A preparation method of a wet synthesis coupled cyclic voltammetry method for constructing an interwoven network structure tungsten / polyaniline composite nanomaterial, a product and application thereof
By growing tungsten oxide nanowires in situ on the surface of the current collector and synthesizing tungsten oxide/polyaniline composite nanomaterials with an interwoven network structure, the conductivity and capacity problems of zinc-ion battery cathode materials were solved, achieving high-efficiency electrode performance and energy storage capacity.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2023-06-25
- Publication Date
- 2026-03-27
AI Technical Summary
Existing zinc-ion battery cathode materials have poor conductivity, significant capacity decay, and short operating cycles. Furthermore, traditional preparation methods result in high interfacial resistance and severe loss of active sites, failing to meet commercial requirements.
Tungsten oxide nanowires were grown in situ on the surface of a current collector using a wet synthesis coupled cyclic voltammetry method. Tungsten oxide/polyaniline composite nanomaterials with an interwoven network structure were then synthesized on the surface of the nanowires. Polyaniline was used to improve conductivity and reduce Zn2+ insertion resistance, thereby constructing a high-porosity network structure.
This improved the specific energy storage capacity of zinc-ion batteries, shortened the ion diffusion path, reduced the interface resistance, and eliminated the need for binders, thus achieving highly efficient electrode material performance.
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Figure CN116855071B_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the field of electrochemical energy storage technology, and in particular to a preparation method of a grain-induced construction of a multi-valence composite vanadium-based hydroxide nanomaterial with a vertical sheet structure and application thereof as an electrode material of a secondary aqueous zinc ion battery. BACKGROUND
[0002] With the development of society and the improvement of scientific and technological level, people's life is increasingly improved, and the demand for resource development is increasingly increased. Various electronic products have become an indispensable necessary element in modern social life. The widespread use puts forward higher requirements for the production and storage of electric energy. Fossil energy is still the main source of electric energy, but it is a non-renewable energy and cannot meet the demand of sustainable development strategy. In addition, green energy such as wind energy and solar energy has the characteristics of intermittency (non-uniform distribution in space and instability in time), which easily leads to interruption of electric energy output and mismatch between power supply energy density and power grid. Therefore, it is of great importance to solve environmental problems and energy utilization problems to vigorously develop research on energy storage technology and develop energy storage equipment.
[0003] The storage and continuous output of electric energy are the key to realize the sustainable power supply and sustainable development of green energy. Electrochemical energy storage devices have great potential in this field. Aqueous secondary batteries belong to green electrochemical energy storage devices and have the characteristics of safety and environmental protection. Among many aqueous secondary battery systems, secondary aqueous zinc ion batteries (AZIBs) are favored, mainly because: (1) compared with lithium, sodium, potassium, magnesium and aluminum, zinc has a low redox potential (-0.76V, relative to the standard hydrogen electrode) and a stable reversible redox reaction in a water environment, which can be directly used as a negative electrode of a battery; (2) the zinc negative electrode has a high theoretical capacity (820mAh / g and 5855mAh / cm 3 ), low cost, green environmental protection, and good stability in air.
[0004] For zinc ion batteries in a specific electrolyte environment, the specific capacity value is largely determined by the positive electrode material. Therefore, the development of zinc ion deintercalation positive electrode materials with high specific capacity is the key to obtaining high-energy-density AZIBs. Although certain achievements have been made in the exploration and research of electrode materials so far, there are still great challenges in the material level and even the entire aqueous zinc ion battery system, which leads to the fact that it still cannot replace lithium ion batteries to meet the needs of business. Therefore, it is still an important direction for the secondary aqueous zinc ion battery to seek breakthroughs to continue to explore new materials with great energy storage potential.
[0005] In recent years, the research on the positive electrode materials based on ZIBs mainly includes manganese oxides, vanadium oxides, prussian blue and its analogues, transition metal dihalides and organic compounds. Among them, manganese oxides (MnO, MnO2, Mn2O3, MnO4) and vanadium-based oxides show the best zinc storage potential in terms of zinc storage capacity. However, the current research results show that the zinc ion battery based on the two types of positive electrode has poor rate performance, significant capacity decay and short working cycle. The further development of new materials makes people begin to pay attention to the electrochromic material of trioxide (WO3) which is essentially active cation, but research shows that trioxide belongs to a kind of semiconductor material with wide band gap, so the conductivity is poor, and the high charge density such as Zn 2+ insertion in the +6 valence tungsten lattice shows high repulsive resistance, which hinders its application in secondary aqueous zinc ion batteries.
[0006] In addition, the secondary aqueous zinc ion nanomaterials prepared at present are powder materials, that is, the active material is mixed and ground with conductive activated carbon and binder substances, and the obtained powder material is loaded on the surface of the current collector through coating process. The preparation process cannot avoid the addition of non-conductive binder, and is affected by the mixing and coating process, which easily causes large interface resistance or contact resistance of the electrode and poor conductivity. At the same time, the mixed non-conductive binder also causes the loss of part of the active sites of the active carrier. SUMMARY
[0007] The technical problem to be solved by the present application is to provide a preparation method for synthesizing a wet interwoven network structure tungsten trioxide / polyaniline composite nanomaterial by coupling cyclic voltammetry, which can effectively improve the conductivity of tungsten trioxide on one hand, and the nitrogen-containing functional groups can effectively weaken the high charge density Zn 2+ repulsive resistance of +6 valence tungsten in the trioxide lattice during the insertion process, accelerate the kinetics of ion diffusion, and the interwoven network structure constructed by the method has high porosity, which can fully expose the active sites, construct a rich electrolyte / electrode interface, shorten the diffusion path of ions and improve the diffusion coefficient of ions. At the same time, the interwoven network structure tungsten trioxide / polyaniline composite nanomaterial prepared by the method can be directly used as the electrode of the battery without the intervention of low conductivity and non-energy storage active binder.
[0008] The technical scheme adopted by the present application to solve the above problems is:
[0009] The application discloses a preparation method of a wet synthesis coupled cyclic voltammetry method for constructing interwoven network structure tungsten oxide / polyaniline composite nanomaterials.
[0010] According to the above scheme, the concentration of Na2WO4·2H2O in the reaction solution is in the range of 0.001±0.0003M, the concentration of (NH4)2SO4 is in the range of 0.01±0.003M, the concentration of hydrochloric acid is in the range of 3.0±0.03M, the pH of the solution is about 3.0, and the total volume of the solution is about 40ml.
[0011] Further, the reaction solution is poured into a 60ml hydrothermal kettle, and a current collector with a size of 1×2cm 2 is placed in the reaction solution.
[0012] According to the above scheme, the hydrothermal kettle is placed in an intelligent box-type resistance furnace, the reaction temperature is 180℃, and the reaction time is 6 hours. After the reaction is completed, the hydrothermal kettle is taken out, and the current collector material in the hydrothermal kettle is taken out and placed in an intelligent box-type resistance furnace for drying, the drying temperature is 450℃, and the drying time is 3 hours.
[0013] Further, the dried current collector is used as a working electrode, a polished carbon rod is used as a counter electrode, an Ag / AgCl electrode is used as a reference electrode, an H2SO4 solution containing an aniline monomer is used as a reaction solution, and a normal-temperature cyclic voltammetry method is used to finally synthesize interwoven network structure tungsten oxide / polyaniline composite nanomaterials on the surface of the current collector.
[0014] According to the above scheme, the electrolyte used in the cyclic voltammetry method is 1M H2SO4, the volume percentage of aniline is 0.4%, and the volume of the electrolyte is 50ml. The voltage range is 0V to -0.6V, the scanning speed is 0.005V / s, and the cyclic scanning number is 40.
[0015] Further, after the scanning is completed, the current collector is taken out, washed with a large amount of deionized water until the pH of the deionized water is close to 7.0, and dried in a vacuum drying box.
[0016] According to the above scheme, the vacuum drying temperature is 120℃, the drying vacuum degree is -0.8Pa, and the vacuum drying time is 1 hour.
[0017] According to the above scheme, the current collector substrate can be either a foamed nickel or a carbon cloth, such as Shanghai Hesen HCP330, etc. Further, taking the carbon cloth as an example, the carbon cloth current collector needs to be pretreated before being used as a working electrode, that is, the carbon cloth is sequentially placed in 10% HCl solution, ethanol and acetone for ultrasonic treatment for 10 minutes, and then taken out and dried, with a drying temperature of 60 DEG C and a drying time of 12 hours.
[0018] The self-supporting tungsten oxide positive electrode nanomaterial prepared by the method of the application is uniformly covered on the surface of the current collector, presents yellow color under naked eye observation, and presents fish scale-like lamella in microstructure without agglomeration.
[0019] The interwoven network structure tungsten oxide / polyaniline composite nanomaterial prepared by the above method is used as a positive electrode material of a secondary aqueous zinc ion battery for the first time. The nanowire interwoven network structure of the tungsten oxide / polyaniline composite nanomaterial directly synthesized on the surface of a current collector such as carbon cloth or foamed nickel by the method of the application has high porosity, which provides guarantee for exposing abundant active sites (increasing specific surface area), and the large aspect ratio of the nanowire can guide the electron to conduct along the axial direction, while the polyaniline conductive polymer can effectively improve the conductivity of the tungsten trioxide. In addition, the lone pair electrons of the nitrogen functional group of the polyaniline weaken the intercalation energy barrier of Zn 2+ to some extent, and improve the diffusion kinetics process of Zn 2+ The interwoven network structure tungsten oxide / polyaniline composite nanomaterial prepared by the method can be directly used as an electrode of a battery without intervention of a binder with low conductivity and no energy storage activity.
[0020] Compared with the prior art, the application has the following beneficial effects:
[0021] Firstly, the interwoven network structure tungsten oxide / polyaniline composite nanomaterial can be grown on the surface of any current collector substrate material by using a simple wet synthesis coupled with a convenient electrochemical cyclic voltammetry method, and the preparation process is simple and economical without the aid of a nanotube template material with no energy storage activity.
[0022] Secondly, the interwoven network structure tungsten oxide / polyaniline composite nanomaterial can be directly grown on the surface of a current collector and constructed to form an interwoven network structure, and the obtained interwoven network structure is closely connected with the current collector, that is, it can be directly used as an electrode of a battery, which can guarantee a low interface resistance and does not need to intervene a binder with low conductivity and no energy storage activity.
[0023] Third, the tungsten oxide / polyaniline composite nanomaterial prepared in this invention is used for the first time as the positive electrode in aqueous zinc-ion batteries (AZIBs). This is a novel material suitable for use as a positive electrode in AZIBs. The preparation method successfully avoids the loss of some active sites due to the lack of an active intermediate carrier material, thus improving the effective activity of the electrode. The tungsten oxide / polyaniline composite nanomaterial prepared in this invention is uniformly distributed along the surface of carbon cloth or nickel foam current collector, forming an interwoven nanowire network structure without agglomeration. The interwoven nanowire network constitutes a rich porous structure, providing a large contact interface for electrolyte penetration, shortening the ion diffusion path. Simultaneously, the lone pair electrons of the nitrogen-containing functional groups in polyaniline can, to some extent, weaken the Zn... 2+ The intercalation energy barrier of Zn is increased. 2+ The diffusion kinetics process ultimately increases the ion diffusion coefficient and improves the specific energy storage capacity of the active material. Under the same preparation conditions, the interwoven network structure tungsten oxide / polyaniline composite nanomaterials constructed by the wet synthesis coupled with cyclic voltammetry described in this invention have a specific energy storage capacity approximately 3.5 times that of oxide cathode nanomaterials prepared by simple hydrothermal synthesis in secondary aqueous zinc-ion battery applications.
[0024] Fourth, the discharge voltage plateau of the self-supporting tungsten oxide cathode nanomaterial described in this invention reaches 1.2V-0.2V; its corresponding energy storage specific capacity is 0.1A·g. -1 Up to 390 mAh·g at current density -1 It is close to the theoretical specific capacity value of 462 mAh·g based on two-electron transfer. -1 . Attached Figure Description
[0025] Figure 1 The image shows a SEM image of the interwoven network structure tungsten oxide / polyaniline composite nanomaterial prepared in Example 1.
[0026] Figure 2 The image shows the EDS diagram of the interwoven network structure tungsten oxide / polyaniline composite nanomaterial prepared in Example 1.
[0027] Figure 3 The image shows the XRD pattern of the interwoven network structure tungsten oxide / polyaniline composite nanomaterial prepared in Example 1.
[0028] Figure 4 XPS image of the interwoven network structure tungsten oxide / polyaniline composite nanomaterial prepared in Example 1.
[0029] Figure 5 The image shows the CA charge-discharge curves of the interwoven network structure tungsten oxide / polyaniline composite nanomaterial prepared in Example 1. Detailed Implementation
[0030] For better understanding of the present application, the following examples are further illustrated the content of the present application, but the present application is not limited to the following examples.
[0031] In the following examples, the area of the electrode Pt sheet is 1.5 x 1.5 cm 2 , and the area of the carbon cloth current collector is 1 x 2 cm 2 .
[0032] Example 1
[0033] An interwoven network structure tungsten oxide / polyaniline composite nanomaterial is prepared according to the following steps:
[0034] 1) Pretreatment of the carbon cloth current collector
[0035] The carbon cloth is cut into an area of 1 x 2 cm 2 , and is sequentially placed in 50 ml of 10% HCl solution, ethanol and acetone for ultrasonic treatment for 10 minutes each, and then taken out and placed in a 60°C electric oven for 12 hours for use as a working electrode.
[0036] 2) Preparation of WO3 nanowires on the surface of the current collector
[0037] An aqueous solution containing sodium tungstate dihydrate (Na2WO4·2H2O) and ammonium sulfate ((NH4)2SO4) is prepared as a reaction solution, wherein the concentration of Na2WO4·2H2O is in the range of 0.001 ± 0.0003 M, the concentration of ammonium sulfate ((NH4)2SO4) is in the range of 0.01 ± 0.003 M, the concentration of hydrochloric acid is about 3.0 ± 0.03 M, the pH of the solution is about 3.0, and the total volume of the solution is about 40 ml. The reaction solution is poured into a 60 ml hydrothermal kettle, and the current collector in step 1) is placed in the hydrothermal kettle vertically against the inner wall. The hydrothermal kettle is placed in an intelligent box-type electric resistance furnace, and the temperature is set to 180°C for 6 hours.
[0038] 3) Drying of the WO3 nanowire current collector material
[0039] The hydrothermal kettle in step 2) is taken out after the reaction is completed, the current collector is taken out, washed with a large amount of deionized water until the pH of the washing solution approaches 7.0, and then dried in an intelligent box-type electric resistance furnace, with a drying temperature of 450°C and a drying time of 3 hours.
[0040] 4) Preparation of an interwoven network structure tungsten oxide / polyaniline composite nanomaterial
[0041] Using the current collector from step 3) as the working electrode, the polished carbon rod as the counter electrode, the Ag / AgCl electrode as the reference electrode, and a 1M H2SO4 solution containing aniline monomer as the electrolyte (aniline volume percentage 0.4%, electrolyte volume 50ml), the cyclic voltammetry was set with an initial voltage of 0V, a maximum voltage of 1.2V, and a minimum voltage of -0.2V. The scan proceeded from 0V to 1.2V, then reversed back to -0.2V, and then back to 0V, constituting one cycle. The scan rate was 0.05V / s, and a total of three cycles were performed.
[0042] 5) Drying of interwoven network structure tungsten oxide / polyaniline composite nanomaterials
[0043] The interwoven network structured tungsten oxide / polyaniline composite nanomaterials prepared in step 4) were removed from the electrolyte and rinsed with plenty of deionized water until the pH of the rinsing solution was close to 7.0. Then, they were placed in a vacuum drying oven for drying. The vacuum drying temperature was 120℃, the vacuum degree was -0.8 Pa, and the vacuum drying time was 1 hour.
[0044] Example 2
[0045] The difference between this embodiment and Example 1 is that aniline accounts for 1% of the volume of the electrolyte.
[0046] Example 3
[0047] The difference between this embodiment and Embodiment 1 is that aniline accounts for 2% of the volume of the electrolyte.
[0048] Example 4
[0049] The difference between this embodiment and Example 1 is that aniline accounts for 4% of the volume of the electrolyte.
[0050] like Figure 1 As shown, the tungsten oxide / polyaniline composite nanomaterial prepared by this invention uniformly covers the surface of the current collector, and the formed nanowire interwoven network exhibits a honeycomb-like orderly arrangement with high porosity. The nanowires are approximately 1 μm long and approximately 10 nm in diameter.
[0051] from Figure 2 As can be seen, the composite material prepared by this invention successfully combines polyaniline and tungsten oxide uniformly.
[0052] from Figure 3 As can be seen, the XRD patterns of PANI / WO3 composites with different aniline monomer volume fractions all match the peak positions in the standard card (PDF#01-085-2459), indicating that WO3 is hexagonal in shape. The hexagonal crystal structure has the largest channel size compared to the monoclinic and triclinic crystal structures, which is beneficial for Zn. 2+The intercalation and deintercalation of the PANI are also proved. Meanwhile, it is proved that the combination of PANI does not cause too much change of the crystal structure of the WO3 electrode material. The prepared composite material successfully uniformly combines polyaniline and tungsten oxide.
[0053] From Figure 5 It can be seen that the W4f spectrum can be convoluted into two peaks, the peaks appearing at the binding energy of 35.8ev, 35.9ev and 36ev are related to W4f7 / 2, and the peaks appearing at 38.1ev and 38ev are related to W4f5 / 2, and these spectrum peaks are characteristic peaks of hexavalent tungsten, which can prove that the W element in the prepared tungsten oxide / polyaniline composite nanomaterial is mainly in the form of W 6+ .
[0054] The application of the interwoven network structure tungsten oxide / polyaniline composite nanomaterial prepared by the wet synthesis coupled with cyclic voltammetry in the secondary water-based zinc ion battery is mainly compared with the pure tungsten trioxide nanomaterial by determining the energy storage specific capacity.
[0055] The determination of the energy storage specific capacity is that the prepared interwoven network structure tungsten oxide / polyaniline composite nanomaterial is used as a positive electrode, a zinc sheet with a purity of 99.9% is used as a counter electrode and a reference electrode, the area of the positive electrode and the zinc sheet is 1x2cm 2 and 1.5x1.5cm 2 , respectively, a saturated zinc sulfate solution is used as an electrolyte, and the open circuit of the working electrode relative to the zinc sheet is about 1.8V. The absolute value of the charge and discharge current density is set to 0.1A·g -1 . Firstly, the electrode is discharged at a current density of-0.1A·g -1 , and then the electrode is charged at a current density of 0.1A·g -1 , until the voltage is 1.8V. The above process is repeated for five times.
[0056] The preparation process of the tungsten oxide positive electrode nanomaterial for comparison is as follows: 1) carbon cloth is cut into 1x2cm 2The area of the carbon cloth was measured, and the carbon cloth was sequentially placed in 50 ml of 10% HCl solution, ethanol, and acetone for 10 minutes of ultrasonic treatment each, and then taken out and placed in a 60°C electric oven for 12 hours. 2) An aqueous solution containing sodium tungstate dihydrate (Na2WO4·2H2O) and ammonium sulfate ((NH4)2SO4) was prepared as a reaction solution, wherein the concentration of Na2WO4·2H2O was in the range of 0.001±0.0003 M, the concentration of ammonium sulfate ((NH4)2SO4) was in the range of 0.01±0.003 M, the pH of the solution was adjusted to about 3.0 using hydrochloric acid with a concentration of about 3.0±0.03 M, and the total volume of the solution was about 40 ml. The reaction solution was poured into a 60 ml hydrothermal kettle, and the treated carbon cloth was placed in the hydrothermal kettle vertically against the inner wall. The hydrothermal kettle was placed in an intelligent box-type electric resistance furnace, and the temperature was set to 180°C for 6 hours. 3) The carbon cloth was taken out, washed with a large amount of deionized water until the pH of the washing water solution was close to 7.0, and then dried in an intelligent box-type electric resistance furnace, with a drying temperature of 450°C and a drying time of 3 hours.
[0057] From Figure 5 It can be seen that, under the same discharge current density, the specific capacity of the secondary water-based zinc ion battery with the interwoven network structure tungsten oxide / polyaniline composite nanomaterial constructed by wet synthesis coupled with cyclic voltammetry as the positive electrode is about 3.5 times that of the battery with pure tungsten trioxide nanomaterial as the positive electrode.
[0058] The above only describes the preferred embodiments of the present application, and it should be noted that, for those skilled in the art, without departing from the inventive concept, several improvements and changes can be made, which are all within the protection scope of the present application.
Claims
1. A method for preparing a wet-synthesized coupling cyclic voltammetry-constructed interwoven network structure tungsten oxide / polyaniline composite nanomaterial, characterized in that, First, the tungsten oxide nanowires are grown in situ on the surface of the current collector by wet synthesis method, then the current collector treated by wet synthesis is used as the working electrode, the polished carbon rod is used as the counter electrode, the Ag / AgCl electrode is used as the reference electrode, the H2SO4 solution containing aniline monomer is used as the reaction solution, and the interwoven network structure tungsten oxide / polyaniline composite nanomaterials are finally synthesized on the surface of the current collector by normal temperature cyclic voltammetry; The wet synthesis uses an aqueous solution containing sodium tungstate dihydrate Na2WO4·2H2O and ammonium sulfate (NH4)2SO4 as the reaction solution, and hydrochloric acid is used to adjust the pH of the solution; The concentration of Na2WO4·2H2O in the reaction solution is in the range of 0.0005-0.0015 M, the concentration of (NH4)2SO4 is in the range of 0.005-0.015 M, and the concentration of hydrochloric acid is in the range of 2.5-3.5 M; The wet synthesis is performed by pouring the reaction solution into an autoclave and placing the current collector into the reaction solution; The reaction temperature of the wet synthesis is 180℃, and the reaction time is 6 hours; after the reaction is completed, the current collector is taken out, washed with a large amount of deionized water until the pH of the washing water solution is 7.0, and then dried in an intelligent box-type electric resistance furnace, with a drying temperature of 450℃ and a drying time of 3 hours; The cyclic voltammetry has a starting voltage of 0V, a maximum voltage of 1.2V, and a minimum voltage of -0.2V, and one cycle is from 0V to 1.2V, then from 1.2V to -0.2V, and then from -0.2V to 0V, with a scan rate of 0.05V / s, and a total of three cycles.
2. The preparation method of the wet synthetic coupled cyclic voltammetry constructed interwoven network structure tungsten oxide / polyaniline composite nanomaterial according to claim 1, characterized in that, The concentration of Na2WO4·2H2O in the reaction solution is in the range of 0.001±0.0003 M, the concentration of (NH4)2SO4 is in the range of 0.01±0.003 M, and the concentration of hydrochloric acid is in the range of 3.0±0.03 M; the pH of the reaction solution is 3.0, and the total volume is 40ml.
3. The method according to claim 1, wherein the method is characterized in that, The wet synthesis employs a hydrothermal reactor volume of 60 ml, and the current collector has dimensions of 1 x 2 cm 2 .
4. The method according to claim 1, wherein the method is characterized in that, The electrolyte used in the cyclic voltammetry is 1M H2SO4, with an aniline volume percentage of 0.4%, and the volume of the electrolyte is 50ml.
5. The method according to claim 1, wherein the method is characterized in that, Further, the interwoven network structure tungsten oxide / polyaniline composite nanomaterials are washed with a large amount of deionized water until the pH of the washing water solution is 7.0, and then dried in a vacuum drying oven.
6. The interwoven network structure tungsten oxide / polyaniline composite nanomaterials prepared by the method of claim 1.
7. The application of the interwoven network structure tungsten oxide / polyaniline composite nanomaterials prepared by the method of any one of claims 1-5 as electrode materials for secondary aqueous zinc ion batteries.
Citation Information
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