed gas with a mixing ratio of 4:1, the control equipment power is less than 150W, and the treatment time is more than 10 minutes.

[0021] As a further description of the above technical solution:

[0022] In the above-mentioned S4, the post-processing of the material is performed, specifically including hot pressing processing of the material, sintering processing of the material and annealing processing of the material.

[0023] As a further description of the above technical solution:

[0024] In the S4, the hot pressing treatment of the material provides a temperature of 60-80°C, the sintering treatment of the material provides a temperature of 1300-1500°C, and the sintering is performed for 3-5 hours. During the sintering process, an inert gas is introduced into the equipment. After sintering, the material is naturally cooled and then annealed.

[0025] As a further description of the above technical solution:

[0026] In S5, the finished product is taken and subjected to key performance tests, specifically including structural tests and electrochemical tests.

[0027] As a further description of the above technical solution:

[0028] In said S5, the structural test specifically comprises observing the crystal phase and micromorphology by using XRD and SEM, and the electrochemical test specifically comprises measuring the ionic conductivity by using EIS.

[0029] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are:

[0030] In the present invention, the method adopts plasma treatment technology. Plasma treatment etches surface impurities (such as organic residues) and introduces lithium-philic functional groups, thereby reducing the interfacial impedance between the electrolyte and the electrode and improving the overall quality of the prepared electrolyte. The oxygen-containing groups introduced by the oxygen plasma promote the uniform wetting of lithium metal, reduce the nucleation overpotential, and inhibit dendrite puncture. The above method solves the bottleneck problems of low ionic conductivity, large interfacial cation resistance, and easy growth of dendrites in traditional solid-state electrolytes. At the same time, it has the advantages of environmentally friendly process and controllable cost, providing a key technical path for the industrialization of high-energy density and high-safety solid-state batteries. The overall method has good practical application effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 The present invention is a flow chart of a method for preparing a plasma-modified composite solid electrolyte. DETAILED DESCRIPTION

[0032] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts shall fall within the scope of protection of the present invention.

[0033] Example 1

[0034] See also Figure 1 The present invention provides a technical solution: a method for preparing a plasma-modified composite solid electrolyte, comprising the following steps:

[0035] S1. Prepare materials and pre-treat them. The materials include an electrolyte matrix, additives, and target modified materials. The electrolyte matrix is ​​LLZO (lithium lanthanum zirconium oxide), LATP (lithium aluminum titanium phosphorus oxide), and PEO (polyethylene oxide). The additives include conductive fillers, plasticizers, and binders. The target modified material is one of nano-ceramic particles or polymer coating materials. The pre-treatment process is as follows: place the raw materials in a vacuum drying device, increase the temperature in the device to 60°C, dry for 10 hours, remove moisture from the raw materials, and place them in a ball milling device. Control the speed to 300 r / min and ball mill for 8 hours to make the material powder, which is then passed through a 200-mesh sieve.

[0036] S2. Precursor preparation is performed using a composite electrolyte. The preparation method adopts dry pressing and a solvent preparation method. Specifically, PEO and lithium salt are dissolved in acetonitrile or THF, stirred for 12 hours, and then ceramic filler is added thereto. Ultrasonic treatment is performed for 1 hour. The filler is LLZO nanoparticles, and the filler amount accounts for 10wt%. Dry pressing is performed, specifically, LLZO is mixed with a polymer binder, 150Mpa is provided, and cold pressing is performed;

[0037] S3, performing plasma modification treatment, wherein a radio frequency (RF) low-temperature plasma system equipment is used, the treatment gas is an Ar / O2 mixed gas, the mixing ratio is 4:1, the equipment power is controlled to be less than 150W, and the treatment time is more than 10 minutes;

[0038] S4, post-processing of the material, specifically including hot pressing, sintering and annealing. The hot pressing temperature is 60°C, the sintering temperature is 1300°C, and the sintering time is 3 hours. During the sintering process, inert gas is introduced into the equipment. After sintering, the material is naturally cooled and then annealed.

[0039] S5. Take the finished product and conduct key performance tests, including structural testing and electrochemical testing. The structural test specifically uses XRD and SEM to observe the crystal phase and micromorphology, and the electrochemical test specifically uses EIS to measure ionic conductivity.

[0040] In this embodiment, the method adopts plasma treatment technology. Plasma treatment etches surface impurities (such as organic residues) and introduces lithium-philic functional groups, thereby reducing the interfacial impedance between the electrolyte and the electrode and improving the overall quality of the prepared electrolyte. The oxygen-containing groups introduced by oxygen plasma promote uniform wetting of lithium metal, reduce nucleation overpotential, and inhibit dendrite penetration.

[0041] Example 2

[0042] See also Figure 1 The present invention provides a technical solution: a method for preparing a plasma-modified composite solid electrolyte, comprising the following steps:

[0043] S1. Prepare materials and pre-treat them. The materials include an electrolyte matrix, additives, and target modified materials. The electrolyte matrix is ​​LLZO (lithium lanthanum zirconium oxide), LATP (lithium aluminum titanium phosphorus oxide), and PEO (polyethylene oxide). The additives include conductive fillers, plasticizers, and binders. The target modified material is a polymer coating material. The pre-treatment process is as follows: place the raw materials in a vacuum drying device, increase the temperature in the device to 65°C, dry for 11 hours, remove moisture from the raw materials, and place them in a ball milling device. Control the speed to 400 r / min and ball mill for 10 hours to make the material powdered and pass through a 220-mesh sieve.

[0044] S2. Preparing a precursor using a composite electrolyte, wherein the preparation method adopts a solvent preparation method, specifically, dissolving PEO and lithium salt in acetonitrile or THF, stirring for 14 hours, then adding ceramic filler therein, and ultrasonically treating for 1 hour, wherein the filler is LLZO nanoparticles, and the filler amount accounts for 20wt%, and dry pressing is performed, specifically, mixing LLZO with a polymer binder, providing 180Mpa, and performing cold pressing;

[0045] S3, performing plasma modification treatment, wherein a radio frequency (RF) low-temperature plasma system equipment is used, the treated gas is an Ar mixed gas, the mixing ratio is 4:1, the equipment power is controlled to be less than 150W, and the treatment time is more than 10 minutes;

[0046] S4, post-processing of the material, specifically including hot pressing treatment, sintering treatment and annealing treatment of the material. The hot pressing treatment of the material provides a temperature of 70°C, and the sintering treatment of the material provides a temperature of 1350°C, and the sintering is carried out for 4 hours. During the sintering process, inert gas is introduced into the equipment. After sintering, the material is naturally cooled and then annealed.

[0047] S5. Take the finished product and conduct key performance tests, including structural testing and electrochemical testing. The structural test specifically uses XRD and SEM to observe the crystal phase and micromorphology, and the electrochemical test specifically uses EIS to measure ionic conductivity.

[0048] In this embodiment, the method solves the bottleneck problems of low ionic conductivity, large interfacial cation resistance, and easy growth of dendrites in traditional solid-state electrolytes, while also having the advantages of environmentally friendly process and controllable costs, providing a key technical path for the industrialization of high-energy density and high-safety solid-state batteries. The overall method has good practical application effect.

[0049] Example 3

[0050] See also Figure 1 The present invention provides a technical solution: a method for preparing a plasma-modified composite solid electrolyte, comprising the following steps:

[0051] S1. Prepare materials and pre-treat them. The materials include an electrolyte matrix, additives, and target modified materials. The electrolyte matrix is ​​LLZO (lithium lanthanum zirconium oxide), LATP (lithium aluminum titanium phosphorus oxide), and PEO (polyethylene oxide). The additives include conductive fillers, plasticizers, and binders. The target modified material is nano-ceramic particles. The pre-treatment process is as follows: place the raw materials in a vacuum drying device, increase the temperature in the device to 70°C, dry for 12 hours, remove moisture from the raw materials, and place them in a ball milling device. Control the speed to 500 r / min and ball mill for 12 hours to make the material powdered and pass through a 260-mesh sieve.

[0052] S2. Precursor preparation is performed using a composite electrolyte. The preparation method adopts a solvent preparation method. Specifically, PEO and lithium salt are dissolved in acetonitrile, stirred for 16 hours, and then ceramic filler is added thereto. The filler is LLZO nanoparticles, and the filler amount accounts for 30wt%. Dry pressing is performed, specifically, LLZO is mixed with a polymer binder, 200Mpa is provided, and cold pressing is performed;

[0053] S3, performing plasma modification treatment, wherein a radio frequency (RF) low-temperature plasma system equipment is used, the treated gas is an O2 mixed gas, the mixing ratio is 4:1, the power of the control equipment is less than 150W, and the treatment time is more than 10 minutes;

[0054] S4, post-processing of the material, specifically including hot pressing, sintering and annealing. The hot pressing temperature is 80°C, the sintering temperature is 1500°C, and the sintering time is 5 hours. During the sintering process, inert gas is introduced into the equipment. After sintering, the material is naturally cooled and then annealed.

[0055] S5. Take the finished product and conduct key performance tests, including structural testing and electrochemical testing. The structural test specifically uses XRD and SEM to observe the crystal phase and micromorphology, and the electrochemical test specifically uses EIS to measure ionic conductivity.

[0056] In this embodiment, the method adopts plasma treatment technology. Plasma treatment etches surface impurities (such as organic residues) and introduces lithium-philic functional groups, thereby reducing the interfacial impedance between the electrolyte and the electrode and improving the overall quality of the prepared electrolyte. The oxygen-containing groups introduced by the oxygen plasma promote the uniform wetting of lithium metal, reduce the nucleation overpotential, and inhibit dendrite puncture. The above method solves the bottleneck problems of low ionic conductivity, large interfacial positive resistance, and easy growth of dendrites in traditional solid-state electrolytes. At the same time, it has the advantages of environmentally friendly process and controllable cost, providing a key technical path for the industrialization of high-energy density and high-safety solid-state batteries. The overall method has good practical application effect.

[0057] Example 4

[0058] See also Figure 1 The present invention provides a technical solution: a method for preparing a plasma-modified composite solid electrolyte, comprising the following steps:

[0059] S1. Prepare materials and pretreat them. The materials include an electrolyte matrix, additives, and target modified materials. The electrolyte matrix is ​​LLZO (lithium lanthanum zirconium oxide), LATP (lithium aluminum titanium phosphorus oxide), and PEO (polyethylene oxide). The additives include conductive fillers, plasticizers, and binders. The target modified material is nano-ceramic particles. The pretreatment process is as follows: place the raw materials in a vacuum drying device, increase the temperature in the device to 70°C, dry for 12 hours, remove moisture from the raw materials, and place them in a ball milling device. Control the speed to 500r / min and ball mill for 12 hours to make the material powdered and pass through a 240-mesh sieve.

[0060] S2. Precursor preparation is performed using a composite electrolyte. The preparation method adopts a solvent preparation method. Specifically, PEO and lithium salt are dissolved in acetonitrile, stirred for 16 hours, and then ceramic filler is added thereto. The ceramic filler is LLZO nanoparticles, and the filler amount accounts for 30wt%. Dry pressing is performed, specifically, LLZO is mixed with a polymer binder, 190Mpa is provided, and cold pressing is performed.

[0061] S3, performing plasma modification treatment, wherein a radio frequency (RF) low-temperature plasma system equipment is used, the treated gas is an O2 mixed gas, the mixing ratio is 4:1, the power of the control equipment is less than 150W, and the treatment time is more than 10 minutes;

[0062] S4, post-processing of the material, specifically including hot pressing, sintering and annealing. The hot pressing temperature is 70°C, the sintering temperature is 1400°C, and the sintering time is 5 hours. During the sintering process, inert gas is introduced into the equipment. After sintering, the material is naturally cooled and then annealed.

[0063] S5. Take the finished product and conduct key performance tests, including structural testing and electrochemical testing. The structural test specifically uses XRD and SEM to observe the crystal phase and micromorphology, and the electrochemical test specifically uses EIS to measure ionic conductivity.

[0064] The above description is only a preferred specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any technician familiar with the technical field, within the technical scope disclosed by the present invention, who makes equivalent replacements or changes based on the technical solution and inventive concept of the present invention, should be covered by the scope of protection of the present invention.

Claims

1. A method for preparing a plasma-modified composite solid electrolyte, characterized in that: The steps include: S1. Prepare materials and pre-process them; S2. Preparing a precursor using a composite electrolyte; S3, performing plasma modification treatment; S4, post-processing of materials; S5. Take the finished product and conduct key performance tests.

2. The method for preparing a plasma-modified composite solid electrolyte according to claim 1, wherein: In S1, materials are prepared and pretreated. The materials include an electrolyte matrix, additives, and target modified materials. The electrolyte matrix is ​​LLZO (lithium lanthanum zirconium oxide), LATP (lithium aluminum titanium phosphorus oxide), and PEO (polyethylene oxide). The additives include conductive fillers, plasticizers, and binders. The target modified material is one of nano-ceramic particles or polymer coating materials.

3. The method for preparing a plasma-modified composite solid electrolyte according to claim 1, wherein: In S1, the pretreatment process is specifically as follows: placing the raw materials in a vacuum drying device, raising the temperature in the device to 60-70°C, drying for 10-12 hours to remove moisture from the raw materials, and placing them in a ball milling device, controlling the speed to 300-500 r / min, ball milling for 8-12 hours to make the material into powder, and passing through a 200-260 mesh sieve.

4. The method for preparing a plasma-modified composite solid electrolyte according to claim 1, wherein: In the above-mentioned S2, a composite electrolyte is used to prepare a precursor, and the preparation method adopts one of a solvent preparation method and a dry pressing method.

5. The method for preparing a plasma-modified composite solid electrolyte according to claim 1, wherein: In the S2, a solvent preparation method is adopted, specifically, PEO and lithium salt are dissolved in acetonitrile or THF, stirred for 12-16 hours, and then ceramic filler is added thereto, ultrasonically treated for 1-2 hours, the filler is LLZO nanoparticles, the filler amount accounts for 10-30wt%, and dry pressing is performed, specifically, LLZO is mixed with a polymer binder, 150-200Mpa is provided, and cold pressing is performed.

6. The method for preparing a plasma-modified composite solid electrolyte according to claim 1, characterized in that: In S3, plasma modification treatment is performed, wherein a radio frequency (RF) low-temperature plasma system equipment is used, the treated gas is an Ar / O2 mixed gas with a mixing ratio of 4:1, the control equipment power is less than 150W, and the treatment time is more than 10 minutes.

7. The method for preparing a plasma-modified composite solid electrolyte according to claim 1, wherein: In the above-mentioned S4, the post-processing of the material is performed, specifically including hot pressing processing of the material, sintering processing of the material and annealing processing of the material.

8. The method for preparing a plasma-modified composite solid electrolyte according to claim 1, characterized in that: In the S4, the hot pressing treatment of the material provides a temperature of 60-80°C, the sintering treatment of the material provides a temperature of 1300-1500°C, and the sintering is performed for 3-5 hours. During the sintering process, an inert gas is introduced into the equipment. After sintering, the material is naturally cooled and then annealed.

9. The method for preparing a plasma-modified composite solid electrolyte according to claim 1, wherein: In S5, the finished product is taken and subjected to key performance tests, specifically including structural tests and electrochemical tests.

10. The method for preparing a plasma-modified composite solid electrolyte according to claim 1, characterized in that: In said S5, the structural test specifically comprises observing the crystal phase and micromorphology by using XRD and SEM, and the electrochemical test specifically comprises measuring the ionic conductivity by using EIS.

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