Semi-solid sodium-ion battery and preparation method and application thereof

Abstract

The application belongs to the technical field of sodium ion battery materials, and particularly relates to a semi-solid sodium ion battery and a preparation method and application thereof. The electrolyte of the semi-solid sodium ion battery is a composite electrolyte; the composite electrolyte comprises the following preparation raw materials in parts by weight: 60-85 parts of Na-beta-Al2O3@Na / Ti-MOF, 25-35 parts of a sodium salt electrolyte and 0-5 parts of a binder; wherein the preparation raw materials of the Na-beta-Al2O3@Na / Ti-MOF comprise Na-beta-Al2O3 ceramic particles, tetraisopropyl titanate, sodium hydroxide and 2-amino terephthalic acid. The semi-solid sodium ion battery provided by the application has high rapid charging capacity and high rate discharge performance of the battery.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of sodium ion battery materials, and particularly relates to a semi-solid sodium ion battery and a preparation method and application thereof. BACKGROUND

[0002] The semi-solid sodium ion battery is a transitional battery between a traditional liquid battery and a full-solid battery, and the electrolyte thereof is in a "solid-liquid mixed" state. The solid state part is usually a solid electrolyte framework or particle composed of oxides, sulfides or polymers, and the liquid state part is an organic liquid electrolyte (such as a carbonate solvent) containing a sodium salt (such as NaPF6 or NaClO4). The solid state and the liquid state are mixed to form an electrolyte system with a certain flowability but more like a gel or slurry, similar to "jelly" or "paste". In the solid-liquid mixed electrolyte, the transport mechanism and rate of sodium ions are different inside the solid electrolyte, inside the liquid electrolyte and at the interface between the two. When sodium ions cross the "solid-liquid" boundary, they need to overcome an additional energy barrier, forming a transport "bottleneck", which greatly limits the rapid charging capacity and high-rate discharge performance of the battery. SUMMARY

[0003] To solve the above problems, the application provides a semi-solid sodium ion battery and a preparation method and application thereof. At least one aspect of the above technical problems is solved.

[0004] The application is implemented by the following technical solutions:

[0005] In a first aspect, the application provides a semi-solid sodium ion battery, and the electrolyte is a composite electrolyte.

[0006] The composite electrolyte comprises the following preparation raw materials in parts by weight:

[0007] 60-85 parts of Na-β-Al2O3@Na / Ti-MOF, 25-35 parts of a sodium salt electrolyte and 0-5 parts of a binder.

[0008] The preparation raw materials of the Na-β-Al2O3@Na / Ti-MOF include Na-β-Al2O3 ceramic particles, tetraisopropyl titanate, sodium hydroxide and 2-amino terephthalic acid.

[0009] In a second aspect, the application provides a preparation method of the above semi-solid sodium ion battery, and the preparation of the composite electrolyte comprises the following steps:

[0010] The Na-β-Al2O3@Na / Ti-MOF, the sodium salt electrolyte and the binder are mixed in a predetermined ratio.

[0011] In a third aspect, the present application provides an application of the above-mentioned semi-solid sodium ion battery in the field of new energy.

[0012] Compared with the prior art, the semi-solid sodium ion battery provided by the present application has at least the following beneficial technical effects:

[0013] The semi-solid sodium ion battery provided by the present application contains Na-β-Al2O3@Na / Ti-MOF in the composite electrolyte, the Na / Ti-MOF is in-situ loaded on the surface of the Na-β-Al2O3 ceramic particles, the Na-β-Al2O3 ceramic particles are modified, which not only improves the stability of the structural framework of the Na-β-Al2O3, but also promotes the wettability of the Na-β-Al2O3 and the sodium salt electrolyte, so that the interface wettability between the Na-β-Al2O3 and the sodium salt electrolyte is improved, thereby improving the ion transmission rate and finally improving the rapid charging capacity and high-rate discharge performance of the battery.

[0014] Compared with the prior art, the preparation method of the semi-solid sodium ion battery provided by the present application has at least the following beneficial technical effects:

[0015] In the preparation method of the semi-solid sodium ion battery provided by the present application, the Na-β-Al2O3@Na / Ti-MOF, the sodium salt electrolyte and the binder are mixed, the sodium salt electrolyte seeps into the pores between the Na-β-Al2O3@Na / Ti-MOF particles and the pores of the Na-β-Al2O3@Na / Ti-MOF itself, and cooperates with the binder as a "bridge" to connect the discrete Na-β-Al2O3@Na / Ti-MOF solid particles, forming a continuous ion transmission path of solid-liquid-solid. The semi-solid sodium ion battery prepared has rapid charging capacity and high-rate discharge performance. DETAILED DESCRIPTION

[0016] In order to make the purpose, technical scheme and advantages of the present application clearer and more apparent, the present application is described and explained below in combination with embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and do not limit the present application. Based on the embodiments provided by the present application, all other embodiments obtained by those of ordinary skill in the art without creative labor fall within the scope of the present application.

[0017] It is apparent that the following description is merely some examples or embodiments of the present application, and the present application can also be applied to other similar situations without creative labor for those skilled in the art. In addition, it can be understood that although the efforts made in the development process can be complex and lengthy, some design, manufacture or production changes made on the basis of the disclosed technology of the present application are only routine technical means for those skilled in the art related to the disclosed content of the present application, and should not be understood as insufficient disclosure of the present application.

[0018] However, unnecessary detailed descriptions can be omitted. For example, there are cases where detailed descriptions of well-known matters, repeated descriptions of substantially the same structures are omitted. This is to avoid the following description from becoming unnecessarily lengthy and to facilitate understanding by those skilled in the art. In addition, the following description is provided in order for those skilled in the art to fully understand the present application, and is not intended to limit the subject matter recited in the claims.

[0019] Unless otherwise specified, all embodiments and optional embodiments of the present application can be combined with each other to form new technical solutions, and all technical features and optional technical features of the present application can be combined with each other to form new technical solutions.

[0020] The first aspect of the embodiment of the present application provides a semi-solid sodium ion battery, wherein the electrolyte is a composite electrolyte, and the composite electrolyte comprises the following preparation raw materials by weight:

[0021] 60-85 parts of Na-β-Al2O3@Na / Ti-MOF, 25-35 parts of a sodium salt electrolyte, and 0-5 parts of a binder;

[0022] The preparation raw materials of the Na-β-Al2O3@Na / Ti-MOF include Na-β-Al2O3 ceramic particles, tetraisopropyl titanate, sodium hydroxide, and 2-amino terephthalic acid.

[0023] The semi-solid sodium ion battery provided by the embodiment of the present application contains Na-β-Al2O3@Na / Ti-MOF in the composite electrolyte, the Na / Ti-MOF is in-situ loaded on the surface of the Na-β-Al2O3 ceramic particles, the Na-β-Al2O3 ceramic particles are modified, the stability of the structural framework of the Na-β-Al2O3 is improved, the wettability of the Na-β-Al2O3 and the sodium salt electrolyte is promoted, the interface wettability between the Na-β-Al2O3 and the sodium salt electrolyte is improved, and the ion transmission rate is improved, thereby improving the rapid charging capacity and high-rate discharge performance of the battery.

[0024] In other embodiments, the composite electrolyte comprises the following preparation raw materials by weight:

[0025] 60 parts to 85 parts of Na-β-Al2O3@Na / Ti-MOF, 25 parts to 35 parts of a sodium salt electrolyte, and 1 part to 5 parts of a binder.

[0026] In some embodiments, the composite electrolyte comprises the following weight proportions of the preparation raw materials:

[0027] 60 parts to 85 parts of Na-β-Al2O3@Na / Ti-MOF, 25 parts to 35 parts of a sodium salt electrolyte, and 1 part to 5 parts of a binder.

[0028] In some embodiments, the composite electrolyte comprises the following weight proportions of the preparation raw materials:

[0029] 60 parts to 85 parts of Na-β-Al2O3@Na / Ti-MOF, and 25 parts to 35 parts of a sodium salt electrolyte.

[0030] In some embodiments, the average particle size of the Na-β-Al2O3 ceramic particles is 1 μm to 5 μm.

[0031] In some embodiments, in the preparation raw materials of the Na-β-Al2O3@Na / Ti-MOF, the mass molar ratio of the Na-β-Al2O3 ceramic particles, tetraisopropyl titanate, sodium hydroxide, and 2-amino terephthalic acid is 1 g: (1 mmol to 1.5 mmol):(0.02 mmol to 0.05 mmol):(2.5 mmol to 3 mmol).

[0032] In some embodiments, the sodium salt electrolyte comprises a sodium salt and an organic carbonate mixed solvent.

[0033] In some embodiments, the sodium salt comprises at least one of sodium perchlorate (NaClO4), sodium hexafluorophosphate (NaPF6), sodium bis(trifluoromethanesulfonyl)imide (NaTFSI), and sodium bisfluorosulfonylimide (NaFSI).

[0034] In some embodiments, in the sodium salt electrolyte, the concentration of sodium is 1 mol / L to 1.2 mol / L.

[0035] In some embodiments, the organic carbonate mixed solvent is a mixture of ethylene carbonate (EC), propylene carbonate (PC), and dimethyl carbonate (DMC).

[0036] In some embodiments, the volume ratio of ethylene carbonate (EC), propylene carbonate (PC), and dimethyl carbonate (DMC) is 1:1:1.

[0037] In some embodiments, the binder comprises a polyvinylidene fluoride-hexafluoropropylene copolymer.

[0038] In some embodiments, the polyvinylidene fluoride-hexafluoropropylene copolymer has an average molecular weight of 400,000 to 600,000.

[0039] In some embodiments, in the semi-solid sodium ion battery, the positive electrode active material in the positive electrode sheet includes at least one of NaNiO2, NaMnO2, NaNi 1 / 3 Fe 1 / 3 Mn 1 / 3 O2, NaFePO4, Na3V2(PO4)3@C, Na2Fe2(SO4)3@C@GO, Na2FePO4F / C.

[0040] In some embodiments, in the semi-solid sodium ion battery, the material of the negative electrode sheet includes a sodium sheet.

[0041] The second aspect of the embodiment of the present application provides a preparation method of a semi-solid sodium ion battery, and the preparation of the composite electrolyte includes the following steps:

[0042] S10. Mix Na-β-Al2O3@Na / Ti-MOF, a sodium salt electrolyte, and a binder according to a preset ratio.

[0043] The preparation method of the semi-solid sodium ion battery provided by the embodiment of the present application mixes Na-β-Al2O3@Na / Ti-MOF, a sodium salt electrolyte, and a binder, the sodium salt electrolyte seeps into the pores between the Na-β-Al2O3@Na / Ti-MOF particles and its own pores, and cooperates with the binder as a "bridge" to connect the discrete Na-β-Al2O3@Na / Ti-MOF solid particles, forming a continuous ion transmission path of solid-liquid-solid. The semi-solid sodium ion battery prepared has the capabilities of fast charging and high rate discharging.

[0044] In some embodiments, in the step S10, the preparation of Na-β-Al2O3@Na / Ti-MOF includes the following steps:

[0045] S101. Mix a sodium hydroxide methanol solution, titanium isopropylate, a 2-amino terephthalic acid mixed solution, Na-β-Al2O3 ceramic particles, and water to obtain a mixed solution, and then perform a solvothermal reaction.

[0046] In the preparation of the above Na-β-Al2O3@Na / Ti-MOF, the sodium hydroxide methanol solution, titanium isopropylate, 2-amino terephthalic acid mixed solution, Na-β-Al2O3 ceramic particles, and water are mixed to obtain a mixed solution, and then a solvothermal reaction is performed, which can enable Na / Ti-MOF to be generated in situ and inserted in the Na-β-Al2O3 ceramic particles, thereby improving the structural stability of the Na-β-Al2O3 ceramic particles.

[0047] In some embodiments, in the step S101, the preparation of the sodium hydroxide methanol solution includes the following steps:

[0048] S1011. Mixing sodium hydroxide and methanol (MeOH).

[0049] In some embodiments, in the step S101, the molar concentration of sodium hydroxide in the sodium hydroxide methanol solution is 1 mol / L-1.2 mol / L.

[0050] In some embodiments, in the step S101, the preparation of the 2-amino terephthalic acid mixed solution includes the following steps:

[0051] S1012. Mixing 2-amino terephthalic acid, N,N-dimethylformamide (DMF) and methanol (MeOH).

[0052] In the preparation of the 2-amino terephthalic acid mixed solution, DMF is a good solvent for high-temperature reaction, and MeOH helps the mixing and preliminary hydrolysis of titanium alkoxide.

[0053] In some embodiments, in the step S1012, the mass-volume ratio of 2-amino terephthalic acid, N,N-dimethylformamide (DMF) and methanol (MeOH) is (0.05g-0.08g):(1ml-2ml):1ml.

[0054] In some embodiments, in the step S101, the mixing process includes the following steps:

[0055] S1013. After dispersing Na-β-Al2O3 ceramic particles and tetraisopropyl titanate in the 2-amino terephthalic acid mixed solution, drop the sodium hydroxide methanol solution, and then add water.

[0056] In some embodiments, in the step S1013, the molar volume ratio of tetraisopropyl titanate and water is 1 mmol:(0.3ml-0.4ml).

[0057] In some embodiments, in the step S101, the solvothermal reaction includes the following steps:

[0058] S1014. After heating the mixed solution to 120℃-130℃, keep the temperature and react.

[0059] In the solvothermal reaction, the mixed solution is kept at 120℃-130℃ for reaction, and DMF and methanol are used as mixed solvents. The polarity and coordination ability of the mixed solvents make the slow and orderly growth of Na / Ti-MOF crystal nucleus. During the crystallization process of MOF in the pores of Na-β-Al2O3 ceramic particles, part of Na +The carboxylic acid oxygen atoms are captured around the framework, in crystal defect sites or channels, achieving in-situ doping.

[0060] In some embodiments, in the step S1014, the heating rate is 2-3°C / min.

[0061] In some embodiments, in the step S1014, the holding reaction time is 24-26h. In this case, the holding reaction for 24-26h can give the Na / Ti-MOF crystals sufficient time to grow in the Na-β-Al2O3 ceramic particles, obtaining a product with high crystallinity.

[0062] In some embodiments, in the step S10, the preparation of Na-β-Al2O3@Na / Ti-MOF further comprises the following steps:

[0063] S102. Obtaining the solid product obtained by the solvothermal reaction, washing the solid product and vacuum drying to constant weight to obtain Na-β-Al2O3@Na / Ti-MOF.

[0064] In the preparation of the above Na-β-Al2O3@Na / Ti-MOF, the unreacted raw materials are removed by washing, and the residual DMF, methanol and other solvents in the channels of Na-β-Al2O3@Na / Ti-MOF are removed by vacuum drying to constant weight, obtaining activated Na-β-Al2O3@Na / Ti-MOF with open channels, and further improving the specific surface area and adsorption performance of Na-β-Al2O3@Na / Ti-MOF.

[0065] In some embodiments, in the step S102, the solid product obtained by the solvothermal reaction is obtained by centrifugation.

[0066] In some embodiments, the centrifugal speed is 2800-3200rpm.

[0067] In some embodiments, the centrifugation time is 5-8min.

[0068] In some embodiments, in the step S102, the washing comprises the following steps:

[0069] S1021. Washing the solid product with N,N-dimethylformamide, and then washing with anhydrous ethanol.

[0070] In the above washing, the N,N-dimethylformamide washing displaces the residual reactants and high-boiling solvent mother liquor in the channels; the anhydrous ethanol washing removes residual N,N-dimethylformamide

[0071] In some embodiments, in the step S1021 described above, the number of times of washing the solid product with N,N-dimethylformamide is 2-3 times.

[0072] In some embodiments, in the step S1021 described above, the number of times of washing with anhydrous ethanol is 3-4 times.

[0073] In some embodiments, in the step S102 described above, the drying temperature is 100-120°C.

[0074] In some embodiments, in the step S10 described above, the mixing of Na-β-Al2O3@Na / Ti-MOF, sodium salt electrolyte and binder comprises the following steps:

[0075] S103. After the sodium salt electrolyte is dropped into Na-β-Al2O3@Na / Ti-MOF under ball milling, the binder is added and the ball milling is continued.

[0076] In the mixing step described above, the sodium salt electrolyte is dropped into Na-β-Al2O3@Na / Ti-MOF, so that the sodium salt is infiltrated in the pore channels of Na-β-Al2O3@Na / Ti-MOF, the discrete solid particles are connected to form a continuous solid-liquid-solid ion transmission path; then the binder is added to improve the viscosity of the electrolyte.

[0077] In some embodiments, in the step S103 described above, the dropping speed of the sodium salt electrolyte is 10-20 d / min.

[0078] In some embodiments, in the step S103 described above, the time for continuing the ball milling is 2-3 h.

[0079] The following is further illustrated in conjunction with specific embodiments.

[0080] For the convenience of illustration, in the following sodium ion battery:

[0081] (1) In the positive electrode sheet, the positive active material is NaNiO2; the material of the negative electrode sheet is sodium sheet;

[0082] (2) The positive current collector and the negative current collector are both aluminum foil.

[0083] (3) Preparation of the positive electrode sheet: NaNiO2: carbon nanotube: polyvinylidene fluoride are mixed in a mass ratio of 90:5:5, a solvent N-methyl pyrrolidone (NMP) is added to adjust the viscosity, and a positive electrode slurry is prepared; the positive electrode slurry is uniformly coated on the surface (perpendicular to the thickness direction) of the aluminum foil (positive current collector) and dried, then rolled and cut to obtain a positive electrode sheet containing a positive electrode film layer.

[0084] (4) The average molecular weight of the polyvinylidene fluoride-hexafluoropropylene copolymer is 500,000.

[0085] Embodiment 1

[0086] Embodiment 1 provides a semi-solid sodium ion battery, wherein the raw materials for preparing the composite electrolyte are composed of components in the following weight proportions:

[0087] 70 parts of Na-β-Al2O3@Na / Ti-MOF, 30 parts of a sodium salt electrolyte, and 3 parts of a polyvinylidene fluoride-hexafluoropropylene copolymer.

[0088] The raw materials for preparing the Na-β-Al2O3@Na / Ti-MOF are Na-β-Al2O3 ceramic particles, tetraisopropyl titanate, sodium hydroxide, and 2-amino terephthalic acid, and the mass molar ratio is 1 g:1 mmol:0.04 mmol:2.5 mmol;

[0089] The average particle size of the Na-β-Al2O3 ceramic particles is 3 μm;

[0090] The sodium salt electrolyte is a mixture of sodium hexafluorophosphate (NaPF6) and an organic carbonate mixed solvent, and the concentration of sodium is 1 mol / L;

[0091] The organic carbonate mixed solvent is a mixture of ethylene carbonate (EC), propylene carbonate (PC), and dimethyl carbonate (DMC) in a volume ratio of 1:1:1.

[0092] The embodiment also provides a preparation method of the semi-solid sodium ion battery of the embodiment, and the steps are as follows:

[0093] E10. Preparation of the composite electrolyte

[0094] E101. Preparation of Na-β-Al2O3@Na / Ti-MOF

[0095] E1011. Preparation of a sodium hydroxide methanol solution: sodium hydroxide and methanol (MeOH) are mixed to obtain a sodium hydroxide methanol solution with a molar concentration of sodium hydroxide of 1 mol / L.

[0096] E1012. Preparation of a 2-amino terephthalic acid mixed solution: 2-amino terephthalic acid, N,N-dimethylformamide (DMF), and methanol (MeOH) are mixed to obtain a 2-amino terephthalic acid mixed solution.

[0097] The mass volume ratio of 2-amino terephthalic acid, N,N-dimethylformamide (DMF), and methanol (MeOH) is 0.05 g:1 ml:1 ml.

[0098] E1013. Preparation of the mixed solution: after dispersing Na-β-Al2O3 ceramic particles and tetraisopropyl titanate in a 2-amino terephthalic acid mixed solution, drop a sodium hydroxide methanol solution, and then drop water to obtain the mixed solution.

[0099] The molar volume ratio of tetraisopropyl titanate and water is 1 mmol:0.3 ml.

[0100] E1014. Solvothermal reaction: after heating the mixed solution to 120℃ at a heating rate of 2℃ / min, keep the temperature for 24h.

[0101] E1015. Post-treatment: centrifuge the solid product obtained by solvothermal reaction, wash the solid product with N,N-dimethylformamide, and then wash with anhydrous ethanol; after washing, vacuum dry to constant weight to obtain Na-β-Al2O3@Na / Ti-MOF.

[0102] The centrifugal speed is 3000rpm, and the time is 5min;

[0103] The number of times of washing the solid product with N,N-dimethylformamide is 3 times;

[0104] The number of times of washing with anhydrous ethanol is 3 times;

[0105] The drying temperature is 120℃.

[0106] E102. Under ball milling, drop the sodium salt electrolyte into Na-β-Al2O3@Na / Ti-MOF, then add a binder, and continue ball milling to obtain a composite electrolyte.

[0107] The drop rate of the sodium salt electrolyte is 15d / min;

[0108] The time for continuing ball milling is 2h.

[0109] E20. Assembly: assemble the positive electrode sheet, the composite electrolyte prepared in this embodiment, and the negative electrode sheet to obtain a semi-solid sodium ion battery.

[0110] Example 2

[0111] Example 2 provides a semi-solid sodium ion battery, wherein the preparation raw materials of the composite electrolyte are basically the same as those in Example 1, except that:

[0112] The weight parts of the preparation raw materials are as follows:

[0113] 60 parts of Na-β-Al2O3@Na / Ti-MOF, 25 parts of sodium salt electrolyte, and 1 part of polyvinylidene fluoride-hexafluoropropylene copolymer.

[0114] The embodiment also provides a preparation method of the semi-solid sodium ion battery of the embodiment, and steps are basically the same as those of the embodiment 1, except that:

[0115] The weight parts of the preparation raw materials are as follows:

[0116] 60 parts of Na-β-Al2O3@Na / Ti-MOF, 25 parts of a sodium salt electrolyte and 1 part of polyvinylidene fluoride-hexafluoropropylene copolymer.

[0117] Embodiment 3

[0118] The embodiment 3 provides a semi-solid sodium ion battery, wherein preparation raw materials of a composite electrolyte are basically the same as those of the embodiment 1, except that:

[0119] The weight parts of the preparation raw materials are as follows:

[0120] 85 parts of Na-β-Al2O3@Na / Ti-MOF, 35 parts of a sodium salt electrolyte and 5 parts of polyvinylidene fluoride-hexafluoropropylene copolymer.

[0121] The embodiment also provides a preparation method of the semi-solid sodium ion battery of the embodiment, and steps are basically the same as those of the embodiment 1, except that:

[0122] The weight parts of the preparation raw materials are as follows:

[0123] 85 parts of Na-β-Al2O3@Na / Ti-MOF, 35 parts of a sodium salt electrolyte and 5 parts of polyvinylidene fluoride-hexafluoropropylene copolymer.

[0124] Embodiment 4

[0125] The embodiment 4 provides a semi-solid sodium ion battery, wherein preparation raw materials of a composite electrolyte are basically the same as those of the embodiment 1, except that:

[0126] The preparation raw materials and the weight parts are as follows:

[0127] 70 parts of Na-β-Al2O3@Na / Ti-MOF and 25 parts of a sodium salt electrolyte.

[0128] The embodiment also provides a preparation method of the semi-solid sodium ion battery of the embodiment, and steps are as follows:

[0129] E11. Preparation of a composite electrolyte

[0130] E111. Preparation of Na-β-Al2O3@Na / Ti-MOF

[0131] E1111. Preparation of a sodium hydroxide methanol solution: sodium hydroxide and methanol (MeOH) are mixed to obtain a sodium hydroxide methanol solution with a molar concentration of 1 mol / L of sodium hydroxide.

[0132] E1112. Preparation of 2-aminoterephthalic acid mixed solution: 2-aminoterephthalic acid, N,N-dimethylformamide (DMF) and methanol (MeOH) were mixed to obtain a 2-aminoterephthalic acid mixed solution.

[0133] The mass-volume ratio of 2-aminoterephthalic acid, N,N-dimethylformamide (DMF) and methanol (MeOH) is 0.05 g: 1 ml: 1 ml.

[0134] E1113. Preparation of mixed solution: Na-β-Al2O3 ceramic particles and tetraisopropyl titanate were dispersed in the 2-aminoterephthalic acid mixed solution, and then sodium hydroxide methanol solution was added dropwise, followed by the addition of water to obtain a mixed solution.

[0135] The molar-volume ratio of tetraisopropyl titanate and water is 1 mmol: 0.3 ml.

[0136] E1114. Solvothermal reaction: the mixed solution was heated to 120℃ at a heating rate of 2℃ / min and then reacted for 24 h.

[0137] E1115. Post-treatment: the solid product obtained by solvothermal reaction was obtained by centrifugation, and the solid product was washed with N,N-dimethylformamide, and then washed with anhydrous ethanol; after washing, vacuum drying was performed until the weight was constant to obtain Na-β-Al2O3@Na / Ti-MOF.

[0138] The centrifugal speed is 3000 rpm, and the time is 5 min;

[0139] The number of times of washing the solid product with N,N-dimethylformamide is 3 times;

[0140] The number of times of washing with anhydrous ethanol is 3 times;

[0141] The drying temperature is 120℃.

[0142] E112. Under ball milling, the sodium salt electrolyte was added dropwise into Na-β-Al2O3@Na / Ti-MOF, and then the ball milling was continued to obtain a composite electrolyte.

[0143] The drop rate of the sodium salt electrolyte is 15 d / min;

[0144] The time for continuing ball milling is 2 h.

[0145] E21. Assembly: the positive electrode sheet, the composite electrolyte prepared in this embodiment, and the negative electrode sheet were assembled to obtain a semi-solid sodium ion battery.

[0146] Comparative Example 1

[0147] Comparative Example 1 provides a semi-solid sodium ion battery, wherein the preparation raw materials of the electrolyte are composed of the following preparation raw materials in parts by weight:

[0148] 70 parts of Na-β-Al2O3 ceramic particles, 30 parts of a sodium salt electrolyte, and 3 parts of a polyvinylidene-hexafluoropropylene copolymer.

[0149] The average particle size of the Na-β-Al2O3 ceramic particles is 3 μm;

[0150] The sodium salt electrolyte is a mixture of sodium hexafluorophosphate (NaPF6) and an organic carbonate mixed solvent, and the concentration of sodium is 1 mol / L;

[0151] The organic carbonate mixed solvent is a mixture of ethylene carbonate (EC), propylene carbonate (PC), and dimethyl carbonate (DMC) in a volume ratio of 1:1:1.

[0152] Comparative Example 1 provides a semi-solid sodium ion battery, wherein the preparation raw materials of the electrolyte are composed of the following preparation raw materials in parts by weight:

[0153] D10. Electrolyte preparation: After the sodium salt electrolyte is dropped into the Na-β-Al2O3 ceramic particles under ball milling, a binder is added, and the ball milling is continued to obtain the electrolyte.

[0154] The dropping speed of the sodium salt electrolyte is 15 d / min;

[0155] The time for continuing the ball milling is 2 h.

[0156] D20. Assembly: The positive electrode sheet, the electrolyte prepared in step D10, and the negative electrode sheet are assembled to obtain the semi-solid sodium ion battery.

[0157] Comparative Example 2

[0158] Comparative Example 2 provides a semi-solid sodium ion battery, wherein the preparation raw materials of the electrolyte are composed of the following preparation raw materials in parts by weight:

[0159] 70 parts of Na / Ti-MOF, 30 parts of a sodium salt electrolyte, and 3 parts of a polyvinylidene-hexafluoropropylene copolymer.

[0160] The average particle size of the Na / Ti-MOF is 3 μm;

[0161] The sodium salt electrolyte is a mixture of sodium hexafluorophosphate (NaPF6) and an organic carbonate mixed solvent, and the concentration of sodium is 1 mol / L;

[0162] The organic carbonate mixed solvent is a mixture of ethylene carbonate (EC), propylene carbonate (PC), and dimethyl carbonate (DMC) in a volume ratio of 1:1:1.

[0163] The present comparative example provides a preparation method of a semi-solid sodium ion battery of the present comparative example, and the steps are as follows:

[0164] D11. Preparation of Na / Ti-MOF

[0165] D111. Preparation of sodium hydroxide methanol solution: sodium hydroxide and methanol (MeOH) are mixed to obtain a sodium hydroxide methanol solution with a molar concentration of sodium hydroxide of 1 mol / L.

[0166] D112. Preparation of 2-amino terephthalic acid mixed solution: 2-amino terephthalic acid, N,N-dimethylformamide (DMF) and methanol (MeOH) are mixed to obtain a 2-amino terephthalic acid mixed solution.

[0167] Among them, the mass-volume ratio of 2-amino terephthalic acid, N,N-dimethylformamide (DMF) and methanol (MeOH) is 0.05g:1ml:1ml.

[0168] D113. Preparation of mixed solution: after dispersing titanium isopropylate in the 2-amino terephthalic acid mixed solution, drop sodium hydroxide methanol solution to obtain the mixed solution.

[0169] D114. Solvothermal reaction: after heating the mixed solution to 120℃ at a heating rate of 2℃ / min, keep the temperature for 24h.

[0170] D115. Post-treatment: centrifuge the solid product obtained by solvothermal reaction, wash the solid product with N,N-dimethylformamide, and then wash with anhydrous ethanol; after washing, vacuum drying to constant weight to obtain Na / Ti-MOF.

[0171] Among them, the centrifugal speed is 3000rpm, and the time is 5min;

[0172] The number of times of washing the solid product with N,N-dimethylformamide is 3 times;

[0173] The number of times of washing with anhydrous ethanol is 3 times;

[0174] The drying temperature is 120℃.

[0175] D21. Preparation of electrolyte: under ball milling, drop sodium salt electrolyte into Na / Ti-MOF, then add binder, continue ball milling to obtain electrolyte.

[0176] Among them, the drop speed of sodium salt electrolyte is 15d / min;

[0177] The time of continuing ball milling is 2h.

[0178] D31. Assembling: assembling the positive electrode sheet, the electrolyte prepared in step D21, and the negative electrode sheet to obtain a semi-solid sodium ion battery.

[0179] Comparative Example 3

[0180] Comparative Example 3 provides a semi-solid sodium ion battery, wherein the preparation raw materials of the electrolyte are composed of the following preparation raw materials in parts by weight:

[0181] 35 parts of Na / Ti-MOF, 35 parts of Na-β-Al2O3 ceramic particles, 30 parts of a sodium salt electrolyte, and 3 parts of a polyvinylidene fluoride-hexafluoropropylene copolymer.

[0182] The average particle size of the Na / Ti-MOF is 3 μm;

[0183] The average particle size of the Na-β-Al2O3 ceramic particles is 3 μm;

[0184] The sodium salt electrolyte is a mixture of sodium hexafluorophosphate (NaPF6) and an organic carbonate mixed solvent, and the concentration of sodium is 1 mol / L;

[0185] The organic carbonate mixed solvent is a mixture of ethylene carbonate (EC), propylene carbonate (PC), and dimethyl carbonate (DMC) in a volume ratio of 1:1:1.

[0186] The present comparative example provides a preparation method of the semi-solid sodium ion battery of the present comparative example, and the steps are basically the same as those of Comparative Example 2, except that:

[0187] The electrolyte preparation step of step D21 is as follows:

[0188] After the Na / Ti-MOF and the Na-β-Al2O3 ceramic particles are mixed under ball milling, the sodium salt electrolyte is added dropwise, and then the binder is added, and the ball milling is continued to obtain the electrolyte.

[0189] The drop rate of the sodium salt electrolyte is 15 d / min;

[0190] The time for continuing ball milling is 2 h.

[0191] In order to verify the progressiveness of the semi-solid sodium ion battery and the preparation method thereof provided in the embodiments of the present application, the capacity retention rates (%) of the semi-solid sodium ion batteries prepared in the embodiments of the present application and the comparative examples are tested at 25℃ under 3C cycling for 500 times, and the results are shown in Table 1 below.

[0192]

[0193] From Table 1 above, at least the following conclusions can be drawn:

[0194] The capacity retention rate of the sodium ion battery of the comparative example 1 is lower than that of the example, because the sodium metal in the Na-β-Al2O3 ceramic particles can grow in dendritic form at the ceramic grain boundary or defect under long-term cycling or high current density, and finally can penetrate the electrolyte, resulting in internal short circuit of the battery. The sodium ion battery of the comparative example 2 has poor cycle stability, because the Na / Ti-MOF has low ionic conductivity and interface instability. In the comparative example 3, although the Na-β-Al2O3 ceramic particles and the Na / Ti-MOF are used, the physical mixing of the two affects the interface stability between the Na-β-Al2O3 ceramic particles and the Na / Ti-MOF and between the electrolyte and the electrode material, further resulting in rapid capacity attenuation of the battery. It can be seen that the composite electrolyte provided by the example of the application contains Na-β-Al2O3@Na / Ti-MOF, the Na / Ti-MOF is in-situ loaded in the pore channel of the Na-β-Al2O3 ceramic particles, the Na-β-Al2O3 ceramic particles are modified, the stability of the structural framework of the Na-β-Al2O3 is improved, the wettability of the Na-β-Al2O3 and the sodium salt electrolyte is promoted, the interface wettability between the Na-β-Al2O3 and the sodium salt electrolyte is improved, and thus the ion transmission rate is improved, and finally the rapid charging capacity and the high-rate discharge performance of the battery are improved.

[0195] It should be noted that the present application is not limited to the above-described embodiments. The above-described embodiments are only examples, and embodiments having substantially the same configuration and playing the same role and effect as the technical idea within the scope of the technical solution of the present application are included in the technical scope of the present application. Furthermore, within the scope of the main idea of the present application, various modifications that can be thought of by those skilled in the art, other modes constructed by combining part of the configuration elements of the embodiments are also included in the scope of the present application.

Claims

1. A semi-solid sodium-ion battery, characterized by, The electrolyte is a composite electrolyte; The composite electrolyte comprises the following raw materials by weight: 60-85 parts of Na-β-Al2O3@Na / Ti-MOF, 25-35 parts of a sodium salt electrolyte, and 0-5 parts of a binder; The preparation of the Na-β-Al2O3@Na / Ti-MOF comprises the following steps:

2. The semi-solid sodium-ion battery of claim 1, wherein, The preparation of the Na-β-Al2O3@Na / Ti-MOF comprises the following steps: The Na-β-Al2O3 ceramic particles, tetraisopropyl titanate, sodium hydroxide, and 2-amino terephthalic acid are mixed and treated to obtain a mixed solution, and then a solvothermal reaction is performed. At least one of the following (1)-(8) is satisfied: (1) The composite electrolyte comprises the following raw materials by weight: 60-85 parts of Na-β-Al2O3@Na / Ti-MOF, 25-35 parts of a sodium salt electrolyte, and 1-5 parts of a binder; (2) The composite electrolyte comprises the following raw materials by weight: 60-85 parts of Na-β-Al2O3@Na / Ti-MOF, and 25-35 parts of a sodium salt electrolyte; (3) The average particle size of the Na-β-Al2O3 ceramic particles is 1-5 μm; (4) The mass molar ratio of the Na-β-Al2O3 ceramic particles, tetraisopropyl titanate, sodium hydroxide, and 2-amino terephthalic acid is 1 g:1-1.5 mmol:0.02-0.05 mmol:2.5-3 mmol; (5) The sodium salt electrolyte comprises a sodium salt and an organic carbonate mixed solvent; (6) The sodium salt comprises at least one of sodium perchlorate, sodium hexafluorophosphate, sodium bis(trifluoromethylsulfonyl)imide, and sodium bisfluorosulfonylimide; 3. A method of producing a semi-solid sodium-ion battery as claimed in claim 1 or 2, characterized in that, (7) In the sodium salt electrolyte, the concentration of sodium is 1-1.2 mol / L; (8) The binder comprises polyvinylidene fluoride-hexafluoropropylene copolymer.

4. The method of claim 3, wherein the semi-solid sodium-ion battery is prepared by the steps of: The preparation of the composite electrolyte comprises the following steps: The Na-β-Al2O3@Na / Ti-MOF, the sodium salt electrolyte, and the binder are mixed in a predetermined ratio.

5. The method of claim 4, wherein the semi-solid sodium-ion battery is prepared by the steps of: The preparation of the Na-β-Al2O3@Na / Ti-MOF comprises the following steps: The Na-β-Al2O3 ceramic particles, tetraisopropyl titanate, sodium hydroxide, and 2-amino terephthalic acid are mixed and treated to obtain a mixed solution, and then a solvothermal reaction is performed. At least one of the following (1)-(3) is satisfied: (1) The preparation of the sodium hydroxide methanol solution comprises the following steps: Sodium hydroxide and methanol are mixed; (2) In the sodium hydroxide methanol solution, the molar concentration of sodium hydroxide is 1-1.2 mol / L; 6. The method of claim 5, wherein the semi-solid sodium-ion battery is prepared by the steps of: (3) The preparation of the 2-amino terephthalic acid mixed solution comprises the following steps: 2-amino terephthalic acid, N,N-dimethylformamide, and methanol are mixed. At least one of the following (1)-(3) is satisfied: (1) The mixing treatment comprises the following steps: The Na-β-Al2O3 ceramic particles and tetraisopropyl titanate are dispersed in the 2-amino terephthalic acid mixed solution, then the sodium hydroxide methanol solution is added dropwise, and water is added; (2) The solvothermal reaction comprises the following steps: The mixed solution is heated to 120-130°C and then incubated for reaction; (3) In the preparation of the 2-amino terephthalic acid mixed solution, the mass-volume ratio of 2-amino terephthalic acid, N,N-dimethylformamide and methanol is 0.05g-0.08g:1ml-2ml:1ml.

7. The method of claim 6, wherein the semi-solid sodium-ion battery is prepared by a process comprising: At least one of the following (1)-(3) characteristics is satisfied: (1) In the mixing process, the molar volume ratio of tetraisopropyl titanate and water is 1mmol:0.3ml-0.4ml; (2) In the solvothermal reaction, the heating rate is 2℃ / min-3℃ / min; (3) In the solvothermal reaction, the holding reaction time is 24h-26h.

8. The method of claim 7, wherein the semi-solid sodium-ion battery is prepared by the steps of: The preparation of the Na-β-Al2O3@Na / Ti-MOF further includes the following steps: Obtain the solid product obtained by the solvothermal reaction, wash the solid product, and vacuum dry to constant weight to obtain the Na-β-Al2O3@Na / Ti-MOF.

9. The method of claim 8, wherein the semi-solid sodium-ion battery is prepared by a process comprising: At least one of the following (1)-(5) characteristics is satisfied: (1) The washing includes the following steps: After washing the solid product with N,N-dimethylformamide, wash it with anhydrous ethanol; (2) The drying temperature is 100℃-120℃; (3) The mixing of the Na-β-Al2O3@Na / Ti-MOF, the sodium salt electrolyte and the binder includes the following steps: After adding the sodium salt electrolyte into the Na-β-Al2O3@Na / Ti-MOF under ball milling, add the binder and continue ball milling; (4) The drop rate of the sodium salt electrolyte is 10d / min-20d / min; (5) The time for the continued ball milling is 2h-3h.

10. The application of the semi-solid sodium ion battery of claim 1 or 2 in the field of new energy.

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