Positive electrode material and secondary ion battery containing said material

Abstract

To provide a secondary ion battery including a low-cost and high-performance electrode material.SOLUTION: A positive electrode material comprises at least a first active material and a carrier. The first active material is selected from an alkali metal halogen salt or alkali metal sulfite, an alkali-earth metal halogen salt or alkali-earth metal sulfite, an aluminum halide, or zinc halide or zinc sulfite. The carrier has a low-dimension structure. The carrier is selected from a template and / or a second active material. A method for manufacturing a positive electrode material of the invention is easy to operate, and low in production cost. The invention further provides a secondary ion battery including the positive electrode material. The first active material of the positive electrode material hereof has a relatively low molecular weight and a relatively high redox potential and thus, the secondary ion battery of the invention has a relatively high specific capacity and voltage. In addition, the secondary ion battery of the invention is high in safety and offers a wide application prospect.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to the field of battery technology, and in particular to cathode materials and secondary ion batteries containing such materials. [Background technology]

[0002] Existing lithium battery developments are meeting a wide range of needs, from electronic products, power tools, and automobiles to grid-level energy storage. Lithium-ion battery systems based on cathode materials such as lithium iron phosphate and ternary materials currently meet the majority of application scenarios. However, the abundance of lithium element and the cost of materials significantly limit the development of lithium batteries. Therefore, there is an urgent need to develop high-performance, low-cost electrode materials to meet the ever-increasing energy demand.

[0003] To achieve high capacity and high voltage, cathode materials require low molecular weight and high redox potential. Metal halide salts and sulfites combine these two advantages while also being low cost, making them ideal cathode materials. Taking lithium chloride and potassium sulfite as examples, their theoretical energy densities are 2780 and 1320 Wh / kg, respectively, both of which are significantly higher than commercially available cathode materials such as lithium cobalt oxide and lithium manganese oxide. However, their cubic crystal structure and large deionization energy barrier make it difficult to achieve reversible charge / discharge. The present invention achieves reversible charge / discharge by changing the dimensionality or crystalline morphology of the material to reduce the deionization energy barrier. Summary of the Invention

[0004] To solve the above problems, the present invention provides a positive electrode material and a secondary battery containing the material. The present invention creates a positive electrode material containing a halide salt or sulfite salt, which has high specific energy and high voltage, by reducing the dimension of the positive electrode material or changing its crystalline form. The present invention also constructs a secondary ion battery system based on such a material, and the secondary ion battery of the present invention has high specific energy and long cycle characteristics.

[0005] The object of the present invention is achieved by the following technical solutions.

[0006] The present invention provides a positive electrode material including a positive electrode active material including at least a first active material and a support, the first active material is selected from alkali metal halide or sulfite, alkaline earth metal halide or sulfite, aluminum halide, or zinc halide or zinc sulfite; The support has a low-dimensional structure, and the support is selected from a template and / or a second active material.

[0007] According to the present invention, in the positive electrode material, the first active material can be uniformly distributed on the support or within the low-dimensional structure of the support.

[0008] According to the present invention, the low-dimensional structure includes at least one of a zero-dimensional, one-dimensional, two-dimensional, three-dimensional, and multi-stage structure.

[0009] According to the present invention, the low dimensional structure may comprise a crystalline structure or an amorphous structure.

[0010] In the present invention, the low-dimensional structure refers to a structure in which the size of the minimum structural unit is 1 μm or less in at least one dimension, for example, 1 to 100 nm.

[0011] According to the present invention, the template and the second active material have a zero-dimensional, one-dimensional, two-dimensional, three-dimensional, or multi-stage structure. The multi-stage structure described in the present invention refers to a structure that includes at least two of the zero-dimensional, one-dimensional, two-dimensional, and three-dimensional structures.

[0012] Illustratively, the template of the zero-dimensional structure is at least one selected from, for example, quantum dots, nanoparticles, etc., but is not limited thereto.

[0013] Exemplarily, the template having a one-dimensional structure is at least one selected from, for example, a nanowire, a nanotube, a nanoribbon, a nanopore, and the like, but is not limited thereto.

[0014] Exemplarily, the two-dimensional structure template is at least one nanosheet selected from, but not limited to, graphene, MXene, boron nitride, transition metal chalcogenide, metal organic framework compound, covalent organic framework compound, layered metal double hydroxide, transition metal oxide, metal nanosheet, and black phosphorus.

[0015] For example, the multi-stage template may have a low-dimensional structure itself or may be made of a material having a low-dimensional structure, such as at least one selected from the group consisting of activated carbon, metal organic frameworks, covalent organic frameworks, alumina templates, metal foams, and micro-nanostructures fabricated by microfabrication, but is not limited thereto.

[0016] Illustratively, the three-dimensional structure template can be fabricated from any three-dimensional structure material or at least one of the zero-dimensional, one-dimensional, and two-dimensional structure templates, for example, by stacking, assembly, coating, or solution self-assembly.

[0017] In addition, the present invention reduces the deionization energy barrier by reducing the dimensionality of the first active material or destroying or changing its crystalline form via the carrier.

[0018] According to the present invention, at least a portion of the halide or sulfite in the positive electrode material exhibits a low-dimensional structure.

[0019] According to the invention, the support is preferably selected from templates, optionally with or without a second active material.

[0020] According to the present invention, the second active material is any one selected from electrode materials known in the art, preferably at least one of layered oxides, Prussian blue analogues, polyanionic compounds, conductive polymers, and organic materials, such as LiMn2O4, ternary materials, and sodium iron manganese cuprate (Na n Cu x Fe y Mn z O2), sodium iron manganese nickelate (Na n Ni x Fe y Mn z O2), Prussian blue sodium / potassium (Na / K x PR(CN)6, P, R is Fe, Co, Ni, Mn, etc.), K x MnO2, LiFePO4, Sodium iron phosphate (Na x Fe y (PO4) n ), sodium ferrous sulfate (Na x Fe y (SO4) n ), polypyrrole, polyaniline, and other materials.

[0021] Preferably, the second active material is a nanoparticle, and the nanoparticle may be a microsphere. The microsphere in the present invention refers to a spherical structure formed by combining multiple nanoparticles and having a size on the micrometer level. For example, the diameter of the microsphere is 0.1 μm or more, e.g., 0.1 to 100 μm.

[0022] The present invention does not specifically limit the form of the template, and the form of the template may be selected from any form such as a dispersion, a foam, an assembly film, a powder, a slurry, or a gel, for example, a foam.

[0023] According to the present invention, the alkali metal halide salt is at least one selected from lithium chloride, lithium bromide, lithium iodide, sodium chloride, sodium bromide, sodium iodide, potassium chloride, potassium bromide, and potassium iodide.

[0024] According to the present invention, the alkali metal sulfite is at least one selected from lithium sulfite, sodium sulfite, and potassium sulfite.

[0025] According to the present invention, the alkaline earth metal halide salt is at least one selected from magnesium chloride, magnesium bromide, magnesium iodide, calcium chloride, calcium bromide, and calcium iodide.

[0026] According to the invention, the alkaline earth metal sulfite is selected from magnesium sulfite and / or calcium sulfite.

[0027] According to the present invention, the aluminum halide is at least one selected from aluminum chloride, aluminum bromide, and aluminum iodide.

[0028] According to the present invention, the zinc halide is at least one selected from zinc chloride, zinc bromide, zinc iodide, and the like.

[0029] According to the present invention, in the positive electrode material, the first active material accounts for 1 to 99% of the total mass of the positive electrode material, preferably 5 to 90%, for example, 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, or 90%.

[0030] According to the present invention, in the positive electrode material, the support occupies 0.1 to 99% of the total mass of the positive electrode material, preferably 1 to 95%, more preferably 5 to 90%, for example, 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, or 90%.

[0031] The present invention does not specifically limit the mass ratio of the template to the second active material in the support, and the support can be obtained by selecting a mass ratio known in the art, as long as the above-mentioned positive electrode material can be obtained. For example, in the carrier, the mass ratio of the template to the second active material is (0.1 to 1):(0 to 10), for example, (0.1 to 1):0.1, (0.1 to 1):0.2, (0.1 to 1):0.3, (0.1 to 1):0.4, (0.1 to 1):0.5, (0.1 to 1):0.6, (0.1 to 1):0.7, (0.1 to 1):0.8, (0.1 to 1):0.9, (0.1 to 1):1, (0.1 to 1):2, (0.1 to 1):3, (0.1 to 1):4, (0.1 to 1):5, (0.1 to 1):6, (0.1 to 1):7, (0.1 to 1):8, (0.1 to 1):8, or (0.1 to 1):10.

[0032] According to the present invention, the first active material has a low-dimensional structure or a micro-nanocrystalline particle structure.

[0033] According to the present invention, when the first active material is distributed within the low-dimensional structure, the first active material exhibits a low-dimensional structure, and the low-dimensional structure has the meaning described above.

[0034] Illustratively, the first active material in the positive electrode material is selected from KI and exhibits a two-dimensional crystal structure.

[0035] According to the present invention, when the first active material is distributed on the carrier, the first active material is composed of micro-nanocrystalline particles. In the present invention, the mass content of the micro-nanocrystalline particles in the first active material is not specifically limited, and is, for example, 0 to 10%, for example, 0 to 5%, or further, for example, 0 to 1%.

[0036] Preferably, the micro-nanocrystalline particles have a particle size in the range of 0.1 to 5 μm, preferably 0.5 to 5 μm, for example 1 μm.

[0037] According to the present invention, the cathode material may also be processed by methods known in the art, such as carbonization, elution, etc., to obtain a substantially template-free cathode material.

[0038] According to an exemplary technical solution of the present invention, the positive electrode material includes a first active material and a carrier, the carrier contains a second active material, and the first active material and the second active material are combined to form the positive electrode material, for example, the first active material is filled into the pores of nanoparticles or microspheres of the second active material, and combined to form the positive electrode material.

[0039] The present invention further provides a method for preparing the cathode material, which comprises mixing the carrier and a first active material, and then obtaining the cathode material according to the present invention after compounding, wherein the carrier and the first active material have the meanings described above.

[0040] Preferably, when the support is selected from a template, optionally with or without a second active material, the mixing comprises: The template and the first active material are mixed first, and then the second active material is added; or The template and the second active material are mixed first, and then the first active material is added thereto; or The second active material and the first active material are mixed together, and then a template is added.

[0041] According to the present invention, the manufacturing method further comprises that after compounding, the cathode material is optionally treated by any of the methods such as high temperature carbonization or elution.

[0042] According to the present invention, in the production method, the carrier may be pretreated first to obtain a required form, and preferably, after the carrier is pretreated, any form such as a dispersion, a foam, an assembly film, a powder, a slurry, etc. is obtained, for example, a foam.

[0043] According to the present invention, the high-temperature carbonization specifically includes carbonizing the positive electrode material at a high temperature of 400 to 1000° C., for example, at a high temperature of 700° C. Exemplarily, the carbonization time is 1 to 100 hours, for example, 4 hours.

[0044] According to an exemplary technical solution of the present invention, the method for producing the positive electrode material includes: (1) ultrasonically dispersing a carrier to obtain a mixture, and freeze-drying the mixture to obtain a foam; (2) adding dropwise a solution containing a first active material to the foam of step (1) and allowing it to dry naturally to obtain a precursor of a positive electrode material; (3) the precursor of the positive electrode material obtained in step (2) is subjected to high-temperature treatment, and then the positive electrode material is obtained.

[0045] According to the present invention, the carrier and the first active material are defined as above.

[0046] According to the present invention, the mass concentration of the carrier in the mixed solution is 1 to 100 mg / g, for example, 10 mg / g.

[0047] Preferably, step (2) optionally further comprises slicing the foam. The slicing process in the present invention refers to slicing the compressed foam into any size to meet the battery processing requirements. For example, the size may be round or square.

[0048] Preferably, the solution containing the first active material includes the first active material and a solvent. Preferably, the solvent is selected from volatile solvents such as methanol, ethanol, acetone, and dichloromethane. Exemplarily, the solution containing the first active material is selected from a potassium iodide methanol solution.

[0049] Preferably, in the solution containing the first active material, the mass concentration of the first active material is 0.01 to 10 g / mL, for example, 0.1 g / mL.

[0050] According to the present invention, the elution specifically comprises adding the cathode material to an eluent to remove all or part of the template.

[0051] Preferably, the eluent is selected from an organic solvent, a concentrated acid, or a concentrated base. Illustratively, the concentrated acid is selected from concentrated hydrochloric acid.

[0052] According to an exemplary technical solution of the present invention, the method for producing the positive electrode material includes: (1) ultrasonically dispersing a first active material and a carrier in a solvent to obtain a mixed solution, and then drying the mixed solution to obtain a solid material; (2) adding the solid material of step (1) to an eluent to remove all or a portion of the template and obtain an intermediate; (3) drying the intermediate of step (2) and then obtaining the positive electrode material.

[0053] Preferably, the drying can be carried out by any method known in the art, for example, by vacuum drying at 90° C. for 6 hours.

[0054] The present invention further provides a modified cathode material obtained by eluting the template in the cathode material according to the present invention, wherein the template and elution have the meanings as defined above.

[0055] According to the present invention, the modified cathode material is substantially free of the template.

[0056] The present invention further provides an application of the above-mentioned positive electrode material in a secondary ion battery, which is preferably at least one selected from organic secondary ion batteries, aqueous secondary ion batteries, organic / aqueous mixed secondary ion batteries, gel batteries, quasi-solid batteries, and all-solid batteries.

[0057] According to the present invention, the secondary ion battery further comprises an anode material selected from metal or carbon-based anode materials.

[0058] According to the present invention, the metal is at least one selected from lithium, sodium, potassium, magnesium, aluminum, and zinc.

[0059] According to the present invention, the carbon-based negative electrode material may be a commercially available or self-synthesized material, and may be at least one selected from activated carbon, graphite, hard carbon, soft carbon, etc.

[0060] According to the present invention, the secondary ion battery further comprises an electrolytic solution, a gel electrolyte, or a solid electrolyte.

[0061] According to the present invention, the electrolyte is selected from an aqueous electrolyte, an organic electrolyte, or an aqueous / organic mixed electrolyte.

[0062] According to the present invention, the electrolytic solution contains an electrolyte and a solvent.

[0063] According to the present invention, in the electrolytic solution, the electrolyte is at least one selected from the group consisting of lithium salts, sodium salts, potassium salts, calcium salts, magnesium salts, aluminum salts, and zinc salts, but is not limited thereto.

[0064] Exemplarily, the lithium salt is at least one selected from lithium sulfate, lithium nitrate, lithium acetate, lithium perchlorate, lithium chloride, lithium bisfluorosulfonimide (LiFSI), lithium trifluoromethanesulfonate, lithium bistrifluoromethanesulfonimide (LiTFSI), and lithium bis(pentafluoroethylsulfonyl)imide.

[0065] Illustratively, the sodium salt is at least one selected from sodium perchlorate, sodium acetate, sodium nitrate, sodium chloride, sodium sulfate, sodium bisfluorosulfonimide (NaFSI), sodium trifluoromethanesulfonate, sodium bistrifluoromethanesulfonimide, and sodium bis(pentafluoroethylsulfonyl)imide.

[0066] Illustratively, the potassium salt is at least one selected from potassium nitrate, potassium acetate, potassium sulfate, potassium chloride, potassium bisfluorosulfonimide (KFSI), potassium trifluoromethanesulfonate, potassium bistrifluoromethanesulfonimide, and potassium bis(pentafluoroethylsulfonyl)imide.

[0067] Illustratively, the magnesium salt is at least one selected from magnesium trifluoromethanesulfonate, magnesium sulfate, magnesium chloride, magnesium acetate, and magnesium bistrifluoromethanesulfonimide.

[0068] Illustratively, the zinc salt is at least one selected from zinc trifluoromethanesulfonate, zinc sulfate, zinc chloride, zinc acetate, and zinc bistrifluoromethanesulfonimide.

[0069] According to the present invention, the concentration of the electrolyte in the electrolytic solution is 0.01 to 100 mol / L, for example, 0.01 to 20 mol / L, 1 to 10 mol / L, 1 to 100 mol / L, 5 to 70 mol / L, 10 mol / L, 30 mol / L, 50 mol / L, 70 mol / L, or 100 mol / L.

[0070] According to the present invention, the solvent is at least one selected from water or organic solvents such as esters, ethers, and nitriles, but is not limited thereto. Exemplarily, the esters are at least one selected from propylene carbonate, diethyl carbonate, and ethylene carbonate, but are not limited thereto. Exemplarily, the ethers are selected from ethylene glycol dimethyl ether (DME). Exemplarily, the nitriles are selected from acetonitrile.

[0071] Illustratively, the aqueous electrolyte is K(FSI) 0.55 (OTf) 0.45 It is a 0.9H2O aqueous solution.

[0072] Illustratively, the organic electrolyte is selected from KFSI propylene carbonate solution.

[0073] According to the present invention, the gel electrolyte comprises a first polymer body material and an electrolyte selected from the electrolytes described above.

[0074] Preferably, the first polymer body material is at least one selected from polyvinyl alcohol (PVA), polyacrylic acid, polyacrylamide, sodium polyacrylate, polyethylene oxide, polypropylene carbonate, polyether ether ketone, ethylene glycol acrylonitrile block copolymer, and poly(vinylidene fluoride-hexafluoropropene), etc.

[0075] According to the present invention, the gel electrolyte further comprises a deep eutectic gel polymer electrolyte. Preferably, the deep eutectic gel polymer electrolyte comprises a deep eutectic solvent and a deep eutectic electrolyte. Furthermore, the deep eutectic solvent comprises a solid hydrogen bond acceptor (such as a quaternary ammonium salt) and a solid hydrogen bond donor (such as urea and an amide), and the deep eutectic electrolyte comprises at least one of the above electrolyte and polymer.

[0076] According to the present invention, the solid electrolyte is at least one selected from polymer electrolytes, inorganic solid electrolytes, and composite solid electrolytes.

[0077] According to the present invention, the polymer electrolyte comprises a second polymer body and an electrolyte.

[0078] Preferably, said second polymer body comprises at least one of the first polymer body, polyethylene oxide, polypropylene oxide, and the like.

[0079] According to the present invention, the inorganic solid electrolyte is at least one selected from a sulfide solid electrolyte and an oxide solid electrolyte.

[0080] Preferably, the sulfide solid electrolyte includes sulfur-lithium ultrafast ion conductor, sulfur-sodium ultrafast ion conductor and argyrodite type, such as Li3PS4, Na3PS4, Li6PS5Cl, etc.

[0081] Preferably, the oxide solid electrolyte is at least one selected from the group consisting of perovskite type, sodium fast ion conductor type, lithium fast ion conductor type, and garnet type. For example, La 0.8 Sr 0.2 Ga 0.8 Mg 0.2 O3, NaLaS2, La 0.5 Li 0.5 TiO3, Li7La3Zr2O 12 And so on.

[0082] Preferably, the composite electrolyte comprises a polymer electrolyte and a second-phase inorganic filler, wherein the polymer electrolyte has the meaning described above, and the second inorganic filler is selected from the group consisting of TiO2, SiO2, Al2O3, ZrO2, MgO, ZnO, and the like. x and at least one selected from metal oxide nanoparticles such as those mentioned above, zeolite, montmorillonite, and the like.

[0083] According to the present invention, the ion battery has good cycle performance and relatively high energy density.

[0084] For example, 500 mA g -1 At a current density of 100, the capacity retention rate of the aqueous secondary ion battery after 100 charge / discharge cycles is 95% or more, for example, 95 to 99.9%.

[0085] For example, 100 mA g -1 At a current density of 1000, the capacity retention rate of the organic secondary ion battery after 600 charge / discharge cycles is 88% or more.

[0086] In the present invention, the secondary ion battery can be assembled by selecting a method known in the art.

[0087] Illustratively, the method for manufacturing the secondary ion battery includes using the positive electrode sheet as a positive electrode, activated carbon as a negative electrode, and 62 mol / kg K(FSI) 0.55 (OTf) 0.45 Includes aqueous batteries assembled using 0.9H2O aqueous solution as the electrolyte.

[0088] Beneficial Effects: The present invention provides a positive electrode material manufactured using a first active material, which has high versatility. Furthermore, the manufacturing method of the present invention is simple and convenient, and the production cost is low.

[0089] In a secondary ion battery fabricated using the cathode material of the present invention, the first active material in the cathode material comprises low-dimensional structures and / or micro-nanocrystalline particles, which primarily provide capacity. During charge / discharge cycles, some of the low-dimensional structures and / or micro-nanocrystalline particles in the first active material dissolve in the electrolyte or precipitate from the electrolyte, reforming the low-dimensional structures and / or micro-nanocrystalline particles on the support. During battery charge / discharge cycles, the micro-nanocrystalline particles dissolve in the electrolyte as a replenisher and then deposit on the support surface to form a first active material with a low-dimensional structure, ensuring stable battery operation. Because the first active material in the cathode material has a relatively low molecular weight and a relatively high redox potential, the secondary ion battery of the present invention can provide a relatively high specific capacity and voltage, as well as a relatively high energy density. By controlling the concentration of the electrolyte and combining it with the cathode material described in the present invention, the aqueous secondary battery of the present invention can improve the energy density and cycle stability of aqueous positive electrode materials, thereby meeting the needs for industrialization of aqueous secondary batteries. [Brief explanation of the drawings]

[0090] [Figure 1] 1A and 1B are microstructure diagrams of the KBr / rGO / AC positive electrode sheet of Example 1-A, in which (a) is a scanning electron microscope (SEM) image and (b-d) are spectroscopic analyses. [Figure 2]1 shows the charge / discharge curves of the aqueous battery of Example 1-A. [Figure 3] 1 is a graph showing the cycle performance of the aqueous battery of Example 1-A after 500 charge / discharge cycles. [Figure 4] Figure 1 shows the microstructure of the KI / rGO / AC positive electrode sheet of Example 1-B, where (a) is an SEM image, (b-d) are spectroscopic analyses, and (e, f) are transmission electron microscope (TEM) images. [Figure 5] FIG. 10 is a transmission electron microscope image of the KI / rGO / AC positive electrode sheet in Example 1-B after 100 cycles. [Figure 6] 1 shows charge / discharge curves of all batteries in Example 1-B. [Figure 7] 1 shows charge / discharge curves of the batteries in Examples 2 to 4. [Figure 8] 10 is a graph showing the cycle performance of the battery in Example 5 after 600 charge / discharge cycles. [Figure 9] 1 is a graph showing the cycle performance of the battery in Example 6-B after 200 charge / discharge cycles. [Figure 10] TEM images before (a) and after (b) template elution from the NaCl-based cathode material in Example 7. [Figure 11] 10 is a graph showing the cycle performance of the organic gel battery in Example 9 after 300 charge / discharge cycles. [Figure 12] 10 is a graph showing the cycle performance of the battery in Comparative Example 2 after 10 charge / discharge cycles. [Figure 13] 10 is a graph showing the cycle performance of the battery in Comparative Example 3 after 100 charge / discharge cycles. DETAILED DESCRIPTION OF THE INVENTION

[0091] The present invention will be described in more detail below with reference to specific examples. It should be understood that the following examples are merely illustrative of the present invention and do not limit the scope of the claims of the present invention. Any technology realized based on the above content of the present invention is included in the scope of the claims of the present invention.

[0092] Unless otherwise specified, the experimental methods used in the following examples are conventional methods, and the reagents, materials, etc. used in the following examples are commercially available unless otherwise specified.

[0093] In the following examples, unless otherwise specified, the electrochemical performance of all batteries is tested at 25°C.

[0094] Example 1-A Potassium ion battery 1. Preparation of the cathode material: (1) An aqueous dispersion containing graphene oxide (GO, 3 mg / g) and activated carbon (AC, 7 mg / g) was ultrasonically dispersed for 2 hours to obtain a mixture. Five mL of the mixture was then added to a 3.5 cm diameter culture dish, frozen in a low-temperature refrigerator at -80°C for 2 hours, and then freeze-dried at -60°C for 40 hours to obtain a GO / AC foam.

[0095] (2) The GO / AC foam was punched into circular sheets with a diameter of 11 mm. 200 μL of KBr methanol solution (25 mg / mL) was then dropped onto each circular sheet. After placing the sheet in a fume hood for 48 h, the KBr / GO / AC samples were obtained after the methanol had completely evaporated.

[0096] (3) The KBr / GO / AC sample prepared in step (2) was carbonized at high temperature in a tubular furnace at 700 °C for 4 h to obtain the positive electrode sheet, KBr / reduced graphene oxide (rGO) / AC. The microstructure of the KBr / rGO / AC cathode is shown in Figure 1. SEM images and spectroscopic analysis of the figure show that KBr is distributed relatively uniformly throughout the foam, and the average particle size of its microcrystalline particles is 1 μm.

[0097] 2. Preparation of aqueous battery: The KBr / rGO / AC cathode sheet was used as the cathode, AC was used as the anode, and 62 mol / kg K(FSI) 0.55 (OTf) 0.45A 0.9H2O aqueous solution was used as the electrolyte, and a glass fiber (GFF) separator was used to assemble the entire battery. The mass of the KBr positive electrode sheet was 2 mg, and the mass of the AC negative electrode was 12 mg. Figure 2 shows the charge-discharge curve of the battery at a current density of 500 mA / g. The discharge specific capacity was 150 mAh / g, and the capacity retention rate after 500 cycles was 86% (Figure 3).

[0098] Example 1-B 1. Cathode material production: Steps (1) to (3) were the same as in Example 1-A, except that KBr in step (2) was replaced with KI, and finally a KI / rGO / AC positive electrode sheet was produced.

[0099] Figure 4 shows the microstructure of the KI / rGO / AC positive electrode sheet. From the figure, it was observed that KI was distributed relatively uniformly throughout the foam. Transmission electron microscope images revealed two-dimensional KI crystals with a lattice spacing of 0.35 nm corresponding to the 200 crystal plane. Elemental analysis revealed that the mass fraction of KI in the positive electrode sheet was 50%.

[0100] 2. Half-cell fabrication: A half-cell was fabricated using the KI / rGO / AC material as the positive electrode, potassium metal as the negative electrode, an 8 mol / L solution of KFSI in propylene carbonate as the electrolyte, and GFF as the separator. The mass of the positive electrode active material, KI, was 3.7 mg. After 100 charge-discharge cycles at a current density of 100 mA / g, the half-cell still maintained a capacity retention rate of 94%. Figure 5 shows a TEM image of the positive electrode sheet after 100 charge-discharge cycles. Lattice distortion and lattice fringes of the KI crystals were observed in the image.

[0101] 3. Full-cell fabrication: A full-cell was fabricated using the KI / rGO / AC material as the positive electrode, prepotassified graphite as the negative electrode, an 8 mol / L KFSI propylene carbonate solution as the electrolyte, and GFF as the separator. The mass of the positive electrode active material, KI, was 3.7 mg, and the mass of the negative electrode active material, 3 mg. Figure 6 shows the charge-discharge curve of the full-cell at a current density of 500 mA / g. The discharge specific capacity was 113 mAh / g, and the capacity retention rate remained at 73% after 800 charge-discharge cycles.

[0102] Example 2 Lithium-ion battery 1. Preparation of cathode materials: The preparation method of this example was the same as that of Example 1-A, except that in step (2), methanol solutions of LiCl, LiBr, and LiI were dropped onto the circular sheets to prepare LiCl / rGO / AC cathode sheets, LiBr / rGO / AC cathode sheets, and LiI / rGO / AC cathode sheets, respectively. The mass fractions of the active materials LiCl, LiBr, and LiI in the cathode sheets were 45%, 51%, and 48%, respectively.

[0103] 2. Battery assembly: Half-cells were assembled using the LiCl / rGO / AC cathode sheet, LiBr / rGO / AC cathode sheet, and LiI / rGO / AC cathode sheet of this example as the cathode, metallic lithium as the anode, a 10 mol / L LiFSI propylene carbonate solution as the electrolyte, and GFF as the separator. Figure 7a-c shows the charge-discharge curves of the three types of batteries at a current density of 100 mA / g, and the discharge specific capacities were 315, 153, and 117 mAh / g, respectively.

[0104] Example 3 Sodium-ion battery 1. Preparation of cathode materials: The preparation method in this example was the same as in Example 1-A, except that in step (2), NaCl, NaBr, and NaI methanol solutions or a water-methanol mixture solution were dropped onto the circular sheets to prepare NaCl / rGO / AC cathode sheets, NaBr / rGO / AC cathode sheets, and NaI / rGO / AC cathode sheets, respectively. The mass fractions of the active materials NaCl, NaBr, and NaI in the cathode sheets were 52%, 46%, and 48%, respectively.

[0105] 2. Battery assembly: Half-cells were assembled using the NaCl / rGO / AC cathode sheet, NaBr / rGO / AC cathode sheet, and NaI / rGO / AC cathode sheet of this example as the cathode, sodium metal as the anode, 6 mol / L NaFSI propylene carbonate solution as the electrolyte, and GFF as the separator. Figure 7(d)–(f) show the charge–discharge curves of the three types of batteries at a current density of 100 mA / g, respectively. The discharge specific capacities were 116, 156, and 177 mAh / g, respectively.

[0106] Example 4 Zinc-ion battery 1. Preparation of cathode materials: The preparation method of this example was the same as that of Example 1-A, except that in step (2), methanol solutions of ZnCl, ZnBr, and ZnI were dropped onto the circular sheets to prepare ZnCl / rGO / AC cathode sheets, ZnBr / rGO / AC cathode sheets, and ZnI / rGO / AC cathode sheets, respectively. The mass fractions of the active materials ZnCl, ZnBr, and ZnI in the cathode sheets were 47%, 46%, and 46%, respectively.

[0107] 2. Battery Assembly: Half-cells were assembled using the three materials of this example as the cathode, metallic zinc as the anode, a 2 mol / L Zn(TFSI)2 solution in acetonitrile as the electrolyte, and GFF as the separator. Figure 7 (g)-(i) show the charge-discharge curves of the three batteries at a current density of 100 mA / g, and the discharge specific capacities were 174, 163, and 108 mAh / g, respectively.

[0108] Example 5 Sulfites 1. Preparation of Cathode Material: The preparation method for the cathode material in this example was the same as in Example 1-A, except that in step (2), a K2SO3 solution (0.1 g / mL) in water and methanol was added dropwise to the circular sheet. In step (3), the K2SO3 / GO / AC sample was carbonized in a tubular furnace at 500 °C for 4 h to obtain a K2SO3 / rGO / AC cathode sheet, of which the average particle size of the K2SO3 microcrystalline particles was 3 μm. Elemental analysis revealed that the mass fraction of K2SO3 in the K2SO3 / rGO / AC cathode sheet was 45%.

[0109] 2. Assembly of aqueous battery: The fabrication method of this example was the same as that of Example 1-A, except that the positive electrode material was KSO / rGO / AC, where the mass of the active material KSO was 2 mg. The battery maintained a capacity retention rate of 82% after 1000 charge-discharge cycles at a current density of 500 mA / g.

[0110] 3. Half-cell assembly: K2SO3 / rGO / AC was used as the positive electrode material, potassium metal as the negative electrode material, and 6 mol / L KFSI in DME solution as the electrolyte. Figure 8 shows the cycle performance graph of the battery after 600 charge-discharge cycles at a current density of 100 mA / g. The battery still maintained a capacity retention rate of 88% after 600 charge-discharge cycles.

[0111] Example 6-A Addition of a Second Active Material 1. Preparation of cathode material: (1) 0.5 g of sodium iron manganese nickelate (NaNi 1 / 3 Fe 1 / 3 Mn 1 / 3O2, the second active material) was added to 2 mL of a 0.1 g / mL NaBr (first active material) methanol solution and magnetically stirred for 12 h. The mixture was then placed in a fume hood until the methanol completely evaporated, and then dried in a blower box at 90 °C for 6 h. The dried solid was then crushed and prepared for use. This method allowed NaBr to fill the pores of the microspheres and form a composite cathode material.

[0112] (2) 0.5 g of the above positive electrode material was taken and prepared into a slurry in a ratio of 8:1:1 (active material:conductive carbon black:PVDF), which was then coated on an aluminum foil current collector and dried. The slurry was then punched into a positive electrode sheet with a diameter of 11 mm for use, of which the mass of the positive electrode active material NaBr was 1 mg and the mass of the sodium iron manganese nickelate was 2.5 mg.

[0113] 2. Battery assembly: A battery was assembled using the above cathode sheet as the cathode, metallic sodium as the anode, 6 mol / L NaFSI propylene carbonate solution as the electrolyte, and GFF as the separator. After 800 charge-discharge cycles at a current density of 500 mA / g, the battery maintained a high capacity retention rate of 93.5%.

[0114] Example 6-B Addition of a Second Active Material 1. Preparation of cathode material: same as in Example 6-A, except that NaNi 1 / 3 Fe 1 / 3 Mn 1 / 3 The solution was to replace O2 with lithium iron phosphate (LiFePO4) and NaBr with LiBr.

[0115] 2. Half-cell assembly: A half-cell was assembled using the LiFePO4 / LiBr cathode, metallic lithium anode, a 10 mol / L LiFSI propylene carbonate solution as the electrolyte, and GFF as the separator. The positive electrode active material was LiBr with a mass of 1.0 mg and LiFePO4 with a mass of 2.5 mg. Figure 9 shows the cycle performance of the battery after 200 charge-discharge cycles at a current density of 100 mA / g. The capacity retention rate remained high at 98.6% after 200 charge-discharge cycles.

[0116] Example 7 Template Elution 1. Preparation of cathode material: (1) 0.1 g of TiO2 nanosheets was added to 100 mL of a 0.01 g / mL NaCl solution in methanol (1:1 by mass) and stirred for 12 hours. The dispersion was then heated to 50 °C until the solvent was completely evaporated. NaCl was electrostatically coupled to the TiO2 nanosheets, resulting in a uniform deposition of some of the nanoparticles on the surface (Figure 10a). The solid was then dried in a blower box at 90 °C for 6 hours. The dried solid was then added to concentrated hydrochloric acid. Since TiO2 nanosheets are soluble in concentrated hydrochloric acid but NaCl is insoluble, the template was removed by etching, leaving only the low-dimensional structure of the NaCl. The template elution process did not destroy the NaCl structure; some of the nanoparticles remained nanoparticles, and the particle size remained essentially unchanged before and after elution (Figure 10b). After elution of the template, the resulting NaCl solid was dried under vacuum at 90°C for 6 h, and the dried solid was ground and prepared for use.

[0117] (2) Step (1) was repeated several times to obtain 0.5 g of the above NaCl solid, which was then slurried in a ratio of 7:2:1 (NaCl:conductive carbon black:PVDF), coated onto an aluminum foil current collector, dried, and punched into a sheet with a diameter of 11 mm for use.

[0118] 2. Half-cell assembly: A half-cell was assembled using the above NaCl as the positive electrode, metallic sodium as the negative electrode, a 6 mol / L propylene carbonate solution of NaFSI as the electrolyte, and GFF as the separator, where the mass of the positive electrode active material NaCl was 1.8 mg. After 600 charge-discharge cycles at a current density of 100 mA / g, the half-cell still maintained a high capacity retention of 93%.

[0119] Example 8 Gel battery 1. Hydrogel preparation method: 0.05 mol NaClO4 and 5 g PVA were added to 5 mL of deionized water and stirred at room temperature for 20 minutes. After that, the mixture was heated to 95°C and stirred for 2 hours to obtain a homogeneous gel solution. The mixture was then added to a 6 cm diameter culture dish and left in a refrigerator at -20°C for 4 hours. After molding, a PVA-NaClO4 gel was obtained, which was then punched into 16 mm diameter sheets using a hole punch for use.

[0120] 2. Full-cell assembly: A full-cell was assembled using the NaI / rGO / AC cathode sheet prepared in Example 3 as the positive electrode, AC as the negative electrode, and PVA-NaClO4 as the gel electrolyte. After 100 charge-discharge cycles at a current density of 500 mA / g, the battery achieved a high capacity retention rate of 95%.

[0121] Example 9 Organic gel battery 1. Preparation method of the organic gel: 0.3 g of polyethylene oxide (PEO) and 4.5 mL of 1 mol / L NaFSI propylene carbonate solution were magnetically stirred for 12 h, then added to a 6 cm diameter culture dish and left at room temperature for 7 days to obtain a PEO-NaFSI-PC organic gel electrolyte, which was then punched into a 16 mm diameter sheet for use.

[0122] 2. Half-cell assembly: A battery was assembled using the NaI / rGO / AC cathode sheet prepared in Example 3 as the cathode, metallic sodium as the anode, and PEO-NaFSI-PC as the gel electrolyte. Figure 11 shows the cycle performance of the battery. After 300 charge-discharge cycles at a current density of 100 mA / g, the battery still maintained a capacity retention rate of 86%.

[0123] Example 10 Organic / Aqueous Mixed Electrolyte Battery A battery was assembled using the ZnI2 / rGO / AC cathode, zinc metal anode, a 2 mol / L Zn(TFSI)2 mixed solvent (acetonitrile and water in a volume ratio of 10:1) as the electrolyte, and GFF as the separator. The battery achieved a capacity retention rate of 89% after 200 charge-discharge cycles at a current density of 100 mA / g.

[0124] Example 11 All-solid-state battery Solid electrolyte preparation method: 0.4 g of poly(vinylidene fluoride-hexafluoropropene) (PVDF-HFP) was dissolved in 5 mL of dry N,N-dimethylformamide and stirred thoroughly for 24 h. 0.1 g of lithium bistrifluoromethanesulfonimide (LiTFSI) was added and stirred for another 24 h to obtain a homogeneous mixed solution. The mixed slurry was quickly poured into a tetrafluoroethylene mold and then slowly vacuumed and dried for 48 h. The dried solid electrolyte membrane PVDF-HFP-LiTFSI was gently peeled from the mold and quickly transferred to a glove box. It was then punched into a 16 mm diameter sheet for use.

[0125] Half-cell assembly: A solid-state battery was assembled using the LiI / rGO / AC cathode from Example 2, metallic lithium as the anode, and the above solid electrolyte. The battery achieved a high capacity retention of 89% after 800 charge-discharge cycles at a current density of 100 mA / g.

[0126] Comparative Example 1 1. Preparation of KBr positive electrode sheet: A slurry was prepared by mixing analytical grade KBr, conductive carbon black, and PVDF in a mass ratio of 8:1:1. The slurry was then coated onto an aluminum foil current collector and dried in a drying oven at 100°C for 6 hours. After that, a circular positive electrode sheet with a diameter of 11 mm was obtained and prepared for use (the mass of KBr was 3 mg).

[0127] 2. Assembly of aqueous battery: The above KBr was used as the positive electrode, and 62 mol / kg K(FSI) 0.55 (OTf) 0.45 An aqueous battery was assembled and tested using a 0.9H2O aqueous solution as the electrolyte and GFF as the separator. After 50 charge-discharge cycles at a current density of 500 mA / g, the capacity retention rate of the aqueous battery was only 42%. The discharge specific capacity was 50 mAh / g, which was only 30% of that of Example 1-A.

[0128] Comparative Example 2 NaNi of Example 6-A 1 / 3 Fe 1 / 3 Mn 1 / 3 A battery was assembled using an O2 / NaBr cathode sheet as the cathode, metallic sodium as the anode, a 2 mol / L NaFSI propylene carbonate solution as the electrolyte, and GFF as the separator. Figure 12 shows the cycle performance of the aqueous battery. After 10 charge-discharge cycles at a current density of 500 mA / g, the capacity retention rate was only 23.3%.

[0129] Comparative Example 3 1. Preparation of cathode material: The difference between the preparation method of the cathode material in this comparative example and that in Example 1-B is that no carrier is added, and K2SO3 is used as the first active material to prepare a slurry with carbon black to prepare a K2SO3 cathode sheet. The steps are as follows: A slurry of K2SO3, conductive carbon black, and PVDF was prepared in an 8:1:1 ratio by mass, and then coated onto an aluminum foil current collector. The slurry was dried in a drying oven at 100°C for 6 hours to obtain a circular cathode sheet with a diameter of 11 mm, which was ready for use (the mass of the active material K2SO3 was 3 mg).

[0130] 2. Half-cell assembly: A battery was assembled and tested using the material of this comparative example as the cathode, potassium metal as the anode, and a 6 mol / L KFSI solution in DME as the electrolyte. Figure 13 shows the cycle performance of the battery. After 100 charge-discharge cycles at a current density of 0.1 A / g, the capacity retention rate was only 39%. The discharge specific capacity of the battery was 105 mAh / g, only 55% of the discharge specific capacity of the half-cell of Example 5.

[0131] Although the embodiments of the present invention have been described above, the present invention is not limited to the above embodiments. Any modifications, equivalent replacements, improvements, etc. made within the scope of the claims of the present invention without departing from the spirit and principles of the present invention are also included within the scope of the claims of the present invention.

Claims

1. A method for producing a positive electrode material, comprising mixing a carrier and a first active material and then carbonizing the mixture, the first active material is selected from alkali metal halide or sulfite, alkaline earth metal halide or sulfite, aluminum halide, or zinc halide or zinc sulfite; The support is selected from a two-dimensional template or a combination of the template with a second active material; The two-dimensional structure template is at least one nanosheet selected from graphene oxide, metal organic framework compounds, and covalent organic framework compounds. A method for producing a positive electrode material.

2. In the positive electrode material, the first active material is uniformly distributed on the support or within the two-dimensional structure of the support, and / or the second active material has a zero-dimensional, one-dimensional, or two-dimensional structure; At least a portion of the halide or sulfite in the positive electrode material exhibits a zero-dimensional, one-dimensional, or two-dimensional structure. The method according to claim 1 .

3. the two-dimensional structure comprises a crystalline structure or an amorphous structure; and / or The second active material is LiMn 2 O 4 , ternary material, sodium iron manganese cuprate (Na n Cu x Fe y Mn z O 2 ), Sodium iron manganese nickelate (Na n Ni x Fe y Mn z O 2 ), Prussian blue sodium / potassium (Na / K x PR (CN) 6 (P, R are Fe, Co, Ni, Mn)), K 0.5 MnO 2 , LiFePO 4 , polypyrrole, polyaniline materials, and / or The second active material is a nanoparticle, and the nanoparticle can be configured as a microsphere. The method according to claim 1 .

4. The alkali metal halide salt is at least one selected from lithium chloride, lithium bromide, lithium iodide, sodium chloride, sodium bromide, sodium iodide, potassium chloride, potassium bromide, and potassium iodide, and / or The alkali metal sulfite is at least one selected from lithium sulfite, sodium sulfite, and potassium sulfite, and / or The alkaline earth metal halide salt is at least one selected from magnesium chloride, magnesium bromide, magnesium iodide, calcium chloride, calcium bromide, and calcium iodide, and / or the alkaline earth metal sulfite is selected from magnesium sulfite and / or calcium sulfite, and / or The aluminum halide is at least one selected from aluminum chloride, aluminum bromide, and aluminum iodide, and / or The zinc halide is at least one selected from zinc chloride, zinc bromide, and zinc iodide. The manufacturing method according to any one of claims 1 to 3.

5. In the positive electrode material, the first active material accounts for 1 to 99% of the total mass of the positive electrode material; and / or Preferably, in the positive electrode material, the support accounts for 0.1 to 95% of the total mass of the positive electrode material, and / or In the carrier, the mass ratio of the template to the second active material is (0.1 to 1):(0 to 10), and / or The first active material has a low-dimensional structure or a micro-nanocrystalline particle structure, and the low-dimensional structure is at least one selected from a zero-dimensional structure, a one-dimensional structure, and a two-dimensional structure; and / or In the positive electrode material, when the first active material is distributed within the low-dimensional structure, the first active material exhibits a low-dimensional structure; and / or When the first active material is distributed on the support, the first active material comprises micro-nanocrystalline particles; and / or In the positive electrode material, the content of the low-dimensional structure in the first active material is higher than the content of the microcrystalline particles; The method according to claim 1 .

6. the positive electrode material includes the first active material and the support, the support includes the second active material, and the first active material and the second active material combine to form the positive electrode material; The method according to claim 1 .

7. the first active material is filled into the pores of the nanoparticles or microspheres of the second active material and combined to form the positive electrode material; The method according to claim 3 .

8. the support is selected from the combination of the template with the second active material; The mixing The template and the first active material are mixed first, and then the second active material is added; or The template and the second active material are mixed first, and then the first active material is added thereto; or The second active material and the first active material are mixed together, and then a template is added. The method according to claim 1 .

9. The method further comprises treating the cathode material after composite by a method of elution; In the production method, the carrier is pretreated to obtain any form such as a dispersion, a foam, an assembly film, a powder, or a slurry; 2. The method according to claim 1, wherein the carbonization treatment comprises carbonizing the positive electrode material at a high temperature of 400 to 1000°C.

10. the elution includes adding the cathode material to an eluent to remove all or a portion of the template; The method according to claim 9 .

11. The method for producing the positive electrode material includes: (1) ultrasonically dispersing the carrier to obtain a mixture, and freeze-drying the mixture to obtain a foam; (2) adding a solution containing a first active material dropwise to the foam of step (1) and allowing it to dry naturally to obtain a precursor of a positive electrode material; (3) subjecting the precursor of the positive electrode material obtained in step (2) to high temperature treatment, and then obtaining the positive electrode material; The method according to claim 1 .

12. 10. The application of the positive electrode material obtained by the method of claim 1 in secondary ion batteries.

13. The secondary ion battery is at least one selected from an aqueous secondary ion battery, an organic secondary ion battery, an organic / aqueous mixed secondary ion battery, a gel battery, a quasi-solid battery, and an all-solid battery.

13. The application according to claim 12.

14. The secondary ion battery further includes a negative electrode material selected from a metal material or a carbon-based negative electrode material.

14. The application according to claim 13 .

15. the carbon-based negative electrode material is at least one selected from AC, graphite, hard carbon, and soft carbon; The metal material is at least one selected from lithium, sodium, potassium, magnesium, aluminum, and zinc.

15. The application according to claim 14.

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