All-solid-state rechargeable battery and method for manufacturing electrolyte thereof

Abstract

The present invention relates to a method for manufacturing a full solid-state rechargeable battery and its electrolyte. The full solid-state rechargeable battery according to the present invention comprises a high potential cathode material with the ability to store sodium ions, a metal sodium anode, and a full solid-state electrolyte interposed between the cathode and the anode. The electrolyte comprises an inorganic porous framework, a ferroelectric material modification layer attached to the surface of the porous framework, and an organic polymer filled in the pores of the porous framework and the pores of the modification layer. The full solid-state rechargeable battery according to the present invention with the ferroelectric material modification layer has a lower interfacial impedance and a higher room temperature cycling stability.

Description

Technical Field

[0001] This invention relates to an electrochemical energy storage device and a method for manufacturing the electrolyte thereof, and more particularly to a method for manufacturing an all-solid-state rechargeable battery and its electrolyte thereof. Background Technology

[0002] All-solid-state rechargeable batteries utilize solid-state electrolytes to provide a safer rechargeable battery experience. Among various solid-state electrolyte systems, polymer composite electrolytes have attracted attention due to their ability to maintain close contact with the electrodes. However, current solid-state rechargeable batteries using polymer composite electrolytes are difficult to cycle at room temperature, especially when using metallic sodium as the negative electrode, resulting in severe capacity decay and significantly limiting the application of current polymer all-solid-state rechargeable batteries. Summary of the Invention

[0003] According to one aspect, the present invention provides an all-solid-state rechargeable battery comprising a positive electrode, a negative electrode, and an electrolyte between the positive and negative electrodes. The positive electrode comprises a high-potential positive electrode material capable of storing sodium ions. The negative electrode is metallic sodium. The electrolyte comprises a porous framework of NASICON sodium ion material, a modifying layer attached to the surface of the porous framework, and a polymer filling the pores of the porous framework and the pores of the modifying layer.

[0004] Preferably, the modifying layer is a perovskite-structured ferroelectric material. More preferably, the perovskite-structured ferroelectric material is one of the following: sodium potassium niobate, lead zirconate titanate, or sodium bismuth titanate.

[0005] Preferably, the porous framework comprises Na3Zr2Si2PO12 with a NASICON structure.

[0006] Preferably, the polymer comprises an organic polymer and a sodium salt, wherein the organic polymer is one or a combination of the following: polyethylene oxide, polyvinylidene fluoride, and polyacrylonitrile; and the sodium salt is one or a combination of the following: sodium bis(trifluoromethanesulfonyl)imide, sodium perchlorate, sodium bis(fluoromethanesulfonyl)imide, sodium trifluoromethanesulfonate, and sodium hexafluorophosphate.

[0007] Preferably, the mass ratio of the modification layer to the porous skeleton is 2.4:100.

[0008] Preferably, the porous framework has a porosity of greater than or equal to 18 vol% and less than or equal to 56 vol%.

[0009] According to another aspect, the present invention provides a method for manufacturing an all-solid-state rechargeable battery electrolyte, the method comprising:

[0010] a. Coating the surface of the porous skeleton with a precursor solution of the modification layer material;

[0011] b. Sinter the precursor solution and the porous framework to form a porous crystal modification layer on the surface of the porous framework;

[0012] c. Filling the pores of the porous framework with the modified layer attached with molten polymer material; and

[0013] d. Solidify the molten polymer to form a composite electrolyte, wherein the composite electrolyte comprises a porous framework, a modification layer attached to the surface of the porous framework, and a polymer filling the pores of the porous framework and the pores of the modification layer. Brief description of the attached figures

[0014] Figure 1 This is a flowchart illustrating a method for manufacturing an all-solid-state rechargeable battery according to an embodiment of the present invention.

[0015] Figure 2 The X-ray diffraction pattern of the electrolyte of an all-solid-state rechargeable battery according to an embodiment of the present invention is shown.

[0016] Figure 3 for Figure 2 A magnified view of a portion of the image.

[0017] Figure 4 The images shown are FE-SEM images (a1, a2, a3) and TEM image (a4) of an inorganic porous framework modified with ferroelectric material according to embodiments of the present invention, and FE-SEM images (b1, b2 and b3) of a polymer composite electrolyte modified with ferroelectric material.

[0018] Figure 5 This is an electrochemical resistance diagram of a polymer composite electrolyte with a ferroelectric material modification layer in an all-solid-state rechargeable battery according to an embodiment of the present invention, at room temperature.

[0019] Figure 6 This is a graph showing the discharge capacity of an all-solid-state sodium metal battery with a ferroelectric material modification layer, according to an embodiment of the present invention, as a function of cycle number.

[0020] Figure 7 The discharge capacity of an all-solid-state sodium metal battery without a ferroelectric material modification layer varies with the number of cycles.

[0021] Figure 8 The graph shows the electrochemical resistance test results after long-term cycling at room temperature, illustrating the electrochemical resistance of an all-solid-state sodium metal battery with a ferroelectric material modification layer and an all-solid-state sodium metal battery without a ferroelectric material modification layer, according to embodiments of the present invention.

[0022] Figure 9This is a schematic diagram of the interface resistance test results after long-term cycling at room temperature, showing the interface resistance of an all-solid-state sodium metal battery with a ferroelectric material modification layer and an all-solid-state sodium metal battery without ferroelectric material modification at the interface, according to an embodiment of the present invention. Detailed Implementation

[0023] This invention provides an all-solid-state rechargeable battery, comprising a positive electrode, a negative electrode, and an electrolyte between the positive and negative electrodes. The positive electrode is made of a high-potential positive electrode material capable of storing sodium ions. The negative electrode is metallic sodium. The electrolyte comprises a porous framework of NASICON sodium ion material, a modification layer attached to the surface of the porous framework, and a polymer filling the pores of the porous framework and the pores of the modification layer.

[0024] According to one embodiment, the all-solid-state rechargeable battery of the present invention is an all-solid-state sodium metal battery. The modifying layer of the all-solid-state sodium metal battery is a perovskite-structured ferroelectric material with a high Curie temperature, for example, the modifying layer can be a perovskite-structured ferroelectric material with a Curie temperature higher than 300°C. The perovskite-structured ferroelectric material includes materials such as potassium sodium niobate, lead zirconate titanate, or sodium bismuth titanate. The porous framework can be made of an inorganic electrolyte, which can be, for example, an oxide with a sodium fast ion conductor (NASICON) structure.

[0025] The polymers include organic polymers and sodium salts. The organic polymers may be, for example, one or a combination of polyethylene oxide, polyvinylidene fluoride, and polyacrylonitrile; the sodium salts may be selected from one or a combination of sodium bis(trifluoromethanesulfonyl)imide, sodium perchlorate, sodium bis(fluorosulfonyl)imide, sodium trifluoromethanesulfonate, and sodium hexafluorophosphate.

[0026] In one embodiment, the inorganic electrolyte is Na3Zr2Si2PO12 with a NASICON structure and its dopants; and the polymer is a mixture of polyethylene oxide and sodium bis(trifluoromethanesulfonyl)imide. Preferably, the polymer electrolyte is composed of polyethylene oxide and sodium bis(trifluoromethanesulfonyl)imide in an EO:Na molar ratio of 12:1.

[0027] The aforementioned polymer composite all-solid-state electrolyte with a ferroelectric material modification layer can be prepared according to... Figure 1 The method shown in 100 is used for manufacturing. (As shown) Figure 1 As shown, in step 110 of method 100, a ferroelectric precursor solution is coated onto the surface of an inorganic electrolyte framework of a NASICON structure. The coating step can be achieved by methods such as drop coating, spin coating, or spray coating. In one embodiment, a K0.5Na0.5NbO3 precursor solution can be uniformly coated onto both sides of the Na3Zr2Si2PO12 framework of a NASICON structure in air.

[0028] In step 120, the porous framework coated with the ferroelectric material precursor solution prepared in step 110 is subjected to high-temperature sintering to form a ferroelectric material modification layer on the surface of the porous framework. The porous framework coated with the K0.5Na0.5NbO3 precursor solution in step 110 can be dried in air at 100°C, pyrolyzed at 550°C, and sintered at 750°C to form a firmly bonded porous crystalline layer of K0.5Na0.5NbO3 on the surface of the Na3Zr2Si2PO12 porous framework, thereby obtaining a Na3Zr2Si2PO12 porous framework with a NASICON structure and a K0.5Na0.5NbO3 modification layer. Preferably, the mass ratio of K0.5Na0.5NbO3 to Na3Zr2Si2PO12 in the sintered porous framework is 2.4:100.

[0029] In step 130, the method fills the pores of a porous framework with a modified surface layer, prepared in step 120, with molten polymer filling the pores. In step 140, the method solidifies the molten polymer obtained in step 130 to obtain a porous framework with a ferroelectric material modified layer and polymer filling the pores, thereby obtaining a polymer composite all-solid-state electrolyte with a ferroelectric material modified layer. For example, molten polymer can be filled into the pores of a porous framework with a ferroelectric material modified layer on its surface using a vacuum infiltration method.

[0030] In one embodiment, a K0.5Na0.5NbO3-modified polymer composite electrolyte is prepared by vacuum infiltration into a porous NASICON-structured Na3Zr2Si2PO12 framework with a K0.5Na0.5NbO3 modified layer. Molten polymer is filled and solidified in a vacuum oven at 80–130°C, for example, at 110°C. Preferably, the polymer electrolyte is first filled from one side of the NASICON-structured Na3Zr2Si2PO12 porous framework, and this filling is repeated multiple times until both sides of the porous framework are wetted and filled with molten polymer electrolyte. Then, the porous framework with the modified layer and wetted with molten polymer electrolyte is solidified to obtain a polymer composite electrolyte with a K0.5Na0.5NbO3 modified layer that is fully filled with polymer electrolyte.

[0031] The polymer composite all-solid-state electrolyte with a ferroelectric material modification layer obtained after step 140 is pressed into a thin film, which can then be used as the electrolyte for an all-solid-state sodium metal battery according to an embodiment of the present invention. For example, the polymer composite electrolyte with a K0.5Na0.5NbO3 modification layer can be pressed into a dense thin film with a thickness of 300 micrometers to 600 micrometers, and the positive and negative electrode sheets can be respectively pressed tightly onto the dense thin film electrolyte to produce an all-solid-state rechargeable battery according to the present invention.

[0032] The NASICON-structured inorganic electrolyte framework used in step 110 can be prepared, for example, by a sol-gel method. In one embodiment, the NASICON-structured Na3Zr2Si2PO12 framework can be prepared in an air atmosphere by a sol-gel method.

[0033] Specifically, a clear sol solution can be prepared by dissolving zirconium butoxide solution, tetraethyl butyrate, tris(methylene)triphosphonic acid solution, and sodium acetate in ethanol solvent according to a stoichiometric ratio and mixing them uniformly. An excess of 10% sodium acetate can be added to the sol solution to compensate for sodium ion loss during subsequent heat treatment. Then, polyvinylpyrrolidone and ethanolamine, two chemical stabilizers, are mixed in a 1:1 molar ratio and added to the sol solution to control the porosity of the final porous framework. The sol solution is heated at 50°C for 4 hours to transform it into a wet gel. The wet gel is then heated at 200°C for 24 hours to completely transform it into a dry gel powder, which is then pressed into a dense dry gel sheet. The dry gel sheet is sintered at a high temperature (preferably 1025°C) within the range of 1025°C to 1050°C for 8 hours, controlled at a heating rate of 5°C / min, to achieve complete crystallization and form a porous NASICON-structured inorganic electrolyte framework. The porosity of the final porous framework can be controlled by adjusting the molar ratio of the mixed chemical stabilizer to Na3Zr2Si2PO12. For example, when the ratio of stabilizer to Na3Zr2Si2PO12 is 1:1, the porosity of the porous framework is 18 vol% (volume percentage). When the ratio of stabilizer to Na3Zr2Si2PO12 is 2:1, the porosity of the porous framework is 56 vol%. According to a preferred embodiment, the NASICON-structured inorganic electrolyte porous framework of the present invention has a porosity greater than or equal to 18 vol% and less than or equal to 56 vol%.

[0034] The ferroelectric material precursor solution used in step 110 can also be prepared by the sol-gel method. In one embodiment, the ferroelectric material precursor solution of K0.5Na0.5NbO3 can be prepared by the sol-gel method under dry nitrogen and at room temperature.

[0035] Specifically, potassium acetate, sodium acetate, and niobium ethoxide can be uniformly mixed and dissolved in 2-methoxyethanol solvent at a K:Na:Nb molar ratio of 0.6:0.6:1.05. Then, a mixture of chemical stabilizers—monoethanolamine, ethanolamine, and ethylenediaminetetraacetic acid—is added to the solution at a molar ratio of 0.84:1.26:0.25:1 to K0.5Na0.5NbO3, and the solution concentration is adjusted to 0.3 mol / L. Adding small amounts of potassium and sodium raw materials can compensate for the loss of these two elements during subsequent heat treatment. Furthermore, the addition of chemical stabilizers such as monoethanolamine, ethanolamine, and ethylenediaminetetraacetic acid can effectively reduce further losses of potassium and sodium during subsequent heat treatment.

[0036] The polymer electrolyte used in step 130 can be prepared in air. In one embodiment, polyethylene oxide (Mv 600,000) and sodium bis(trifluoromethanesulfonyl)imide are uniformly dissolved in ethanol solvent at an EO:Na molar ratio of 12:1 under heating conditions at 45°C. Subsequently, the above solution is coated onto a glass substrate and heated at 60°C for 24 hours to completely dry it, thereby obtaining a polymer electrolyte, such as the polyethylene oxide and sodium bis(trifluoromethanesulfonyl)imide polymer electrolyte obtained in this exemplary embodiment.

[0037] As described above, the polymer composite all-solid electrolyte with a ferroelectric material modification layer obtained after step 140 can be pressed into a thin film to serve as the electrolyte for the all-solid rechargeable battery according to the present invention. This all-solid sodium metal battery can be manufactured by cold-pressing and encapsulating the positive electrode, the polymer composite electrolyte film with a ferroelectric material modification layer, and the sodium metal negative electrode at room temperature to create the all-solid rechargeable battery according to the present invention.

[0038] In one embodiment, the positive electrode sheet, the ferroelectric modified polymer composite electrolyte film, and the sodium metal negative electrode sheet can be cold-pressed and encapsulated at room temperature in a glove box filled with argon gas into a battery case such as a coin cell, thereby obtaining an all-solid-state rechargeable battery with a positive electrode | ferroelectric modified layer - polymer composite electrolyte - ferroelectric modified layer | sodium metal negative electrode structure.

[0039] In one embodiment, the positive electrode comprises a mixture of a positive electrode active material, a conductive carbon material, and a polymer binder. The positive electrode active material can be a polyanionic, Prussian blue, or layered oxide material. Preferably, the positive electrode active material is a polyanionic Na3V2(PO4)3 or its dopants. For example, the positive electrode active material can be Na3V1.85Fe0.15(PO4)3.

[0040] In one embodiment, the positive electrode can be manufactured by the following method:

[0041] First, the positive electrode active material powder, conductive carbon black Super-P, and binder polyvinylidene fluoride were mixed and dissolved in 1-methyl-2-pyrrolidone solvent at a mass ratio of 7:2:1 to prepare the positive electrode material slurry. The positive electrode active material was Na3V1.85Fe0.15(PO4)3.

[0042] Subsequently, the above-mentioned positive electrode material slurry is uniformly coated onto the aluminum foil current collector and dried in a vacuum oven at 120°C for 8 hours to prepare the positive electrode of the all-solid-state rechargeable battery according to the present invention.

[0043] In one embodiment, the all-solid-state rechargeable battery (positive electrode | ferroelectric-modified polymer composite electrolyte | negative electrode) according to the present invention has a Na3V1.85Fe0.15(PO4)3|K0.5Na0.5NbO3-Na3Zr2Si2PO12-K0.5Na0.5NbO3|Na structure. The electrolyte with the ferroelectric modification layer is bonded together from a polymer electrolyte.

[0044] The all-solid-state rechargeable battery according to the present invention has effectively reduced battery interface impedance and high room temperature cycling stability. These beneficial effects are detailed in the following examples.

[0045] Example 1

[0046] Example 1 aims to test and present the crystal structure, microstructure, and electrochemical impedance spectroscopy of the electrolyte of the all-solid-state rechargeable battery according to the present invention. In Example 1, the experimental method may include testing the crystal structure of the porous framework of the ferroelectric-modified inorganic electrolyte and the ferroelectric-modified polymer composite electrolyte using an X-ray diffractometer (XRD). The X-ray diffractometer may be, for example, a Shimadzu XRD-6000 X-ray diffractometer.

[0047] The experimental methods may further include using field emission scanning electron microscopy (FE-SEM) and transmission electron microscopy (TEM) to test and analyze the microstructure and elemental distribution of the electrolyte of the all-solid-state rechargeable battery according to the present invention. The field emission scanning electron microscope may be, for example, the Hitachi S-4300. The transmission electron microscope may be, for example, the Tecnai from FEI. TM G2 F30 transmission electron microscope.

[0048] The experimental method may also include testing the electrochemical resistance spectrum of the electrolyte of the all-solid-state rechargeable battery according to the present invention using an impedance analyzer. The impedance analyzer may be, for example, a Solartron (EIS) 1260-1287 impedance analyzer.

[0049] Because the prepared electrolyte is highly flexible, aluminum foil can be directly attached as electrodes to both surfaces of the electrolyte during testing. In one example, the test voltage was 10mV and the frequency was 1MHz to 1Hz.

[0050] The ionic conductivity σ of the electrolyte can be calculated using the following formula (1).

[0051] σ=t / (RA) (1)

[0052] Where t is the thickness of the sample under test, A is the test area, and R is the total resistance measured from the electrochemical resistance spectrum.

[0053] Figure 2 The experimentally measured X-ray diffraction pattern is shown. For example... Figure 2 As shown, the inorganic electrolyte framework with the ferroelectric material modification layer only contains sodium fast ion conductors (NASICON) and perovskite structures, indicating that the ferroelectric material modification layer on the surface of the inorganic electrolyte framework does not affect the crystal structure of the inorganic electrolyte framework. Furthermore, the main peaks in the XRD results of the ferroelectric material-modified polymer composite electrolyte are consistent with the structures of polyethylene oxide crystals (PDF 00-067-1538), perovskites (PDF04-007-9793), and sodium fast ion conductors (PDF 01-076-1449), and no obvious impurity phases were observed. This is consistent with the structure of... Figure 2 Enlarged view of part of frame A in the middle Figure 3 This can be seen more clearly in the middle.

[0054] Figure 4 The images show experimentally measured FE-SEM and TEM images (a1, a2, a3, and a4) of the inorganic porous framework with ferroelectric material modification layers, and FE-SEM images (b1, b2, and b3) of the polymer composite electrolyte with ferroelectric material modification layers. Specifically, a1 shows the surface morphology of the inorganic porous framework with ferroelectric material modification layers at low magnification, where the ferroelectric material modification layer presents porous island-like regions 410; a2 shows the distribution of Nb element 420 on the surface of the inorganic porous framework with ferroelectric material modification layers; a3 shows the distribution of Si element 430 on the surface of the inorganic porous framework with ferroelectric material modification layers; a4 shows the microstructure of the inorganic porous framework with ferroelectric material modification layers at high magnification; b1 shows the low-magnification cross-sectional morphology of the polymer composite electrolyte with ferroelectric material modification layers; b2 shows the high-magnification surface morphology of the polymer composite electrolyte with ferroelectric material modification layers; and b3 shows the high-magnification cross-sectional morphology of the polymer composite electrolyte with ferroelectric material modification layers.

[0055] exist Figure 4As shown in a1-a3, the ferroelectric material modification layer forms a porous island-like region 410 on the surface of the Na3Zr2Si2PO12 porous framework, and the pores of the inorganic porous framework with the ferroelectric material modification layer are at the nanoscale (see a4); while as shown in b1-b3, in the finally obtained polymer composite electrolyte with a ferroelectric material modification layer and high flexibility, the polymer fully fills the pores of the porous framework and forms a coating layer on the outer surface of the inorganic ceramic particles.

[0056] Figure 5 This is a graph showing the electrochemical resistance of a polymer composite electrolyte with a ferroelectric material modification layer at room temperature, as experimentally measured. Figure 5 As shown, the room-temperature electrochemical resistance spectrum of the polymer composite electrolyte with a ferroelectric material modification layer exhibits a typical Nyquist curve. The intercept of the slanted line on the real axis in the resistance spectrum represents the total resistance of the electrolyte. According to... Figure 5 The intercept can be calculated using formula (1). At room temperature, the total ionic conductivity of the ferroelectric modified polymer composite electrolyte is relatively high, approximately 7.0 × 10⁻⁵ Siemens / cm (S / cm).

[0057] Example 2

[0058] Example 2 aims to test and demonstrate the constant current long-cycle charge-discharge performance of an all-solid-state sodium metal battery electrolyte with a ferroelectric material modification layer manufactured according to the method of the present invention.

[0059] In Example 2, the experimental method included using the LAND battery testing system to conduct a constant current long-cycle charge-discharge comparison test on an all-solid-state sodium metal battery with an interface ferroelectric material modification layer and an all-solid-state sodium metal battery without ferroelectric material modification at room temperature, wherein the test voltage was 2.5 to 4.0 volts (V) and the test current was 11.8 mA / g.

[0060] Figure 6 This is a graph showing the change in discharge capacity of an all-solid-state sodium metal battery with a ferroelectric material modification layer as a function of cycle number, as measured experimentally. Figure 7 This is a graph showing the discharge capacity of an all-solid-state sodium metal battery without a ferroelectric material modification layer as a function of cycle number, as experimentally measured. Figure 6 As shown, at room temperature, the all-solid-state sodium metal battery with a ferroelectric material modification layer exhibits an initial discharge capacity of 79.9 mAh / g. After 170 charge-discharge cycles, the battery demonstrates a capacity retention of up to 71.7%. In comparison, Figure 7 The all-solid-state sodium metal battery without a ferroelectric material modification layer exhibits a low initial discharge capacity of only 57 mAh / g at room temperature. Furthermore, the battery experiences rapid capacity decay during cycling. After 170 charge-discharge cycles, its capacity retention is only 13.0%.

[0061] Example 3

[0062] Example 3 aims to test the electrochemical impedance spectroscopy and interfacial resistance of an all-solid-state sodium metal battery with a ferroelectric material modification layer, manufactured according to the method of the present invention, after long-term charge-discharge cycling. In Example 3, the experimental method includes testing the electrochemical impedance spectroscopy of the all-solid-state sodium metal battery with and without the ferroelectric material modification layer at room temperature using a resistance analyzer after long-term charge-discharge cycling. The impedance analyzer is, for example, a Solartron 1260-1287 model impedance analyzer. The test voltage can be set to 10 millivolts (mV), and the frequency to be from 1 MHz to 1 Hz.

[0063] Figure 8 The graph shows the electrochemical resistance values ​​after long-term cycling at room temperature, obtained experimentally. It illustrates the electrochemical resistance values ​​of an all-solid-state sodium metal battery with a ferroelectric material modification layer and an all-solid-state sodium metal battery without a ferroelectric material modification layer at the interface. Figure 8 As shown, the resistivity spectrum X of an all-solid-state sodium metal battery without an interfacial ferroelectric material modification layer and the resistivity spectrum Y of an all-solid-state sodium metal battery with an interfacial ferroelectric material modification layer both contain two semicircles (one high-frequency semicircle and one mid-frequency semicircle) and a low-frequency straight line. The high-frequency semicircle represents the positive electrode-electrolyte interface resistance, and the mid-frequency semicircle represents the negative electrode-electrolyte interface resistance. Figure 8 It can be seen that the interfacial resistance of the all-solid-state sodium metal battery with a ferroelectric material modification layer is significantly lower than that of the all-solid-state sodium metal battery without a ferroelectric material modification layer. Experiments show that the electrolyte with a ferroelectric modification layer can effectively improve the ion conduction at the electrode-electrolyte interface in the all-solid-state sodium metal battery, thereby improving the battery's cycle stability.

[0064] Figure 9 This is a schematic diagram showing the interfacial resistance values ​​after long-term cycling at room temperature, as measured experimentally. It illustrates the interfacial resistance values ​​of an all-solid-state sodium metal battery with ferroelectric material modification and an all-solid-state sodium metal battery without ferroelectric material modification. Figure 9 As shown, at room temperature, the positive electrode-electrolyte interface resistance (e.g., approximately 2 kΩ as shown in 820) and negative electrode-electrolyte interface resistance (e.g., approximately 33.8 kΩ as shown in 840) of an all-solid-state sodium metal battery with a ferroelectric material modification layer are significantly lower than those of the positive electrode-electrolyte interface resistance (e.g., approximately 9.3 kΩ as shown in 810) and negative electrode-electrolyte interface resistance (e.g., approximately 205 kΩ as shown in 830) of an all-solid-state sodium metal battery without a ferroelectric material modification layer. Experiments demonstrate that the ferroelectric material modification layer can effectively improve ion conduction at the electrode-electrolyte interface and enhance the cycle stability of the battery.

[0065] As can be understood from the above experimental examples, the polymer composite electrolyte with ferroelectric material modification layer according to the present invention has a high room temperature ionic conductivity (e.g., about 7.0 × 10⁻⁵ Siemens / cm); ferroelectric material modification can effectively reduce the interfacial resistance between the positive electrode and the electrolyte and the negative electrode and the electrolyte in all-solid-state batteries. All-solid-state sodium metal batteries with ferroelectric material modification layer operate stably at room temperature. For example, the initial discharge capacity under constant current charge-discharge at room temperature (current about 11.8 mA / g) is about 79.9 mAh / g, and after 170 cycles, its capacity retention is as high as about 71.7%.

[0066] The embodiments, specific examples, and application scenarios of the present invention have been presented for illustrative and descriptive purposes, but are not intended to be exhaustive or limiting. Various modifications and variations will be readily apparent to those skilled in the art. The examples and embodiments were chosen and described to explain the principles and practical applications of the technical solution of the present invention, and to enable those skilled in the art to understand the various embodiments of the present invention, which may include various modifications suitable for the intended specific purpose.

[0067] Therefore, although illustrative exemplary embodiments have been described herein with reference to the accompanying drawings, it should be understood that the description is not restrictive and that those skilled in the art can make various other changes and modifications thereto without departing from the scope of this disclosure or the inventive concept and implementation.

Claims

1. An all-solid-state rechargeable battery, characterized in that, The all-solid-state rechargeable battery includes: Positive electrode, wherein the positive electrode comprises a high-potential positive electrode material having the ability to store sodium ions; The negative electrode is metallic sodium; and The electrolyte located between the positive and negative electrodes comprises a porous framework of NASICON sodium ion material, a modification layer attached to the surface of the porous framework, and a polymer filling the pores of the porous framework and the modification layer. The modified layer is a perovskite-structured ferroelectric material. The mass ratio of the modified layer to the porous skeleton is 2.4:

100. The polymer comprises an organic polymer and a sodium salt, wherein the organic polymer is one or a combination of the following: polyethylene oxide, polyvinylidene fluoride, and polyacrylonitrile; and the sodium salt is one or a combination of the following: sodium bis(trifluoromethanesulfonyl)imide, sodium perchlorate, sodium bis(trifluoromethanesulfonyl)imide, sodium trifluoromethanesulfonate, and sodium hexafluorophosphate.

2. The all-solid-state rechargeable battery according to claim 1, characterized in that, The perovskite-structured ferroelectric material is one of the following materials: potassium sodium niobate, lead zirconate titanate, or sodium bismuth titanate.

3. The all-solid-state rechargeable battery according to claim 1, characterized in that, The porous framework comprises Na3Zr2Si2PO12 with a NASICON structure.

4. The all-solid-state rechargeable battery according to claim 1, characterized in that, The porous framework has a porosity of greater than or equal to 18 vol% and less than or equal to 56 vol%.

5. A method for manufacturing an all-solid-state rechargeable battery electrolyte, characterized in that, The method includes the following steps: a. A precursor solution of a modification layer material is coated onto the surface of a porous framework, wherein the modification layer is a perovskite-structured ferroelectric material, and the mass ratio of the modification layer to the porous framework is 2.4:100; b. Sinter the precursor solution and the porous framework to form a porous crystal modification layer on the surface of the porous framework; c. Filling the pores of the porous framework with the modified layer attached with molten polymer material; and d. Solidifying the molten polymer to form a composite electrolyte, wherein the composite electrolyte comprises a porous framework, a modification layer attached to the surface of the porous framework, and a polymer filling the pores of the porous framework and the pores of the modification layer, wherein the polymer comprises an organic polymer and a sodium salt, wherein the organic polymer is one or a combination of the following: polyethylene oxide, polyvinylidene fluoride, polyacrylonitrile; and the sodium salt is one or a combination of the following: sodium bis(trifluoromethanesulfonyl)imide, sodium perchlorate, sodium bis(trifluoromethanesulfonyl)imide, sodium trifluoromethanesulfonate, and sodium hexafluorophosphate.

6. The method according to claim 5, characterized in that, The perovskite-structured ferroelectric material is one of the following materials: potassium sodium niobate, lead zirconate titanate, or sodium bismuth titanate.

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