A surface amorphous vanadium-based prussian blue analogue electrode material for aqueous ammonium ion batteries and a preparation method and application thereof
Patent Information
- Application Number
- CN202611257795.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-08-19
- Publication Date
- 2026-10-16
AI Technical Summary
钒基普鲁士蓝类似物同时具有V和Fe多价氧化还原中心，能够提供较丰富的电化学反应路径，但其实际容量、离子/电子传输动力学以及长期循环中的表面结构稳定性仍有进一步提升空间
[0020] This invention employs a hydrothermal co-precipitation method combined with a tubular furnace and gentle heat treatment, eliminating the need for introducing additional coating components or complex heterogeneous phases. The process is simple and easily reproducible and scaled up. Gentle heat treatment in an inert atmosphere helps maintain the main structure of vanadium-based Prussian blue analogues and V... 4+ /V 5+ Under conditions of relatively stable proportions, an amorphous reconstruction layer is formed on the crystal surface, achieving localized surface structure control. This facilitates electron transfer and NH4+. + Migration provides additional driving force, resulting in higher specific capacity.
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Figure CN122916169A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of new energy technology and relates to a surface amorphous vanadium-based Prussian blue analog electrode material for aqueous ammonium-ion batteries, its preparation method and application. Specifically, it relates to an electrode material for constructing an amorphous reconstruction layer on the surface of a vanadium-based Prussian blue analog through mild heat treatment under an inert atmosphere, its preparation method, and its application as a positive electrode material in aqueous ammonium-ion batteries. Background Technology
[0002] With the rapid development of renewable energy, aqueous energy storage systems, which combine safety, low cost, and environmental friendliness, have attracted widespread attention. Compared to non-aqueous batteries that use organic electrolytes, aqueous batteries are non-flammable, have high electrolyte ionic conductivity, and require mild assembly conditions. Ammonium ions (NH4+) + Ammonium ion is a non-metallic charge carrier with low molar mass, small hydrated size and special tetrahedral configuration. It can be rapidly transported in aqueous solution through the formation and breaking of hydrogen bonds. Therefore, aqueous ammonium ion batteries have good application potential.
[0003] Prussian blue and its analogues possess an open three-dimensional framework, large ion channels, tunable transition metal active centers, and relatively high operating potentials, making them promising cathode materials for aqueous ammonium-ion batteries. Vanadium-based Prussian blue analogues, possessing both V and Fe multivalent redox centers, can provide a richer electrochemical reaction pathway, but their actual capacity, ion / electron transport kinetics, and surface structure stability during long-term cycling still have room for further improvement. Summary of the Invention
[0004] This invention employs a mild thermal reconstruction strategy to amorphize the surface of vanadium-based Prussian blue analogues, thereby increasing electron transport rate and structural adaptability, resulting in an electrode material with high specific capacitance.
[0005] The technical solution adopted in this invention is: a surface-amorphous vanadium-based Prussian blue analog electrode material for aqueous ammonium-ion batteries, the preparation method of which includes the following steps:
[0006] 1) Preparation of precursor solution: NH4VO3 and K3[Fe(CN)6] were added to ultrapure water and mixed, and then anhydrous oxalic acid H2C2O4 was added and stirred to form a homogeneous precursor solution;
[0007] 2) Preparation of V-PBAs: The precursor solution obtained in step 1) was transferred to a polytetrafluoroethylene-lined reactor for hydrothermal coprecipitation reaction. After natural cooling, it was washed with deionized water and ethanol, centrifuged and dried to obtain vanadium-based Prussian blue analogs V-PBAs.
[0008] 3) Surface amorphization: The obtained V-PBAs are placed in a tube furnace and subjected to mild heat treatment under an inert atmosphere. After cooling, vanadium-based Prussian blue analogs with an amorphous reconstruction layer on the surface are obtained.
[0009] Further, in step 1), the molar ratio of NH4VO3:K3[Fe(CN)6]:H2C2O4 in the mixed solution of the precursor solution is 1:1:(2-3).
[0010] Furthermore, in step 1), the volume of ultrapure water added is 50-80 mL.
[0011] Further, in step 1), anhydrous oxalic acid is added and stirred for 20-60 minutes.
[0012] Further, in step 2), the hydrothermal treatment conditions are: hydrothermal treatment at 150℃-200℃ for 6 h-10 h.
[0013] Furthermore, in step 3), the inert gas is argon or nitrogen.
[0014] Furthermore, in step 3), the heat treatment temperature is 150-300 ℃.
[0015] Furthermore, in step 3), the heat treatment time is 1-4 hours.
[0016] A surface-amorphous vanadium-based Prussian blue analog electrode material prepared according to the above preparation method.
[0017] The present invention relates to the application of surface-amorphous vanadium-based Prussian blue analog electrode materials in ammonium-ion batteries.
[0018] Furthermore, the application of surface-amorphous vanadium-based Prussian blue analog electrode materials as positive electrode materials in ammonium-ion batteries.
[0019] The beneficial effects of this invention are as follows:
[0020] This invention employs a hydrothermal co-precipitation method combined with a tubular furnace and gentle heat treatment, eliminating the need for introducing additional coating components or complex heterogeneous phases. The process is simple and easily reproducible and scaled up. Gentle heat treatment in an inert atmosphere helps maintain the main structure of vanadium-based Prussian blue analogues and V... 4+ / V 5+ Under conditions of relatively stable proportions, an amorphous reconstruction layer is formed on the crystal surface, achieving localized surface structure control. This facilitates electron transfer and NH4+. + Migration provides additional driving force, resulting in higher specific capacity.
[0021] The dimensional-amorphous local microenvironment structure proposed in this invention can induce interfacial charge redistribution, band bending, and the establishment of a built-in electric field, which facilitates electron transfer and NH4+. + Migration provides additional driving force without significantly altering the vanadium-based main framework. This invention offers a simple preparation process that requires no additional polymer coating or introduction of complex heterogeneous components, providing a surface modulation method for high-performance vanadium-based Prussian blue analogue ammonium-ion battery cathode materials. Attached Figure Description
[0022] Figure 1 This is a transmission electron microscope (TEM) image of the V-PBAs electrode prepared in step 2) of Example 1.
[0023] Figure 2 This is a transmission electron microscope (TEM) image of the V-PBAs-150 electrode prepared in step 3) of Example 1.
[0024] Figure 3 This is a transmission electron microscope (TEM) image of the V-PBAs-200 electrode prepared in step 3) of Example 2.
[0025] Figure 4 This is a transmission electron microscope (TEM) image of the V-PBAs-250 electrode prepared in step 3) of Example 3.
[0026] Figure 5 These are the V 2p X-ray photoelectron (XPS) spectra of V-PBAs and V-PBAs-200 electrodes.
[0027] Figure 6 These are X-ray diffraction (XRD) spectra of V-PBAs, V-PBAs-150, V-PBAs-200, and V-PBAs-250 electrodes.
[0028] Figure 7 For V-PBAs and V-PBAs-200 electrode materials at 10 mV s -1 The cyclic voltammetry curve below.
[0029] Figure 8 For V-PBAs, V-PBAs-150, V-PBAs-200 and V-PBAs-250 electrode materials at 0.1 A g -1 The constant current charge-discharge curves are shown below. Detailed Implementation
[0030] A surface-amorphous vanadium-based Prussian blue analog electrode material for aqueous ammonium-ion batteries, the preparation method includes the following steps:
[0031] 1) Preparation of precursor solution: 0.468 g ammonium metavanadate NH4VO3 and 1.317 g potassium ferricyanide K3[Fe(CN)6] were added to 70 mL of ultrapure water and mixed. Then 0.900 g H2C2O4 was added and stirred for 20-60 min to form a homogeneous precursor solution.
[0032] 2) Preparation of V-PBAs: The precursor solution obtained in step 1) was transferred to a polytetrafluoroethylene-lined reactor for hydrothermal coprecipitation reaction, and hydrothermally treated at 150℃-200℃ for 6 h-10 h. After natural cooling, it was washed with deionized water and ethanol, centrifuged and dried to obtain vanadium-based Prussian blue analogs V-PBAs;
[0033] 3) Surface amorphization: The obtained V-PBAs were placed in a tube furnace and subjected to mild heat treatment under an inert atmosphere at 150-300 °C for 1-4 hours. After cooling, vanadium-based Prussian blue analogs with an amorphous reconstructed layer on the surface were obtained.
[0034] Example 1
[0035] A surface-amorphous vanadium-based Prussian blue analog electrode material for aqueous ammonium-ion batteries, the preparation method includes the following steps:
[0036] 1) Preparation of precursor solution: 0.468 g NH4VO3 and 1.317 g K3[Fe(CN)6] were added to 70 mL of ultrapure water and mixed. Then 0.900 g H2C2O4 was added and stirred for 30 min to form a homogeneous precursor solution.
[0037] 2) Preparation of V-PBAs: The precursor solution obtained in step 1) was transferred to a polytetrafluoroethylene-lined reactor for hydrothermal coprecipitation reaction, and hydrothermally treated at 180℃ for 8 h. After natural cooling, it was washed with deionized water and ethanol, centrifuged and dried to obtain vanadium-based Prussian blue analogs V-PBAs;
[0038] 3) Surface amorphization: The obtained V-PBAs were placed in a tube furnace and subjected to mild heat treatment at 150 °C for 2 hours under an inert atmosphere. After cooling, vanadium-based Prussian blue analogue V-PBAs-150 with an amorphous reconstruction layer on the surface was obtained.
[0039] Example 2
[0040] A surface-amorphous vanadium-based Prussian blue analog electrode material for aqueous ammonium-ion batteries, the preparation method includes the following steps:
[0041] 1) Preparation of precursor solution: 0.468 g NH4VO3 and 1.317 g K3[Fe(CN)6] were added to 70 mL of ultrapure water and mixed. Then 0.900 g H2C2O4 was added and stirred for 30 min to form a homogeneous precursor solution.
[0042] 2) Preparation of V-PBAs: The precursor solution obtained in step 1) was transferred to a polytetrafluoroethylene-lined reactor for hydrothermal coprecipitation reaction, and hydrothermally treated at 180℃ for 8 h. After natural cooling, it was washed with deionized water and ethanol, centrifuged and dried to obtain vanadium-based Prussian blue analogs V-PBAs;
[0043] 3) Surface amorphization: The obtained V-PBAs were placed in a tube furnace and subjected to mild heat treatment under an inert atmosphere at 200 °C for 2 hours. After cooling, vanadium-based Prussian blue analogue V-PBAs-200 with an amorphous reconstruction layer on the surface was obtained.
[0044] Figure 5 These are the V 2p X-ray photoelectron (XPS) spectra of V-PBAs and V-PBAs-200. (Source: [Insert source here]) Figure 5 It can be seen that V in both samples is V 4+ / V 5+ Mixed valence states exist, and V before and after calcination at 200 ℃ 4+ / V 5+ The relative proportions and peak positions of the V-related components did not change significantly, indicating that the heat treatment did not significantly alter the overall oxidation state of the V-centered structure, and the V-related main coordination framework remained basically stable.
[0045] Example 3
[0046] A surface-amorphous vanadium-based Prussian blue analog electrode material for aqueous ammonium-ion batteries, the preparation method includes the following steps:
[0047] 1) Preparation of precursor solution: 0.468 g NH4VO3 and 1.317 g K3[Fe(CN)6] were added to 70 mL of ultrapure water and mixed. Then 0.900 g H2C2O4 was added and stirred for 30 min to form a homogeneous precursor solution.
[0048] 2) Preparation of V-PBAs: The precursor solution obtained in step 1) was transferred to a polytetrafluoroethylene-lined reactor for hydrothermal coprecipitation reaction, and hydrothermally treated at 180℃ for 8 h. After natural cooling, it was washed with deionized water and ethanol, centrifuged and dried to obtain vanadium-based Prussian blue analogs V-PBAs;
[0049] 3) Surface amorphization: The obtained V-PBAs were placed in a tube furnace and subjected to mild heat treatment under an inert atmosphere at 250 °C for 2 hours. After cooling, vanadium-based Prussian blue analogue V-PBAs-250 with an amorphous reconstruction layer on the surface was obtained.
[0050] Figures 1 to 4 Images shown are transmission electron microscope (TEM) images of V-PBAs, V-PBAs-150, V-PBAs-200, and V-PBAs-250 electrode materials. It can be seen that with increasing calcination temperature, an amorphous layer begins to appear and its thickness gradually increases. This also confirms that a mild heat treatment strategy can reconstruct the surface morphology of V-PBAs.
[0051] Figure 6 These are the X-ray diffraction (XRD) spectra of V-PBAs, V-PBAs-150, V-PBAs-200, and V-PBAs-250 electrodes. During heat treatment at 150–200 °C, the main crystalline phase of vanadium-based Prussian blue was maintained; upon further increasing the temperature to 250 °C, the diffraction peaks broadened further and the background increased, indicating a significant intensification of structural disorder.
[0052] Example 4
[0053] Application of surface-amorphous vanadium-based Prussian blue analog electrode materials as positive electrode materials in ammonium-ion batteries
[0054] Methods: Using a surface-amorphous vanadium-based Prussian blue analog electrode material as the working electrode, carbon paper as the counter electrode, a saturated calomel electrode as the reference electrode, and 1 M ammonium sulfate as the electrolyte, constant current charge-discharge tests and cyclic voltammetry scan tests were performed on the electrode material in a potential range of -0.3 V to 1.1 V.
[0055] Figure 7 For V-PBAs and V-PBAs-200 at 10 mV s -1 Cyclic voltammetry curves were obtained. The CV area increased under heat treatment at 200 °C, which significantly enhanced the available redox reactions.
[0056] Figure 8 For V-PBAs, V-PBAs-150, V-PBAs-200 and V-PBAs-250 electrode materials at 0.1 A g -1 The constant current charge-discharge curves were obtained. The electrochemical performance of V-PBAs-200 was improved by 80% compared to V-PBAs, reaching 129.1 mAh g⁻¹. -1 The high specific capacity is followed by the sacrifice of the effective crystalline framework as the temperature continues to rise, thus reducing the capacity.
Claims
1. A method for preparing a surface-amorphous vanadium-based Prussian blue analog electrode material for aqueous ammonium-ion batteries, characterized in that, Includes the following steps: 1) Preparation of precursor solution: NH4VO3 and K3[Fe(CN)6] were added to ultrapure water and mixed, and then anhydrous oxalic acid H2C2O4 was added and stirred to form a homogeneous precursor solution; 2) Preparation of V-PBAs: The precursor solution obtained in step 1) was transferred to a polytetrafluoroethylene-lined reactor for hydrothermal coprecipitation reaction. After natural cooling, it was washed with deionized water and ethanol, centrifuged and dried to obtain vanadium-based Prussian blue analogs V-PBAs. 3) Surface amorphization: The obtained V-PBAs are placed in a tube furnace and subjected to mild heat treatment under an inert atmosphere. After cooling, vanadium-based Prussian blue analogs with an amorphous reconstruction layer on the surface are obtained.
2. The preparation method according to claim 1, characterized in that, In step 1), the molar ratio of NH4VO3:K3[Fe(CN)6]:H2C2O4 in the mixed solution of the precursor solution is 1:1:(2-3).
3. The preparation method according to claim 1, characterized in that, After adding anhydrous oxalic acid in step 1), stir for 20-60 minutes.
4. The preparation method according to claim 1, characterized in that, The conditions for the hydrothermal coprecipitation reaction described in step 2) are: hydrothermal treatment at 150℃-200℃ for 6 h-10 h.
5. The preparation method according to claim 1, characterized in that, In step 3), the inert gas is argon or nitrogen.
6. The preparation method according to claim 1, characterized in that, In step 3), the heat treatment temperature is 150-300 ℃ and the heat treatment time is 1-4 h.
7. A surface-amorphous vanadium-based Prussian blue analog electrode material prepared according to the preparation method of any one of claims 1-6.
8. The application of a surface-amorphous vanadium-based Prussian blue analog electrode material according to any one of claims 7 in an ammonium-ion battery.
9. The application according to claim 8, characterized in that, Application of surface-amorphous vanadium-based Prussian blue analog electrode materials as positive electrode materials in ammonium-ion batteries.