Thick slurry electrode, preparation method and lithium slurry battery

Abstract

The invention relates to a thick paste electrode, a preparation method and a lithium paste battery, and the preparation method of the thick paste electrode comprises the following steps: dispersing an original material oxide in a first solvent, and sequentially carrying out ultrasonic treatment, first heat treatment, freeze drying and second heat treatment to obtain three-dimensional porous conductive aerogel; mixing and stirring the three-dimensional porous conductive aerogel, the active particles, the ionic liquid and the electrolyte to obtain electrode slurry; performing 3D printing on the electrode slurry on a current collector to obtain a thick slurry electrode; the original material oxide comprises any one or a combination of at least two of a graphene oxide, a carbon nanotube oxide or an MXene oxide. The active particles are filled in the pores of the three-dimensional porous conductive aerogel particles to form a stable integrated structure, and the active particles are matched with the ionic liquid to construct a slurry microenvironment system, so that high electronic conductivity and ionic conductivity can be kept for a long time; 3D printing is easy and convenient to operate, and the shape, size and thickness can be accurately controlled.

Description

Technical Field

[0001] This invention belongs to the field of large-scale electrochemical energy storage technology, and relates to a lithium slurry battery, particularly to a thick slurry electrode, a preparation method, and a lithium slurry battery. Background Technology

[0002] Battery active materials include positive electrode active materials and negative electrode active materials. Positive electrode active materials include lithium iron phosphate, lithium manganese iron phosphate, lithium cobalt oxide, lithium manganese oxide, high-nickel ternary materials, and lithium-rich manganese-based materials, while negative electrode materials include graphite, mesophase carbon microspheres, and lithium titanate. These materials possess high ion storage capacity, but they generally suffer from low conductivity, requiring the addition of conductive agents to improve the conductivity of the active materials. However, the addition of conductive agents will reduce the energy density of the battery to some extent.

[0003] Lithium slurry batteries achieve energy storage by directly mixing active materials, conductive agents, and electrolytes as electrodes. Since the solubility of the active materials in lithium slurry batteries is no longer a limiting factor, their energy density can be several times that of typical aqueous flow batteries. However, in lithium slurry battery electrode systems, especially when preparing large-capacity thick electrode systems, the amount of conductive agent added needs to reach a certain value to construct a complete conductive network structure and achieve good electronic conduction.

[0004] CN119050273A discloses a lithium slurry battery electrode and its component ratio screening method and application. By exploring the effects of different components such as active materials, conductive agents, dispersants, and electrolytes on conductivity, viscosity, and specific capacity, it was found that when the amount of active material added is 8 wt%, the amount of conductive agent added is 0.5 wt%, which cannot improve the conductivity of the slurry; however, when the amount added reaches 1 wt%, the conductivity improves. CN116130604A discloses a slurry battery electrode and its preparation method, which improves the conductivity and mechanical stability of the electrode by adding 1 wt% to 10 wt% of conductive agent to the slurry and winding it with polymer fibers.

[0005] However, due to sedimentation and volume changes, the internal conductive network of the slurry is in a state of dynamic change. Active materials may detach from the conductive network, leading to a sharp drop in conductivity and severely affecting battery performance. In addition, lithium slurry batteries have a low ion transport rate, and the manufacturing process of thick electrodes is more complicated and has poor consistency, further limiting the application of lithium slurry batteries.

[0006] Therefore, how to develop a simple, precise, and adjustable method for preparing thick slurry electrodes, and to make them have good conductivity, mechanical stability, and ion transport rate, thereby improving the electrochemical performance and stability of lithium slurry batteries, is an urgent problem to be solved in the field. Summary of the Invention

[0007] To address the shortcomings of existing technologies, this invention aims to provide a thick slurry electrode, its preparation method, and a lithium slurry battery. This invention utilizes a three-dimensional porous conductive aerogel to fill the pores with active particles, forming a stable, integrated structure. This allows the active particles to be stably anchored within the three-dimensional porous conductive aerogel. Furthermore, by combining it with an ionic liquid to construct a slurry microenvironment system, the thick slurry electrode can maintain high electronic and ionic conductivity over a long period. The 3D printing process is simple and allows for precise control of the shape, size, and thickness of the thick slurry electrode. This preparation method provides a new strategy for solving the problems of current lithium slurry batteries and improving their electrochemical performance and stability.

[0008] To achieve this objective, the present invention adopts the following technical solution:

[0009] In a first aspect, the present invention provides a method for preparing a thick paste electrode, the method comprising the following steps:

[0010] (1) The original material oxide is dispersed in the first solvent and subjected to ultrasonic treatment, first heat treatment, freeze drying and second heat treatment in sequence to obtain a three-dimensional porous conductive aerogel.

[0011] (2) The three-dimensional porous conductive aerogel, active particles, ionic liquid and electrolyte are mixed and stirred to obtain electrode slurry.

[0012] (3) The electrode paste is 3D printed on the current collector to obtain the thick paste electrode.

[0013] The original material oxide includes any one or a combination of at least two of graphene oxide, carbon nanotube oxide, or MXene oxide. Typical but non-limiting combinations include combinations of graphene oxide and carbon nanotube oxide, carbon nanotube oxide and MXene oxide, graphene oxide and MXene oxide, and graphene oxide, carbon nanotube oxide, and MXene oxide.

[0014] This invention utilizes a three-dimensional porous conductive aerogel to fill the pores with active particles, forming a stable, integrated structure. This allows the active particles to be stably anchored within the aerogel. Furthermore, by combining this aerogel with an ionic liquid to create a slurry microenvironment, the thick slurry electrode can maintain high electronic and ionic conductivity over a long period. The 3D printing process is simple and allows for precise control of the shape, size, and thickness of the thick slurry electrode. This preparation method provides a new strategy for addressing current problems in lithium slurry batteries and improving their electrochemical performance and stability.

[0015] Preferably, the first solvent in step (1) comprises any one or a combination of at least two of water, dimethyl sulfoxide, acetonitrile, N-methylpyrrolidone, alcohol solvents, amine solvents, or ester solvents. Typical but non-limiting combinations include combinations of water and dimethyl sulfoxide, combinations of acetonitrile and N-methylpyrrolidone, combinations of alcohols and amines, combinations of amines and esters, combinations of water, dimethyl sulfoxide and acetonitrile, combinations of N-methylpyrrolidone, alcohols and esters, combinations of water, dimethyl sulfoxide, acetonitrile and N-methylpyrrolidone, combinations of N-methylpyrrolidone, alcohols, amines and esters, combinations of water, dimethyl sulfoxide, acetonitrile, N-methylpyrrolidone and alcohols, combinations of water, dimethyl sulfoxide, acetonitrile, N-methylpyrrolidone, alcohols and amines, and combinations of water, dimethyl sulfoxide, acetonitrile, N-methylpyrrolidone, alcohols, amines and esters.

[0016] Preferably, the alcohol solvent includes any one or a combination of at least two of methanol, ethanol, ethylene glycol, propylene glycol, diethylene glycol, polyethylene glycol, or triethylene glycol. Typical but non-limiting combinations include combinations of methanol and ethanol, ethylene glycol and propylene glycol, diethylene glycol and polyethylene glycol, polyethylene glycol and triethylene glycol, methanol, ethanol, and ethylene glycol, propylene glycol, diethylene glycol, and polyethylene glycol, methanol, ethanol, ethylene glycol, and propylene glycol, propylene glycol, diethylene glycol, polyethylene glycol, and triethylene glycol, methanol, ethanol, ethylene glycol, propylene glycol, and diethylene glycol, methanol, ethanol, ethylene glycol, propylene glycol, diethylene glycol, and polyethylene glycol, and methanol, ethanol, ethylene glycol, propylene glycol, diethylene glycol, polyethylene glycol, and triethylene glycol.

[0017] Preferably, the amine solvent comprises any one or a combination of at least two of formamide, N,N-dimethylformamide, ethanolamine, ethylenediamine, diethylamine, triethylamine, ammonia, acetamide, urea, ammonium oxalate monohydrate, or acrylamide. Typical but non-limiting combinations include combinations of formamide and N,N-dimethylformamide, ethanolamine and ethylenediamine, diethylamine and triethylamine, ammonia and acetamide, urea and ammonium oxalate monohydrate, ammonium oxalate monohydrate and acrylamide, formamide, N,N-dimethylformamide and ethanolamine, ethylenediamine, diethylamine and triethylamine, ammonia, acetamide and urea, urea, ammonium oxalate monohydrate and acrylamide, formamide, N,N-dimethylformamide, ethanolamine and ethylenediamine, and diethylamine. Combinations of triethylamine, ammonia, and acetamide; combinations of formamide, N,N-dimethylformamide, ethanolamine, ethylenediamine, and diethylamine; combinations of triethylamine, ammonia, acetamide, urea, and ammonium oxalate monohydrate; combinations of formamide, N,N-dimethylformamide, ethanolamine, ethylenediamine, diethylamine, and triethylamine; combinations of triethylamine, ammonia, acetamide, urea, ammonium oxalate monohydrate, and acrylamide; combinations of formamide, N,N-dimethylformamide, ethanolamine, ethylenediamine, diethylamine, triethylamine, and ammonia; combinations of formamide, N,N-dimethylformamide, ethanolamine, ethylenediamine, diethylamine, triethylamine, ammonia, and acetamide; combinations of formamide, N,N-dimethylformamide, ethanolamine, ethylenediamine, diethylamine, triethylamine, ammonia, acetamide, urea, ammonium oxalate monohydrate, and acrylamide.

[0018] Preferably, the ester solvent includes any one or a combination of at least two of propylene carbonate, γ-butyrolactone, ethylene carbonate, or dimethyl carbonate. Typical but non-limiting combinations include combinations of propylene carbonate and γ-butyrolactone, combinations of ethylene carbonate and dimethyl carbonate, combinations of propylene carbonate, γ-butyrolactone, and ethylene carbonate, combinations of γ-butyrolactone, ethylene carbonate, and dimethyl carbonate, and combinations of propylene carbonate, γ-butyrolactone, ethylene carbonate, and dimethyl carbonate.

[0019] Preferably, the power of the ultrasonic treatment in step (1) is 100W~1000W, for example, it can be 100W, 200W, 300W, 400W, 500W, 600W, 700W, 800W, 900W or 1000W.

[0020] Preferably, the ultrasonic treatment time in step (1) is 10 min to 120 min, for example, it can be 10 min, 20 min, 30 min, 40 min, 50 min, 60 min, 70 min, 80 min, 90 min, 100 min, 110 min or 120 min.

[0021] Preferably, the temperature of the first heat treatment in step (1) is 90℃~200℃, for example, it can be 90℃, 100℃, 110℃, 120℃, 130℃, 140℃, 150℃, 160℃, 170℃, 180℃, 190℃ or 200℃, etc., preferably 120℃~160℃.

[0022] Preferably, the time for the first heat treatment in step (1) is 1h to 24h, for example, it can be 1h, 2h, 4h, 6h, 8h, 10h, 12h, 14h, 16h, 18h, 20h, 22h or 24h, and preferably 6h to 12h.

[0023] This invention, by controlling the temperature of the first heat treatment to 90℃~200℃ and the time to 1h~24h, facilitates the induction of π-π stacking, covalent cross-linking, and gas escape between the oxide layers of the original material, promoting the self-assembly of the layers to form a three-dimensional porous structure, providing a large number of sites for the filling and anchoring of active particles. If the temperature is too low or the time is too short, the degree of cross-linking between the layers is poor and the gas escape is less, affecting the formation of the three-dimensional porous structure; if the temperature is too high or the time is too long, it will intensify the stacking between the layers, resulting in a reduction in pore size and a decrease in anchoring points.

[0024] Preferably, the freeze-drying time in step (1) is 12h to 24h, for example, it can be 12h, 14h, 16h, 18h, 20h, 22h or 24h.

[0025] Preferably, the gas atmosphere of the second heat treatment in step (1) includes N2 and / or Ar.

[0026] Preferably, the temperature of the second heat treatment in step (1) is 200℃~800℃, for example, it can be 200℃, 250℃, 300℃, 350℃, 400℃, 450℃, 500℃, 550℃, 600℃, 650℃, 700℃, 750℃ or 800℃, etc., preferably 300℃~700℃.

[0027] Preferably, the second heat treatment time in step (1) is 0.5h to 8h, for example, it can be 0.5h, 1h, 2h, 3h, 4h, 5h, 6h, 7h or 8h, etc., preferably 2h to 6h.

[0028] This invention, by controlling the temperature of the second heat treatment to 200℃~800℃ and the time to 0.5h~8h, can effectively remove oxygen-containing functional groups, such as hydroxyl and epoxy groups, from the original material oxide while maintaining the three-dimensional porous structure. This reduction of the original material oxide significantly improves its conductivity, resulting in a three-dimensional porous conductive aerogel. This aerogel provides numerous sites for the filling and anchoring of active particles and also acts as a conductive agent to significantly improve the conductivity of thick slurry electrodes. If the temperature is too low or the time is too short, a large number of oxygen-containing functional groups, such as hydroxyl and epoxy groups, remain in the original material oxide, limiting the improvement in conductivity. If the temperature is too high or the time is too long, the layers are prone to sintering and agglomeration, leading to a reduction in pore size and anchoring points.

[0029] Preferably, the average particle size of the active particles in step (2) is 0.1μm to 100μm, for example, it can be 0.1μm, 0.5μm, 1μm, 5μm, 10μm, 20μm, 50μm, 80μm or 100μm, etc.

[0030] Preferably, the average pore size of the three-dimensional porous conductive aerogel in step (2) is 1μm~200μm, for example, it can be 1μm, 5μm, 10μm, 20μm, 50μm, 100μm, 120μm, 150μm or 200μm, etc.

[0031] Preferably, the average particle size of the active particles in step (2) is smaller than the average pore size of the three-dimensional porous conductive aerogel.

[0032] This invention controls the average particle size of the active particles to be 0.1 μm to 100 μm, the average pore size of the three-dimensional porous conductive aerogel to be 1 μm to 200 μm, and ensures that the average particle size of the active particles is smaller than the average pore size of the three-dimensional porous conductive aerogel. This allows the active particles to fill the pores of the three-dimensional porous conductive aerogel particles and form a stable, integrated structure, thereby anchoring them stably within the three-dimensional porous conductive aerogel, significantly improving conductivity and maintaining high conductivity for a long time. If the average pore size of the three-dimensional porous conductive aerogel is too small, the active particles cannot effectively fill the pores, affecting the improvement of conductivity; if the average pore size is too large, the active particles cannot be well anchored within the pores, affecting the stability of high conductivity.

[0033] Preferably, the average particle size of the three-dimensional porous conductive aerogel in step (2) is 50μm~1000μm, for example, it can be 50μm, 100μm, 200μm, 300μm, 400μm, 500μm, 600μm, 700μm, 800μm, 900μm or 1000μm, etc.

[0034] In this invention, the three-dimensional porous conductive aerogel has an average particle size of 50μm~1000μm, which allows the electrode slurry to form a uniform electrode layer on the surface of the current collector and to have good contact with both the current collector and the separator, thereby affecting conductivity.

[0035] Preferably, the active particles in step (2) have a mass fraction of 10wt% to 80wt% in the electrode slurry, for example, 10wt%, 20wt%, 30wt%, 40wt%, 50wt%, 60wt%, 70wt% or 80wt%, etc., preferably 20wt% to 40wt%.

[0036] Preferably, the mass fraction of the three-dimensional porous conductive aerogel in the electrode slurry in step (2) is 0.5wt% to 20wt%, for example, it can be 0.5wt%, 1wt%, 2wt%, 5wt%, 8wt%, 10wt%, 12wt%, 15wt%, 18wt% or 20wt%, etc., preferably 5wt% to 10wt%.

[0037] In this invention, the mass fraction of the three-dimensional porous conductive aerogel in the electrode slurry is 0.5wt%~20wt%. If the content is too low, it cannot provide sufficient pores and anchoring points for the active particles, thus affecting the improvement of conductivity. If the content is too high, it will not only affect the performance of the specific capacity of the active particles, but also increase the solid content of the electrode slurry, resulting in high sedimentation and inability to disperse evenly, thus leading to uneven thick slurry electrodes.

[0038] Preferably, the mass fraction of the ionic liquid in the electrode slurry in step (2) is 0.1wt% to 10wt%, for example, it can be 0.1wt%, 0.5wt%, 1wt%, 2wt%, 3wt%, 5wt%, 8wt% or 10wt%, etc., preferably 1wt% to 5wt%.

[0039] In this invention, the mass fraction of ionic liquid in the electrode slurry is 0.1wt% to 10wt%. If the content is too low, it will not effectively promote the ion transport rate, resulting in a decrease in ionic conductivity. If the content is too high, it will increase the viscosity of the electrode slurry, making the fluidity worse, which will lead to unevenness of the thick slurry electrode.

[0040] Preferably, the active particles in step (2) include positive active particles and / or negative active particles.

[0041] Preferably, the positive electrode active particles comprise any one or a combination of at least two of lithium iron phosphate, lithium manganese iron phosphate, lithium cobalt oxide, lithium manganese oxide, high-nickel ternary materials, or lithium-rich manganese-based materials. Typical but non-limiting combinations include combinations of lithium iron phosphate and lithium manganese iron phosphate, combinations of lithium cobalt oxide and lithium manganese oxide, combinations of high-nickel ternary materials and lithium-rich manganese-based materials, combinations of lithium iron phosphate, lithium manganese iron phosphate, and lithium cobalt oxide, combinations of lithium manganese oxide, high-nickel ternary materials, and lithium-rich manganese-based materials, combinations of lithium iron phosphate, lithium manganese iron phosphate, lithium cobalt oxide, and lithium manganese oxide, combinations of lithium iron phosphate, lithium manganese iron phosphate, lithium cobalt oxide, lithium manganese oxide, and high-nickel ternary materials, and combinations of lithium iron phosphate, lithium manganese iron phosphate, lithium cobalt oxide, lithium manganese oxide, high-nickel ternary materials, and lithium-rich manganese-based materials.

[0042] Preferably, the negative electrode active particles include any one or a combination of at least two of graphite, mesophase carbon microspheres, or lithium titanate. Typical but non-limiting combinations include a combination of graphite and mesophase carbon microspheres, a combination of mesophase carbon microspheres and lithium titanate, a combination of graphite and lithium titanate, and a combination of graphite, mesophase carbon microspheres, and lithium titanate.

[0043] Preferably, the ionic liquid in step (2) includes an alkanolamine ionic liquid with a composition of [XZ]. + [Y] - The ionic liquid or the composition is [CAH]. + [RCOO] - Any one or at least two of the following ionic liquids, typically but not limitingly, include alkanolamine ionic liquids and liquids with the composition [XZ]. + [Y] - The combination of ionic liquids forms [XZ]. + [Y] - The ionic liquid has the composition [CAH]. + [RCOO] - The combination of ionic liquids, including alkanolamine ionic liquids and those with the composition [CAH]. + [RCOO] - A combination of ionic liquids, specifically alkanolamine ionic liquids, with the composition [XZ]. + [Y] - The ionic liquid has the composition [CAH]. + [RCOO] - A combination of ionic liquids.

[0044] Wherein, X includes any one or a combination of at least two of 1-methyl-3-ethyl, 1-methyl-3-propyl, 1-allyl-3-methyl, 1-butyl-3-methyl, 1-hexadecyl-3-methyl, or 1-ethyl-3-methyl. Typical but non-limiting combinations include combinations of 1-methyl-3-ethyl and 1-methyl-3-propyl, combinations of 1-allyl-3-methyl and 1-butyl-3-methyl, combinations of 1-hexadecyl-3-methyl and 1-ethyl-3-methyl, combinations of 1-methyl-3-ethyl, 1-methyl-3-propyl, and 1-allyl-3-methyl, combinations of 1-butyl-3-methyl, 1-hexadecyl-3-methyl, and 1-ethyl-3-methyl. The following combinations of 1-methyl-3-propyl, 1-allyl-3-methyl, and 1-butyl-3-methyl; combinations of 1-methyl-3-ethyl, 1-methyl-3-propyl, 1-allyl-3-methyl, 1-butyl-3-methyl, and 1-hexadecyl-3-methyl; combinations of 1-methyl-3-ethyl, 1-methyl-3-propyl, 1-allyl-3-methyl, 1-butyl-3-methyl, 1-hexadecyl-3-methyl, and 1-ethyl-3-methyl; Z includes any one or at least two combinations of imidazole, pyridine, or pyrrolidine, with typical but non-limiting combinations including combinations of imidazole and pyridine, combinations of pyridine and pyrrolidine, combinations of imidazole and pyrrolidine, and combinations of imidazole, pyridine, and pyrrolidine; Y includes sulfuric acid. Any one or at least two combinations of hydrogen sulfate, dihydrogen phosphate, chloride, bromide, iodide, tetrafluoroborate, or bis(trifluoromethanesulfonyl)imide salts. Typical but non-limiting combinations include combinations of hydrogen sulfate and dihydrogen phosphate, chloride and bromide, iodide and tetrafluoroborate, tetrafluoroborate and bis(trifluoromethanesulfonyl)imide, hydrogen sulfate, dihydrogen phosphate, and chloride, bromide, iodide, and tetrafluoroborate, hydrogen sulfate, dihydrogen phosphate, chloride, and bromide, hydrogen sulfate, dihydrogen phosphate, chloride, bromide, and iodide, hydrogen sulfate, dihydrogen phosphate, chloride, bromide, iodide, and tetrafluoroborate, hydrogen sulfate, dihydrogen phosphate, chloride, bromide, iodide, and tetrafluoroborate. Combinations of salts and bis(trifluoromethanesulfonyl)imide salts; CA includes any one or at least two combinations of piperazine, imidazole, 5-pyrazolone, melamine, cyanuric chloride, or 2-imidazolylethylamine, typical but non-limiting combinations including combinations of piperazine and imidazole, combinations of 5-pyrazolone and melamine, combinations of cyanuric chloride and 2-imidazolylethylamine, combinations of piperazine, imidazole, and 5-pyrazolone, combinations of melamine, cyanuric chloride, and 2-imidazolylethylamine, combinations of piperazine, imidazole, 5-pyrazolone, and melamine, combinations of piperazine, imidazole, 5-pyrazolone, melamine, and cyanuric chloride, combinations of piperazine, imidazole, 5-pyrazolone, melamine, cyanuric chloride, and 2-imidazolylethylamine; R includes H and / or C1-C2 alkyl groups.

[0045] Preferably, the electrolyte in step (2) comprises a second solvent and a lithium salt.

[0046] Preferably, the second solvent comprises any one or a combination of at least two of ethylene carbonate, dimethyl carbonate, diethyl carbonate, methyl ethyl carbonate, or propylene carbonate. Typical but non-limiting combinations include combinations of ethylene carbonate and dimethyl carbonate, diethyl carbonate and methyl ethyl carbonate, methyl ethyl carbonate and propylene carbonate, ethylene carbonate, dimethyl carbonate and diethyl carbonate, diethyl carbonate, methyl ethyl carbonate and propylene carbonate, ethylene carbonate, dimethyl carbonate and diethyl carbonate, diethyl carbonate and methyl ethyl carbonate, and ethylene carbonate, dimethyl carbonate, diethyl carbonate, methyl ethyl carbonate and propylene carbonate; preferably, it is a combination of ethylene carbonate and dimethyl carbonate.

[0047] Preferably, the volume ratio of ethylene carbonate to dimethyl carbonate is (2~4):(6~8), for example, it can be 2:8, 2.5:7.5, 3:7, 3.5:6.5 or 4:6, etc.

[0048] Preferably, the lithium salt comprises any one or a combination of at least two of lithium hexafluorophosphate, lithium tetrafluoroborate, lithium perchlorate, lithium difluorooxalate borate, lithium bis(fluorosulfonyl)imide, or lithium bis(trifluoromethanesulfonyl)imide. Typical but non-limiting combinations include combinations of lithium hexafluorophosphate and lithium tetrafluoroborate, combinations of lithium perchlorate and lithium difluorooxalate borate, combinations of lithium bis(fluorosulfonyl)imide and lithium bis(trifluoromethanesulfonyl)imide, and combinations of lithium hexafluorophosphate, lithium tetrafluoroborate, and lithium difluorooxalate borate. Combinations of lithium oxides, combinations of lithium difluorooxalate borate, lithium bis(fluorosulfonyl)imide and lithium bis(trifluoromethanesulfonyl)imide, combinations of lithium hexafluorophosphate, lithium tetrafluoroborate, lithium perchlorate and lithium difluorooxalate borate, combinations of lithium hexafluorophosphate, lithium tetrafluoroborate, lithium perchlorate, lithium difluorooxalate borate and lithium bis(fluorosulfonyl)imide, combinations of lithium hexafluorophosphate, lithium tetrafluoroborate, lithium perchlorate, lithium difluorooxalate borate, lithium bis(fluorosulfonyl)imide and lithium bis(trifluoromethanesulfonyl)imide.

[0049] Preferably, the lithium salt has a mass fraction of 5wt% to 20wt% in the electrolyte, for example, it can be 5wt%, 6wt%, 7wt%, 8wt%, 9wt%, 10wt%, 12wt%, 14wt%, 16wt%, 18wt%, or 20wt%.

[0050] Preferably, the stirring speed in step (2) is 300 rpm to 800 rpm, for example, it can be 300 rpm, 400 rpm, 500 rpm, 600 rpm, 700 rpm or 800 rpm.

[0051] Preferably, the stirring time in step (2) is 1h to 8h, for example, it can be 1h, 2h, 3h, 4h, 5h, 6h, 7h or 8h.

[0052] Preferably, the stirring temperature in step (2) is 25°C to 45°C, for example, it can be 25°C, 30°C, 35°C, 40°C or 45°C.

[0053] Preferably, the temperature for 3D printing in step (3) is 0℃~50℃, for example, it can be 0℃, 5℃, 10℃, 15℃, 20℃, 25℃, 30℃, 35℃, 40℃, 45℃ or 50℃, etc.

[0054] Preferably, the extrusion speed of the electrode slurry during 3D printing in step (3) is 0.1cm / s to 2cm / s, for example, it can be 0.1cm / s, 0.2cm / s, 0.5cm / s, 0.8cm / s, 1cm / s, 1.2cm / s, 1.5cm / s, 1.8cm / s or 2cm / s, etc.

[0055] Preferably, the current collector in step (3) includes a positive current collector and / or a negative current collector.

[0056] Preferably, the positive current collector comprises aluminum foil and / or carbon-coated aluminum foil.

[0057] Preferably, the negative electrode current collector includes any one or a combination of at least two of aluminum foil, carbon-coated aluminum foil, copper foil, or carbon-coated copper foil. Typical but non-limiting combinations include a combination of aluminum foil and carbon-coated aluminum foil, a combination of copper foil and carbon-coated copper foil, or a combination of aluminum foil, carbon-coated aluminum foil, copper foil, and carbon-coated copper foil.

[0058] Preferably, the thickness of the electrode paste on the current collector in step (3) is 200μm to 3000μm, for example, it can be 200μm, 300μm, 500μm, 800μm, 1000μm, 1500μm, 2000μm, 2500μm, 2800μm or 3000μm, etc.

[0059] Preferably, the preparation method includes the following steps:

[0060] (1) The original material oxide is dispersed in the first solvent and subjected to ultrasonic treatment at a power of 100W~1000W for 10min~120min, first heat treatment at 90℃~200℃ for 1h~24h, freeze drying for 12h~24h, and second heat treatment at 200℃~800℃ in N2 and / or Ar atmosphere for 0.5h~8h to obtain a three-dimensional porous conductive aerogel.

[0061] The original material oxide includes any one or a combination of at least two of graphene oxide, carbon nanotube oxide, or MXene oxide.

[0062] (2) The three-dimensional porous conductive aerogel, active particles, ionic liquid and electrolyte are mixed and stirred at 25℃~45℃ and 300rpm~800rpm for 1h~8h to obtain electrode slurry.

[0063] The active particles have an average particle size of 0.1 μm to 100 μm, the three-dimensional porous conductive aerogel has an average pore size of 1 μm to 200 μm, the active particles have an average particle size smaller than the three-dimensional porous conductive aerogel, the three-dimensional porous conductive aerogel has an average particle size of 50 μm to 1000 μm, the active particles have a mass fraction of 10 wt% to 80 wt% in the electrode slurry, the three-dimensional porous conductive aerogel has a mass fraction of 0.5 wt% to 20 wt% in the electrode slurry, and the ionic liquid has a mass fraction of 0.1 wt% to 10 wt% in the electrode slurry.

[0064] (3) The electrode paste is 3D printed on the current collector to obtain the thick paste electrode.

[0065] The 3D printing temperature is 0℃~50℃, the extrusion speed of the electrode slurry during 3D printing is 0.1cm / s~2cm / s, and the thickness of the electrode slurry on the current collector is 200μm~3000μm.

[0066] In a second aspect, the present invention provides a thick slurry electrode, which is obtained by the preparation method of the thick slurry electrode described in the first aspect.

[0067] Thirdly, the present invention provides a lithium slurry battery, the lithium slurry battery comprising a thick slurry electrode as described in the second aspect.

[0068] The thick slurry electrode is the positive and / or negative electrode of the lithium slurry battery.

[0069] The numerical range described in this invention includes not only the point values ​​listed above, but also any point values ​​within the numerical ranges not listed above. Due to space limitations and for the sake of brevity, this invention will not exhaustively list all the specific point values ​​included in the range.

[0070] Compared with the prior art, the present invention has the following beneficial effects:

[0071] (1) Three-dimensional porous conductive aerogel particles have high electronic conductivity. Their internal pores can accommodate active particles and form a stable integrated structure. No additional conductive agent is needed to form a conductive network structure. This avoids the problems of using ultra-high dispersion equipment and particle agglomeration. It also avoids a series of problems that the slurry electrode needs to reach the conductivity penetration threshold for high conductivity.

[0072] (2) Ionic liquids have high ion transport characteristics and can work together with electrolytes and three-dimensional porous conductive aerogels to construct a microenvironment system for electrochemical reactions of active substances. This serves as a bridge for the good anchoring and contact of active particles in the three-dimensional porous conductive aerogel, significantly improving electronic conductivity and ionic conductivity and maintaining high electronic conductivity and ionic conductivity for a long time. At the same time, it can also increase the viscosity of the slurry to a certain extent, thereby improving the overall stability of the slurry electrode system.

[0073] (3) 3D printing is easy to operate and can precisely control the shape, size and thickness of thick slurry electrodes. It has advantages such as low energy and environmental protection, reduced raw material waste and short preparation cycle. Attached Figure Description

[0074] Figure 1 This is a schematic diagram of the ionic liquid-based thick slurry electrode with active particles filled inside the 3D printed three-dimensional porous conductive aerogel particles of the present invention. Detailed Implementation

[0075] The technical solution of the present invention will be further illustrated below through specific embodiments. Those skilled in the art should understand that the embodiments described are merely illustrative of the present invention and should not be construed as limiting the invention in any way.

[0076] The "range" disclosed in this invention can be defined in the form of a lower limit and an upper limit. A given range is defined by selecting a lower limit and an upper limit, which define the boundaries of the specific range. This type of range definition can include or exclude endpoints; any endpoint can be independently included or excluded, and they can be arbitrarily combined, meaning any lower limit can be combined with any upper limit to form a range. For example, if ranges of 60~120 and 80~110 are listed for specific parameters, it is understood that ranges of 60~110 and 80~120 are also expected. Furthermore, if minimum range values ​​1 and 2 are listed, and maximum range values ​​3, 4, and 5 are also listed, then the following ranges are all expected: 1~3, 1~4, 1~5, 2~3, 2~4, and 2~5. In this invention, unless otherwise stated, the numerical range "a~b" represents a shortened representation of any combination of real numbers between a and b, where a and b are real numbers. For example, the numerical range "0~5" indicates that all real numbers between "0" and "5" have been listed in this article; "0~5" is simply a shortened representation of these numerical combinations. Furthermore, when a parameter is described as an integer ≥2, it is equivalent to listing integers such as 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, etc. For instance, when a parameter is described as an integer selected from "2~10", it is equivalent to listing the integers 2, 3, 4, 5, 6, 7, 8, 9, and 10.

[0077] In this invention, "a combination of at least two" refers to a quantity greater than or equal to two, unless otherwise specified. For example, "any combination of one or at least two" means one or more or more items. It can be understood that when referring to "a combination of at least two," it refers to any suitable combination of multiple items, that is, a combination of "at least two" items carried out in a manner that does not conflict with and enables the implementation of this invention.

[0078] Unless otherwise specified, all embodiments and optional embodiments of the present invention can be combined with each other to form new technical solutions.

[0079] The term "embodiment" as used in this invention means that a specific feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment or implementation of the invention. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a mutually exclusive, independent, or alternative embodiment. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described in this invention can be combined with other embodiments.

[0080] Those skilled in the art will understand that the order in which the steps are written in the methods of the various embodiments does not imply a strict execution order. The detailed execution order of each step should be determined by its function and possible internal logic. Unless otherwise specified, all steps of the present invention may be performed sequentially or randomly, but are preferably performed sequentially. For example, if the method includes steps (a) and (b), it means that the method may include steps (a) and (b) performed sequentially, or it may include steps (b) and (a) performed sequentially. For example, the method may also include step (c), meaning that step (c) can be added to the method in any order. For example, the method may include steps (a), (b), and (c), or it may include steps (a), (c), and (b), or it may include steps (c), (a), and (b), etc.

[0081] In this invention, open-ended technical features or solutions described using terms such as "comprising" do not exclude additional members beyond those listed unless otherwise specified. They can be considered as providing both closed-ended features or solutions comprised of the listed members and open-ended features or solutions that include additional members beyond the listed members. For example, A includes a1, a2, and a3. Unless otherwise specified, it may also include other members or exclude additional members. This can be considered as providing both technical features or solutions where "A is composed of a1, a2, and a3" or "A is selected from a1, a2, and a3," and technical features or solutions where "A includes not only a1, a2, and a3, but also other members."

[0082] In this invention, unless otherwise specified, the features or solutions corresponding to "and / or" include any one of two or more of the related listed items, as well as any and all combinations of the related listed items. These arbitrary and all combinations include any two related listed items, any more related listed items, or a combination of all related listed items. For example, "A and / or B" represents a group consisting of A, B, and "a combination of A and B". "Containing A and / or B" can mean "containing A, containing B, and containing A and B", or "containing A, containing B, or containing A and B", and can be appropriately understood according to the context.

[0083] In this invention, the terms "first aspect," "second aspect," "third aspect," "fourth aspect," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or quantity, nor should they be construed as implicitly indicating the importance or quantity of the indicated technical features. Moreover, "first," "second," "third," "fourth," etc., serve only as a non-exhaustive enumeration and should be understood not to constitute a closed limitation on the quantity.

[0084] In this invention, "optional" means that something is optional, that is, it refers to any one of the two parallel solutions of "having" or "not having". If there are multiple "optional" options in a technical solution, unless otherwise specified, and there are no contradictions or mutual constraints, then each "optional" option is independent.

[0085] In this invention, "room temperature" generally refers to 4℃~35℃, and can refer to 20℃±5℃. In some embodiments of this invention, room temperature refers to 20℃~30℃.

[0086] Example 1

[0087] This embodiment provides a method for preparing a thick paste electrode, the method comprising:

[0088] (1) 15g of graphene oxide was dispersed in 500mL of ethanol and ultrasonically treated for 30min at a power of 500W to obtain a uniformly dispersed graphene oxide suspension. The graphene oxide suspension was then subjected to a first heat treatment at 150℃ for 8h and freeze-dried for 12h. Finally, the freeze-dried solid was placed in a tube furnace and subjected to a second heat treatment at 700℃ for 3h in an Ar environment to obtain a three-dimensional porous conductive graphene aerogel.

[0089] (2) 7g of three-dimensional porous conductive graphene aerogel particles (average pore size of 3μm, average particle size of 90μm), 40g of lithium iron phosphate particles (average particle size of 0.8μm), 3g of 1-ethyl-3-methylimidazolium tetrafluoroborate ionic liquid and 100g of electrolyte (volume ratio of ethylene carbonate and dimethyl carbonate of 3:7, mass fraction of LiPF6 in electrolyte of 10wt%) were mixed and stirred at 35℃ and 600rpm for 3h to obtain electrode slurry.

[0090] (3) Add the electrode paste to the storage chamber of the 3D printing device, set the 3D printing temperature to 30℃ and the electrode paste extrusion speed to 0.5cm / s, and 3D print it on the surface of the aluminum foil current collector in the designed strip structure shape to obtain a thick paste electrode, wherein the thickness of the electrode paste on the aluminum foil current collector is 800μm.

[0091] Example 2

[0092] This embodiment provides a method for preparing a thick paste electrode, the method comprising:

[0093] (1) 15g of carbon nanotube oxide was dispersed in 500mL of N-methylpyrrolidone and ultrasonically treated for 120min at 100W to obtain a uniformly dispersed carbon nanotube oxide suspension. The carbon nanotube oxide suspension was then subjected to a first heat treatment at 120℃ for 12h and freeze-dried for 18h. Finally, the freeze-dried solid was placed in a tube furnace and subjected to a second heat treatment at 300℃ for 6h in a N2 environment to obtain a three-dimensional porous conductive carbon nanotube aerogel.

[0094] (2) 13.5g of three-dimensional porous conductive carbon nanotube aerogel particles (average pore size of 10μm, average particle size of 100μm), 60g of lithium manganese iron phosphate particles (average particle size of 5μm), 1.5g of 1-allyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imine salt ionic liquid and 75g of electrolyte (the volume ratio of ethylene carbonate and dimethyl carbonate is 3:7, and the mass fraction of LiPF6 in the electrolyte is 10wt%) were mixed and stirred at 45℃ and 800rpm for 1h to obtain electrode slurry.

[0095] (3) Add the electrode slurry into the storage chamber of the 3D printing device, set the 3D printing temperature to 0℃ and the electrode slurry extrusion speed to 0.1cm / s, and 3D print it on the surface of the aluminum foil current collector in the designed strip structure shape to obtain a thick slurry electrode, wherein the thickness of the electrode slurry on the aluminum foil current collector is 3000μm.

[0096] Example 3

[0097] This embodiment provides a method for preparing a thick paste electrode, the method comprising:

[0098] (1) 15g of MXene oxide was dispersed in 500mL of water and ultrasonically treated for 10min at a power of 1000W to obtain a uniformly dispersed MXene oxide suspension. The MXene oxide suspension was then subjected to a first heat treatment at 160℃ for 6h and freeze-dried for 24h. Finally, the freeze-dried solid was placed in a tube furnace and subjected to a second heat treatment at 700℃ for 2h in an Ar environment to obtain a three-dimensional porous conductive MXene aerogel.

[0099] (2) 7.5g of three-dimensional porous conductive MXene aerogel particles (average pore size of 5μm and average particle size of 50μm), 30g of lithium cobalt oxide particles (average particle size of 2μm), 7.5g of 1-butyl-3-methylimidazolium tetrafluoroborate ionic liquid and 105g of electrolyte (the volume ratio of ethylene carbonate and dimethyl carbonate is 3:7, and the mass fraction of LiPF6 in the electrolyte is 10wt%) were mixed and stirred at 25℃ and 300rpm for 8h to obtain electrode slurry.

[0100] (3) Add the electrode slurry into the storage chamber of the 3D printing device, set the 3D printing temperature to 50℃ and the electrode slurry extrusion speed to 2cm / s, and 3D print it on the surface of the aluminum foil current collector in the designed strip structure shape to obtain a thick slurry electrode, wherein the thickness of the electrode slurry on the aluminum foil current collector is 200μm.

[0101] Example 4

[0102] This embodiment provides a method for preparing a thick paste electrode. Except for the temperature of the first heat treatment in step (1) being 120°C, all other steps are the same as in embodiment 1.

[0103] Example 5

[0104] This embodiment provides a method for preparing a thick paste electrode. Except for the temperature of the first heat treatment in step (1) being 90°C, all other steps are the same as in embodiment 1.

[0105] Example 6

[0106] This embodiment provides a method for preparing a thick paste electrode. Except for the temperature of the first heat treatment in step (1) being 200°C, all other steps are the same as in embodiment 1.

[0107] Example 7

[0108] This embodiment provides a method for preparing a thick slurry electrode. Except for the first heat treatment time of 6 hours in step (1), all other steps are the same as in embodiment 1.

[0109] Example 8

[0110] This embodiment provides a method for preparing a thick slurry electrode. Except for the first heat treatment time of 1 hour in step (1), all other steps are the same as in embodiment 1.

[0111] Example 9

[0112] This embodiment provides a method for preparing a thick slurry electrode. Except for the first heat treatment time of 24 hours in step (1), all other steps are the same as in embodiment 1.

[0113] Example 10

[0114] This embodiment provides a method for preparing a thick paste electrode. Except for the second heat treatment temperature of 600°C in step (1), all other steps are the same as in embodiment 1.

[0115] Example 11

[0116] This embodiment provides a method for preparing a thick slurry electrode. Except for the second heat treatment temperature of 200°C in step (1), all other steps are the same as in embodiment 1.

[0117] Example 12

[0118] This embodiment provides a method for preparing a thick slurry electrode. Except for the second heat treatment temperature of 800°C in step (1), all other steps are the same as in embodiment 1.

[0119] Example 13

[0120] This embodiment provides a method for preparing a thick slurry electrode. Except for the second heat treatment time of 2 hours in step (1), all other steps are the same as in embodiment 1.

[0121] Example 14

[0122] This embodiment provides a method for preparing a thick slurry electrode. Except for the second heat treatment time of 0.5h in step (1), all other steps are the same as in embodiment 1.

[0123] Example 15

[0124] This embodiment provides a method for preparing a thick slurry electrode. Except for the second heat treatment time of 8 hours in step (1), all other steps are the same as in embodiment 1.

[0125] Example 16

[0126] This embodiment provides a method for preparing a thick slurry electrode. Except for step (2), in which the mass of the three-dimensional porous conductive graphene aerogel particles is 6g and the mass of the electrolyte is 101g, everything else is the same as in Example 1.

[0127] Example 17

[0128] This embodiment provides a method for preparing a thick slurry electrode. Except for step (2), in which the mass of the three-dimensional porous conductive graphene aerogel particles is 1g and the mass of the electrolyte is 106g, everything else is the same as in Example 1.

[0129] Example 18

[0130] This embodiment provides a method for preparing a thick slurry electrode. Except for step (2), in which the mass of the three-dimensional porous conductive graphene aerogel particles is 30g and the mass of the electrolyte is 77g, everything else is the same as in Example 1.

[0131] Example 19

[0132] This embodiment provides a method for preparing a thick slurry electrode. Except for step (2), in which the mass of the 1-ethyl-3-methylimidazolium tetrafluoroborate ionic liquid is 2g and the mass of the electrolyte is 101g, all other steps are the same as in Example 1.

[0133] Example 20

[0134] This embodiment provides a method for preparing a thick slurry electrode. Except for step (2), in which the mass of the 1-ethyl-3-methylimidazolium tetrafluoroborate ionic liquid is 0.5g and the mass of the electrolyte is 102.5g, everything else is the same as in Example 1.

[0135] Example 21

[0136] This embodiment provides a method for preparing a thick slurry electrode. Except for step (2), in which the mass of the 1-ethyl-3-methylimidazolium tetrafluoroborate ionic liquid is 15g and the mass of the electrolyte is 88g, all other steps are the same as in Example 1.

[0137] Example 22

[0138] This embodiment provides a method for preparing a thick slurry electrode. Except for the average pore size of the three-dimensional porous conductive graphene aerogel particles in step (2) being 2 μm, all other steps are the same as in Example 1.

[0139] Example 23

[0140] This embodiment provides a method for preparing a thick slurry electrode. Except for the average pore size of the three-dimensional porous conductive graphene aerogel particles in step (2) being 0.5 μm, all other steps are the same as in Example 1.

[0141] Example 24

[0142] This embodiment provides a method for preparing a thick slurry electrode. Except for the average pore size of the three-dimensional porous conductive graphene aerogel particles in step (2) being 10 μm, all other steps are the same as in Example 1.

[0143] Example 25

[0144] This embodiment provides a method for preparing a thick slurry electrode. Except for the average particle size of the three-dimensional porous conductive graphene aerogel particles in step (2) being 80 μm, all other steps are the same as in Example 1.

[0145] Example 26

[0146] This embodiment provides a method for preparing a thick slurry electrode. Except for the average particle size of the three-dimensional porous conductive graphene aerogel particles in step (2) being 500 μm, all other steps are the same as in Example 1.

[0147] Comparative Example 1

[0148] This comparative example provides a method for preparing a thick slurry electrode. Except for step (1) which is omitted and the three-dimensional porous conductive graphene aerogel particles in step (2) are replaced with graphene oxide particles, everything else is the same as in Example 1.

[0149] Comparative Example 2

[0150] This comparative example provides a method for preparing a thick slurry electrode, which is the same as in Example 1 except that 1-ethyl-3-methylimidazolium tetrafluoroborate ionic liquid is not added in step (2).

[0151] The thick slurry electrodes prepared in Examples 1 to 26 and Comparative Examples 1 to 2 were assembled with lithium sheets to form a lithium slurry battery (3.5cm × 4cm). The assembly process is as follows: the thick slurry electrode was placed in a glove box filled with argon gas, cut and placed flat, then the cut separator was placed on its surface, and finally the lithium sheet was placed on top of the separator. After sealing with aluminum-plastic film, the lithium slurry battery was obtained.

[0152] The conductivity of the thick slurry electrodes prepared in Examples 1 to 26 and Comparative Examples 1 to 2 were tested using a conductivity meter (FE38).

[0153] The electrochemical performance of lithium slurry batteries assembled from the thick slurry electrodes prepared in Examples 1 to 26 and Comparative Examples 1 to 2 was tested using a battery testing system (CT-3008 5V 10A, Land CT 2001A). The specific capacity and capacity retention after 20 cycles were tested under the conditions of voltage 2.2 to 4.0V and rate of 0.1C.

[0154] Table 1 shows the conductivity of the thick slurry electrodes prepared in Examples 1 to 26 and Comparative Examples 1 to 2, the specific capacity of the lithium slurry batteries assembled from them, and the capacity retention rate after 20 cycles.

[0155]

[0156] As can be seen from Table 1, the thick slurry electrodes prepared in Examples 1 to 3 have high conductivity, and the lithium slurry batteries assembled from them have excellent specific capacity and cycle performance.

[0157] Compared with Example 1, Examples 4-6 and Examples 7-9 investigated the effects of the temperature and time of the first heat treatment on the conductivity of the thick slurry electrode and the electrochemical performance and stability of the lithium slurry battery. The results showed that if the temperature of the first heat treatment was too low or the time was too short, the degree of cross-linking between the layers was poor and less gas escaped, which affected the formation of the three-dimensional porous structure and thus reduced the electrode conductivity, battery electrochemical performance and stability. If the temperature of the first heat treatment was too high or the time was too long, it would aggravate the stacking between the layers, resulting in a reduction in pore size and anchoring points, which would also reduce the electrode conductivity, battery electrochemical performance and stability.

[0158] Compared with Example 1, Examples 10-12 and Examples 13-15 investigated the effects of the temperature and time of the second heat treatment on the conductivity of the thick slurry electrode and the electrochemical performance and stability of the lithium slurry battery. The results showed that if the temperature of the second heat treatment was too low or the time was too short, there would be more residual oxygen-containing functional groups, such as hydroxyl and epoxy groups, in the original material oxide, resulting in limited improvement in conductivity, which in turn affected the electrochemical performance and stability of the battery. If the temperature of the second heat treatment was too high or the time was too long, the sheets were prone to sintering and agglomeration, which led to a reduction in pore size and anchoring points, which would also reduce the conductivity of the electrode, the electrochemical performance and stability of the battery.

[0159] Compared with Example 1, Examples 16 to 18 investigated the effect of the mass fraction of three-dimensional porous conductive aerogel in the electrode slurry on the conductivity of thick slurry electrodes and the electrochemical performance and stability of lithium slurry batteries. The results showed that if the content of three-dimensional porous conductive aerogel was too low, it could not provide sufficient pores and anchoring points for the active particles, thus affecting the improvement of conductivity and consequently affecting the electrochemical performance and stability of the battery; if the content of three-dimensional porous conductive aerogel was too high, it would affect the specific capacity of the active particles.

[0160] Compared with Example 1, Examples 19 to 21 investigated the effect of the mass fraction of ionic liquid in the electrode slurry on the conductivity of thick slurry electrodes and the electrochemical performance and stability of lithium slurry batteries. The results showed that if the content of ionic liquid is too low, it cannot effectively promote the ion transport rate, resulting in a decrease in conductivity; if the content of ionic liquid is too high, it will increase the viscosity of the electrode slurry, making the fluidity worse, which in turn leads to unevenness of the thick slurry electrode.

[0161] Compared with Example 1, Examples 22-24 investigated the effect of the average pore size of the three-dimensional porous conductive aerogel on the conductivity of the thick slurry electrode and the electrochemical performance and stability of the lithium slurry battery. The results showed that if the average pore size of the three-dimensional porous conductive aerogel is too small, the active particles cannot effectively fill the pores of the three-dimensional porous conductive aerogel particles, affecting the improvement of conductivity; if the average pore size of the three-dimensional porous conductive aerogel is too large, the active particles cannot be well anchored to the pores of the three-dimensional porous conductive aerogel particles, affecting the stability of high conductivity.

[0162] Compared with Example 1, Examples 25 and 26 investigated the effect of the average particle size of the three-dimensional porous conductive aerogel on the conductivity of the thick slurry electrode and the electrochemical performance and stability of the lithium slurry battery. The results showed that if the average particle size of the three-dimensional porous conductive aerogel is too large, it cannot form a uniform electrode layer on the surface of the current collector, and the contact area with the current collector and the separator is small, which will affect the improvement of the battery's specific capacity.

[0163] Compared with Example 1, Comparative Example 1 did not prepare a three-dimensional porous conductive aerogel. Instead, graphene oxide was directly mixed with active particles, ionic liquid, and electrolyte to prepare the electrode slurry. Since graphene oxide has a sheet structure and does not have a porous structure, the active particles cannot be well anchored or entangled with it. Furthermore, graphene oxide has poor conductivity and cannot effectively improve the conductivity of the thick slurry electrode, thereby affecting the electrochemical performance and stability of the battery.

[0164] Compared with Example 1, no ionic liquid was added in Comparative Example 2, so it was impossible to construct a microenvironment system for electrochemical reactions of active materials together with electrolyte and three-dimensional porous conductive aerogel. The conductivity of the thick slurry electrode and the electrochemical performance and stability of the battery were both poor.

[0165] In summary, this invention achieves a stable, integrated structure by filling the pores of three-dimensional porous conductive aerogel particles with active particles, thus anchoring the active particles stably within the aerogel. Furthermore, by combining it with an ionic liquid to construct a slurry microenvironment system, the thick slurry electrode can maintain high electronic and ionic conductivity for extended periods. The 3D printing process is simple and allows for precise control of the shape, size, and thickness of the thick slurry electrode. This preparation method provides a novel strategy for addressing current problems in lithium slurry batteries and improving their electrochemical performance and stability.

[0166] The applicant declares that the above description is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention fall within the protection and disclosure scope of the present invention.

Claims

1. A method for preparing a thick paste electrode, characterized in that, The preparation method includes the following steps: (1) The original material oxide is dispersed in the first solvent and subjected to ultrasonic treatment, first heat treatment, freeze drying and second heat treatment in sequence to obtain a three-dimensional porous conductive aerogel. (2) The three-dimensional porous conductive aerogel, active particles, ionic liquid and electrolyte are mixed and stirred to obtain electrode slurry; (3) The electrode paste is 3D printed onto the current collector to obtain the thick paste electrode; The original material oxide includes any one or a combination of at least two of graphene oxide, carbon nanotube oxide, or MXene oxide.

2. The preparation method according to claim 1, characterized in that, In step (1), the first solvent includes any one or a combination of at least two of the following: water, dimethyl sulfoxide, acetonitrile, N-methylpyrrolidone, alcohol solvents, amine solvents, or ester solvents; Preferably, the alcohol solvent includes any one or a combination of at least two of methanol, ethanol, ethylene glycol, propylene glycol, diethylene glycol, polyethylene glycol, or triethylene glycol; Preferably, the amine solvent includes any one or a combination of at least two of the following: formamide, N,N-dimethylformamide, ethanolamine, ethylenediamine, diethylamine, triethylamine, ammonia, acetamide, urea, ammonium oxalate monohydrate, or acrylamide. Preferably, the ester solvent includes any one or a combination of at least two of propylene carbonate, γ-butyrolactone, ethylene carbonate, or dimethyl carbonate.

3. The preparation method according to claim 1 or 2, characterized in that, The power of the ultrasonic treatment in step (1) is 100W~1000W; Preferably, the ultrasonic treatment time in step (1) is 10 min to 120 min; Preferably, the temperature of the first heat treatment in step (1) is 90℃~200℃, and more preferably 120℃~160℃; Preferably, the time for the first heat treatment in step (1) is 1h to 24h, and more preferably 6h to 12h; Preferably, the freeze-drying time in step (1) is 12h~24h; Preferably, the gas atmosphere for the second heat treatment in step (1) includes N2 and / or Ar; Preferably, the temperature of the second heat treatment in step (1) is 200℃~800℃, more preferably 300℃~700℃; Preferably, the second heat treatment time in step (1) is 0.5h to 8h, and more preferably 2h to 6h.

4. The preparation method according to any one of claims 1 to 3, characterized in that, The average particle size of the active particles in step (2) is 0.1 μm to 100 μm; Preferably, the average pore size of the three-dimensional porous conductive aerogel in step (2) is 1 μm to 200 μm; Preferably, the average particle size of the active particles in step (2) is smaller than the average pore size of the three-dimensional porous conductive aerogel. Preferably, the average particle size of the three-dimensional porous conductive aerogel in step (2) is 50 μm to 1000 μm; Preferably, the active particles in step (2) have a mass fraction of 10wt%~80wt% in the electrode slurry, more preferably 20wt%~40wt%; Preferably, the mass fraction of the three-dimensional porous conductive aerogel in the electrode slurry in step (2) is 0.5wt%~20wt%, more preferably 5wt%~10wt%; Preferably, the mass fraction of the ionic liquid in the electrode slurry in step (2) is 0.1wt% to 10wt%, and more preferably 1wt% to 5wt%.

5. The preparation method according to any one of claims 1 to 4, characterized in that, The active particles mentioned in step (2) include positive electrode active particles and / or negative electrode active particles; Preferably, the positive electrode active particles include any one or a combination of at least two of lithium iron phosphate, lithium manganese iron phosphate, lithium cobalt oxide, lithium manganese oxide, high-nickel ternary materials, or lithium-rich manganese-based materials. Preferably, the negative electrode active particles include any one or a combination of at least two of graphite, mesophase carbon microspheres, or lithium titanate; Preferably, the ionic liquid in step (2) includes an alkanolamine ionic liquid with a composition of [XZ]. + [Y] - The ionic liquid or the composition is [CAH]. + [RCOO] - The ionic liquid comprises any one or at least two of the following: X includes any one or at least two of 1-methyl-3-ethyl, 1-methyl-3-propyl, 1-allyl-3-methyl, 1-butyl-3-methyl, 1-hexadecyl-3-methyl or 1-ethyl-3-methyl; Z includes any one or at least two of imidazole, pyridine or pyrrolidine; Y includes any one or at least two of hydrogen sulfate, dihydrogen phosphate, chloride, bromide, iodide, tetrafluoroborate or bis(trifluoromethanesulfonyl)imide; CA includes any one or at least two of piperazine, imidazole, 5-pyrazolone, melamine, cyanuric chloride or 2-imidazolylethylamine; and R includes H and / or C1-C2 alkyl. Preferably, the electrolyte in step (2) comprises a second solvent and a lithium salt; Preferably, the second solvent comprises any one or a combination of at least two of ethylene carbonate, dimethyl carbonate, diethyl carbonate, methyl ethyl carbonate, or propylene carbonate, and more preferably a combination of ethylene carbonate and dimethyl carbonate. Preferably, the volume ratio of ethylene carbonate to dimethyl carbonate is (2~4):(6~8); Preferably, the lithium salt comprises any one or a combination of at least two of lithium hexafluorophosphate, lithium tetrafluoroborate, lithium perchlorate, lithium difluorooxalate borate, lithium bis(fluorosulfonyl)imide, or lithium bis(trifluoromethylsulfonyl)imide. Preferably, the lithium salt has a mass fraction of 5wt% to 20wt% in the electrolyte.

6. The preparation method according to any one of claims 1 to 5, characterized in that, The stirring speed in step (2) is 300 rpm to 800 rpm; Preferably, the stirring time in step (2) is 1 hour to 8 hours; Preferably, the stirring temperature in step (2) is 25℃~45℃.

7. The preparation method according to any one of claims 1 to 6, characterized in that, The 3D printing temperature in step (3) is 0℃~50℃; Preferably, the extrusion speed of the electrode slurry during 3D printing in step (3) is 0.1 cm / s to 2 cm / s; Preferably, the current collector in step (3) includes a positive current collector and / or a negative current collector; Preferably, the positive current collector comprises aluminum foil and / or carbon-coated aluminum foil; Preferably, the negative electrode current collector includes any one or a combination of at least two of aluminum foil, carbon-coated aluminum foil, copper foil, or carbon-coated copper foil; Preferably, the thickness of the electrode slurry in step (3) on the current collector is 200 μm to 3000 μm.

8. The preparation method according to any one of claims 1 to 7, characterized in that, The preparation method includes the following steps: (1) The original material oxide is dispersed in the first solvent and subjected to ultrasonic treatment at a power of 100W~1000W for 10min~120min, first heat treatment at 90℃~200℃ for 1h~24h, freeze drying for 12h~24h, and second heat treatment at 200℃~800℃ in N2 and / or Ar atmosphere for 0.5h~8h to obtain a three-dimensional porous conductive aerogel; The original material oxide includes any one or a combination of at least two of graphene oxide, carbon nanotube oxide, or MXene oxide; (2) The three-dimensional porous conductive aerogel, active particles, ionic liquid and electrolyte are mixed and stirred at 25℃~45℃ and 300rpm~800rpm for 1h~8h to obtain electrode slurry; The active particles have an average particle size of 0.1 μm to 100 μm, the three-dimensional porous conductive aerogel has an average pore size of 1 μm to 200 μm, the active particles have an average particle size smaller than the three-dimensional porous conductive aerogel, the three-dimensional porous conductive aerogel has an average particle size of 50 μm to 1000 μm, the active particles have a mass fraction of 10 wt% to 80 wt% in the electrode slurry, the three-dimensional porous conductive aerogel has a mass fraction of 0.5 wt% to 20 wt% in the electrode slurry, and the ionic liquid has a mass fraction of 0.1 wt% to 10 wt% in the electrode slurry. (3) The electrode paste is 3D printed onto the current collector to obtain the thick paste electrode; The 3D printing temperature is 0℃~50℃, the extrusion speed of the electrode slurry during 3D printing is 0.1cm / s~2cm / s, and the thickness of the electrode slurry on the current collector is 200μm~3000μm.

9. A thick paste electrode, characterized in that, The thick slurry electrode is obtained by the preparation method according to any one of claims 1 to 8.

10. A lithium slurry battery, characterized in that, The lithium slurry battery includes the thick slurry electrode as described in claim 9; The thick slurry electrode is the positive and / or negative electrode of the lithium slurry battery.

Images