Zinc ion battery and preparation method thereof

Abstract

The present invention discloses a zinc ion battery and a preparation method thereof. The zinc ion battery comprises a housing filled with an electrolyte, an anode, a diaphragm, and a cathode sequentially spaced within the housing, a top cover with a pouring port being provided on the housing, a negative terminal being welded to the top end of the anode, a positive terminal being welded to the top end of the cathode, and a sealing cap being provided at the pouring port of the top cover. The anode comprises zinc and stainless steel foil, and a composite material coating deposited on one side of the zinc and stainless steel foil, the composite material coating comprising a PC / SiOC composite material, the PC / SiOC composite material comprising porous carbon and a silicon-oxygen-carbon network interpenetrating the porous carbon. The composite material coating of the present invention improves the transmission speed of zinc ions on the anode surface, and the composite material coating also has the characteristics of high electrical conductivity and high electrochemical activity, thereby improving the capacity and rate performance of the zinc ion battery. The fast zinc ion transmission speed and large diffusion area can effectively inhibit dendrite growth, greatly improving the battery cycle life.

Description

Technical Field

[0001] The present invention relates to the technical field of zinc ion batteries, and in particular to a zinc ion battery and a preparation method thereof. Background Art

[0002] Against the backdrop of shrinking traditional energy resources and the resulting environmental pollution, growing demand for consumer electronics, the steady development of electric vehicles, and the integration of renewable energy into the grid, there is an increasing demand for high-energy-density, recyclable, low-cost, and highly reliable environmentally friendly energy storage devices. Among various energy storage devices, lithium-ion batteries (LIBs) dominate the commercial secondary battery market due to their high energy density and long cycle life. However, LIBs suffer from inherent challenges, such as flammable organic electrolytes, the risk of short-circuit explosions caused by electrode dendrite growth, demanding manufacturing and assembly requirements, and scarce lithium resources, which severely hinder their large-scale application. As an emerging and promising alternative energy storage technology, rechargeable aqueous Zn-ion batteries (AZBs) exhibit significant potential for portable electronic applications and large-scale energy storage systems, owing to their high theoretical capacity (820 mAh / g), low redox potential (-0.76 V vs. SHE), abundant reserves, simple manufacturing and assembly, low cost, and safety and environmental friendliness. These advantages hold great promise for applications in portable electronics and large-scale energy storage systems.

[0003] However, zinc-ion batteries face huge challenges in practical application. In particular, the dendrite growth of the metal zinc anode during the cyclic deposition / stripping process is the biggest problem limiting the application of zinc-ion batteries: dendrite growth will continuously consume water during the cycle and produce irreversible byproducts, resulting in low Coulombic efficiency, low capacity and limited cycle life of the zinc-ion battery; at the same time, as the dendrites grow, the surface area of ​​the anode increases, causing corrosion of the anode and increased other surface-related reactions, ultimately leading to continuous consumption of the anode and accelerated degradation of battery performance; more seriously, excessively long dendrites will penetrate the diaphragm, causing the battery to short-circuit and fail. In order to solve the problem of anode dendrite growth and improve the cycle life and rate performance of zinc-ion batteries, people have developed a variety of zinc-ion battery anode preparation methods that take into account the inhibition of dendrite growth. For example, Liu et al. developed a method of coating graphene oxide nanosheets on a zinc metal anode using a casting method to inhibit dendrite growth; invention application CN114094035A discloses a method for preparing an aluminum-zinc alloy coating on a zinc-ion battery anode, which uses magnetron co-sputtering technology to prepare an aluminum-zinc alloy coating on the anode for anode protection; invention application CN112952052A provides a zinc / carbon nanotube foam composite material as an anode material for a zinc-ion battery and discloses in invention application CN112952053A a method for preparing an anode using the composite material through high-temperature reaction and electrodeposition.

[0004] However, the above-mentioned existing zinc-ion battery technology has the following disadvantages: the transmission speed of zinc ions on the anode surface is slow, and the electrical conductivity and electrochemical activity are not high, which limits the capacity and rate performance of the battery; the limited zinc ion diffusion area cannot completely inhibit dendrite growth, and there is still a risk of dendrite generation leading to short circuit, which limits the cycle life; the preparation process is complex and the cost is high.

[0005] Therefore, the existing technology still needs to be improved and developed. Summary of the Invention

[0006] In view of the above-mentioned deficiencies in the prior art, the object of the present invention is to provide a zinc ion battery and a preparation method thereof, aiming to solve the problem that dendrites are easily grown on the anode surface of the existing zinc ion battery, resulting in poor battery capacity and rate performance and short cycle life.

[0007] The technical solutions of the present invention are as follows:

[0008] A zinc ion battery comprises a shell filled with an electrolyte, an anode, a diaphragm, and a cathode sequentially spaced within the shell, an upper cover with a pouring port being provided on the shell, a negative terminal being welded to the upper end of the anode, a positive terminal being welded to the upper end of the cathode, and a sealing cap being provided at the pouring port of the upper cover; the anode being composed of zinc and stainless steel foil, and a composite material coating deposited on one side of the zinc and stainless steel foils, the composite material coating being a grid coating with a hollow center formed by uniformly staggered arrangement of a plurality of horizontal bars and a plurality of vertical bars, the composite material coating being formed by printing ink using low-temperature direct-write 3D printing technology, the ink comprising N-methylpyrrolidone and a PC / SiOC composite material, polyvinylidene fluoride, and conductive carbon black dissolved in the N-methylpyrrolidone, the PC / SiOC composite material being composed of porous carbon and a silicon-oxygen-carbon network interpenetrating the porous carbon.

[0009] The zinc ion battery, wherein the electrolyte is a ZnSO4 deionized water solution.

[0010] In the zinc ion battery, the diaphragm is a polypropylene separator and the cathode is a V2O5 / C flat plate.

[0011] In the zinc ion battery, the materials of the positive terminal and the negative terminal are both copper-based silver-plated alloy.

[0012] The zinc ion battery, wherein the middle hollow is a square hollow, the side length of the square hollow is equal to the line width of the horizontal bar and the vertical bar, the horizontal bar and the vertical bar have the same size, and the line width is 400-420 μm.

[0013] In the zinc ion battery, the thickness of the zinc and stainless steel foils is 0.1 mm, and the thickness of the composite material coating is 500-550 μm.

[0014] A method for preparing a zinc ion battery, comprising the steps of:

[0015] A PC / SiOC composite material, polyvinylidene fluoride, and conductive carbon black are ball-milled and then dissolved in N-methylpyrrolidone to obtain an ink composition, wherein the PC / SiOC composite material is composed of porous carbon and a silicon-oxygen-carbon network interpenetrating on the porous carbon;

[0016] removing lumps and large particles in the ink composition by vacuum filtration, and allowing the composition to stand at room temperature for a predetermined time to prepare ink;

[0017] The ink is printed on one side of zinc and stainless steel foil using low-temperature direct writing 3D printing technology, and after vacuum drying, an anode is prepared;

[0018] Installing the anode, diaphragm and cathode in the shell in sequence, and installing the upper cover with the pouring port on the shell;

[0019] Welding a positive terminal to the upper end of the cathode, welding a negative terminal to the upper end of the anode, and injecting electrolyte from the pouring port of the upper cover until it is full;

[0020] A sealing cover is installed at the pouring port of the upper cover to prepare the zinc ion battery.

[0021] The method for preparing a zinc ion battery, wherein the ink is printed on one side of zinc and stainless steel foil using low-temperature direct writing 3D printing technology, and after vacuum drying, the steps of preparing a dendrite-free anode for a zinc ion battery include:

[0022] The ink is loaded into a syringe barrel connected to a lockable stainless steel blunt nozzle, and the ink in the syringe barrel is squeezed out through the lockable stainless steel blunt nozzle to print the ink on one side of the zinc and stainless steel foils to obtain an anode in an uncured composite material coating;

[0023] The anode in an uncured composite material coating state was placed in a vacuum oven, and the temperature of the vacuum oven was set to 80° C. and maintained for 12 hours to prepare a dendrite-free anode for a zinc ion battery.

[0024] The method for preparing the zinc ion battery, wherein the preparation of the PC / SiOC composite material comprises the steps of:

[0025] Preparation of isoreticular covalently functionalized zirconium-based MOF crystals, namely UiO-66-NH2 crystals;

[0026] Dissolving hexadecyltrimethylammonium bromide in a PDSDA methanol solution in an ultrasonic bath to obtain a PDSDA / CTAB mixed solution; dissolving the UiO-66-NH2 crystals in methanol under magnetic stirring to obtain a UiO-66-NH2 solution;

[0027] The PDSDA / CTAB mixed solution was added to the UiO-66-NH2 solution in an argon environment, stirred at room temperature, and then after the polymerization reaction in the MOFs was completed, argon degassing, sample collection, ethanol washing and vacuum drying were performed to obtain a UiO-66 / PDSDA composite;

[0028] The UiO-66 / PDSDA composite was placed in a tube furnace and subjected to a three-stage pyrolysis process in an argon environment: in the first stage, the temperature was increased from 25°C to 400°C at a heating rate of 2°C / min and then maintained at 400°C for two hours; in the second stage, the temperature was increased from 200°C to 800°C at a heating rate of 2°C / min and maintained at 800°C for four hours; in the third stage, the temperature was decreased from 800°C to room temperature at a cooling rate of 2°C / min.

[0029] The preparation method of the zinc ion battery, wherein the preparation of the UiO-66-NH2 crystal comprises the steps of:

[0030] Dissolve ZrCl4 and H2N-H2BDC in HCON(CH3)2 at the same concentration of 0.02mol / L-0.025mol / L, and then add hydrochloric acid with a volume ratio of hydrochloric acid to HCON(CH3)2 of 1:140 to obtain a mixed solution;

[0031] After stirring the mixed solution at room temperature for 30 minutes, the mixed solution was transferred to a polytetrafluoroethylene-lined high-pressure reactor and heated at 120°C for 10 hours. After heating, the suspension was centrifuged to obtain a yellow powder product, which was subsequently washed with anhydrous ethanol and then transferred to a Schlenk flask and dried at ambient temperature to obtain UiO-66-NH2 crystals.

[0032] Beneficial Effects: Compared with the prior art, the zinc ion battery prepared by the present invention has the characteristics of fast zinc ion transmission speed on the anode surface, high conductivity and electrochemical activity, which improves the battery capacity and rate performance. Thanks to the large zinc ion diffusion area and fast zinc ion transmission speed of the anode surface of the present invention, dendrite growth can be effectively inhibited, greatly improving the battery cycle life. The zinc ion battery of the present invention has the advantages of simple preparation process and low cost. A complete zinc ion battery constructed using the anode prepared by the present invention still has a high capacity of 67 mAh / g after 2453 cycles at a current density of 0.5 A / g, has excellent cycle life and rate performance, is of great significance to the application of environmentally friendly and safe zinc ion battery energy storage technology, and has high practicality. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 The figure is a schematic structural diagram of a zinc ion battery of the present invention.

[0034] Figure 2 Schematic diagram of the structure of the anode in the zinc ion battery of the present invention.

[0035] Figure 3 The present invention is a flow chart of a method for preparing a zinc ion battery.

[0036] Figure 4 Schematic diagram of the chemical reaction principle of the PC / SiOC composite material in the present invention.

[0037] Figure 5 a is a SEM image of the PC / SiOC composite material obtained in Example 1 of the present invention; b is a SEM image of the UiO-66-NH2 crystal obtained in Example 1 of the present invention; c is a SEM image of the PC alone in Example 1 of the present invention.

[0038] Figure 6 a is a TEM image of the PC / SiOC composite material obtained in Example 1 of the present invention; b is a high-resolution TEM image of the PC / SiOC composite material obtained in Example 1 of the present invention.

[0039] Figure 7 Schematic diagram of the cycle life and rate characteristics of the zinc ion batteries of Example 1, Comparative Example 1 and Comparative Example 2 of the present invention at a current density of 0.5 A / g. DETAILED DESCRIPTION

[0040] The present invention provides a zinc ion battery and a method for preparing the same. To make the purpose, technical solution, and effects of the present invention clearer and more specific, the present invention is described in further detail below. It should be understood that the specific embodiments described herein are merely intended to explain the present invention and are not intended to limit the present invention.

[0041] See also Figure 1-Figure 2 The present invention provides a zinc ion battery, as shown in the figure, which includes a shell 1 filled with an electrolyte 2, an anode 3, a diaphragm 4 and a cathode 5 arranged in sequence in the shell 1, an upper cover 6 with a pouring port is provided on the shell 1, a negative terminal 7 is welded to the upper end of the anode 3, a positive terminal 8 is welded to the upper end of the cathode 5, and a sealing cover 9 is provided at the pouring port of the upper cover 6; the anode 3 is composed of zinc and stainless steel foil 301 and a composite material coating 302 deposited on one side of the zinc and stainless steel foil 301, the composite material coating 302 is a grid coating with a hollow center composed of a plurality of horizontal bars and a plurality of vertical bars arranged evenly and staggered, the composite material coating 302 is formed by printing ink using low-temperature direct writing 3D printing technology, the ink includes N-methyl pyrrolidone and a PC / SiOC composite material, polyvinylidene fluoride and conductive carbon black dissolved in the N-methyl pyrrolidone, the PC / SiOC composite material is composed of porous carbon and a silicon oxygen carbon network interpenetrating on the porous carbon.

[0042] Specifically, the PC / SiOC composite material in this invention possesses an electrode-optimized three-dimensional lattice structure that rapidly inverts, carries, and directs divalent zinc ions while limiting direct contact between the organic electrolyte and the anode. Furthermore, the PC / SiOC composite material exhibits strong molecular coordination, providing a larger, rapid diffusion area for zinc ions, effectively controlling dendrite growth. Based on this, the present invention prepares the PC / SiOC composite material into an ink, which is then printed into a film on zinc and stainless steel foil using low-temperature direct-write 3D printing technology to produce the anode. Finally, the anode, separator, and cathode are assembled into a zinc-ion battery. In the present invention, the composite material coating 302 can not only improve the transmission speed of zinc ions on the surface of the anode, but also has the characteristics of high electrical conductivity and high electrochemical activity, which improves the capacity and rate performance of the zinc ion battery. The fast zinc ion transmission speed and large diffusion area of ​​the composite material coating 302 can effectively inhibit dendrite growth and greatly improve the functional requirements of cycle life. A complete zinc ion battery constructed using the anode prepared by the present invention still has a high capacity of 67 mAh / g after 2453 cycles at a current density of 0.5 A / g, has good cycle life and rate performance, is of great significance to the development of dendrite-free zinc ion batteries, and has high practicality.

[0043] In this embodiment, by printing the composite material coating 302 as a grid coating with a central hollow 21, the surface area of ​​the composite material coating is increased macroscopically, thereby increasing the diffusion area of ​​zinc ions, thereby further effectively suppressing dendrite growth. In other words, the dendrite-free anode of the zinc ion battery of the present invention increases the diffusion area of ​​zinc ions from both macroscopic and microscopic perspectives, while also increasing the transmission speed of zinc ions. Therefore, it can greatly suppress dendrite growth, thereby improving the functional requirement of a high cycle life for the battery.

[0044] In some embodiments, the electrolyte is a ZnSO4 deionized water solution, but is not limited thereto; the diaphragm is a polypropylene separator, preferably a 2400 porous polypropylene separator with a thickness of 25 μm produced by Celgard Corporation of the United States; the cathode is a V2O5 / C flat plate, which refers to a flat plate with a V2O5 coating deposited on a carbon flat plate.

[0045] In some embodiments, the materials of the positive terminal and the negative terminal are both copper-based silver-plated alloy, which has the advantages of low contact resistance and no rust.

[0046] In some embodiments, the shell, upper cover and sealing cover are made of ABS engineering plastics, which has the advantages of being strong and aging-resistant.

[0047] In some embodiments, a silicone fluororubber sealing ring is installed at the connection between the upper cover and the shell, and at the connection between the pouring port sealing cover and the upper cover to prevent leakage of the electrolyte.

[0048] In some embodiments, as Figure 2 As shown, the middle hollow is a square hollow, and the side length of the square hollow is equal to the line width of the horizontal bar and the vertical bar. In order to ensure that the grid coating formed by printing has the largest surface area and avoid adhesion between adjacent horizontal bars or adjacent vertical bars during the printing process, this embodiment ensures that the side length of the square hollow is equal to the line width of the horizontal bar and the vertical bar during the printing process. In this embodiment, the horizontal bar and the vertical bar are the same size, and the line width is 400-420μm. As an example, the line width of the horizontal bar and the vertical bar is 409μm, and the side length of the square hollow is also 409μm.

[0049] In some embodiments, the thickness of the zinc and stainless steel foil is 0.1 mm, and the thickness of the composite coating is 500-550 μm. For example, the thickness of the composite coating can be 500 μm, 510 μm, 520 μm, 528 μm, 530 μm, 540 μm, 550 μm, etc.

[0050] In some embodiments, the mass ratio of the PC / SiOC composite material, polyvinylidene fluoride, and conductive carbon black is 8:1:1.

[0051] In some embodiments, a method for preparing a zinc ion battery is also provided, such as Figure 3 As shown, it includes the steps of:

[0052] S10, ball-milling a PC / SiOC composite material, polyvinylidene fluoride, and conductive carbon black, and then dissolving the resultant in N-methylpyrrolidone to obtain an ink composition, wherein the PC / SiOC composite material comprises porous carbon and a silicon-oxygen-carbon network interpenetrating on the porous carbon;

[0053] S20, removing lumps and large particles in the ink composition by vacuum filtration, and allowing the composition to stand at room temperature for a predetermined time to obtain ink;

[0054] S30, printing the ink on one side of zinc and stainless steel foil using low-temperature direct writing 3D printing technology, and performing vacuum drying to obtain an anode;

[0055] S40, installing the anode, diaphragm, and cathode in the housing in sequence, and installing the upper cover with the pouring port on the housing;

[0056] S50, welding a positive terminal to the upper end of the cathode, welding a negative terminal to the upper end of the anode, and injecting electrolyte from the pouring port of the upper cover until it is full;

[0057] S60, installing a sealing cover at the pouring port of the upper cover to produce the zinc ion battery.

[0058] The preparation process of the zinc ion battery provided in this embodiment has the advantages of simple operation and low cost. The zinc ion battery prepared in this embodiment has the characteristics of fast zinc ion transmission speed on the anode surface, high conductivity and electrochemical activity, which improves the capacity and rate performance of the zinc ion battery. The fast zinc ion transmission speed and large diffusion area of ​​the composite material coating can effectively inhibit dendrite growth, greatly improving the cycle life of the battery. The anode prepared using this embodiment achieved an excellent capacity of 99 mAh / g for more than 500 cycles at a current density of 0.45 A / g in a half-cell, and a coulombic efficiency of up to 99.98%. The anode prepared using the present invention to construct a complete zinc ion battery still had a high capacity of 67 mAh / g after 2453 cycles at a current density of 0.5 A / g, with excellent cycle life and rate performance, which is of great significance for the development of dendrite-free zinc ion batteries and has high practicality.

[0059] In this embodiment, the ink has good viscosity characteristics, shear thinning characteristics, and shape retention characteristics. The anode surface coating obtained using the ink has high dimensional accuracy, a smooth surface, and good printability.

[0060] In some embodiments, the ink is printed on one side of zinc and stainless steel foil using low-temperature direct writing 3D printing technology, and after vacuum drying, the steps of preparing a dendrite-free anode for a zinc ion battery include: gently stirring the ink, and then loading it into a 10mL syringe needle connected to a lockable stainless steel blunt nozzle with an inner diameter of 200μm, and then using computer-aided design software SolidWorks Corporation to control the ink flow rate and printing speed in the low-temperature direct writing 3D printer to 18mm / s, and extruding the ink in the syringe needle through the lockable stainless steel blunt nozzle and printing it on one side of the zinc and stainless steel foil to obtain an anode with an uncured composite material coating; placing the anode with the uncured composite material coating in a vacuum oven, setting the temperature of the vacuum oven to 80°C and maintaining it for 12 hours to obtain a cured anode product.

[0061] In some embodiments, the preparation of the PC / SiOC composite material includes the steps of: dissolving ZrCl4 and H2N-H2BDC in HCON(CH3)2 at the same concentration of 0.02 mol / L-0.025 mol / L, and then adding hydrochloric acid, the volume ratio of hydrochloric acid to HCON(CH3)2 is 1:140, to obtain a mixed solution; after stirring the mixed solution at room temperature for 30 minutes, transferring the mixed solution to a polytetrafluoroethylene-lined high-pressure reactor and heating it at 120°C for 10 hours. After heating, the suspension is centrifuged to obtain a yellow powder product, which is then washed with anhydrous ethanol, and then transferred to a Schlenk flask and dried at ambient temperature to obtain UiO-66-NH 2 crystals; dissolving hexadecyltrimethylammonium bromide (CTAB) in a PDSDA (poly[(silyl)diacetylene]) methanol solution in an ultrasonic bath to obtain a PDSDA / CTAB mixed solution; dissolving the UiO-66-NH2 crystals in methanol under magnetic stirring to obtain a UiO-66-NH2 solution; adding the PDSDA / CTAB mixed solution to the UiO-66-NH2 solution in an argon environment, stirring at room temperature, and then completing the polymerization reaction in MOFs, performing argon degassing, sample collection, ethanol washing and vacuum drying to obtain a UiO-66 / PDSDA composite; the UiO-66 / PDSDA The synthesis material was placed in a tubular furnace and subjected to a three-stage pyrolysis process in an argon environment: in the first stage, the temperature was increased from 25°C to 400°C at a heating rate of 2°C / min, and then maintained at 400°C for two hours; in the second stage, the temperature was increased from 200°C to 800°C at a heating rate of 2°C / min and maintained at 800°C for four hours; in the third stage, the temperature was reduced from 800°C to room temperature at a cooling rate of 2°C / min to obtain a PC / SiOC composite material.

[0062] Specifically, if Figure 4As shown, in this embodiment, UiO-66-NH2 crystals are first prepared, and then the PDSDA / CTAB mixed solution is stirred and mixed with the UiO-66-NH2 solution. During this process, the linear PDSDA can react with the -NH2 on the UiO-66-NH2 crystals, so that the PDSDA is bound to the UiO-66-NH2 crystals to generate a UiO-66 / PDSDA composite. Finally, the UiO-66 / PDSDA composite is subjected to a pyrolysis treatment. In the first stage, a polymerization reaction can occur between the multiple PDSDAs in the UiO-66 / PDSDA composite, and / or The PDSDAs between adjacent UiO-66 / PDSDA composites can undergo a polymerization reaction, thereby forming a cross-linked network of PDSDA on UiO-66. In the second stage, high-temperature heating causes the Si-C bonds in the cross-linked network of PDSDA to break, thereby forming a SiOC network. The SiOC network is interpenetrated on the porous carbon matrix to form the PC / SiOC composite material. The matrix of the PC / SiOC composite material is the MOF framework. The composite network SiOC structure expands the specific surface area, conductivity, electrochemical activity, etc. of the material, giving the material a huge advantage in the application of zinc-ion battery anodes.

[0063] In this embodiment, the CTAB, as a surfactant, helps to destroy the polymerization attraction between the PDSDA polymer chains themselves, allowing the PDSDA polymer chains to be better composited to the MOF framework to form a UiO-66 / PDSDA composite.

[0064] In this embodiment, in the PDSDA / CTAB mixed solution, the concentration of PDSDA is 0.01 g / mL, and the concentration of CTAB is 0.005 g / mL; the concentration of the UiO-66-NH2 solution is 0.01455 g / mL; and the mass ratio of the PDSDA / CTAB mixed solution to the UiO-66-NH2 solution is 1:3.

[0065] The present invention will be further explained below by means of specific embodiments:

[0066] Example 1

[0067] A method for preparing a zinc ion battery is provided, comprising the following steps:

[0068] S1. Prepare a composite material for an anode. The specific operations are as follows:

[0069] S101, dissolving 1.50 g, 6.4 mmol of ZrCl4 and 1.56 g, 6.4 mmol of H2N-H2BDC in 280 mL of HCON(CH3)2, and then adding 2 mL of 36 wt% hydrochloric acid so that the volume ratio of hydrochloric acid to HCON(CH3)2 is 1:140, and the concentrations of ZrCl4 and H2N-H2BDC are both 0.023 mol / L, within the range of 0.02 mol / L-0.025 mol / L; then stirring the mixed solution at room temperature for 30 minutes, and then transferring the mixture to a 500 mL polytetrafluoroethylene-lined autoclave and heating it hydrothermally at 120°C for 10 hours. After heating, the suspension is centrifuged to obtain a yellow powder product, which is then washed with anhydrous ethanol, then transferred to a Schlenk flask and dried at ambient temperature to obtain UiO-66-NH2 crystals;

[0070] S102, dissolving 0.5 g of CTAB in a 100 mL PDSDA-methanol solution with a concentration of 0.01 g / mL in an ultrasonic bath to carry out a polymerization reaction to obtain a PDSDA / CTAB mixed solution, so that the concentration of CTAB in the mixed solution is 0.005 g / mL; dissolving 1.455 g of the UiO-66-NH2 crystals obtained in step S101 in 100 mL of methanol in a Schlenk flask under magnetic stirring to obtain a UiO-66-NH2 solution with a concentration of 0.01455 g / L;

[0071] S103, the PDSDA / CTAB mixed solution obtained in step S102 was quickly immersed in an argon environment at a mass ratio of 1:3 into a Schlenk flask containing the UiO-66-NH2 solution obtained in S102, first vigorously stirred at room temperature for 30 minutes, then completed a three-hour MOFs polymerization reaction, then degassed the Schlenk flask with argon, and then collected the sample using a rotary evaporator, washed with ethanol, and finally dried in a vacuum oven set at 80°C overnight to obtain a UiO-66 / PDSDA composite;

[0072] S104. The UiO-66 / PDSDA composition obtained in step S103 is placed in a tubular furnace and subjected to a three-stage pyrolysis process in an argon environment: in the first stage, the temperature is increased from 25°C to 400°C at a heating rate of 2°C / min, and then the temperature is maintained at 400°C for two hours; in the second stage, the temperature is increased from 200°C to 800°C at a heating rate of 2°C / min, and maintained at 800°C for four hours; in the third stage, the temperature is reduced from 800°C to room temperature at a cooling rate of 2°C / min.

[0073] S2. Prepare an anode composite material coating ink suitable for 3D printing. The specific operations are as follows:

[0074] S201, firstly, uniformly mixing the PC / SiOC composite material obtained in step S1 with PVDF and conductive carbon black at a mass ratio of 8:1:1 by planetary ball milling, and then dissolving the mixed powder in NMP solution to obtain a homogeneous ink composition;

[0075] S202: The ink composition in step S201 is subjected to vacuum filtration to remove lumps and large particles to prevent nozzle clogging, and then allowed to stand at room temperature for twelve hours to obtain a stable anode composite coating ink suitable for 3D printing.

[0076] S3. Use low-temperature direct writing 3D printing to print ink on one side of the zinc and stainless steel foils. The specific operations are as follows:

[0077] The ink obtained in step S2 was gently stirred and then loaded into a 10 mL syringe barrel connected to a lockable stainless steel blunt nozzle with an inner diameter of 200 μm. Then, using computer-aided design software SolidWorks Corporation, the ink flow rate and printing speed in a low-temperature direct writing 3D printer were controlled to be 18 mm / s. The ink in the syringe barrel was extruded through the lockable stainless steel blunt nozzle and printed onto one side of the zinc and stainless steel foils to obtain an anode in an uncured state of the composite coating.

[0078] S4. Place the 3D printed anode in a vacuum oven for drying to obtain a cured anode product. The specific operation is as follows: place the anode in the uncured state of the composite material coating obtained in step S3 in a vacuum oven, set the temperature of the vacuum oven to 80°C, and keep it warm for 12 hours to obtain a cured anode product.

[0079] S5. Assemble the battery to obtain a complete zinc ion battery. The specific operations are as follows:

[0080] S501, using the anode obtained in step S4 as the anode, a 2400 porous, 25 μm thick polypropylene separator from Celgard Company of the United States as the separator, 3M ZnSO4 deionized water as the electrolyte, and a V2O5 / C flat plate coated with a V2O5 flat plate as the cathode, and installing the anode, separator, and cathode in a housing;

[0081] S502, installing the upper cover on the housing;

[0082] S503, welding the positive terminal to the upper end of the cathode and the negative terminal to the upper end of the anode;

[0083] S504, injecting electrolyte from the pouring port until it is full;

[0084] S505, installing a pouring port sealing cover at the pouring port of the upper cover to produce a zinc ion battery.

[0085] In order to verify the cycle life and rate performance of the zinc ion battery manufactured by the method proposed in the present invention, a comparative example was set up to compare the electrical performance of the complete battery in Example 2. The comparative example was set up as follows:

[0086] Comparative Example 1

[0087] In Comparative Example 1, the battery manufacturing process is different from that in Example 1. In step S3, the ink is horizontally applied to one side of the zinc and stainless steel foils, instead of using low-temperature direct writing 3D printing technology to print the ink onto one side of the zinc and stainless steel foils. The other steps are the same as in Example 1 to obtain a zinc ion battery.

[0088] Comparative Example 2

[0089] In Comparative Example 2, the battery manufacturing process was different from that in Example 1, except that steps S1 to S4 were not performed. Zinc and stainless steel foil with a thickness of 0.1 mm without any coating were directly used as anodes. The other steps were the same as in Example 1 to obtain a zinc ion battery.

[0090] First, the structural properties of the PC / SiOC composite material prepared by the present invention were verified. The PC / SiOC composite material prepared in Example 1 was characterized for morphology and structure using a JEOL-6700 scanning electron microscope (SEM) and a JEOL-2100F transmission electron microscope (TEM). During the SEM analysis, an energy dispersive X-ray spectrometer was used to perform dispersion spectroscopy (EDS) to obtain detailed information on the element distribution and phase structure of the composite material. The results are as follows: Figure 5 (a) is the SEM image of PC / SiOC composite material, which shows that the spherical particle size of the carbon shell containing ZrO2 in the composite material is about 100nm. Figure 5 (b) is the SEM image of the UiO-66-NH2 crystal obtained in step S1 of Example 1, Figure 5 (c) is the SEM image of PC alone, compared with the attached Figure 5 (a) and (c) Figure 5 (b) and attached Figure 5 (c) shows that the morphology of PC / SiOC composite material after polymerization and pyrolysis is consistent with the initial UiO-66-NH2 crystal morphology; Figure 6 (a) is a TEM image of the PC / SiOC composite, which shows that the PC / SiOC composite retains the structure of the parent UiO-66-NH2 crystal, has retained porosity and is coordinated with the SiOC network interpenetrating with the PC surface, creating a large number of active sites for ion storage; Figure 6(b) is a high-resolution TEM image of the PC / SiOC composite material, showing that the PC / SiOC composite material has obvious screw dislocations, particle clusters and grain boundaries, which are derived from the SiOC coordination between ZrO2 crystals in different adjacent shells, and the interpenetrating SiOC network in PC can serve as a conductive network, creating more active sites and improving the charge transfer performance; the structural performance test of the PC / SiOC composite material shows that: the PC / SiOC composite material in Example 1 obtained by the present invention has an electrode-optimized three-dimensional grid structure, which can quickly reverse, carry and guide divalent zinc ions, while limiting the direct contact between the organic electrolyte and the anode, and has strong molecular coordination, which can provide a larger rapid diffusion area for zinc ions to effectively control dendrite growth.

[0091] Next, the complete batteries in Example 2 and each comparative example were subjected to electrical performance testing and comparison. Rate capacity and cycle performance tests were performed using a LANHE-CT2001A battery tester manufactured by Wuhan Shenglan Electronic Technology Co., Ltd. The test and comparison results are as follows:

[0092] Compare the rate capacity and cycle performance test results of the complete battery: see the attached Figure 7 The zinc ion battery manufactured using the present invention still has a high capacity of 67 mAh / g after 2453 cycles at a current density of 0.5 A / g. In contrast, the zinc ion battery in Comparative Example 1 has a cycle number of 1880 and a capacity of 58 mAh / g; and the zinc ion battery in Comparative Example 2 has a cycle number of 128 and a capacity of 13 mAh / g. Therefore, the comparison between the embodiments and the comparative examples proves that the zinc ion battery manufactured using the method proposed by the present invention has excellent cycle life and rate performance, which is of great significance to the application of environmentally friendly and safe zinc ion battery energy storage technology and has high practicality.

[0093] It should be understood that the application of the present invention is not limited to the above examples. For those skilled in the art, improvements or changes can be made based on the above description. All these improvements and changes should fall within the scope of protection of the claims attached to the present invention.

Claims

1. A zinc ion battery, characterized in that The invention comprises a shell filled with electrolyte, an anode, a diaphragm and a cathode arranged in sequence in the shell, an upper cover with a pouring port is provided on the shell, a negative terminal is welded to the upper end of the anode, a positive terminal is welded to the upper end of the cathode, and a sealing cover is provided at the pouring port of the upper cover; the anode is composed of zinc and stainless steel foil and a composite material coating deposited on one side of the zinc and stainless steel foil, the composite material coating is a grid coating with a hollow middle composed of a plurality of horizontal bars and a plurality of vertical bars arranged evenly and staggered, the composite material coating is formed by printing ink using low-temperature direct writing 3D printing technology, the ink comprises N-methylpyrrolidone and a PC / SiOC composite material, polyvinylidene fluoride and conductive carbon black dissolved in the N-methylpyrrolidone, the PC / SiOC composite material is composed of porous carbon and a silicon-oxygen-carbon network interpenetrating on the porous carbon, and the PC / SiOC composite material has screw dislocations, particle clusters and grain boundaries.

2. The zinc ion battery according to claim 1, wherein The electrolyte is a ZnSO4 deionized water solution.

3. The zinc ion battery according to claim 1, wherein The separator is a polypropylene separator, and the cathode is a V2O5 / C flat plate.

4. The zinc ion battery according to claim 1, wherein The materials of the positive terminal and the negative terminal are both copper-based silver-plated alloy.

5. The zinc ion battery according to claim 1, wherein The middle hollow is a square hollow, the side length of the square hollow is equal to the line width of the horizontal rod and the vertical rod, the horizontal rod and the vertical rod have the same size, and the line width is 400-420 μm.

6. The zinc ion battery according to claim 1, wherein The thickness of the zinc and stainless steel foils is 0.1 mm, and the thickness of the composite material coating is 500-550 μm.

7. A method for preparing a zinc ion battery as claimed in claim 1, characterized in that: Including steps: A PC / SiOC composite material, polyvinylidene fluoride, and conductive carbon black are ball-milled and then dissolved in N-methylpyrrolidone to obtain an ink composition, wherein the PC / SiOC composite material is composed of porous carbon and a silicon-oxygen-carbon network interpenetrating on the porous carbon; removing lumps and large particles in the ink composition by vacuum filtration, and allowing the composition to stand at room temperature for a predetermined time to prepare ink; The ink is printed on one side of zinc and stainless steel foil using low-temperature direct writing 3D printing technology, and after vacuum drying, an anode is prepared; Installing the anode, diaphragm and cathode in the shell in sequence, and installing the upper cover with the pouring port on the shell; Welding a positive terminal to the upper end of the cathode, welding a negative terminal to the upper end of the anode, and injecting electrolyte from the pouring port of the upper cover until it is full; A sealing cover is installed at the pouring port of the upper cover to prepare the zinc ion battery.

8. The preparation method of zinc ion battery according to claim 7, wherein The ink is printed on one side of zinc and stainless steel foil using low-temperature direct writing 3D printing technology, and after vacuum drying, the steps of preparing the anode include: The ink is loaded into a syringe barrel connected to a lockable stainless steel blunt nozzle, and the ink in the syringe barrel is extruded through the lockable stainless steel blunt nozzle to be printed on one side of the zinc and stainless steel foils to obtain an anode in an uncured composite material coating; The anode in an uncured composite material coating was placed in a vacuum oven, and the temperature of the vacuum oven was set to 80° C. and maintained for 12 hours to obtain an anode.

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