Low-cost all-solid-state electrolyte membrane as well as preparation process and application thereof

Abstract

The invention discloses a low-cost all-solid-state electrolyte membrane and a preparation method and application thereof, the all-solid-state electrolyte membrane is prepared from halide solid-state electrolyte, the chemical general formula of the halide solid-state electrolyte is any one of the following general formulas: a general formula I: LinZrmCl (n + 4m), n is more than or equal to 1.5 and less than or equal to 2.5, and m is more than or equal to 0.75 and less than or equal to 0.9; the general formula II is Li3MCl6, wherein M is selected from one of Y, In, Er and Sc; the general formula III is Li (2 + 4x-ax) Zr (1-x) AxCl6, wherein 0 lt; xlt; a is a doped metal element and is selected from one of In, Sc and Zn, and when A is In, a is equal to 3; when A is Sc, a is equal to 3; and when A is Zn, a is equal to 2. According to the low-cost all-solid-state electrolyte membrane as well as the preparation method and the application thereof, the design is reasonable, the production and preparation cost is reduced while high ionic conductivity is maintained, the solid-state electrolyte and the electrolyte membrane which are excellent in comprehensive performance and low in cost are obtained, and the problem that the preparation cost of the solid-state electrolyte and the electrolyte membrane is high at present is solved.

Description

Technical Field

[0001] The present invention belongs to the technical field of battery material preparation, and in particular relates to a low-cost all-solid-state electrolyte membrane and its preparation process and application in lithium-ion batteries. Background Art

[0002] Currently commercialized lithium-ion batteries primarily use graphite or silicon-carbon materials for their negative electrodes, organic electrolytes for their electrolytes, and lithium iron phosphate, nickel-cobalt-manganese ternary materials, lithium cobalt oxide, and lithium manganese oxide for their positive electrodes. Organic electrolytes are volatile, flammable, and explosive, inevitably posing serious safety concerns for battery systems. Compared to liquid electrolytes, solid-state electrolytes can perfectly replace the electrolytes and separators in current commercial lithium-ion batteries.

[0003] Solid-state electrolytes offer the following advantages: i) High safety. They are non-flammable, non-corrosive, non-volatile, and free of liquid leakage. ii) High energy density. Solid-state electrolytes have a wide electrochemical window, making them compatible with high-voltage cathode materials. Solid-state batteries are stable and compact, simplifying battery management. iii) Lightweight. In traditional lithium-ion batteries, the separator and electrolyte together account for nearly 40% of the battery volume and 25% of the mass. Using solid-state electrolytes can reduce both volume and mass. iv) Excellent cycling performance.

[0004] Solid-state electrolytes inhibit the growth of lithium dendrites during battery cycling, greatly improving the cyclability and service life of lithium-ion batteries. Although solid-state batteries have many advantages, the high cost of raw materials and equipment has always restricted the development of solid-state batteries. Currently, the Li-containing raw materials such as Li2CO3, LiNO3, and LiOH used in the preparation of oxide solid electrolytes are priced at approximately US$10.73 / kg, and the price of Li2S, a Li-containing raw material used in the preparation of sulfide solid electrolytes, is as high as $654.18 / kg. Although the price of LiCl, a Li-containing raw material used in the preparation of halide solid electrolytes, is US$5.88 / kg, the elements doped therein are mainly rare earth elements such as Y, Sc, In, etc., and the cost is very high.

[0005] In addition to raw material costs, the preparation cost of solid-state electrolytes is also very high. For example, they require very high sintering temperatures or sintering with inert gas, low-temperature annealing, and a preparation environment with a relative humidity below 1%. In order for all-solid-state batteries to be competitive with existing technologies, some have proposed that the cost of solid-state electrolytes needs to be less than $10 per square meter (note that this includes the cost of raw materials and synthesis / processing costs).

[0006] Therefore, developing a low-cost solid electrolyte and solid electrolyte membrane is one of the most critical factors in solving the commercialization of solid-state batteries. SUMMARY OF THE INVENTION

[0007] OBJECT OF THE INVENTION: In order to overcome the above deficiencies, the object of the present invention is to provide a low-cost all-solid-state electrolyte membrane, its preparation process and application, with low raw material cost and low preparation cost. The synthesis process adopts the method of mechanical ball milling. Compared with traditional synthesis methods such as solid-phase method and co-precipitation, the mechanical ball milling process is simple. The dry process is used to replace the conventional process for preparing solid electrolytes, eliminating the use of a large amount of solvents such as NMP and deionized water and omitting the drying process steps, reducing energy waste and production costs, and at the same time reducing environmental pollution.

[0008] The object of the present invention is achieved through the following technical solutions: A low-cost all-solid-state electrolyte membrane, which is made of a halide solid electrolyte, and the chemical general formula of the halide solid electrolyte is any one of the following general formulas: General formula I: Li

[0011] , (n+4m) , n ,

[0012] , , m , 6。 , Zr m Cl (n+4m) , where 1.5 ≤ n ≤ 2.5, 0.75 ≤ m ≤ 0.9; General formula II: Li3MCl6, where M is selected from one of Y, In, Er, and Sc; General formula III: Li (2+4x-ax) Zr (1-x) A x Cl6, where 0 < x < 1, A is the doped metal element, selected from one of In, Sc, and Zn. When A is In, a = 3; when A is Sc, a = 【3】; when A is Zn, a = 2.

[0009] Preferably, in the general formula II, M is Y or In, and the chemical formula is Li3YCl6 or Li3InCl 6。

[0010] Preferably, in the general formula III, x = 0.2, A is Zn, a = 2, and the chemical formula is Li 2.4 Zr 0.8 A 0.2 Cl 6。

[0011] Furthermore, for the above-mentioned low-cost all-solid-state electrolyte membrane, the chemical general formula of the halide solid electrolyte is Li <00000\12>Zr m Cl (n+4m) , and it is synthesized using LiCl and ZrCl4.

[0012] Preferably, in the general formula I, n = 2, m = 1, and the chemical formula is Li2ZrCl6.

[0013] The present invention also relates to a process for preparing the low-cost all-solid-state electrolyte membrane. When the chemical formula of the halide solid electrolyte is Formula I, the process comprises the following steps: S1 Raw material mixing: Mix the raw materials LiCl and ZrCl4 according to Li n Zr m Cl (n+4m) The stoichiometric ratio is mixed to obtain a mixed powder; S2 ball milling: ball mill the above mixed powder to obtain the halide solid electrolyte Li n Zr m Cl (n+4m) ; S3 fiberization treatment: the above-mentioned halide solid electrolyte Li n Zr m Cl (n+4m) Mixed with a binder for fiberization, the amount of binder added is halide solid electrolyte Li n Zr m Cl (n+4m) 0.1~5wt%, and then ball milling or grinding to obtain Li n Zr m Cl (n+4m) -Binder mixture; S4 heating and rolling treatment: the above Li n Zr m Cl (n+4m) -The binder mixture is heated and pressed to produce an all-solid-state electrolyte membrane.

[0014] Furthermore, the above-mentioned low-cost all-solid-state electrolyte membrane preparation process, when the chemical formula of the halide solid electrolyte is Formula II, comprises the following steps: S1 Raw material mixing: mixing raw materials LiCl and MCl3 according to the stoichiometric ratio of Li3MCl6 to obtain mixed powder; S2 ball milling: ball milling the mixed powder to obtain the halide solid electrolyte Li3MCl6; S3 fiberization treatment: the halide solid electrolyte Li3MCl6 is mixed with a binder for fiberization treatment, wherein the binder is added in an amount of 0.1-5 wt% of the halide solid electrolyte Li3MCl6, and then ball milled or ground to obtain a Li3MCl6-binder mixture; S4 heating and rolling treatment: the above-mentioned Li3MCl6 binder mixture is subjected to heating and rolling treatment to prepare an all-solid-state electrolyte membrane.

[0015] Furthermore, the above-mentioned low-cost all-solid-state electrolyte membrane preparation process, when the chemical formula of the halide solid electrolyte is Formula III, comprises the following steps: S1 raw material mixing: raw materials LiCl, ZrCl4 and ACl a Press Li (2+4x-ax) Zr (1-x) A x Cl6 in a stoichiometric ratio to obtain a mixed powder; S2 ball milling: ball mill the above mixed powder to obtain the halide solid electrolyte Li (2+4x-ax) Zr (1-x) A x Cl6; S3 fiberization treatment: the above-mentioned halide solid electrolyte Li (2+4x-ax) Zr (1-x) A x Cl6 is mixed with a binder for fiberization, and the amount of binder added is the halide solid electrolyte Li (2+4x-ax) Zr (1-x) A x 0.1~5wt% of Cl6, then ball milling or grinding to obtain Li (2+4x-ax) Zr (1-x) A x Cl6-binder mixture; S4 heating and rolling treatment: the above Li (2+4x-ax) Zr (1-x) A x The Cl6-binder mixture is subjected to heating and rolling pressing treatment to prepare an all-solid electrolyte membrane.

[0016] Furthermore, in the above-mentioned preparation process of the low-cost all-solid-state electrolyte membrane, the ball milling process parameters in S2 are as follows: the ball milling speed is 300-900 rpm, the ball milling time is 32-72 hours, and the ball milling jar needs to be opened every 10-20 hours of ball milling to scrape the powder attached to the wall of the ball milling jar and then ball milled; the ball milling beads have 2-4 specifications, and the diameter of each specification is 2-10 mm; the ball-to-material ratio of the ball milling treatment is (10-15):1.

[0017] Preferably, the ball milling process parameters in S2 are: the ball milling speed is 400 rpm, the ball milling time is 72 hours, and the ball milling jar needs to be opened every 16 hours of ball milling to scrape the powder attached to the wall of the ball milling jar and then ball milled; the ball milling beads have two specifications of diameters of 3 mm and 6 mm, and the mass ratio of large and small ball milling beads is 3:1; the ball-to-material ratio of ball milling treatment is 12:1.

[0018] Furthermore, in the above-mentioned preparation process of the low-cost all-solid-state electrolyte membrane, the S2 also includes an ion conductivity test, which specifically includes the following contents: the prepared halide solid electrolyte is placed in a quantitative amount of (0.4~1) g into a sealed insulating mold with a diameter of 10~16 mm and the powder is kept flat, and cold-pressed into tablets. The pressure of the cold-pressed tablets is 0.5~3 tons, and the pressure holding time is 3~8 minutes. Then, the sealed insulating mold is connected to the electrochemical workstation for ion conductivity testing.

[0019] The ionic conductivity of the prepared halide solid electrolyte is greater than 1×10 -4 S / cm, reaching the qualified standard of solid electrolyte and meeting the requirements for battery use.

[0020] Preferably, the prepared halide solid electrolyte is placed in a sealed insulating mold with a diameter of 10 to 16 mm in a quantitative amount of 0.6 g.

[0021] Furthermore, in the above-mentioned low-cost all-solid-state electrolyte membrane preparation process, the sealed insulating mold includes a mold, an insulating plate, and a wire; insulating plates are provided at the upper and lower ends of the mold to serve as insulation; and wires are provided on the outer side of the upper and lower parts of the mold for connecting to an external circuit.

[0022] Furthermore, in the above-mentioned preparation process of the low-cost all-solid-state electrolyte membrane, the mold includes an upper mold and an insulating mold, the upper mold and the insulating mold are arranged correspondingly above and below, the insulating mold is the main part of the mold, and a mold cavity for providing powder pressing is arranged inside it; the mold also includes a pressing rod, which is arranged at the bottom of the upper mold and above the insulating mold, and is used to apply pressure to the powder in the mold cavity; the mold also includes a discharge rod, which is arranged below the insulating mold; the mold also includes a gasket, which is arranged in the mold cavity and is located below the powder; the mold also includes a sealing ring, which is arranged in the mold cavity to ensure the sealing inside the mold cavity; the mold also includes a demolding sleeve, which is sleeved on the outside of the mold during the demolding process.

[0023] Furthermore, in the above-mentioned low-cost all-solid-state electrolyte membrane preparation process, the binder in S3 is a mixture of one or more of PTFE, cellulose mesh, nylon mesh, and Kevlar mesh; the ball milling process parameters in S3 are: the ball milling speed is 200~600 rpm, the ball milling time is 6~12 hours, and the ball milling jar needs to be opened every 2 hours of ball milling to scrape the powder attached to the wall of the ball milling jar and then ball milled. The ball milling beads have 2~4 specifications, and the diameter of each specification is 2~10 mm; the ball-to-material ratio of the ball milling treatment is (10~15):1; the grinding time in S3 is 20~60 minutes.

[0024] Preferably, the binder in S3 is PTFE, and the amount of the PTFE binder added is 1 wt% of the halide solid electrolyte.

[0025] Preferably, S3 adopts ball milling, and its process parameters are: the ball milling speed is 400 rpm, the ball milling time is 8 hours, and the ball milling jar needs to be opened every 2 hours of ball milling to scrape the powder attached to the wall of the ball milling jar and then ball milled. The diameters of the ball milling beads are 3 mm and 6 mm, and the mass ratio of large and small ball milling beads is 3:1; the ball-to-material ratio of the ball milling treatment is 12:1.

[0026] Preferably, the step S3 is grinding, and the grinding time is 45 minutes.

[0027] Furthermore, in the above-mentioned low-cost all-solid-state electrolyte membrane preparation process, the heating rolling treatment process parameters in S4 are set as follows: the number of heating rolling is 3 to 8 times, the temperature of the pressing roller is 80 to 100°C, the speed of the heating roller press is 5 to 10 m / min, and the pressure is 2 to 20 t.

[0028] Preferably, the speed of the heated roller press is 5 m / min and the pressure is 5 t.

[0029] The present invention also relates to the application of the low-cost all-solid-state electrolyte membrane, which is applied to lithium-ion batteries and has excellent comprehensive performance and low cost.

[0030] Compared with the prior art, the present invention has the following beneficial effects: (1) The low-cost all-solid-state electrolyte membrane disclosed in the present invention uses LiCl and ZrCl4 to synthesize the halide solid electrolyte Li. n Zr m Cl (n+4m) (especially Li2ZrCl6), these two raw materials are cheap, making the raw material cost of this solid electrolyte several orders of magnitude lower than that of all current chloride solid electrolytes; (2) The low-cost all-solid-state electrolyte membrane disclosed in the present invention performs well in maintaining high ionic conductivity and can meet the requirements of lithium-ion batteries for ion transmission efficiency; it has excellent comprehensive performance, and has the characteristics of high safety performance, high energy density, light weight, and excellent cycle performance of solid electrolytes. It is non-flammable, non-corrosive, non-volatile, and does not have liquid leakage problems; it has a wide electrochemical window and can match high-voltage positive electrode materials; it can inhibit the growth of lithium dendrites during battery cycling, thereby improving the cyclability and service life of lithium-ion batteries; (3) The present invention discloses a low-cost all-solid-state electrolyte membrane preparation process. Traditional solid-state electrolyte preparation has stringent requirements on the environment and process, such as high-temperature sintering, sintering with inert gas, low-temperature annealing, and preparation in an environment with a relative humidity below 1%, which is very costly. The synthesis process of the present invention adopts a mechanical ball milling method, which is simpler and less expensive than traditional solid-phase method, co-precipitation and other synthesis methods. At the same time, the use of a dry process to replace the conventional process for preparing solid-state electrolytes eliminates the use of large amounts of solvents such as NMP and deionized water, omits the drying process step, and reduces energy waste and production costs. (4) The application of the low-cost all-solid-state electrolyte membrane disclosed in the present invention reduces the cost of solid-state electrolytes by reducing the cost of raw materials and preparation costs, providing key support for the commercial development of lithium-ion solid-state batteries, and helping to promote the widespread application of lithium-ion solid-state batteries in various fields, with broad market prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 Impedance diagram of the halide solid electrolyte LZC prepared in an embodiment of the present invention under different pressures; Figure 2 : is a powder X-ray diffraction pattern of the halide solid electrolyte LZC prepared in an embodiment of the present invention; Figure 3 Impedance diagram of the PTFE-LZC solid electrolyte membrane prepared in Example 1 of the present invention under different pressures; Figure 4 Impedance diagrams of the PTFE-LZC solid electrolyte membrane of LZC prepared by dry ball milling in Example 1 of the present invention and the PTFE-LZC solid electrolyte membrane of LZC prepared by low-temperature annealing in Comparative Example 1 under different pressures; Figure 5 ionic impedance diagram of the PTFE-LZC solid electrolyte membrane prepared in Example 1 of the present invention; Figure 6 ionic impedance diagram of the PEO-LZC solid electrolyte membrane prepared in Comparative Example 2 of the present invention; Figure 7 1 is a performance diagram of a Li|PTFE-LZC|Li symmetric battery fabricated using the PTFE-LZC solid electrolyte membrane prepared in Example 1 of the present invention; Figure 8 This is a physical picture of the PTFE-LZC solid electrolyte membrane prepared in Example 1 of the present invention; Figure 9 This is a physical picture of the sealing insulation mold and ion conductivity test of the present invention; Figure 10 This is a schematic structural diagram of the sealing insulation mold during pressing according to the present invention; Figure 11 This is a schematic structural diagram of the sealing insulation mold of the present invention during flipping and demoulding; In the picture: Mold 1, upper mold 11, insulating mold 12, mold cavity 121, pressing rod 13, lower rod 14, gasket 15, sealing ring 16, demoulding sleeve 17, insulating plate 2, wire 3, powder a. DETAILED DESCRIPTION

[0032] The following examples 1 to 5 and comparative examples 1 to 2 are combined with the attached Figure 1 、 2 , 3, 4, 5, 6, 7, 8, 9, 10, 11 and specific experimental data clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described 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 creative work shall fall within the scope of protection of the present invention.

[0033] Unless otherwise specified, the materials, methods and equipment used in the embodiments of the present invention are conventional materials, methods and equipment in this technical field.

[0034] The following Examples 1 to 5 and Comparative Examples 1 to 2 provide a halide solid electrolyte, a solid electrolyte membrane, and a preparation method thereof.

[0035] Example 1 The halide solid electrolyte of Example 1 is Li2ZrCl6 (LZC), and its preparation includes the following steps: S1 raw material mixing: mixing raw materials LiCl and ZrCl4 according to the stoichiometric ratio of Li2ZrCl6 to obtain mixed powder; S2 ball milling: The mixed powder is dry-milled to obtain the halide solid electrolyte Li2ZrCl6; the ball milling process parameters are as follows: the ball milling speed is 400 rpm, the ball milling time is 72 hours, and after every 16 hours of ball milling, the ball mill jar needs to be opened and the powder attached to the wall of the ball mill jar needs to be scraped and then ball milled; the ball milling beads have two specifications of diameters of 3mm and 6mm, and the mass ratio of large and small ball milling beads is 3:1; the ball-to-material ratio of ball milling treatment is 12:1.

[0036] S3 ion conductivity test: The prepared halide solid electrolyte Li2ZrCl6 was placed in a sealed insulating mold with a diameter of 12mm at a fixed amount of 0.6g and the powder was kept flat. The tablets were cold pressed at a pressure of 1.5 tons and a holding time of 5 minutes. The sealed insulating mold was then connected to an electrochemical workstation for ion conductivity testing. The ion conductivity test showed that the ion conductivity of the halide solid electrolyte Li2ZrCl6 prepared by dry ball milling was greater than 1×10 -4 S / cm, reaching the qualified standard of solid electrolyte.

[0037] The solid electrolyte membrane of Example 1 is PTFE-Li2ZrCl6 (PTFE-LZC), and its preparation includes the following steps: S1 Fiberization treatment: The halide solid electrolyte Li2ZrCl6 and the binder PTFE are mixed for fiberization treatment, with the binder added in an amount of 1wt% of the halide solid electrolyte Li2ZrCl6, and then ball milled to obtain a Li2ZrCl6-binder mixture; wherein the ball milling process parameters are: a ball milling speed of 400 rpm, a ball milling treatment time of 8 hours, and after every 2 hours of ball milling, the ball milling jar needs to be opened and the powder attached to the wall of the ball milling jar needs to be scraped and then ball milled. The ball milling beads have two specifications of diameters of 3mm and 6mm, and the mass ratio of large and small ball milling beads is 3:1; the ball-to-material ratio of the ball milling treatment is 12:1; S4 heating and rolling treatment: The above-mentioned Li2ZrCl6-binder mixture is subjected to heating and rolling treatment to obtain a PTFE-LZC solid electrolyte membrane; wherein, the number of heating and rolling is 6 times, the temperature of the pressing roller is 80°C, the speed of the heating roller press is 5m / min, and the pressure is 5t.

[0038] The ionic conductivity test of the prepared PTFE-LZC solid electrolyte membrane of Example 1 was carried out, specifically: a PTFE-LZC solid electrolyte membrane with a diameter of 13 mm was cut and placed in a sealed insulating mold and the membrane surface was kept flat. After the sealed insulating mold was assembled, a downward pressure of 2 tons was applied to the sealed insulating mold for pressing. After the pressure was maintained for 5 minutes, the sealed insulating mold was connected to the electrochemical workstation for ionic conductivity testing. According to the ionic conductivity test, at room temperature, the ionic conductivity of the PTFE-LZC solid electrolyte membrane of Example 1 was greater than 4×10 -4 S / cm.

[0039] Example 2 The halide solid electrolyte of Example 2 is Li2ZrCl6 (LZC), and its preparation method is the same as that of Example 1.

[0040] The solid electrolyte membrane of Example 2 is PTFE-Li2ZrCl6 (PTFE-LZC), and its preparation includes the following steps: S1 Fiberization treatment: The halide solid electrolyte Li2ZrCl6 and the binder PTFE are mixed for fiberization treatment, with the binder added in an amount of 1wt% of the halide solid electrolyte Li2ZrCl6, and then ball milled to obtain a Li2ZrCl6-binder mixture; wherein the ball milling process parameters are: a ball milling speed of 400 rpm, a ball milling treatment time of 8 hours, and after every 2 hours of ball milling, the ball milling jar needs to be opened and the powder attached to the wall of the ball milling jar needs to be scraped and then ball milled. The ball milling beads have two specifications of diameters of 3mm and 6mm, and the mass ratio of large and small ball milling beads is 3:1; the ball-to-material ratio of the ball milling treatment is 12:1; S4 heating and rolling treatment: The above-mentioned Li2ZrCl6-binder mixture is subjected to heating and rolling treatment to obtain the PTFE-LZC solid electrolyte membrane of Example 2; wherein, the number of heating and rolling is 4 times, the temperature of the pressing roller is 100°C, the speed of the heating roller press is 5m / min, and the pressure is 5t.

[0041] The ionic conductivity test of the prepared PTFE-LZC solid electrolyte membrane of Example 2 was carried out, specifically: a PTFE-LZC solid electrolyte membrane with a diameter of 13 mm was cut and placed in a sealed insulating mold and the membrane surface was kept flat. After the mold was assembled, a downward pressure of 2 tons was applied to the sealed insulating mold for pressing. After the pressure was maintained for 5 minutes, the sealed insulating mold was connected to the electrochemical workstation for ionic conductivity testing. According to the ionic conductivity test, at room temperature, the ionic conductivity of the PTFE-LZC solid electrolyte membrane of Example 2 was greater than 1×10 -4 S / cm.

[0042] Example 3 The halide solid electrolyte of Example 3 is Li3InCl6 (LIC), and its preparation includes the following steps: S1 raw material mixing: mixing the raw materials LiCl and InCl3 according to the stoichiometric ratio of Li3InCl6 to obtain a mixed powder; S2 ball milling: The mixed powder is dry-milled to obtain the halide solid electrolyte Li3InCl6; the ball milling process parameters are as follows: the ball milling speed is 400 rpm, the ball milling time is 72 hours, and after every 16 hours of ball milling, the ball mill jar needs to be opened and the powder attached to the wall of the ball mill jar needs to be scraped and then ball milled; the ball milling beads have two specifications of diameters of 3mm and 6mm, and the mass ratio of large and small ball milling beads is 3:1; the ball-to-material ratio of ball milling treatment is 12:1.

[0043] S3 ion conductivity test: The prepared halide solid electrolyte Li3InCl6 was placed in a 12mm sealed insulating mold at a fixed weight of 0.6g and kept flat. The tablets were cold pressed at a pressure of 1.5 tons and a holding time of 5 minutes. The sealed insulating mold was then connected to an electrochemical workstation for ion conductivity testing. The ion conductivity test showed that the ion conductivity of the halide solid electrolyte Li3InCl6 prepared by dry ball milling was greater than 1×10 -4 S / cm, reaching the qualified standard of solid electrolyte.

[0044] The solid electrolyte membrane of Example 3 is PTFE-Li3InCl6 (PTFE-LIC), and its preparation includes the following steps: S1 Fiberization treatment: The halide solid electrolyte Li3InCl6 and the binder PTFE are mixed for fiberization treatment, with the binder added in an amount of 1wt% of the halide solid electrolyte Li3InCl6, and then ball milled to obtain a Li3InCl6-binder mixture; wherein the ball milling process parameters are: a ball milling speed of 400 rpm, a ball milling treatment time of 8 hours, and after every 2 hours of ball milling, the ball milling jar needs to be opened, the powder attached to the wall of the ball milling jar needs to be scraped and then ball milled, the ball milling beads have two specifications of diameters of 3mm and 6mm, and the mass ratio of large and small ball milling beads is 3:1; the ball-to-material ratio of the ball milling treatment is 12:1; S4 Heating and rolling treatment: The above-mentioned Li3InCl6-binder mixture was subjected to heating and rolling treatment to obtain the PTFE-LIC solid electrolyte membrane of Example 3; wherein the number of heating and rolling treatments was 4 times, the temperature of the pressing roller was 100°C, the speed of the heating roller press was 5m / min, and the pressure was 5t.

[0045] The ionic conductivity test of the prepared PTFE-LIC solid electrolyte membrane of Example 3 was performed, specifically: a PTFE-LIC solid electrolyte membrane with a diameter of 13 mm was cut and placed in a sealed insulating mold and the membrane surface was kept flat. After the sealed insulating mold was assembled, a downward pressure of 2 tons was applied to the sealed insulating mold for pressing. After the pressure was maintained for 5 minutes, the sealed insulating mold was connected to the electrochemical workstation for ionic conductivity testing. According to the ionic conductivity test, at room temperature, the ionic conductivity of the PTFE-LIC solid electrolyte membrane of Example 3 was greater than 1×10 -4 S / cm.

[0046] Example 4 The halide solid electrolyte of Example 4 is Li3YCl6 (LYC), and its preparation includes the following steps: S1 Raw material mixing: mixing raw materials LiCl and YCl3 according to the stoichiometric ratio of Li3YCl6 to obtain mixed powder; S2 ball milling: The mixed powder is dry-milled to obtain the halide solid electrolyte Li3YCl6; the ball milling process parameters are as follows: the ball milling speed is 400 rpm, the ball milling time is 72 hours, and after every 16 hours of ball milling, the ball mill jar needs to be opened and the powder attached to the wall of the ball mill jar needs to be scraped and then ball milled; the ball milling beads have two diameters of 3mm and 6mm, and the mass ratio of large and small ball milling beads is 3:1; the ball-to-material ratio of ball milling is 12:1.

[0047] S3 ion conductivity test: The prepared halide solid electrolyte Li3YCl6 was placed in a 12mm sealed insulating mold at a fixed weight of 0.6g and kept flat. The tablets were cold pressed at a pressure of 1.5 tons and a holding time of 5 minutes. The sealed insulating mold was then connected to an electrochemical workstation for ion conductivity testing. The ion conductivity test showed that the ion conductivity of the halide solid electrolyte Li3YCl6 prepared by dry ball milling was greater than 1×10 -4 S / cm, reaching the qualified standard of solid electrolyte.

[0048] The solid electrolyte membrane of Example 4 is PTFE-Li3YCl6 (PTFE-LYC), and its preparation includes the following steps: S1 Fiberization treatment: The halide solid electrolyte Li3YCl6 and the binder PTFE are mixed for fiberization treatment, the amount of the binder added is 1wt% of the halide solid electrolyte Li3YCl6, and then ball milling is performed to obtain a Li3YCl6-binder mixture; wherein the ball milling process parameters are: the ball milling speed is 40 rpm, the ball milling time is 8 hours, and after every 2 hours of ball milling, the ball milling jar needs to be opened, the powder attached to the wall of the ball milling jar needs to be scraped and then ball milled. The ball milling beads have two specifications of diameters of 3mm and 6mm, and the mass ratio of large and small ball milling beads is 3:1; the ball-to-material ratio of the ball milling treatment is 12:1; S4 heating and rolling treatment: The above-mentioned Li3YCl6-binder mixture was subjected to heating and rolling treatment to obtain the PTFE-LYC solid electrolyte membrane of Example 4; wherein, the number of heating and rolling treatments was 4 times, the temperature of the pressing roller was 100°C, the speed of the heating roller press was 5m / min, and the pressure was 5t.

[0049] The ionic conductivity test of the prepared PTFE-LYC solid electrolyte membrane of Example 4 was carried out, specifically: a PTFE-LYC solid electrolyte membrane with a diameter of 13 mm was cut and placed in a sealed insulating mold and the membrane surface was kept flat. After the mold was assembled, a downward pressure of 2 tons was applied to the sealed insulating mold for pressing. After the pressure was maintained for 5 minutes, the sealed insulating mold was connected to the electrochemical workstation for ionic conductivity testing. According to the ionic conductivity test, at room temperature, the ionic conductivity of the PTFE-LYC solid electrolyte membrane of Example 4 was greater than 1×10 -4 S / cm.

[0050] Example 5 The halide solid electrolyte of Example 5 is Li 2.4 Zr 0.8 A 0.2 Cl6 (LZZC), its preparation includes the following: S1 Raw material mixing: Mix the raw materials LiCl, ZrCl4, ZnCl2 according to Li 2.4 Zr 0.8 A 0.2 Cl6 in a stoichiometric ratio to obtain a mixed powder; S2 ball milling: dry ball mill the above mixed powder to obtain the halide solid electrolyte Li 2.4 Zr 0.8 A 0.2 Cl6; the ball milling process parameters are as follows: the ball milling speed is 400 rpm, the ball milling time is 72 hours, and the ball milling jar needs to be opened every 16 hours to scrape the powder attached to the wall of the ball milling jar and then ball milled; the ball milling beads have two specifications of diameters of 3 mm and 6 mm, and the mass ratio of large and small ball milling beads is 3:1; the ball-to-material ratio of ball milling is 12:1.

[0051] S3 ion conductivity test: The prepared halide solid electrolyte Li 2.4 Zr 0.8 A 0.2 Cl6 was placed into a 12mm sealed insulating mold with a fixed amount of 0.6g and kept flat. The tablets were cold pressed with a pressure of 1.5 tons and a holding time of 5 minutes. The sealed insulating mold was then connected to an electrochemical workstation for ion conductivity testing. 2.4 Zr 0.8 A 0.2 The ionic conductivity of Cl6 is greater than 1×10 -4 S / cm, reaching the qualified standard of solid electrolyte.

[0052] The solid electrolyte membrane of Example 5 is PTFE-Li 2.4 Zr0.8 A 0.2 Cl6 (PTFE-LZZC), its preparation includes the following: S1 Fiberization treatment: The above-mentioned halide solid electrolyte Li 2.4 Zr 0.8 A 0.2 Cl6 is mixed with binder PTFE for fiberization, and the amount of binder added is the halide solid electrolyte Li 2.4 Zr 0.8 A 0.2 1wt% of Cl6, and then ball milling to obtain Li 2.4 Zr 0.8 A 0.2 Cl6-binder mixture; wherein, the ball milling process parameters are: ball milling speed of 400 rpm, ball milling time of 8 hours, every 2 hours of ball milling, the ball mill needs to be opened, the powder adhering to the wall of the ball mill needs to be scraped and then ball milled, the ball milling beads have two specifications of diameters of 3mm and 6mm, and the mass ratio of large and small ball milling beads is 3:1; the ball-to-material ratio of ball milling is 12:1; S4 heating and rolling treatment: the above Li 2.4 Zr 0.8 A 0.2 The Cl6-binder mixture was subjected to heating and rolling treatment to obtain the PTFE-LZZC solid electrolyte membrane of Example 5; wherein, the number of heating and rolling was 4 times, the temperature of the pressing roller was 100°C, the speed of the heating roller press was 5m / min, and the pressure was 5t.

[0053] The ionic conductivity test of the prepared PTFE-LZZC solid electrolyte membrane of Example 5 was carried out, specifically: a PTFE-LZZC solid electrolyte membrane with a diameter of 13 mm was cut and placed in a sealed insulating mold and the membrane surface was kept flat. After the sealed insulating mold was assembled, a downward pressure of 2 tons was applied to the sealed insulating mold for pressing. After the pressure was maintained for 5 minutes, the sealed insulating mold was connected to the electrochemical workstation for ionic conductivity testing. According to the ionic conductivity test, at room temperature, the ionic conductivity of the PTFE-LZZC solid electrolyte membrane of Example 5 was greater than 1×10 -4 S / cm.

[0054] Comparative Example 1 The halide solid electrolyte of Comparative Example 1 is Li2ZrCl6 (LZC), which is prepared by low-temperature annealing. The preparation includes the following steps: S1 raw material mixing: mixing raw materials LiCl and ZrCl4 according to the stoichiometric ratio of Li2ZrCl6 to obtain mixed powder; S2 ball milling: The mixed powder is ball milled to obtain the halide solid electrolyte Li2ZrCl6; the ball milling process parameters are as follows: the ball milling speed is 400 rpm, the ball milling time is 6 hours, and after every 3 hours of ball milling, the ball mill jar needs to be opened and the powder attached to the wall of the ball mill jar needs to be scraped and then ball milled; the ball milling beads have two specifications of diameters of 3mm and 6mm, and the mass ratio of large and small ball milling beads is 3:1; the ball-to-material ratio of ball milling treatment is 8:1.

[0055] S3 low-temperature annealing: The ball-milled halide solid electrolyte Li2ZrCl6 is subjected to low-temperature annealing at a temperature of 250~350℃ for 4~5h. To prevent the halide solid electrolyte Li2ZrCl6 from being exposed to air and causing property changes, all low-temperature annealing experiments are carried out with the sample sealed in a vacuum quartz tube.

[0056] S4 ion conductivity test: 0.6g of the low-temperature annealed halide solid electrolyte Li2ZrCl6 was placed in a 12mm sealed insulating mold and kept flat. The cold pressing tablets were pressed at a pressure of 1.5 tons and the pressure was maintained for 5 minutes. The sealed insulating mold was then connected to an electrochemical workstation for ion conductivity testing. The ion conductivity test showed that the ion conductivity of the halide solid electrolyte Li2ZrCl6 prepared by low-temperature annealing was greater than 1×10 -6 S / cm.

[0057] The solid electrolyte membrane of Comparative Example 1 is PTFE-Li2ZrCl6 (PTFE-LZC), and its preparation includes the following steps: S1 Fiberization treatment: The halide solid electrolyte Li2ZrCl6 of Comparative Example 1 was mixed with a binder PTFE for fiberization treatment, wherein the binder was added in an amount of 1 wt% of the halide solid electrolyte Li2ZrCl6, and then ball milled to obtain a Li2ZrCl6-binder mixture; wherein the ball milling process parameters were as follows: a ball milling speed of 400 rpm, a ball milling time of 8 hours, and after every 2 hours of ball milling, the ball milling jar was opened, the powder attached to the wall of the ball milling jar was scraped off, and then ball milled again. The ball milling beads had two diameters of 3 mm and 6 mm, and the mass ratio of the large and small ball milling beads was 3:1; the ball-to-material ratio during ball milling was 12:1; S4 heating and rolling treatment: The above-mentioned Li2ZrCl6-binder mixture is subjected to heating and rolling treatment to obtain the PTFE-LZC solid electrolyte membrane of Comparative Example 1; wherein, the number of heating and rolling is 6 times, the temperature of the pressing roller is 80°C, the speed of the heating roller press is 5m / min, and the pressure is 5t.

[0058] The ionic conductivity test of the prepared PTFE-LZC solid electrolyte membrane of Comparative Example 1 was carried out, specifically: a PTFE-LZC solid electrolyte membrane with a diameter of 13 mm was cut and placed in a sealed insulating mold and the membrane surface was kept flat. After the sealed insulating mold was assembled, a downward pressure of 2 tons was applied to the sealed insulating mold for pressing. After the pressure was maintained for 5 minutes, the sealed insulating mold was connected to the electrochemical workstation for ionic conductivity testing. According to the ionic conductivity test, at room temperature, the ionic conductivity of the PTFE-LZC solid electrolyte membrane of Comparative Example 1 was greater than 3.8×10 -6 S / cm.

[0059] Comparative Example 2 Comparative Example 2 is a solid polymer electrolyte membrane PEO-Li2ZrCl6 (PEO-LZC), which is prepared by a conventional wet method (solvent evaporation method). The preparation includes the following steps: S1: PEO (Mw = 600,000) and LiTFSI were dissolved in anhydrous acetonitrile at a stoichiometric ratio of EO:Li of 20:1. A rotor was added and heated at 60°C and 3500 rpm for 6-8 h to prepare a mixed solution. S2: Add the halide solid electrolyte Li2ZrCl6 prepared in Example 1 to the mixed solution, where the amount of the halide solid electrolyte Li2ZrCl6 added is 60wt% of PEO, and continue heating and rotating at a temperature of 60°C and a speed of 3500 rpm for 6 hours to obtain a PEO-LZC precursor solution; S3: Degassing the PEO-LZC precursor solution in a degassing machine; S4: Pour the degassed PEO-LZC precursor solution into a polytetrafluoroethylene plate containing a groove. After the PEO-LZC precursor solution is naturally air-dried to form a film, remove the PEO-LZC film from the polytetrafluoroethylene plate and place it in a vacuum drying oven to evaporate the residual solvent. The heating temperature is 60-80°C and the heating time is 12-24 hours to obtain the PEO-LZC solid polymer electrolyte membrane of Comparative Example 2.

[0060] The ionic conductivity test of the prepared PEO-LZC solid polymer electrolyte membrane of Comparative Example 2 was performed. A PEO-LZC solid electrolyte membrane with a diameter of 13 mm was cut and placed in a sealed insulating mold while keeping the membrane surface flat. After assembling the sealed insulating mold, a downward pressure of 2 tons was applied to the mold for pressing. After the pressure was maintained for 5 minutes, the sealed insulating mold was connected to an electrochemical workstation for ionic conductivity testing. The ionic conductivity test showed that the ionic conductivity of the PEO-LZC solid electrolyte membrane of Comparative Example 2 was 6.2×10 -5 S / cm.

[0061] In addition, if Figure 10 、 11 As shown, the sealed insulating mold prepared and used in the above embodiments of the present invention includes a mold 1, an insulating plate 2, and a wire 3. An insulating plate 2 is provided at the upper and lower ends of the mold 1 to play an insulating role, prevent current conduction, protect the safety of operators, and ensure the electrical insulation performance of the mold during operation. A wire 3 is provided at the upper and lower parts of the mold 1 for connecting to an external circuit, namely, an electrochemical workstation.

[0062] Furthermore, the mold 1 includes an upper mold 11, an insulating mold 12, a press rod 13, a lower mold rod 14, a gasket 15, a sealing ring 16 and a demoulding sleeve 17. The upper mold 11 and the insulating mold 12 are arranged correspondingly up and down. The insulating mold 12 is the main part of the mold 1. A mold cavity 121 is provided inside the insulating mold 12 for providing a pressing of the powder a. The insulating mold 12 itself has insulating properties to ensure an insulating environment for the operation of the mold 1. The press rod 13 is arranged at the bottom of the upper mold 11 and above the insulating mold 12. It is used to apply pressure to the powder a in the mold cavity 121 and is a key component for realizing the pressing process. The lower mold rod 14 is arranged below the insulating mold 12. During the demoulding process, the lower mold rod 14 is taken out, the mold 1 is inverted as a whole, and pressed downward to push the pressed material out of the mold 1. The gasket 15 is arranged in the mold cavity 121 and below the powder a. It plays a role in protecting the mold, evenly dispersing pressure and ensuring flatness after pressing. Sealing ring 16 is disposed within mold cavity 121, surrounding mold cavity 121 of insulating mold 12. Its primary function is to ensure the tightness of mold 1, preventing leakage of powder material A and maintaining a stable internal environment when a specific environment is required. Demolding sleeve 17 is positioned externally of mold 1 during the demolding process and is used to assist in removing the pressed material from mold 1.

[0063] like Figure 10 、 11 As shown, the working process of the sealing insulation mold is as follows: 1. Pressing process 1. First, put the powder a into the mold cavity 121 of the insulating mold 12. The pressing rod 13 moves downward under the action of external power (power provided by equipment such as a press, and the sealed insulating mold must be placed in the center of the press) and gradually approaches the powder a.

[0064] 2. When the pressing rod 13 contacts the powder a, it continues to apply pressure to compress the powder. During the pressing process, the sealing ring 16 and the gasket 15 ensure the sealing inside the mold 1 to prevent the powder a from leaking. At the same time, the gasket 15 helps to evenly distribute the pressure to ensure the pressing effect.

[0065] 3. When the powder a is pressed to the desired shape and density, the pressing rod 13 stops applying pressure and the pressing process is completed.

[0066] 2. Flip demoulding process 1. First, put the demoulding sleeve 17 on the outside of the mold 1 (as shown in the figure, the demoulding sleeve 17 has been put on during the flip demoulding process).

[0067] 2. The mold 1 is turned over as a whole (as shown in the figure during the demoulding process) so that the blanking rod 14 originally located at the bottom is at the top.

[0068] 3. The material removal rod 14 moves downward under the action of external power or its own structure, pushing the pressed material. At the same time, the demoulding sleeve 17 assists in removing the material from the insulating mold 12, completing the demoulding operation.

[0069] Note that the sealing insulation mold needs to be used in conjunction with a transfer fixture.

[0070] The working pressure gauge of the sealing insulation mold is shown in Table 1.

[0071] Table 1 Working pressure gauge of sealing insulation mold Diameter of sealing insulation mold (mm) Maximum working pressure (tons) 10 <1 12 <1.5 13 <2 16 <3 Effect verification The impedance test of the halide solid electrolyte LZC prepared in the embodiment of the present invention was carried out under different pressures. The test results are as follows: Figure 1 shown.

[0072] from Figure 1 It can be seen that the greater the pressure applied to the halide solid electrolyte LZC, the higher its ionic conductivity. This is because under high pressure, the contact between LZC particles is closer and the ion transfer impedance becomes lower, which makes the ionic conductivity higher.

[0073] The halide solid electrolyte LZC prepared in the embodiment of the present invention was subjected to XRD test, and the test results are as follows: Figure 2 shown.

[0074] from Figure 2 It can be seen that the halide solid electrolyte LZC prepared in the present invention is a pure phase, and the positions of the XRD peaks correspond one to one with the standard card.

[0075] The impedance test of the PTFE-LZC solid electrolyte membrane prepared in Example 1 of the present invention was carried out under different pressures. The test results are as follows: Figure 4 shown.

[0076] Depend on Figure 3 It can be obtained that: Similarly, the greater the pressure applied to the PTFE-LZC solid electrolyte membrane, the higher its ionic conductivity. This is also because under high pressure, the contact between LZC particles is closer and the ion transfer impedance becomes lower, which makes the ionic conductivity higher.

[0077] Impedance tests were conducted on the PTFE-LZC solid electrolyte membrane of LZC prepared by dry ball milling in Example 1 of the present invention and the PTFE-LZC solid electrolyte membrane of LZC prepared by low temperature annealing in Comparative Example 1 at different pressures. The test results are shown in FIG. Figure 5 shown.

[0078] Depend on Figure 4 It can be obtained that the impedance of the PTFE-LZC solid electrolyte membrane of LZC prepared by low-temperature annealing in Comparative Example 1 is much greater than that of the PTFE-LZC solid electrolyte membrane of LZC prepared by dry ball milling in Example 1. This is because the LZC prepared by dry ball milling is amorphous and has low ion transfer impedance, while the LZC prepared by low-temperature annealing is crystalline and Li+ is almost difficult to transmit.

[0079] The impedance test was carried out on the PTFE-LZC solid electrolyte membrane prepared in Example 1 of the present invention and the PEO-LZC solid electrolyte membrane prepared in Comparative Example 2. The test results are as follows: Figure 5 、 6 shown.

[0080] from Figure 5 、 6 It can be seen that although the ionic impedance of the PTFE-LZC solid electrolyte membrane prepared in Example 1 of the present invention is greater than the impedance of the LZC raw material, the ionic conductivity is still greater than 1×10 -4 S / cm, which meets the requirements for battery use. In contrast, the impedance of the PEO-LZC solid electrolyte membrane prepared in Example 2 is greater than 10000Ω, and the ionic conductivity is calculated to be about 6.2×10 -5 S / cm, which cannot meet the requirements of battery use. This is because the ion transmission performance of PEO at room temperature is low (such as Figure 6 shown).

[0081] The PTFE-LZC solid electrolyte membrane of Example 1, which was cut into pieces with a diameter of 13 mm, was used to prepare a stainless steel sheet|PEO-LZC solid electrolyte membrane|stainless steel sheet symmetrical battery (Li|PTFE-LZC|Li symmetrical battery). Performance tests were performed on the battery. The test results are shown in FIG. Figure 7 shown.

[0082] Depend on Figure 7 It can be obtained that the Li|PTFE-LZC|Li symmetric battery made by using the PTFE-LZC solid electrolyte membrane prepared in Example 1 of the present invention can be 2 and 0.2mA / cm 2The PTFE-LZC solid electrolyte membrane can operate stably at a current density of 1000 nm. This is due to the excellent ionic conductivity and excellent mechanical stability of the PTFE-LZC solid electrolyte membrane, which inhibits the growth of lithium dendrites. At the same time, the PTFE-LZC solid electrolyte membrane also has excellent flexibility, which can improve the interface contact of the solid-state battery. Figure 8 shown.

[0083] In summary, the present invention provides a low-cost halide solid electrolyte, solid electrolyte membrane and preparation method thereof, which reduces the cost of production and preparation while maintaining high ionic conductivity, obtains a solid electrolyte with excellent comprehensive performance and low cost, and can solve the problem that the preparation cost of the current solid electrolyte is very high. The preparation process adopts the method of mechanical ball milling. Compared with traditional solid phase method, coprecipitation and other methods, the mechanical ball milling process is simpler and more cost-effective. At the same time, the use of a dry process to replace the conventional process for preparing solid electrolytes eliminates the use of a large amount of solvents such as NMP and deionized water and omits the process steps of drying, reduces great energy waste and production costs, and the use of solvent-free reduces environmental pollution.

[0084] The present invention has many specific application paths, and the above is only a preferred embodiment of the present invention. It should be noted that the above embodiments are only used to illustrate the present invention and are not intended to limit the scope of protection of the present invention. For those skilled in the art, several improvements can be made without departing from the principles of the present invention, and these improvements should also be considered as the scope of protection of the present invention.

Claims

1. A low-cost all-solid-state electrolyte membrane, characterized in that: The all-solid-state electrolyte membrane is made of a halide solid electrolyte, and the chemical formula of the halide solid electrolyte is any one of the following general formulas: General formula I: Li n Zr m Cl (n+4m) , where 1.5≤n≤2.5, 0.75≤m≤0.9; General formula II: Li3MCl6, wherein M is selected from one of Y, In, Er, and Sc; General formula III: Li (2+4x-ax) Zr (1-x) A x Cl6, where 0 < x < 1, A is the doped metal element and is selected from one of In, Sc, and Zn. When A is In, a = 3; when A is Sc, a = 3; when A is Zn, a = 2.

2. The low-cost all-solid-state electrolyte membrane according to claim 1, characterized in that: The chemical formula of the halide solid electrolyte is Li n Zr m Cl (n+4m) , and is synthesized using LiCl and ZrCl4.

3. The method for preparing a low-cost all-solid-state electrolyte membrane according to claim 1, wherein: The steps include: S1 Raw material mixing: When the chemical formula of the halide solid electrolyte is general formula I, the raw materials LiCl and ZrCl4 are mixed according to Li n Zr m Cl (n+4m) When the chemical formula of the halide solid electrolyte is Formula II, the raw materials LiCl and MCl3 are mixed in a stoichiometric ratio of Li3MCl6; when the chemical formula of the halide solid electrolyte is Formula III, the raw materials LiCl, ZrCl4 and ACl a Press Li (2+4x-ax) Zr (1-x) A x After being fully mixed, a mixed powder is obtained; S2 ball milling: ball milling the mixed powder to obtain a halide solid electrolyte; S3 fiberization treatment: the halide solid electrolyte is mixed with a binder for fiberization treatment, wherein the binder is added in an amount of 0.1 to 5 wt% of the halide solid electrolyte, and then ball milled or ground to obtain a mixture; S4 heating and rolling-pressing treatment: the above mixture is subjected to heating and rolling-pressing treatment to prepare an all-solid-state electrolyte membrane.

4. The method for preparing a low-cost all-solid-state electrolyte membrane according to claim 3, characterized in that: The ball milling process parameters in S2 are as follows: the ball milling speed is 300-900 rpm, the ball milling time is 32-72 hours, the ball milling jar needs to be opened every 10-20 hours of ball milling, the powder attached to the wall of the ball milling jar needs to be scraped and then ball milled; the ball milling beads have 2-4 specifications, and the diameter of each specification is 2-10 mm; the ball-to-material ratio of the ball milling process is (10-15):

1.

5. The method for preparing a low-cost all-solid-state electrolyte membrane according to claim 3, characterized in that: The S2 also includes an ion conductivity test, which specifically includes the following: placing the prepared halide solid electrolyte in a quantitative amount of (0.4~1) g into a sealed insulating mold and keeping the powder flat, and cold pressing the tablets. The pressure of the cold pressing tablets is 0.5~3 tons, and the pressure holding time is 3~8 minutes. Then, the sealed insulating mold is connected to the electrochemical workstation for ion conductivity testing.

6. The method for preparing a low-cost all-solid-state electrolyte membrane according to claim 5, characterized in that: The sealed insulating mold comprises a mold (1), an insulating plate (2), and a conductive wire (3); insulating plates (2) are provided at the upper and lower ends of the mold (1) to perform an insulating function; conductive wires (3) are provided on the outer side of the upper and lower parts of the mold (1) to connect to an external circuit.

7. The method for preparing a low-cost all-solid-state electrolyte membrane according to claim 6, characterized in that: The mold (1) comprises an upper mold (11) and an insulating mold (12), wherein the upper mold (11) and the insulating mold (12) are arranged correspondingly up and down, and the insulating mold (12) is the main body of the mold (1), and a mold cavity (121) for providing powder pressing is arranged therein; the mold (1) further comprises a pressing rod (13), wherein the pressing rod (13) is arranged at the bottom of the upper mold (11) and above the insulating mold (12), and is used to apply pressure to the powder in the mold cavity (121); the mold (1) further comprises a lowering rod (14), the blanking rod (14) is arranged below the insulating mold (12); the mold (1) further includes a gasket (15), the gasket (15) is arranged in the mold cavity (121) and is located below the powder; the mold (1) further includes a sealing ring (16), the sealing ring (16) is arranged in the mold cavity (121) and is used to ensure the sealing inside the mold cavity (121); the mold (1) further includes a demoulding sleeve (17), the demoulding sleeve (17) is sleeved on the outside of the mold (1) during the demoulding process.

8. The method for preparing a low-cost all-solid-state electrolyte membrane according to claim 3, characterized in that: The binder in S3 is a mixture of one or more of PTFE, cellulose mesh, nylon mesh, and Kevlar mesh; the ball milling process parameters in S3 are: the ball milling speed is 200-600 rpm, the ball milling time is 6-12 hours, and the ball milling jar needs to be opened every 2 hours of ball milling to scrape the powder attached to the wall of the ball milling jar and then ball milled. The ball milling beads have 2-4 specifications, and the diameter of each specification is 2-10 mm; the ball-to-material ratio of the ball milling treatment is (10-15):1; the grinding time in S3 is 20-60 minutes.

9. The method for preparing a low-cost all-solid-state electrolyte membrane according to claim 3, characterized in that: The process parameters of the heating rolling treatment in S4 are set as follows: the number of heating rolling is 3 to 8 times, the temperature of the pressing roller is 80 to 100° C., the speed of the heating roller press is 5 to 10 m / min, and the pressure is 2 to 20 t.

10. The use of the low-cost all-solid-state electrolyte membrane according to claim 1, characterized in that: The all-solid-state electrolyte membrane is applied to lithium-ion batteries.

Images