3D printing construction flexible zinc ion battery positive electrode and preparation method and application thereof

Abstract

The application discloses a 3D printing construction flexible zinc ion battery positive electrode and a preparation method and application thereof. Polyvinylidene fluoride and N-methyl pyrrolidone are mixed, heated and stirred to form a gel, carbon nanotube coated MOF-based composite material and carbon black are added, and ball milling is conducted to prepare printable positive electrode ink; the printable positive electrode ink is loaded into a syringe, the syringe is connected to a pneumatic control device of a printer, uniform extrusion of the mild ink is conducted, after printing is completed, the obtained electrode is placed in a fume hood, drying and removal of the flux are conducted. The 3D printing construction flexible zinc ion battery positive electrode is prepared by the method of 3D printing, a three-dimensional network structure of carbon nanotube coated MOF material and carbon black is prepared, fast transmission of zinc ions is ensured, high specific capacity and long cycle stability are achieved, meanwhile, the 3D printing construction flexible zinc ion battery positive electrode has good flexibility, the preparation process is simple, time consumption is short, and the 3D printing construction flexible zinc ion battery positive electrode has good industrialization prospect.

Description

Technical Field

[0001] This invention relates to the field of electrode technology, specifically to a 3D-printed flexible zinc-ion battery cathode, its preparation method, and its application. Background Technology

[0002] In recent years, the rapid development of microelectronics technology and the integration of electronic devices have placed higher demands on the area, safety, and energy density of energy storage devices. Traditional energy storage devices such as lithium-ion batteries have limited their application and development due to their poor safety profile. Among next-generation energy storage devices, aqueous zinc-ion batteries have attracted widespread attention due to their high safety, environmental friendliness, and low cost.

[0003] Zinc (Zn) is abundant and inexpensive in the Earth's crust. Zn metal is stable in air, allowing zinc-ion batteries to be assembled and manufactured in air, significantly reducing production costs. The aqueous electrolyte used in zinc-ion batteries is non-toxic to humans, environmentally friendly, and does not pose safety risks such as combustion. Therefore, aqueous zinc-ion batteries are a promising energy storage system. However, research on cathode materials for aqueous zinc-ion batteries is still in its early stages. Currently, the most commonly used cathode material for aqueous zinc-ion batteries is MnO2, but this material contains Zn... 2+ The slow storage kinetics and the ease with which the material dissolves in the electrolyte, coupled with the lack of flexibility of the MnO2 electrode fabricated by traditional coating processes, limit the further application of zinc-ion batteries in complex scenarios. Summary of the Invention

[0004] To address the shortcomings of existing technologies, the present invention aims to propose a 3D-printed flexible zinc-ion battery cathode, its preparation method, and its application. A carbon nanotube-coated UiO-66-NH2@MnO2 composite cathode with a three-dimensional layered network structure is prepared using 3D printing. The periodic pores constructed by 3D printing, together with the abundant mesopores in the UiO-66-NH2@MnO2 composite material, form a layered porous structure, ensuring rapid zinc ion transport and mitigating electrode deformation during charging and discharging. Therefore, this cathode exhibits excellent rate performance and long-cycle stability, while also possessing good flexibility, adaptable to various microelectronic device applications. The preparation process is simple, time-efficient, and shows promising industrialization prospects.

[0005] To address the problems in the existing technology, the technical solution adopted by this invention is as follows:

[0006] A method for fabricating a flexible zinc-ion battery cathode using 3D printing includes the following steps:

[0007] S1. Preparation of printable positive electrode ink:

[0008] Polyvinylidene fluoride (PVDF) and N-methylpyrrolidone (N-Methylpyrrolidone) are mixed and heated and stirred at 55-65°C to form a gel. Then, carbon nanotube-coated MOF-based composite material and carbon black are added, and the mixture is ball-milled for 1-3 hours to obtain a printable positive electrode ink. The mass ratio of PVDF, N-methylpyrrolidone, carbon nanotube-coated MOF-based composite material, and carbon black is 2-4:0.5-1:8-10:0.5-1.

[0009] S2.3D printing process:

[0010] Printable positive electrode ink is loaded into a syringe, which is then connected to the printer's air pressure control device. The printer is then started, and the preset program of the 3D model is run. The air pressure of the air pressure control device is adjusted to uniformly squeeze out the mild ink. After printing, the obtained electrode is placed in a fume hood to dry and remove the flux, thus obtaining a 3D printed flexible zinc-ion battery electrode.

[0011] As an improvement, the preparation method of the carbon nanotube-coated MOF-based composite material in step S1 is as follows:

[0012] Step 1: Benzoic acid, zirconium tetrachloride, and 2-aminoterephthalic acid are weighed in a mass ratio of 4-4.5:0.5-1:0.3-0.7 and mixed in N,N-dimethylformamide to obtain solution A. Potassium permanganate and manganese sulfate monohydrate are weighed in a mass ratio of 3-3.5:5-5.5 and added to deionized water. After magnetic stirring for 1 hour, solution B is obtained and slowly added to solution A. The mixed solution is transferred to a polytetrafluoroethylene reactor and hydrothermally reacted at 120-140℃ for 20-24 hours. After centrifugation, washing, and drying, UiO-66-NH2@MnO2 composite material is obtained.

[0013] Step 2: Under inert gas protection, the UiO-66-NH2@MnO2 composite material is heated to 200-300℃ and held at that temperature for one hour. Then, the temperature is replaced with hydrogen gas, and the temperature is increased to 450℃ at a rate of 5℃ / min. Then, the temperature is rapidly increased to 600-700℃ at a rate of 20℃ / min, and the hydrogen gas is replaced with n-hexane. The reaction is held at that temperature for 20-40 min. After the holding time is completed, the n-hexane is replaced with an inert gas, and the mixture is cooled to room temperature to obtain the carbon nanotube-coated MOF-based composite material.

[0014] A further improvement is that the hydrogen flow rate in step T2 is 120-150 mg / min, and the n-hexane flow rate is 0.1-0.3 mL / min.

[0015] The 3D-printed flexible zinc-ion battery cathode prepared by the above method has a periodic layered grid, which is conducive to electrolyte penetration and has high flexibility. It can still maintain structural stability when bent at 45°-180°. After 100 charge-discharge cycles after bending, the capacity retention rate of the 3D-printed flexible zinc-ion battery cathode is still 95.3%.

[0016] The above-mentioned application of 3D printing to construct flexible zinc-ion battery cathodes in the preparation of zinc-ion batteries.

[0017] A zinc-ion battery comprising the above-mentioned 3D-printed flexible zinc-ion battery positive electrode, wherein the zinc-ion battery has a specific capacity of 97.6 mAh / g at a current density of 2 A / g and a capacity retention of 92.3% after 1000 charge-discharge cycles.

[0018] Beneficial effects:

[0019] Compared with existing technologies, this invention utilizes 3D printing technology to achieve layer-by-layer printing and positive electrode printing without metal current collectors, further improving mass loading and thus increasing areal capacity. The 3D-printed flexible zinc-ion battery positive electrode has a three-dimensional layered network structure, ensuring rapid zinc ion transport and exhibiting high specific capacity and long-term cycle stability. Furthermore, the electrode prepared by this invention possesses excellent flexibility, making it suitable for various complex scenarios. The fabrication process is simple and time-efficient, providing a new direction for the commercial application of aqueous zinc-ion batteries. Attached Figure Description

[0020] Figure 1 This is a flowchart illustrating the fabrication process of the flexible zinc-ion battery cathode prepared by 3D printing according to Example 3 of the present invention.

[0021] Figure 2 The positive electrode prepared by 3D printing in Example 3 of this invention and its flexibility test;

[0022] Figure 3 This is a SEM image of the 3D-printed flexible electrode prepared in Example 3 of the present invention;

[0023] Figure 4 The rate performance diagram of the 3D printed flexible electrode prepared in Example 3 of the present invention;

[0024] Figure 5 This is a long-cycle performance diagram of the 3D-printed flexible electrode prepared in Example 3 of the present invention;

[0025] Figure 6 The capacity retention rate of the 3D printed flexible electrode prepared in Example 3 of this invention after 100 charge-discharge cycles after bending. Detailed Implementation

[0026] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0027] Example 1

[0028] A method for fabricating a flexible zinc-ion battery cathode using 3D printing includes the following steps:

[0029] T1. Mix 4g benzoic acid, 0.5g zirconium tetrachloride, and 0.3g 2-aminoterephthalic acid and add them to 200mL of N,N-dimethylformamide to obtain solution A. Add 3g potassium permanganate and 5g manganese sulfate monohydrate to 150mL of deionized water and stir magnetically for 1 hour to obtain solution B. Then slowly add solution A and transfer the mixed solution to a hydrothermal reactor. React hydrothermally at 120℃ for 20h. Centrifuge, wash three times alternately with deionized water and ethanol, and dry at 60℃ for 24 hours to obtain UiO-66-NH2@MnO2 material.

[0030] T2. Under nitrogen protection, the UiO-66-NH2@MnO2 material was heated to 300℃, then the nitrogen was replaced with hydrogen at a flow rate of 120 mg / min, and the temperature was increased to 450℃ at a rate of 5℃ / min. Then, the temperature was rapidly increased to 600℃ at a rate of 20℃ / min, and the hydrogen was replaced with n-hexane at a flow rate of 0.1 mL / min. The reaction was held at this temperature for 20 min. After the holding time was completed, the n-hexane was replaced with nitrogen, and the mixture was cooled to room temperature to obtain a carbon nanotube-coated MOF-based composite material.

[0031] S1. Preparation of printable positive electrode ink

[0032] 2g of polyvinylidene fluoride and 0.5g of N-methylpyrrolidone were mixed and heated to 55°C, stirred to form a gel, 8g of carbon nanotube-coated MOF-based composite material prepared in step T2 and 0.5g of carbon black were added, and ball milling was performed for 1 hour to obtain printable positive electrode ink.

[0033] S2 3D printing process

[0034] Printable positive electrode ink is loaded into a 100μm needle syringe, which is then connected to the air pressure control device of the 3D printer. The 3D printer is then started, the preset program of the 3D model is run, and the air pressure of the air pressure control device is adjusted to uniformly squeeze the printing ink at a pressure of 50kPa. After printing, the obtained electrode is placed in a fume hood to dry naturally.

[0035] Example 2

[0036] A method for fabricating a flexible zinc-ion battery cathode using 3D printing includes the following steps:

[0037] T1. Mix 4.5g benzoic acid, 1g zirconium tetrachloride, and 0.7g 2-aminoterephthalic acid and add them to 200mL of N,N-dimethylformamide to obtain solution A. Add 3.5g potassium permanganate and 5.5g manganese sulfate monohydrate to 200mL of deionized water and stir magnetically for one hour to obtain solution B. Then slowly add the mixture to solution A. Transfer the mixed solution to a hydrothermal reactor and hydrothermally react at 140℃ for 24h. Centrifuge, wash three times alternately with deionized water and ethanol, and dry at 60℃ for 24 hours to obtain UiO-66-NH2@MnO2 material.

[0038] T2. Under nitrogen protection, the UiO-66-NH2@MnO2 material was heated to 300℃, then the nitrogen was replaced with hydrogen at a flow rate of 150 mg / min, and the temperature was increased to 450℃ at a rate of 5℃ / min. Then, the temperature was rapidly increased to 600℃ at a rate of 20℃ / min, and the hydrogen was replaced with n-hexane at a flow rate of 0.3 mL / min. The reaction was held at this temperature for 20 min. After the holding time was completed, the n-hexane was replaced with nitrogen, and the mixture was cooled to room temperature to obtain a carbon nanotube-coated MOF-based composite material.

[0039] S1. Preparation of printable positive electrode ink: 4g of polyvinylidene fluoride and 1g of N-methylpyrrolidone were mixed and heated to 65°C, stirred to form a gel, 10g of carbon nanotube-coated MOF-based composite material prepared in Example 2 and 1g of carbon black were added, and the mixture was ball-milled for 3h to obtain printable positive electrode ink.

[0040] S2 3D printing process

[0041] Printable positive electrode ink is loaded into a 100μm needle syringe, which is then connected to the air pressure control device of the 3D printer. The 3D printer is then started, the preset program of the 3D model is run, and the air pressure of the air pressure control device is adjusted to uniformly squeeze the printing ink at a pressure of 50kPa. After printing, the obtained electrode is placed in a fume hood to dry naturally.

[0042] Example 3

[0043] A method for fabricating a flexible zinc-ion battery cathode using 3D printing includes the following steps:

[0044] T1. 4.2g benzoic acid, 0.7g zirconium tetrachloride, and 0.3-0.7g 2-aminoterephthalic acid were mixed and added to 200mL of N,N-dimethylformamide to obtain solution A. 3.3g potassium permanganate and 5.2g manganese sulfate monohydrate were added to 200mL of deionized water and stirred magnetically for one hour to obtain solution B. Then, solution B was slowly added to solution A. The mixed solution was transferred to a hydrothermal reactor and hydrothermally reacted at 130℃ for 20h. After centrifugation, the solution was washed three times alternately with deionized water and ethanol, and dried at 60℃ for 24h to obtain UiO-66-NH2@MnO2 material.

[0045] T2. Under nitrogen protection, the UiO-66-NH2@MnO2 material was heated to 250℃, then the nitrogen was replaced with hydrogen at a flow rate of 120 mg / min, and the temperature was increased to 450℃ at a rate of 5℃ / min. Then, the temperature was rapidly increased to 600℃ at a rate of 20℃ / min, and the hydrogen was replaced with n-hexane at a flow rate of 0.2 mL / min. The reaction was held at this temperature for 20 min. After the holding time was completed, the n-hexane was replaced with nitrogen, and the mixture was cooled to room temperature to obtain a carbon nanotube-coated MOF-based composite material.

[0046] S1. Preparation of printable positive electrode ink:

[0047] 3g of polyvinylidene fluoride and 0.7g of N-methylpyrrolidone were mixed and heated to 60°C, stirred to form a gel, and 9g of carbon nanotube-coated MOF-based composite material prepared in Example 3 and 0.7g of carbon black were added. The mixture was ball-milled for 2 hours to obtain a printable positive electrode ink.

[0048] S2 3D printing process

[0049] Printable positive electrode ink is loaded into a 100μm needle syringe, which is then connected to the air pressure control device of the 3D printer. The 3D printer is then started, the preset program of the 3D model is run, and the air pressure of the air pressure control device is adjusted to uniformly squeeze the printing ink at a pressure of 50kPa. After printing, the obtained electrode is placed in a fume hood to dry naturally.

[0050] Figure 2 The positive electrode prepared in Example 3 was subjected to a flexibility test, which involved bending it by 90° and 180°. As can be seen from the figure, the positive electrode material of the present invention still has an intact structure after bending.

[0051] Comparative Example 1

[0052] Compared with Example 3, the difference is that step T2 was not performed, and the carbon nanotube-coated MOF-based composite material in step S1 was replaced with the UiO-66-NH2@MnO2 material prepared in step T1.

[0053] Comparative Example 2

[0054] Compared with Example 3, the difference is that in step T1, solution B was not added to solution A. Solution A was only subjected to hydrothermal reaction at 130°C for 20 hours, centrifuged, washed three times alternately with deionized water and ethanol, and dried at 60°C for 24 hours to obtain pure UiO-66-NH2 material. Furthermore, in step S1, the carbon nanotube-coated MOF-based composite material was replaced with the prepared pure UiO-66-NH2 material.

[0055] The remaining steps are the same as step S2 in Example 3.

[0056] The 3D-printed flexible zinc-ion battery positive electrodes prepared in Examples 1-3 and Comparative Examples 1-2 were used to assemble aqueous zinc-ion button batteries (the negative electrode is zinc metal, the electrolyte is 2 mol / L ZnSO4 solution, and the separator is glass fiber), and the pseudocapacitive contribution ratio (%) of these batteries at different scan rates was tested. The results are shown in Table 1.

[0057] Table 1. Pseudocapacitive contribution percentage of different cathode materials at different scan rates (%)

[0058]

[0059] As shown in the table above, the 3D-printed flexible zinc-ion batteries prepared in Examples 1-3 of this invention have a higher capacitance contribution ratio, and Example 3 has the highest capacitance contribution, indicating that it has the ability to store the best charge quickly and maintain excellent electrochemical performance under high current density.

[0060] The 3D-printed flexible zinc-ion battery positive electrode prepared in Example 3 was used to assemble an aqueous zinc-ion button battery (zinc metal as the negative electrode, 2 mol / L ZnSO4 solution as the electrolyte, and glass fiber as the separator). Constant current charge-discharge tests were conducted to obtain the discharge specific capacity (mAh / g) at different current densities. The results are shown in […]. Figure 4 As shown in the figure, the 3D-printed flexible zinc-ion battery prepared in Example 3 of this invention still has a specific capacity of 97.6 mAh / g at a current density of 2 A / g, exhibiting excellent rate performance.

[0061] The 3D-printed flexible zinc-ion battery positive electrode prepared in Example 3 was used to assemble an aqueous zinc-ion button battery (the negative electrode is zinc metal, the electrolyte is a 2 mol / L ZnSO4 solution, and the separator is glass fiber). Cyclic charge-discharge tests were conducted at a current density of 1 A / g. The results are shown in […]. Figure 5 As shown in the figure, the 3D-printed flexible zinc-ion battery prepared in Example 3 of this invention retains 92.3% of its capacity after 1000 charge-discharge cycles, demonstrating excellent long-cycle stability.

[0062] The 3D-printed flexible zinc-ion battery cathode assembly pouch cell prepared in Example 3 was used to construct the battery. Long-cycle performance was tested after 100 bending cycles. The results are shown in [Figure 1]. Figure 6 As shown in the figure, the 3D-printed flexible zinc-ion battery cathode prepared in Example 3 of this invention retains 95.3% of its capacity after 100 charge-discharge cycles following bending, demonstrating excellent flexibility.

Claims

1. A method for fabricating a flexible zinc-ion battery cathode using 3D printing, characterized in that, Includes the following steps: S1. Preparation of printable positive electrode ink: Polyvinylidene fluoride (PVDF) and N-methylpyrrolidone (NMP) are mixed and heated and stirred at 55-65°C to form a gel. Then, carbon nanotube-coated MOF-based composite material and carbon black are added, and the mixture is ball-milled for 1-3 hours to obtain a printable positive electrode ink. The mass ratio of PVDF, NMP, NMP, and carbon nanotube-coated MOF-based composite material to carbon black is 2-4:0.5-1:8-10:0.5-1. The preparation method of the carbon nanotube-coated MOF-based composite material is as follows: Step 1: Benzoic acid, zirconium tetrachloride, and 2-aminoterephthalic acid are weighed and mixed in a mass ratio of 4-4.5:0.5-1:0.3-0.7, and then added to N,N-dimethylformamide to obtain solution A. Potassium permanganate and manganese sulfate monohydrate are weighed in a mass ratio of 3-3.5:5-5.5 and added to deionized water. The mixture is magnetically stirred for 1 hour to obtain solution B. Solution B is then slowly added to solution A. The mixed solution is transferred to a polytetrafluoroethylene reactor and hydrothermally reacted at 120-140℃ for 20-24 hours. After centrifugation, washing, and drying, UiO-66-NH2@MnO2 material is obtained. Step 2: Under inert gas protection, the UiO-66-NH2@MnO2 material is heated to 200-300℃ and held for 1 hour, then replaced with hydrogen. The temperature is then increased to 450℃ at a rate of 5℃ / min, and then rapidly increased to 600-700℃ at a rate of 20℃ / min. The hydrogen is then replaced with n-hexane, and the reaction is held for 20-40 minutes. After the holding period, the n-hexane is replaced with an inert gas, and the mixture is cooled to room temperature to obtain the carbon nanotube-coated MOF-based composite material. S2. 3D printing process: Printable positive electrode ink is loaded into a syringe, which is then connected to the printer's air pressure control device. The printer is then started, and the preset program of the 3D model is run. The air pressure of the air pressure control device is adjusted to uniformly squeeze out the mild ink. After printing, the obtained electrode is placed in a fume hood to dry, thus obtaining a 3D printed flexible zinc-ion battery electrode.

2. The method for preparing a flexible zinc-ion battery cathode using 3D printing according to claim 1, characterized in that, In step 2, the hydrogen flow rate is 120-150 mg / min, and the n-hexane flow rate is 0.1-0.3 mL / min.

3. A 3D-printed flexible zinc-ion battery cathode prepared by the preparation method according to any one of claims 1-2, characterized in that, The 3D-printed flexible zinc-ion battery cathode has a periodic layered grid, which is conducive to electrolyte penetration and can maintain structural stability even when bent at 45°-180°. After bending 100 times and undergoing 100 charge-discharge cycles, the capacity retention rate of the 3D-printed flexible zinc-ion battery cathode is still 95.3%.

4. The application of the flexible zinc-ion battery cathode constructed by 3D printing according to claim 3 in the preparation of zinc-ion batteries.

5. A zinc-ion battery, characterized in that, The 3D-printed flexible zinc-ion battery cathode of claim 3 has a specific capacity of 97.6 mAh / g at a current density of 2 A / g and a capacity retention of 92.3% after 1000 charge-discharge cycles.

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