CN112421105A - Solid composite electrolyte membrane preparation process and solid composite electrolyte membrane - Google Patents
Solid composite electrolyte membrane preparation process and solid composite electrolyte membrane Download PDFInfo
- Publication number
- CN112421105A CN112421105A CN202011304731.7A CN202011304731A CN112421105A CN 112421105 A CN112421105 A CN 112421105A CN 202011304731 A CN202011304731 A CN 202011304731A CN 112421105 A CN112421105 A CN 112421105A
- Authority
- CN
- China
- Prior art keywords
- electrolyte solution
- viscosity
- membrane
- porous flexible
- flexible membrane
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Images
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M10/00—Secondary cells; Manufacture thereof
- H01M10/05—Accumulators with non-aqueous electrolyte
- H01M10/056—Accumulators with non-aqueous electrolyte characterised by the materials used as electrolytes, e.g. mixed inorganic/organic electrolytes
- H01M10/0564—Accumulators with non-aqueous electrolyte characterised by the materials used as electrolytes, e.g. mixed inorganic/organic electrolytes the electrolyte being constituted of organic materials only
- H01M10/0565—Polymeric materials, e.g. gel-type or solid-type
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M10/00—Secondary cells; Manufacture thereof
- H01M10/05—Accumulators with non-aqueous electrolyte
- H01M10/052—Li-accumulators
- H01M10/0525—Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M2300/00—Electrolytes
- H01M2300/0017—Non-aqueous electrolytes
- H01M2300/0065—Solid electrolytes
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M2300/00—Electrolytes
- H01M2300/0088—Composites
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
- Y02E60/10—Energy storage using batteries
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Electrochemistry (AREA)
- Manufacturing & Machinery (AREA)
- Chemical Kinetics & Catalysis (AREA)
- General Chemical & Material Sciences (AREA)
- Dispersion Chemistry (AREA)
- General Physics & Mathematics (AREA)
- Inorganic Chemistry (AREA)
- Condensed Matter Physics & Semiconductors (AREA)
- Physics & Mathematics (AREA)
- Materials Engineering (AREA)
- Conductive Materials (AREA)
- Secondary Cells (AREA)
Abstract
A solid composite electrolyte membrane and a preparation process thereof. The preparation process of the solid composite electrolyte membrane comprises the steps of using a porous flexible membrane as a support matrix of the composite electrolyte membrane, respectively and sequentially dipping and coating a low-viscosity electrolyte solution and a high-viscosity electrolyte solution on at least one side surface of the porous flexible membrane and in a pore structure of the porous flexible membrane step by step, and drying to obtain the solid composite electrolyte membrane; wherein the viscosity of the high-viscosity electrolyte solution is higher than that of the low-viscosity electrolyte solution, and the thickness of the solid composite electrolyte membrane is 5-120 μm.
Description
Technical Field
The invention relates to the technical field of lithium ions, in particular to a solid composite electrolyte membrane and a preparation process thereof.
Background
The main use of commercial lithium ion batteries is currently organic liquid electrolytes. However, the organic solvent has the characteristics of flammability, easy leakage, easy volatilization and the like, and potential risks of overcharge, short circuit and the like of the battery cause certain potential safety hazards in the use of the liquid organic electrolyte lithium ion battery. The all-solid-state lithium battery is expected to solve the safety problems of electrolyte leakage, combustion, short circuit caused by penetration of a lithium dendrite through a diaphragm and the like in the liquid lithium battery.
Solid electrolytes are classified into solid inorganic electrolytes and solid polymer electrolytes. Solid inorganic electrolytes have high ionic conductivity, but their poor processability and flexibility limit their commercial applications. The solid polymer electrolyte is expected to be commercially applied due to the advantages of good flexibility, interface compatibility, suitability for large-area processing and the like. However, the existing solid polymer electrolyte membrane is usually prepared by a solution casting membrane forming method, the electrolyte membrane prepared by the method has lower mechanical property, the thickness is not easy to be thinned, and even if the electrolyte membrane is obtained, the performance of the electrolyte membrane is far from the requirement. Moreover, the method has long time consumption, low production efficiency and difficult thickness control, is not suitable for large-scale mass production, and the contact interface of the positive and negative electrodes and the electrolyte membrane has poor contact or unstable contact when the battery is assembled, so that the requirement of large-scale production of the all-solid-state battery cannot be met. The existing solid polymer electrolyte mainly using polyethylene oxide (PEO) has low melting point of PEO electrolyte, and the positive electrode and the negative electrode are easy to be short-circuited after the temperature of the battery exceeds the melting point of the electrolyte.
Disclosure of Invention
The invention aims to provide a composite electrolyte membrane preparation process and a composite electrolyte membrane, wherein the composite electrolyte membrane can be controlled in thickness, can be thinned, has higher mechanical property and is easy to realize batch production.
In order to solve the technical problems, the invention provides a preparation process of a solid composite electrolyte membrane, which comprises the steps of using a porous flexible membrane as a support matrix of the composite electrolyte membrane, respectively and sequentially dipping and coating a low-viscosity electrolyte solution and a high-viscosity electrolyte solution on at least one side surface of the porous flexible membrane and in a pore structure of the porous flexible membrane in a step-by-step manner, and drying to obtain the solid composite electrolyte membrane; wherein the viscosity of the high-viscosity electrolyte solution is higher than that of the low-viscosity electrolyte solution, and the thickness of the solid composite electrolyte membrane is 5-120 μm.
Optionally, dissolving and dispersing a polymer matrix, a lithium salt and an inorganic solid electrolyte in a solvent, stirring until the polymer and the lithium salt are completely dissolved, and adjusting the mass ratio of the polymer matrix to obtain a low-viscosity electrolyte solution and a high-viscosity electrolyte solution, wherein the polymer matrix accounts for 0.5-40 wt%, the lithium salt accounts for 5-50 wt%, the oxide electrolyte accounts for 0-60 wt%, and the required mass of the polymer matrix of the low-viscosity electrolyte solution is lower than that of the high-viscosity electrolyte solution.
Optionally, the polymer matrix is one or a combination of any more of polyethylene oxide, polypropylene carbonate, polyacrylonitrile, polyvinylidene fluoride and polysiloxane; the lithium salt is any one or combination of more of lithium bistrifluoromethanesulfonylimide, lithium hexafluorophosphate, lithium perchlorate, lithium hexafluoroarsenate, lithium bis (oxalato) borate and lithium difluoro (oxalato) borate; the inorganic solid electrolyte is any one or combination of more of lithium super-ion conductor, sodium super-ion conductor, perovskite, garnet and LiPON; the solvent is any one or combination of acetonitrile, ethylene carbonate, dimethyl carbonate, diethyl carbonate, acetone and ethyl acetate.
Alternatively, the polymer matrix in the low viscosity electrolyte solution and the high viscosity electrolyte solution are the same type.
Alternatively, the polymer matrix in the low viscosity electrolyte solution and the high viscosity electrolyte solution are different in kind.
Optionally, the porous flexible membrane is any one of PE, PP, PET, PI, PVDF, PAN, and cellulose membranes, and has a porosity of 40-90%, a pore size of 0.1-15 micrometers, and a thickness of 5-100 micrometers.
Optionally, the drying temperature is 40-120 ℃.
Optionally, the step dip coating step comprises:
immersing the porous flexible membrane into a low-viscosity electrolyte solution for 1-60 min to enable the low-viscosity electrolyte solution to uniformly permeate into a pore structure of the porous flexible membrane;
and (3) immersing the obtained porous flexible membrane attached with the low-viscosity electrolyte solution into the high-viscosity electrolyte solution for 1-60 min, so that the high-viscosity electrolyte solution permeates into the pore structure of the porous flexible membrane and is attached to the surface of the porous flexible membrane.
Optionally, the porous flexible membrane attached with the high-viscosity electrolyte solution is then immersed in the high-viscosity electrolyte solution for 1min to 60min, so that the high-viscosity electrolyte solution permeates into pores of the porous flexible membrane and is attached to the surface of the porous flexible membrane.
The invention also provides a solid composite electrolyte membrane, which comprises a porous flexible membrane serving as a supporting matrix, wherein one side or two sides of the porous flexible membrane are sequentially coated with a low-viscosity electrolyte solution layer and a high-viscosity electrolyte solution layer respectively, a pore structure of the porous flexible membrane is filled with the low-viscosity electrolyte solution, and the thickness of the solid composite electrolyte membrane is 5-120 mu m.
In conclusion, the preparation method of the invention adopts the step-by-step immersion of the high-low viscosity electrolyte solution, because the low-viscosity electrolyte solution has low viscosity and good slurry fluidity, the preparation method is more favorable for penetrating into the pores of the porous membrane, shortens the dip coating time and improves the coating efficiency. And the viscosity of the high-viscosity electrolyte solution has high adhesion efficiency, so that the coating efficiency is improved.
And the porous flexible membrane is used as a supporting matrix, so that the mechanical property of the composite electrolyte membrane is improved, the short circuit risk of battery assembly is reduced, the porous membrane has enough tensile strength to meet the batch production requirement of lithium batteries, and the large porosity and the proper pore diameter provide enough lithium ion migration paths and prevent the short circuit of the batteries. The whole preparation method is simple, high in production efficiency, easy to realize roll-to-roll mass production, capable of realizing large-scale amplification, convenient for battery lamination or winding assembly, and capable of preventing poor contact or instability of contact interfaces of the positive and negative pole pieces and the electrolyte membrane.
Drawings
FIG. 1 is a schematic view of a composite electrolyte membrane provided in an embodiment of the invention;
fig. 2 is a surface topography of a composite electrolyte membrane obtained by compounding a PEO-based electrolyte and a PE porous membrane provided in an example of the present invention;
fig. 3 is a surface topography of a composite electrolyte membrane obtained by compounding a PEO-based electrolyte and a PET porous membrane provided in an embodiment of the present invention;
fig. 4 is an electrochemical impedance graph of a PEO-based/PE porous membrane composite electrolyte membrane and a pure PEO-based solid electrolyte membrane provided in examples of the present invention, curve 1 is an impedance curve of a pure PEO-based electrolyte membrane, and curve 2 is an impedance curve of a PE O-based/PE porous membrane composite electrolyte membrane;
FIG. 5 is a graph of tensile properties of a PEO-based/PE porous membrane composite electrolyte membrane and a pure PEO-based solid electrolyte membrane, wherein a curve 1 is a tensile curve of the pure PEO-based electrolyte membrane, and a curve 2 is a tensile curve of the PEO-based/PE porous membrane composite electrolyte membrane;
fig. 6 is a schematic view of a tooling apparatus for preparing a solid composite electrolyte membrane by a dip coating method.
Detailed Description
The following detailed description of embodiments of the present invention is provided in connection with the accompanying drawings and examples. The following examples are intended to illustrate the invention but are not intended to limit the scope of the invention.
In each embodiment of the present invention, the boundary value between the viscosity of the high-viscosity electrolyte solution and the viscosity of the low-viscosity electrolyte solution is defined as 4000mpa · s, and in other embodiments, the boundary value between the viscosity of the high-viscosity electrolyte solution and the viscosity of the low-viscosity electrolyte solution may be any value such as 3000mpa · s, 5000mpa · s, 4500 mpa · s, 3500mpa · s, 7000mpa · s, 8000mpa · s, and the like. Alternatively, different decomposition values may be used to define: the viscosity of the high viscosity electrolyte solution is above a first critical value and the viscosity of the low viscosity electrolyte solution is below a second critical value, for example, the viscosity of the high viscosity electrolyte solution is above 10000 mpa-s, the viscosity of the low viscosity electrolyte solution is below 5000 mpa-s, and so on.
The surface of the porous membrane of the present invention may be pretreated: chemical bonds of a surface molecular structure can be broken or rearranged through corona treatment, the surface roughness of the membrane is increased, and the membrane is easier to be soaked by an electrolyte solution, so that the dip-coating time is shortened, and the preparation efficiency of the electrolyte membrane is improved.
Example 1:
1. electrolyte solution preparation: dissolving and dispersing polymer matrix PEO, lithium salt lithium bistrifluoromethanesulfonylimide LiTFS I and inorganic oxide electrolyte LLZTO in a mixed solvent of ethylene carbonate and dimethyl carbonate, and stirring until the polymer and the lithium salt are completely dissolved to respectively obtain a low-viscosity electrolyte solution and a high-viscosity electrolyte solution. Wherein, when the proportion of the polymer matrix is 3 wt%, the proportion of the lithium salt is 30 wt%, the proportion of the oxide electrolyte is 5 wt%, and the viscosity of the electrolyte solution is about 2000mpa · s, and the electrolyte solution is low-viscosity electrolyte solution. When the proportion of the polymer matrix is 5 wt%, the proportion of the lithium salt is 30 wt%, the proportion of the oxide electrolyte is 5 wt%, and the viscosity of the electrolyte solution is 19000mpa · s, the electrolyte solution is a high-viscosity electrolyte solution.
2. Preparing a solid composite electrolyte membrane:
the first step is as follows: and injecting the low-viscosity electrolyte solution into a dip-coating trough 1 of the design tool, and soaking the PE porous membrane into the electrolyte solution for 5min to ensure that the low-viscosity electrolyte solution uniformly permeates into the pore structure of the porous flexible membrane. The PE porous membrane has the thickness of 12 mu m, the porosity of 48 percent and the pore diameter range of 0.1 mu m-0.7 mu m.
The second step is that: and (3) immersing the porous flexible membrane with the electrolyte solution obtained in the first step into a high-viscosity electrolyte solution (in a design tool dip-coating trough 2) for 5min, so that the high-viscosity electrolyte solution permeates into pores of the porous flexible membrane and is attached to the surface of the porous flexible membrane.
The third step: and (3) drying the porous flexible membrane attached with the electrolyte solution obtained in the second step by using a 60 ℃ oven tunnel furnace, and obtaining a composite electrolyte membrane with the thickness of about 30 microns after drying, wherein the specific structure of the composite electrolyte membrane is shown in figure 1, the porous flexible membrane is used as a supporting matrix 10, one side or two sides of the porous flexible membrane are sequentially coated with a low-viscosity electrolyte solution layer 20 and a high-viscosity electrolyte solution layer 30 respectively, the pore structure of the porous flexible membrane is also filled with the low-viscosity electrolyte solution 20, and the surface appearance of the SEM of the porous flexible membrane is shown in figure 2. The tensile strength was about 45MPa, see FIG. 5, curve 2. Ionic conductivity of about 4 x 10 at room temperature-6S/cm, see FIG. 4, curve 2.
Example 2:
1. electrolyte solution preparation: dissolving and dispersing a polymer matrix PEO, a lithium salt LiTFSI and an inorganic oxide electrolyte L LZTO in a mixed solvent of ethylene carbonate and dimethyl carbonate, and stirring until the polymer and the lithium salt are completely dissolved. The polymer matrix accounts for 3 wt%, the lithium salt accounts for 30 wt%, the oxide electrolyte accounts for 5 wt%, and the electrolyte solution has a viscosity of about 2000mpa · s and is a low-viscosity electrolyte solution. The polymer matrix accounts for 5 wt%, the lithium salt accounts for 30 wt%, the oxide electrolyte accounts for 5 wt%, and the electrolyte solution has a viscosity of 19000mpa · s and is a high-viscosity electrolyte solution.
2. Preparing a solid composite electrolyte membrane:
the first step is as follows: and injecting the low-viscosity electrolyte solution into a dip-coating trough 1 of the design tool, and soaking the PE porous membrane into the electrolyte solution for 20min to ensure that the low-viscosity electrolyte solution uniformly permeates into the pore structure of the porous flexible membrane. The PE porous film has the thickness of 12 mu m, the porosity of 48 percent and the pore diameter of 0.1-0.7 mu m.
The second step is that: and (3) immersing the porous flexible membrane with the electrolyte solution obtained in the first step into a high-viscosity electrolyte solution (in a dip coating trough 2 of a design tool) for 20min, so that the high-viscosity electrolyte solution permeates into pores of the porous flexible membrane and is attached to the surface of the porous flexible membrane.
The third step: and (3) drying the porous flexible membrane attached with the electrolyte solution obtained in the second step by using a 60 ℃ oven tunnel furnace to obtain a composite electrolyte membrane with the thickness of about 32 microns after drying. Tensile strength of about 43MPa, ionic conductivity of about 4 x 10 at room temperature-6S/cm。
Example 3:
1. electrolyte solution preparation: dissolving and dispersing a polymer matrix PEO, a lithium salt LiTFSI and an inorganic oxide electrolyte L LZTO in a mixed solvent of ethylene carbonate and dimethyl carbonate, and stirring until the polymer and the lithium salt are completely dissolved. The polymer matrix accounts for 3 wt%, the lithium salt accounts for 30 wt%, the oxide electrolyte accounts for 5 wt%, and the electrolyte solution has a viscosity of about 2000mpa · s and is a low-viscosity electrolyte solution. The polymer matrix accounts for 5 wt%, the lithium salt accounts for 30 wt%, the oxide electrolyte accounts for 5 wt%, and the electrolyte solution has a viscosity of 19000mpa · s and is a high-viscosity electrolyte solution.
2. Preparing a solid composite electrolyte membrane:
the first step is as follows: and injecting the low-viscosity electrolyte solution into a dip-coating trough 1 of the design tool, and soaking the PET porous membrane into the electrolyte solution for 5min to ensure that the low-viscosity electrolyte solution uniformly permeates into the pore structure of the porous flexible membrane. The thickness of the PET porous membrane is 14 μm, the porosity is 57%, and the pore diameter is 1-3 μm.
The second step is that: and (3) immersing the porous flexible membrane with the electrolyte solution obtained in the first step into a high-viscosity electrolyte solution (in a design tool dip-coating trough 2) for 5min, so that the high-viscosity electrolyte solution permeates into pores of the porous flexible membrane and is attached to the surface of the porous flexible membrane.
The third step: and (3) drying the porous flexible membrane attached with the electrolyte solution obtained in the second step by using a 60 ℃ oven tunnel furnace to obtain a composite electrolyte membrane with the thickness of about 25 microns after drying, wherein the surface appearance of the composite electrolyte membrane is shown in figure 3. Tensile strength of about 20MPa, and ionic conductivity of about 4.5 x 10 at room temperature-6S/cm。
Example 4:
1. electrolyte solution preparation: dissolving and dispersing polymer matrix PEO, lithium salt LiTFSI and inorganic oxide electrolyte LLZTO in a mixed solvent of ethylene carbonate and dimethyl carbonate, and stirring until the polymer and the lithium salt are completely dissolved. The polymer matrix accounts for 3.4 wt%, the lithium salt accounts for 30 wt%, the oxide electrolyte accounts for 5 wt%, and the electrolyte solution has a viscosity of about 2700mpa · s and is a low-viscosity electrolyte solution. The polymer matrix accounts for 7 wt%, the lithium salt accounts for 30 wt%, the oxide electrolyte accounts for 5 wt%, and the electrolyte solution has a viscosity of 40000mpa · s and is a high-viscosity electrolyte solution.
2. Preparing a solid composite electrolyte membrane:
the first step is as follows: and injecting the low-viscosity electrolyte solution into a dip-coating trough 1 of the design tool, and soaking the PET porous membrane into the electrolyte solution for 5min to ensure that the low-viscosity electrolyte solution uniformly permeates into the pore structure of the porous flexible membrane. The thickness of the PET porous membrane is 14 μm, the porosity is 57%, and the pore diameter is 1-3 μm.
The second step is that: and (3) immersing the porous flexible membrane with the electrolyte solution obtained in the first step into a high-viscosity electrolyte solution (in a design tool dip-coating trough 2) for 5min, so that the high-viscosity electrolyte solution permeates into pores of the porous flexible membrane and is attached to the surface of the porous flexible membrane.
The third step: and (3) drying the porous flexible membrane attached with the electrolyte solution obtained in the second step by using a 60 ℃ oven tunnel furnace to obtain a composite electrolyte membrane with the thickness of about 34 microns after drying. Tensile strength of about 16MPa, and ionic conductivity of about 4.54 x 10 at room temperature-6S/cm。
Example 5:
1. electrolyte solution preparation: dissolving and dispersing polymer matrix PEO, lithium salt LiTFSI and inorganic oxide electrolyte LLZTO in a mixed solvent of ethylene carbonate and dimethyl carbonate, and stirring until the polymer and the lithium salt are completely dissolved. The polymer matrix accounts for 3 wt%, the lithium salt accounts for 30 wt%, the oxide electrolyte accounts for 5 wt%, and the electrolyte solution has a viscosity of about 2000mpa · s and is a low-viscosity electrolyte solution. The polymer matrix accounts for 5 wt%, the lithium salt accounts for 30 wt%, the oxide electrolyte accounts for 5 wt%, and the electrolyte solution has a viscosity of 19000mpa · s and is a high-viscosity electrolyte solution.
2. Preparing a solid composite electrolyte membrane:
the first step is as follows: and injecting the low-viscosity electrolyte solution into a dip-coating trough 1 of the design tool, and soaking the PET porous membrane into the electrolyte solution for 5min to ensure that the low-viscosity electrolyte solution uniformly permeates into the pore structure of the porous flexible membrane. The thickness of the PET porous membrane is 14 μm, the porosity is 57%, and the pore diameter is 1-3 μm.
The second step is that: and (3) immersing the porous flexible membrane with the electrolyte solution obtained in the first step into a high-viscosity electrolyte solution (in a design tool dip-coating trough 2) for 5min, so that the high-viscosity electrolyte solution permeates into pores of the porous flexible membrane and is attached to the surface of the porous flexible membrane.
The third step: and (3) immersing the porous flexible membrane attached with the electrolyte solution obtained in the second step into a high-viscosity electrolyte solution (in a dip coating trough 3 of a design tool) for 5min, so that the high-viscosity electrolyte solution permeates into pores of the porous flexible membrane and is attached to the surface of the porous flexible membrane.
The fourth step: and (4) drying the porous flexible membrane attached with the electrolyte solution obtained in the third step by using a 60 ℃ oven tunnel furnace to obtain a composite electrolyte membrane with the thickness of about 31 microns after drying. Tensile strength of about 18MPa, and ionic conductivity of about 4.51 x 10 at room temperature-6S/cm。
Example 6:
1. electrolyte solution preparation:
PEO electrolyte solution preparation: dissolving and dispersing polymer matrix PEO, lithium salt LiTFSI and inorganic oxide electrolyte LLZTO in a mixed solvent of ethylene carbonate and dimethyl carbonate, and stirring until the polymer and the lithium salt are completely dissolved. The polymer matrix accounts for 3 wt%, the lithium salt accounts for 30 wt%, the oxide electrolyte accounts for 5 wt%, and the electrolyte solution has a viscosity of about 2000mpa · s and is a low-viscosity electrolyte solution. The polymer matrix accounts for 5 wt%, the lithium salt accounts for 30 wt%, the oxide electrolyte accounts for 5 wt%, and the electrolyte solution has a viscosity of 19000mpa · s and is a high-viscosity electrolyte solution.
Preparing a PPC electrolyte solution: dissolving and dispersing a polymer matrix PPC, a lithium salt LiODFB and an inorganic oxide electrolyte LLZTO in a mixed solvent of ethylene carbonate and dimethyl carbonate, and stirring until the polymer and the lithium salt are completely dissolved. The polymer matrix accounts for 10 wt%, the lithium salt accounts for 30 wt%, the oxide electrolyte accounts for 5 wt%, and the electrolyte solution has a viscosity of about 20000mpa · s and is a high-viscosity electrolyte solution.
2. Preparing a solid composite electrolyte membrane:
the first step is as follows: and injecting the low-viscosity PEO electrolyte solution into a dip-coating trough 1 of the design tool, and soaking the PET porous membrane into the electrolyte solution for 5min to ensure that the low-viscosity electrolyte solution uniformly permeates into the pore structure of the porous flexible membrane. The thickness of the PET porous membrane is 14 μm, the porosity is 57%, and the pore diameter is 1-3 μm.
The second step is that: and (3) immersing the porous flexible membrane with the electrolyte solution obtained in the first step into the high-viscosity PPC electrolyte solution (in a dip coating trough 2 of a design tool) for 5min, so that the high-viscosity electrolyte solution permeates into pores of the porous flexible membrane and is attached to the surface of the porous flexible membrane.
The third step: and (3) immersing the porous flexible membrane attached with the electrolyte solution obtained in the second step into a high-viscosity PEO electrolyte solution (in a design tool dip-coating trough 3) for 5min, so that the high-viscosity electrolyte solution permeates into pores of the porous flexible membrane and is attached to the surface of the porous flexible membrane.
The fourth step: and (4) drying the porous flexible membrane attached with the electrolyte solution obtained in the third step by using a 60 ℃ oven tunnel furnace to obtain a composite electrolyte membrane with the thickness of about 30 microns after drying. Tensile strength of about 17MPa, and ionic conductivity of about 7.6 x 10 at room temperature-6S/cm。
The tooling device adopted in each embodiment of the invention is shown in fig. 6, wherein a porous membrane unreeling mechanism 1 is connected with an electrolyte solution trough device 3, the tail end of the electrolyte solution trough device is connected with an oven 3 provided with a heating mechanism 4, and the tail end of the oven is provided with a reeling mechanism 5. The number of the electrolytic solution tank means may be set according to choice.
Comparative example 1:
1. electrolyte solution preparation: dissolving and dispersing polymer matrix PEO, lithium salt LiTFSI and inorganic oxide electrolyte LLZTO in acetonitrile solvent, and stirring until the polymer and the lithium salt are completely dissolved. The polymer matrix is 3 wt%, the lithium salt is 30 wt%, the oxide electrolyte is 5 wt%, and the viscosity of the electrolyte solution is about 2000mpa · s.
2. Preparing a solid composite electrolyte membrane: and (3) injecting the electrolyte solution into a polytetrafluoroethylene mold, and drying and curing in a vacuum oven at 50 ℃ to obtain the composite electrolyte membrane with the thickness of about 200 microns. The tensile strength was 2.9MPa, see FIG. 5, curve 1. Ionic conductivity of about 5 x 10 at room temperature-6S/cm, see FIG. 4, Curve 1.
Comparative example 2:
1. electrolyte solution preparation: dissolving and dispersing polymer matrix PEO, lithium salt LiTFSI and inorganic oxide electrolyte LLZTO in a mixed solvent of ethylene carbonate and dimethyl carbonate, and stirring until the polymer and the lithium salt are completely dissolved. The polymer matrix is 3 wt%, the lithium salt is 30 wt%, the oxide electrolyte is 5 wt%, and the viscosity of the electrolyte solution is about 2000mpa · s.
2. Preparing a solid composite electrolyte membrane: and injecting the partial electrolyte solution into a polytetrafluoroethylene mold, and drying and curing in a vacuum oven at 50 ℃ to obtain the composite electrolyte membrane with the thickness of about 40 microns. Tensile strength of 1.4MPa, and ionic conductivity of about 4.7 x 10 at room temperature-6S/cm。
By comparing the data of the examples, it can be found that the tensile strength of the composite electrolyte membranes prepared in the present invention is more than 15Mpa, the tensile strength of the composite electrolyte membranes prepared from the PE porous membrane is more than 40Mpa, and the tensile strength is less than 3Mpa although the similar thickness can be barely achieved by the method of the comparative examples. The ion conductivities of the comparative examples and the comparative examples are very similar at room temperature, which shows that the ion conductivity is not reduced even if the porous flexible membrane is used for increasing the mechanical property.
The preparation method adopts the step-by-step immersion of the high-low viscosity electrolyte solution, because the low-viscosity electrolyte solution has low viscosity and good slurry fluidity, the preparation method is more favorable for penetrating into the pores of the porous membrane, shortens the dip-coating time and improves the coating efficiency. And the viscosity of the high-viscosity electrolyte solution has high adhesion efficiency, so that the coating efficiency is improved.
And the porous flexible membrane is used as a supporting matrix, so that the mechanical property of the composite electrolyte membrane is improved, the short circuit risk of battery assembly is reduced, the porous membrane has enough tensile strength to meet the batch production requirement of lithium batteries, and the large porosity and the proper pore diameter provide enough lithium ion migration paths and prevent the short circuit of the batteries. The whole preparation method is simple, high in production efficiency, easy to realize roll-to-roll mass production, capable of realizing large-scale amplification, convenient for battery lamination or winding assembly, and capable of preventing poor contact or instability of contact interfaces of the positive and negative pole pieces and the electrolyte membrane.
Furthermore, the thickness of the composite electrolyte membrane can be controlled by adjusting the mass ratio of the polymer matrix in the electrolyte solution and the dip-coating times, so that the thickness of the final composite membrane can be controlled, and the thickness can be controlled to be less than 120 μm, while the thicknesses obtained by the existing preparation methods are all more than 120 μm, and even if the thickness is controlled to be less than 120 μm, the mechanical properties are poor. The thickness of the composite electrolyte membrane is in direct proportion to the mass ratio of the polymer matrix, and increases along with the increase of the mass ratio; the thickness of the composite electrolyte membrane is proportional to the number of dip-coating times, and increases as the number of dip-coating times increases.
Wherein the surface of the supporting substrate in example 6 is coated with electrolyte solutions of different polymers, and the polymer electrolyte solutions with high voltage oxidation resistance and compatibility with the low voltage negative electrode are respectively coated on both sides of the porous flexible membrane substrate, so that when the porous flexible membrane substrate is applied to an all-solid-state battery, the stability requirements of the positive electrode high voltage and the negative electrode low voltage can be simultaneously met, the electrochemical stability window of the polymer electrolyte membrane is effectively expanded, and the ionic conductivity of the polymer electrolyte membrane at room temperature reaches 7.6 x 10-6S/cm。
It will be understood by those skilled in the art that in the present disclosure, the terms "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate orientations or positional relationships that are based on those shown in the drawings, which are merely for convenience in describing the present invention and for simplicity in description, and do not indicate or imply that the referenced devices or elements must have a particular orientation, be constructed in a particular orientation, and be operated, and thus the above-described terms should not be construed as limiting the invention.
Although the present invention has been described with reference to the preferred embodiments, it should be understood that various changes and modifications can be made therein by those skilled in the art without departing from the spirit and scope of the invention as defined by the appended claims.
Claims (10)
1. A process for preparing a solid composite electrolyte membrane, comprising:
using a porous flexible membrane as a support matrix of the composite electrolyte membrane, respectively and sequentially dip-coating and attaching a low-viscosity electrolyte solution and a high-viscosity electrolyte solution onto at least one side surface of the porous flexible membrane and in a pore structure of the porous flexible membrane step by step, and drying to obtain the solid composite electrolyte membrane;
wherein the viscosity of the high-viscosity electrolyte solution is higher than the viscosity of the low-viscosity electrolyte solution,
the thickness of the solid composite electrolyte membrane is 5-120 μm.
2. The process for preparing a solid composite electrolyte membrane according to claim 1, wherein the low viscosity electrolyte solution and the high viscosity electrolyte solution are obtained by dissolving and dispersing a polymer matrix, a lithium salt and an inorganic solid electrolyte in a solvent, stirring until the polymer and the lithium salt are completely dissolved, and adjusting the mass ratio of the polymer matrix, wherein the polymer matrix accounts for 0.5 wt% to 40 wt%, the lithium salt accounts for 5 wt% to 50 wt%, the oxide electrolyte accounts for 0 wt% to 60 wt%, and the required mass of the polymer matrix of the low viscosity electrolyte solution is lower than that of the high viscosity electrolyte solution.
3. The process for preparing a solid composite electrolyte membrane according to claim 2, wherein the polymer matrix is one or a combination of any more of polyethylene oxide, polypropylene carbonate, polyacrylonitrile, polyvinylidene fluoride, and polysiloxane; the lithium salt is any one or combination of more of lithium bistrifluoromethanesulfonylimide, lithium hexafluorophosphate, lithium perchlorate, lithium hexafluoroarsenate, lithium bis (oxalato) borate and lithium difluoro (oxalato) borate; the inorganic solid electrolyte is any one or combination of more of a lithium super-ion conductor, a sodium super-ion conductor, perovskite, garnet and LiPON; the solvent is any one or combination of acetonitrile, ethylene carbonate, dimethyl carbonate, diethyl carbonate, acetone and ethyl acetate.
4. The process for preparing a solid composite electrolyte membrane according to claim 2, wherein the polymer matrix in the low-viscosity electrolyte solution and the high-viscosity electrolyte solution is the same kind.
5. The process for preparing a solid composite electrolyte membrane according to claim 2, wherein the polymer matrices in the low viscosity electrolyte solution and the high viscosity electrolyte solution are different in kind.
6. The process for preparing a solid composite electrolyte membrane according to any one of claims 1 to 5, wherein the porous flexible membrane is any one of PE, PP, PET, PI, PVDF, PAN and cellulose membrane, and has a porosity of 40-90%, a pore diameter of 0.1-15 μm and a thickness of 5-100 μm.
7. The process for producing a solid composite electrolyte membrane according to any one of claims 1 to 5, wherein the baking temperature is 40 ℃ to 120 ℃.
8. The process for producing a solid composite electrolyte membrane according to any one of claims 1 to 5, wherein the step-by-step dip coating step includes:
immersing the porous flexible membrane into the low-viscosity electrolyte solution for 1-60 min to ensure that the low-viscosity electrolyte solution uniformly permeates into the pore structure of the porous flexible membrane;
and (3) immersing the obtained porous flexible membrane attached with the low-viscosity electrolyte solution into the high-viscosity electrolyte solution for 1-60 min, so that the high-viscosity electrolyte solution permeates into the pore structure of the porous flexible membrane and is attached to the surface of the porous flexible membrane.
9. The process for preparing a solid composite electrolyte membrane according to claim 8, wherein the porous flexible membrane to which the high viscosity electrolyte solution is attached is then immersed in the high viscosity electrolyte solution for 1min to 60min to allow the high viscosity electrolyte solution to penetrate into pores of the porous flexible membrane and to be attached to the surface of the porous flexible membrane.
10. A solid composite electrolyte membrane comprising:
the method comprises the following steps of taking a porous flexible membrane as a supporting matrix, sequentially coating a low-viscosity electrolyte solution layer and a high-viscosity electrolyte solution layer on one side or two sides of the porous flexible membrane respectively, filling a low-viscosity electrolyte solution into a pore structure of the porous flexible membrane, and enabling the thickness of the solid composite electrolyte membrane to be 5-120 mu m.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202011304731.7A CN112421105A (en) | 2020-11-19 | 2020-11-19 | Solid composite electrolyte membrane preparation process and solid composite electrolyte membrane |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202011304731.7A CN112421105A (en) | 2020-11-19 | 2020-11-19 | Solid composite electrolyte membrane preparation process and solid composite electrolyte membrane |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN112421105A true CN112421105A (en) | 2021-02-26 |
Family
ID=74773683
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202011304731.7A Pending CN112421105A (en) | 2020-11-19 | 2020-11-19 | Solid composite electrolyte membrane preparation process and solid composite electrolyte membrane |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN112421105A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112909316A (en) * | 2021-01-18 | 2021-06-04 | 合肥工业大学 | Commercial diaphragm-based sandwich-structure polymer composite solid electrolyte membrane and preparation method thereof |
| CN113363561A (en) * | 2021-03-29 | 2021-09-07 | 万向一二三股份公司 | High-strength solid electrolyte membrane and preparation method and application thereof |
Citations (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5700300A (en) * | 1996-08-12 | 1997-12-23 | Valence Technology, Inc. | Electrolyte coating system for porous electrodes |
| JP2000195549A (en) * | 1998-12-25 | 2000-07-14 | Matsushita Electric Ind Co Ltd | Manufacture of battery |
| CN101471187A (en) * | 2007-11-29 | 2009-07-01 | Tdk株式会社 | Method of manufacturing photoelectric conversion device, and photoelectric conversion device |
| CN102768903A (en) * | 2012-08-09 | 2012-11-07 | 中国振华（集团）新云电子元器件有限责任公司 | Method for manufacturing high-voltageconducting polymer electrolytic capacitor |
| CN106654362A (en) * | 2016-12-07 | 2017-05-10 | 珠海光宇电池有限公司 | Composite solid electrolyte membrane, preparation method and lithium-ion battery |
| CN106816617A (en) * | 2015-11-30 | 2017-06-09 | 东丽先端材料研究开发（中国）有限公司 | A kind of preparation method of composites polymer electrolytes film |
| CN109167090A (en) * | 2018-08-28 | 2019-01-08 | 长沙矿冶研究院有限责任公司 | A kind of film build method of polymer-based solid state electrolyte |
| CN110459803A (en) * | 2019-08-20 | 2019-11-15 | 昆山宝创新能源科技有限公司 | Composite electrolyte membrane and its preparation method and application |
| CN111554970A (en) * | 2020-05-11 | 2020-08-18 | 苏州清陶新能源科技有限公司 | Solid electrolyte and preparation method and application thereof |
| CN111564664A (en) * | 2020-05-18 | 2020-08-21 | 哈尔滨理工大学 | Method for preparing battery polymer electrolyte film by using polyethylene glycol and paper pulp as matrix gel method |
-
2020
- 2020-11-19 CN CN202011304731.7A patent/CN112421105A/en active Pending
Patent Citations (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5700300A (en) * | 1996-08-12 | 1997-12-23 | Valence Technology, Inc. | Electrolyte coating system for porous electrodes |
| JP2000195549A (en) * | 1998-12-25 | 2000-07-14 | Matsushita Electric Ind Co Ltd | Manufacture of battery |
| CN101471187A (en) * | 2007-11-29 | 2009-07-01 | Tdk株式会社 | Method of manufacturing photoelectric conversion device, and photoelectric conversion device |
| CN102768903A (en) * | 2012-08-09 | 2012-11-07 | 中国振华（集团）新云电子元器件有限责任公司 | Method for manufacturing high-voltageconducting polymer electrolytic capacitor |
| CN106816617A (en) * | 2015-11-30 | 2017-06-09 | 东丽先端材料研究开发（中国）有限公司 | A kind of preparation method of composites polymer electrolytes film |
| CN106654362A (en) * | 2016-12-07 | 2017-05-10 | 珠海光宇电池有限公司 | Composite solid electrolyte membrane, preparation method and lithium-ion battery |
| CN109167090A (en) * | 2018-08-28 | 2019-01-08 | 长沙矿冶研究院有限责任公司 | A kind of film build method of polymer-based solid state electrolyte |
| CN110459803A (en) * | 2019-08-20 | 2019-11-15 | 昆山宝创新能源科技有限公司 | Composite electrolyte membrane and its preparation method and application |
| CN111554970A (en) * | 2020-05-11 | 2020-08-18 | 苏州清陶新能源科技有限公司 | Solid electrolyte and preparation method and application thereof |
| CN111564664A (en) * | 2020-05-18 | 2020-08-21 | 哈尔滨理工大学 | Method for preparing battery polymer electrolyte film by using polyethylene glycol and paper pulp as matrix gel method |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112909316A (en) * | 2021-01-18 | 2021-06-04 | 合肥工业大学 | Commercial diaphragm-based sandwich-structure polymer composite solid electrolyte membrane and preparation method thereof |
| CN112909316B (en) * | 2021-01-18 | 2023-02-28 | 合肥工业大学 | Commercial diaphragm-based sandwich-structure polymer composite solid electrolyte membrane and preparation method thereof |
| CN113363561A (en) * | 2021-03-29 | 2021-09-07 | 万向一二三股份公司 | High-strength solid electrolyte membrane and preparation method and application thereof |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN110581314B (en) | Multilayer-structure composite solid electrolyte membrane, preparation method thereof and solid battery | |
| CN109004271B (en) | Composite solid electrolyte membrane and preparation method and application thereof | |
| CN112701348B (en) | Polymer solid electrolyte, all-solid lithium battery and preparation method thereof | |
| CN111244537A (en) | Composite solid electrolyte, solid battery and preparation method thereof | |
| US11069940B2 (en) | Ionically conductive material for electrochemical generator and production methods | |
| CN112133961B (en) | Gel electrolyte precursor and application thereof | |
| CN109192922B (en) | Solid-state lithium ion battery anode with special structure and preparation method thereof | |
| CN110581311A (en) | composite solid electrolyte membrane, preparation method thereof and solid battery | |
| CN110581304A (en) | Solid-state battery and preparation method thereof | |
| CN112421105A (en) | Solid composite electrolyte membrane preparation process and solid composite electrolyte membrane | |
| CN113839005B (en) | Gel composite positive electrode for solid-state battery and preparation method thereof | |
| CN111073184B (en) | Gel electrolyte film for secondary battery, preparation and application thereof | |
| CN109841836A (en) | A kind of compound metal lithium electrode of gel and its preparation method and application | |
| CN111244395A (en) | Lithium ion pole piece, preparation method thereof and lithium ion battery | |
| CN115775909A (en) | High-concentration lithium salt sulfide composite solid electrolyte membrane, and preparation method and application thereof | |
| CN114759253A (en) | Preparation method of ultra-thin, light and high-mechanical-strength PEO-based solid electrolyte with cellulose membrane as supporting layer | |
| Zhang et al. | Mechanically robust epoxy resin-based gel polymer electrolyte stabilizing ion deposition for high-performance lithium metal batteries | |
| CN115663279A (en) | Solid electrolyte with high ionic conductivity, preparation method thereof and solid battery | |
| KR101868574B1 (en) | Method of manufacturing lithium metal electrode material | |
| CN112018440B (en) | Composite solid electrolyte and preparation method thereof | |
| CN115051028A (en) | Nanofiber-based composite solid electrolyte stable to lithium, and preparation method and application thereof | |
| CN114284554A (en) | Preparation method of gel lithium ion battery and prepared gel lithium ion battery | |
| CN113745654A (en) | Preparation method for in-situ generation of semi-interpenetrating network high-voltage polymer electrolyte | |
| CN115668524A (en) | Battery cell comprising a special porous solid electrolyte foam | |
| CN112909316A (en) | Commercial diaphragm-based sandwich-structure polymer composite solid electrolyte membrane and preparation method thereof |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| RJ01 | Rejection of invention patent application after publication | ||
| RJ01 | Rejection of invention patent application after publication |
Application publication date: 20210226 |