A laponite material having a single orientation card house structure and a method of making the same

Abstract

The application provides a kind of lithium smectite material with single orientation card house structure and its preparation method, belongs to battery material preparation technical field.The preparation method includes the following steps: S1: lithium smectite, LiCl powder is weighed, dispersed and dissolved in water, pH value is adjusted with LiOH solution, oil bath heating stirring, to obtain lithium smectite suspension by peeling off;S2: the lithium smectite suspension is centrifuged multiple times and washed with water, then freeze-dried to obtain lithium smectite nanosheet;S3: lithium smectite nanosheet is ultrasonically dispersed in water, a small amount of binder is added, and after sufficient stirring, lithium smectite sheet card house structure is formed in water, which is poured on the pre-frozen polytetrafluoroethylene film, and the ice template method is used for bottom-up freezing, and then vacuum freeze-drying to obtain lithium smectite material with single orientation card house structure.The material has nanosheet with consistent direction and stable structure, which can improve the ionic conductivity of composite solid electrolyte.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of battery material preparation, and particularly relates to a lithium smectite material with a single orientation card house structure and a preparation method thereof. BACKGROUND

[0002] Due to the lowest standard electrode potential (-3.04 V, vs. SHE) and high theoretical capacity (3862 mAh·g -1 ), lithium metal has a wide application prospect in secondary batteries. However, liquid electrolytes have safety hazards such as flammability, leakage, and toxicity, which limit their use. The application of solid electrolytes in lithium-ion batteries not only eliminates these safety hazards, prolongs the service life, but also improves the energy density and other electrochemical properties. Generally, all-solid-state electrolytes are divided into polymer electrolytes, inorganic ceramic electrolytes, and composite solid electrolytes. Inorganic ceramic electrolytes have high ionic conductivity and mechanical strength, but their brittleness and interface problems with electrodes limit their application. Polymer electrolytes have flexibility, but their low ionic conductivity at room temperature and poor mechanical strength make them difficult to be used as electrolytes in practical applications. Composite solid electrolytes combine the advantages of inorganic ceramic electrolytes and polymer electrolytes, and the ceramic fillers in them can inhibit the growth of lithium dendrites and improve the ionic conductivity, while the polymer can make the electrolyte interface with the electrode have good contact, so they have long-term development prospects in energy storage.

[0003] The size, morphology, surface state, addition amount, and aggregation state of the ceramic fillers greatly affect the performance of the composite solid electrolyte and the all-solid-state lithium metal battery. Current research and improvement ideas include preparing one-dimensional nanofibers or two-dimensional nanosheets in vertical arrays to improve the ionic conductivity of the composite solid electrolyte, or constructing 3D inorganic fillers to form a continuous lithium ion rapid transmission channel in the composite solid electrolyte.

[0004] However, the one-dimensional nanofibers or two-dimensional nanosheets in vertical arrays in the composite solid electrolyte are in a thermodynamically unstable state, and have relatively poor structural stability. During the long cycle process of the lithium battery, they tend to be disordered due to the deposition and intercalation of lithium, high temperature, and external mechanical force, etc., which greatly affects the performance of the battery. In addition, the usual 3D inorganic filler construction method requires a large amount of inorganic fillers, and prolongs the lithium ion transmission path. Therefore, there is an urgent need for structural design and preparation of high-performance ceramic fillers for composite solid electrolytes. SUMMARY

[0005] The purpose of the present application is to provide a lithium smectite material with a single orientation card house structure and a preparation method thereof to overcome the above-mentioned deficiencies of the prior art.

[0006] In order to achieve the above object, the present application adopts the following technical solutions:

[0007] The first object of the present application is to provide a preparation method of a lithium smectite material with a single orientation card house structure, comprising the following steps:

[0008] Step S1, weigh lithium smectite Na x (Mg 3-x ,Li x )Si3O9, 0≤x≤1 and LiCl powder, disperse and dissolve in water, adjust the pH value with LiOH solution, heat and stir in an oil bath for a certain time, and peel off to obtain a lithium smectite suspension;

[0009] Step S2, centrifuge and water wash the lithium smectite suspension in step S1 multiple times, and then freeze-dry to obtain lithium smectite nanosheets;

[0010] Step S3, take an appropriate amount of lithium smectite nanosheets in step S2, ultrasonically disperse in water, add a binder, fully stir, and then cast on a pre-frozen polytetrafluoroethylene film, use an ice template method to freeze from bottom to top, and then vacuum freeze-dry to obtain a lithium smectite material with a single orientation card house structure.

[0011] Further, in step S1, the mass ratio of lithium smectite Na x (Mg 3-x ,Li x )Si3O9 (0≤x≤1), 0≤x≤1 and LiCl powder is 1:3-1:5.

[0012] Further, the mass ratio of lithium smectite Na x (Mg 3-x ,Li x )Si3O9 and LiCl powder to water is 1:8-1:10, and a LiOH solution is prepared with LiOH powder to adjust the pH of the lithium smectite suspension to 12-13.

[0013] Further, the temperature of the oil bath heating is 110℃-120℃.

[0014] Further, in step S2, after each centrifugation, the supernatant is separated and removed, and then dispersed in water and centrifuged again until the pH is adjusted to 7-8.

[0015] Further, in step S3, the binder is polyethylene oxide or sodium carboxymethyl cellulose.

[0016] Further, the amount of the binder added is 1%-5% of the mass of the lithium smectite nanosheets.

[0017] The second object of the present application is to provide a lithium smectite material with a single orientation card house structure prepared by the above preparation method.

[0018] Further, the lithium smectite nanosheets in the card house structure are staggered and arranged with each other, and the lithium smectite nanosheets are single oriented to form a through hole with a polygonal shape.

[0019] Further, the content of the lithium smectite nanosheets in the lithium smectite material is not less than 95%.

[0020] Compared with the prior art, the present application has the following beneficial effects:

[0021] (1) The present application provides a preparation method of a lithium smectite material with a single orientation card house structure. The edges and faces of the exfoliated lithium smectite nanosheets have different electrical properties. When dispersed in water, the lithium smectite nanosheets close to each other can attract each other with the edges and faces to form a card house structure. A water-soluble polymer binder is simultaneously added in water to stabilize the card house structure. Then, the card house structure is single oriented by freeze-drying, which has good mechanical strength and structural stability.

[0022] (2) The lithium smectite material provided by the present application has a single orientation of the lithium smectite nanosheets in the structure. The introduction of a composite solid electrolyte can have a lithium ion rapid transmission channel consistent with the direction of the electric field.

[0023] (3) The lithium smectite material with a single orientation card house structure provided by the present application is used for preparing a composite solid electrolyte. A smaller amount of ceramic filler can be used to obtain a composite solid electrolyte with good mechanical strength and structural stability.

[0024] (4) The lithium smectite material provided by the present application has a single orientation card house structure, which can simultaneously improve the ionic conductivity and structural stability of the composite solid electrolyte, and is beneficial to improve the performance of the all-solid-state battery. BRIEF DESCRIPTION OF DRAWINGS

[0025] Figure 1 Preparation flow chart of the lithium smectite material with a single orientation card house structure;

[0026] Figure 2 X-ray diffraction pattern of the lithium smectite material prepared in Example 1 of the present application;

[0027] Figure 3 AFM image of the lithium smectite nanosheet prepared in Example 1 of the present application;

[0028] Figure 4 SEM image of the lithium smectite material prepared in Example 1 of the present application;

[0029] Figure 5 SEM and EDS images of the lithium smectite material prepared in Example 1 of the present application;

[0030] Figure 6 SEM image of cross section of the hectorite material prepared for Example 1 of the present invention;

[0031] Figure 7 BET plot of the hectorite material prepared for Example 1 of the present invention;

[0032] Figure 8 Impedance test result plot of the PEO- Hectorite Cardhouse Structure Composite Solid Electrolyte prepared using Example 1 of the present invention;

[0033] Figure 9 Ionic conductivity test result plot of the PEO- Hectorite Cardhouse Structure Composite Solid Electrolyte prepared using Example 1 of the present invention;

[0034] Figure 10 Ionic transference number test result plot of the PEO- Hectorite Cardhouse Structure Composite Solid Electrolyte prepared using Example 1 of the present invention;

[0035] Figure 11 SEM image of the hectorite material prepared for Example 2 of the present invention;

[0036] Figure 12 Impedance test result plot of the PEO- Hectorite Cardhouse Structure Composite Solid Electrolyte prepared using Example 2 of the present invention;

[0037] Figure 13 Ionic conductivity test result plot of the PEO- Hectorite Cardhouse Structure Composite Solid Electrolyte prepared using Example 2 of the present invention;

[0038] Figure 14 Ionic transference number test result plot of the PEO- Hectorite Cardhouse Structure Composite Solid Electrolyte prepared using Example 2 of the present invention;

[0039] Figure 15 Impedance test result plot of the PEO- Hectorite Cardhouse Structure Composite Solid Electrolyte prepared using Example 3 of the present invention;

[0040] Figure 16 Ionic conductivity test result plot of the PEO- Hectorite Cardhouse Structure Composite Solid Electrolyte prepared using Example 3 of the present invention;

[0041] Figure 17 Impedance test result plot of the PCL- Hectorite Cardhouse Structure Composite Solid Electrolyte prepared using Example 4 of the present invention;

[0042] Figure 18 Ionic conductivity test result plot of the PCL- Hectorite Cardhouse Structure Composite Solid Electrolyte prepared using Example 4 of the present invention;

[0043] Figure 19 Figure 4 shows the results of the ion migration number test of the PCL-laponite card house structure composite solid electrolyte prepared in Example 4. DETAILED DESCRIPTION

[0044] In order to make the objectives, technical solutions and advantages of the present application clearer, the embodiments of the present application are described in detail below, and the examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference signs represent the same or similar elements or elements having the same or similar functions throughout. The embodiments described below by referring to the accompanying drawings are exemplary and are only used to explain the present application, and cannot be understood as a limitation of the present application.

[0045] Reference Figure 1 Figure 1 shows the preparation flow chart of the laponite material with single orientation card house structure of the present application. The following examples are all implemented according to the flow chart.

[0046] Example 1

[0047] The present embodiment provides a preparation method of a laponite material with single orientation card house structure.

[0048] The specific steps are as follows:

[0049] (1) 4 g of laponite Li2Mg2Si3O9 and 16.956 g of LiCl·H2O powder were weighed into 200 mL of deionized water and stirred to disperse uniformly, 0.0479 g of LiOH was dissolved in 50 mL of deionized water solution, and then added dropwise into the laponite dispersion to adjust the pH value of the solution to 12-13. After ultrasonic dispersion treatment, the dispersion was heated and stirred in an oil bath at 110°C for 24 h at a speed of 500 r min -1 . Then centrifugation was performed at a speed of 4000 r min -1 for 5 min. After centrifugation, the upper clear solution was separated and removed, then deionized water was added to disperse the bottom solid of the centrifuge tube, and the centrifugation-dispersion operation was repeated five times to obtain a laponite dispersion with a pH of 8. The above laponite dispersion was frozen in a freezer for 2 h, and then freeze-dried to obtain laponite nanosheets.

[0050] (2) 0.064 g of the lithium smectite nanosheets were dispersed in 10 mL of deionized water, stirred at room temperature for 30 min, and then ultrasonically treated for 15 min. PEO (polyethylene oxide) with a mass of 5% of the lithium smectite nanosheets was added as a binder, and the mixture was stirred at room temperature for 2 h to obtain a uniform dispersion. A PTFE film was evenly attached to a glass plate, placed in a freezer at -15°C for 30 min, and then the uniform lithium smectite dispersion was poured onto the PTFE, and heat preservation foam was placed around and above the PTFE. The mixture was placed in the freezer for 2 h, and the ice template caused the lithium smectite nanosheets to form a single orientation arrangement perpendicular to the PTFE film. The frozen lithium smectite nanosheets were placed in a freeze dryer, a vacuum degree of 1 Pa and a temperature of -60°C were set, and vacuum freeze drying was performed for 10 h to obtain a lithium smectite material with a single orientation card house structure.

[0051] Example 2

[0052] The present example provides a method for preparing a lithium smectite material with a single orientation card house structure.

[0053] (1) 4 g of lithium smectite Li2Mg2Si3O9 and 24.156 g of LiCl·H2O powder were stirred and dispersed in 200 mL of deionized water. 0.0479 g of LiOH was dissolved in 50 mL of a deionized water solution, and then added dropwise to the lithium smectite dispersion to adjust the pH of the solution to 12-13. The dispersion was ultrasonically treated and then heated and stirred in an oil bath at 110°C for 24 h at a rotation speed of 500 r / min. -1 Then, centrifugation was performed at a rotation speed of 4000 r / min -1 for 4 min. After centrifugation, the supernatant was separated and removed, and then deionized water was added to disperse the solids at the bottom of the centrifuge tube. The centrifugation-dispersion operation was repeated seven times to obtain a lithium smectite dispersion with a pH of 7-8. The lithium smectite dispersion was frozen in a freezer for 2 h, and then freeze-dried to obtain lithium smectite nanosheets.

[0054] (2) 0.064 g of the lithium smectite nanosheets were dispersed in 10 mL of deionized water, stirred at room temperature for 30 min, and then ultrasonically treated for 15 min. PEO with a mass of 4% of the lithium smectite nanosheets was added as a binder, and the mixture was stirred at room temperature for 2 h to obtain a uniform dispersion. A PTFE film was evenly attached to a glass plate, placed in a freezer at -15°C for 30 min, and then the uniform lithium smectite dispersion was poured onto the PTFE, and heat preservation foam was placed around and above the PTFE. The mixture was placed in the freezer for 2 h, and the ice template caused the lithium smectite nanosheets to form a single orientation arrangement perpendicular to the PTFE film. The frozen lithium smectite nanosheets were placed in a freeze dryer, a vacuum degree of 1 Pa and a temperature of -60°C were set, and vacuum freeze drying was performed for 10 h. Then, the mixture was placed in an oven at 40°C for 2 h to obtain a lithium smectite material with a single orientation card house structure.

[0055] Example 3

[0056] The present example provides a method for preparing a lithium smectite material having a single orientation card house structure.

[0057] (1) 4 g of lithium smectite Li2Mg2Si3O9 and 24.156 g of LiCl·H2O powder were weighed into 200 mL of deionized water and stirred to disperse uniformly. 0.0479 g of LiOH was dissolved in 50 mL of deionized water solution, and then added dropwise into the lithium smectite dispersion to adjust the pH of the solution to 12-13. After ultrasonic dispersion treatment, the dispersion was heated and stirred in an oil bath at 110°C for 24 h at a speed of 500 r / min. -1 Then centrifugation was performed at a speed of 4000 r / min -1 for 4 min. After centrifugation, the supernatant was separated and removed, and then deionized water was added to disperse the solids at the bottom of the centrifuge tube. The centrifugation-dispersion operation was repeated seven times to obtain a lithium smectite dispersion with a pH of 7-8. The lithium smectite dispersion was frozen in a freezer for 2 h, and then freeze-dried to obtain lithium smectite nanosheets.

[0058] (2) 0.064 g of lithium smectite nanosheets were dispersed in 10 mL of deionized water, and after stirring at room temperature for 30 min, ultrasonic dispersion was performed for 15 min. PEO with a mass of 3% of the lithium smectite nanosheets was added as a binder, and the mixture was stirred at room temperature for 2 h to obtain a uniform dispersion. A PTFE film was evenly attached to a glass plate, and then placed in a freezer at -15°C for 30 min. The lithium smectite dispersion was then poured onto the PTFE film, and heat-insulating foam was placed around and above the PTFE film. The mixture was placed in a freezer for 2 h, and the ice template caused the lithium smectite nanosheets to form a single orientation arrangement perpendicular to the PTFE film. The frozen lithium smectite nanosheets were placed in a freeze dryer, and vacuum freeze-drying was performed at a vacuum degree of 1 Pa and a temperature of -60°C for 10 h. Then the mixture was placed in a 50°C oven for 1 h to obtain a lithium smectite material having a single orientation card house structure.

[0059] Example 4

[0060] The present example provides a method for preparing a lithium smectite material having a single orientation card house structure.

[0061] (1) 8 g of Na 0.3 Mg 2.7 Li 0.3 Si4O 10(OH)2, 48.312 g of LiCl-H2O powder was dispersed in 400 mL of deionized water, 0.479 g of LiOH was dissolved in 50 mL of deionized water solution, and then the lithium smectite dispersion was added dropwise to adjust the pH of the solution to 12-13. The dispersion was ultrasonically dispersed and then heated and stirred at 120°C for 24 h in an oil bath at a speed of 500 r / min -1 . Then centrifugation was performed at a speed of 4000 r / min -1 for 5 min. After centrifugation, the supernatant was separated, and then deionized water was added to disperse the solids at the bottom of the centrifuge tube. The centrifugation-dispersion operation was repeated eight times to obtain a lithium smectite dispersion with a pH of 7-8. The lithium smectite dispersion was frozen in a freezer for 4 h, and then freeze-dried to obtain lithium smectite nanosheets.

[0062] (2) 0.064 g of lithium smectite nanosheets was dispersed in 10 mL of deionized water, and then stirred at room temperature for 2 h and ultrasonically dispersed for 15 min. CMC with a mass of 5% of the lithium smectite nanosheets was added as a binder, and then stirred at room temperature for 2 h to obtain a uniform dispersion. A PTFE film was evenly attached to a glass plate, and then placed in a freezer at -15°C for 2 h. Then, the lithium smectite uniform dispersion was poured on the PTFE, and heat preservation foam was placed around and above the PTFE. The ice mold made the lithium smectite nanosheets form a single orientation arrangement perpendicular to the PTFE film. The frozen lithium smectite nanosheets were placed in a freeze dryer, and vacuum freeze-drying was performed at a vacuum degree of 5 Pa and a temperature of -60°C for 12 h. Then, the lithium smectite nanosheets were placed in an oven at 60°C for 30 min to obtain lithium smectite material with a single orientation card house structure.

[0063] In order to better illustrate the single orientation card house structure of the lithium smectite material of the present application, the present inventors have conducted the following research:

[0064] Performance characterization:

[0065] The lithium smectite material was characterized by an electron microscope, and examples 1-4 all had similar morphologies. The following is described by taking example 1 as an example:

[0066] Reference Figure 2 is an X-ray diffraction pattern of the lithium smectite material. After the single orientation card house structure was formed by freeze-drying, the diffraction peak at (004) became weaker, and the diffraction peaks at (110) and (200) became stronger, indicating that the signal of the edge of the lithium smectite nanosheet increased and the signal on the surface decreased, further indicating the formation of the single orientation card house structure.

[0067] Reference Figure 3 is an AFM image of the lithium smectite nanosheet after exfoliation. The thickness is between 20-40 nm.

[0068] Reference Figure 4 and Figure 11 , the SEM image of the hectorite material, the hectorite nanosheets interweave with each other to form a card house structure.

[0069] Reference Figure 5 , the surface element distribution map of the hectorite material, the signals of O, Mg and Si elements distributed on the card house skeleton are stronger, and the overall distribution is more uniform.

[0070] Reference Figure 6 , the cross-sectional SEM image of the hectorite material, the hectorite nanosheets are oriented vertically upward.

[0071] Reference Figure 7 , the BET image of the hectorite material, it can be seen from the adsorption-desorption curve that the structure has good adsorption and desorption gas capacity, indicating that the internal has a pore structure, and the specific surface area of such structure is as high as 142.9 m 2 / g.

[0072] In order to better illustrate the performance characteristics of the hectorite material of the present application, the present inventors have also carried out the following research:

[0073] (1) The hectorite material prepared in Example 1 was added dropwise with a PEO / LiTFSI anhydrous acetonitrile solution, and after drying, a PEO- hectorite card house structure composite solid electrolyte was obtained, the impedance test thereof at 30-90℃ is shown in Figure 8 , the ion conductivity calculated is shown in Figure 9 , the ion conductivity at 60℃ is 8.9x10 -4 S cm -1 . The ion transference number was tested by steady-state current method, the ion conductivity at 60℃ was 0.32, as shown in Figure 10 .

[0074] (2) The hectorite material prepared in Example 2 was added dropwise with a PEO / LiTFSI anhydrous acetonitrile solution, and after drying, a PEO- hectorite card house structure composite solid electrolyte was obtained, the impedance test thereof at 30-80℃ is shown in Figure 12 , the ion conductivity calculated is shown in Figure 13 , the ion conductivity at 60℃ is 2.9x10 -4 S cm -1 . The ion transference number was tested by steady-state current method, the ion conductivity at 60℃ was 0.266, as shown in Figure 14 .

[0075] (3) The lithium saponite material prepared in Example 3 was added dropwise to an anhydrous acetonitrile solution of PEO / LiTFSI, and after drying, a PEO-lithium saponite carboxylic composite solid electrolyte was obtained. Its impedance test at 30℃-80℃ is as follows: Figure 15 As shown, the ionic conductivity was calculated as follows: Figure 16 As shown, the ionic conductivity at 60℃ is 2.9 × 10⁻⁶. -4 S cm -1 The ion transport number was measured using the steady-state current method, and the ionic conductivity at 60℃ was 0.266. Figure 16 As shown.

[0076] (4) The lithium saponite material prepared in Example 4 was added dropwise to an anhydrous acetonitrile solution of PEO / LiTFSI, and after drying, a PCL-lithium saponite carboxylic composite solid electrolyte was obtained. Its impedance test at 30℃-80℃ is as follows: Figure 17 As shown, the ionic conductivity was calculated as follows: Figure 18 As shown, the ionic conductivity at 60℃ is 7.3 × 10⁻⁶. -4 S cm -1 The ion transport number was measured using the steady-state current method, and the ionic conductivity at 60℃ was 0.661. Figure 19 As shown.

[0077] Table 1 shows a comparison of the performance of the PEO-lithium saponite carboxylic composite solid electrolyte prepared in Example 1 with that of solid electrolytes disclosed in the prior art. The solid electrolyte containing the lithium saponite material of the present invention has excellent ionic conductivity.

[0078] Table 1.

[0079] System Ionic conductivity Ionic transference number References PEO-Ga203 4.85 x 10 -4 S cm -1 ]]> 0.272 1 P(VDF-CTFE) 3.4 x 10 -4 S cm -1 ]]> 0.43 2 PAO / PMMA-LASO 5.67 x 10 -6 S cm -1 ]]> - 3 PLLZO v / PPL]]> 5.91 x 10 -5 S cm -1 ]]> - 4 PEO-LLTP 2.04 x 10 -4 S cm -1 ]]> 0.59 5 Example 1 8.9 x 10 -4 S cm -1 ]]> 0.32 -

[0080] References

[0081] [1] Guangdong University of Technology. A PEO-based composite solid electrolyte containing inorganic oxides and its preparation method and polymer solid lithium battery: CN202211601958.7[P]. 2023-04-28.

[0082] [2] Yangtze River Delta Research Institute of University of Electronic Science and Technology of China (Quzhou). A method for preparing a high lithium-ion conductivity composite solid electrolyte: CN202211546630.X[P]. 2023-04-04.

[0083] [3] Wanxiang A123 Co., Ltd. A three-dimensional PEO polymer composite solid electrolyte containing modified inorganic filler, preparation method and solid lithium-ion battery: CN202110818527.5[P]. 2022-05-27.

[0084] [4] Yu, G., et al., Plasma optimized Li7La3Zr2O 12 with vertically aligned ion diffusion pathways in composite polymer electrolyte for stable solid-state lithium metal batteries. CHEMICAL ENGINEERING JOURNAL, 2022. 430(1), 132874.

[0085] [5] Liu, C., et al., A flexible, ion-conducting solid electrolyte with vertically bicontinuous transfer channels toward high performance all-solid-state lithium batteries. CHEMICAL ENGINEERING JOURNAL, 2021. 404, 126517.

[0086] The above not involved, applicable to the prior art.

[0087] Although some specific embodiments of the present application have been described in detail by way of examples, it should be understood that the examples are only for the purpose of illustration and not intended to limit the scope of the present application, and those skilled in the art can make various modifications or supplements to the described specific embodiments or replace them with similar ways without deviating from the direction of the present application or exceeding the scope defined by the appended claims. Those skilled in the art should understand that any modification, equivalent replacement, improvement, etc. made according to the technical essence of the present application to the above embodiments shall be included in the protection scope of the present application.

Claims

1. A method for producing a lithium smectite material having a single orientation card house structure, characterized by, The nanosheets of the cardhouse structure of the hectorite are staggered and oriented in a single direction, forming polygonal holes, and the preparation method comprises the following steps: S1, take the hectorite Na x (Mg 3-x ,Li x )Si3O9, 0≤x≤1 and LiCl powder, wherein the mass ratio of hectorite Na x (Mg 3-x ,Li x )Si3O9 and LiCl powder is 1:3~1:5, dispersed and dissolved in water, the pH value is adjusted to 12~13 with LiOH solution, heated and stirred in an oil bath at 110 ℃~120 ℃ for a certain time, and then peeled to obtain a hectorite suspension; S2. The hectorite suspension in step S1 is subjected to multiple centrifugal water washing, and then freeze-dried to obtain hectorite nanosheets; S3. A proper amount of the hectorite nanosheets in step S2 is ultrasonically dispersed in water, a binder is added, and after being fully stirred, it is poured on a pre-frozen polytetrafluoroethylene film, an ice template method is used for bottom-up freezing, and then vacuum freeze-drying is performed to obtain a hectorite material with a single orientation cardhouse structure.

2. The production method according to claim 1, wherein In step S2, after each centrifugation, the supernatant is separated and then dispersed in water for centrifugation again until the pH is adjusted to 7-8.

3. The production method according to claim 1, wherein In step S3, the binder is polyethylene oxide or sodium carboxymethyl cellulose.

4. The production method according to claim 3, wherein The amount of the binder added is 1%-5% of the mass of the hectorite nanosheets.

5. A hectorite material having a single orientation cardhouse structure, characterized in that, The preparation method is prepared by using any one of claims 1-4.

6. The hectorite material of claim 5 wherein, The content of the hectorite nanosheets in the hectorite material is not less than 95%. The preparation method is prepared by using any one of claims 1-4. The content of the hectorite nanosheets in the hectorite material is not less than 95%.

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