Preparation method of manganese octacyanomanganate nanoparticle / carbon nanotube composite material and application of manganese octacyanomanganate nanoparticle / carbon nanotube composite material to water-based zinc ion battery positive electrode
By preparing manganese octacyanomolybdate nanoparticle/carbon nanotube composite materials, the problems of low specific capacity and poor cycle stability of aqueous zinc-ion battery cathode materials were solved, and a high-performance aqueous zinc-ion battery cathode material was realized.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- JIANGSU UNIV
- Filing Date
- 2024-04-30
- Publication Date
- 2026-05-12
AI Technical Summary
There is a lack of suitable cathode materials for existing aqueous zinc-ion batteries. Traditional cathode materials have low specific capacity and poor cycle stability, and there is a lack of research on second transition metals.
In-situ self-assembly of manganese octacyanomolybdate nanoparticles/carbon nanotubes was prepared. Mn2+ was adsorbed onto carboxylated carbon nanotubes via electrostatic interaction and co-precipitated with [Mo(CN)8]4- to form a composite material of Mn2[Mo(CN)8] nanoparticles and carbon nanotubes.
It improves the conductivity and structural stability of the material, provides high specific capacity and good cycle stability, and is suitable for aqueous zinc-ion battery cathode materials.
Smart Images
Figure CN118458798B_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of composite material technology, and relates to nanocomposite materials, particularly to a method for preparing a manganese octacyanomolybdate nanoparticle / carbon nanotube (Mn2[Mo(CN)8] / CNTs) composite material and its application in the positive electrode of an aqueous zinc-ion battery. Technical Background
[0002] With rapid socio-economic development, the reserves of traditional fossil fuels are dwindling, while the demand for energy is increasing daily. There is a need to develop new renewable energy sources such as solar, hydropower, tidal, geothermal, and wind power. Therefore, large-scale stationary energy storage systems must be developed to ensure the distribution and supply of electricity. Rechargeable batteries are considered the most promising energy storage devices due to their high efficiency and durability. Lithium-ion batteries, with their high energy density and excellent cycle performance, have become leaders in the energy storage field. However, considering the poor safety and high cost of lithium-ion batteries, there is an urgent need to explore safe, environmentally friendly, and low-cost alternative battery systems.
[0003] Recently, aqueous zinc-ion batteries have gained favor among researchers as a novel type of rechargeable battery. The stability of metallic Zn in aqueous electrolytes and its suitable electrode potential (-0.762 V vs SHE) allow it to be directly used as the negative electrode in aqueous zinc-ion batteries. Furthermore, metallic Zn possesses a high theoretical capacity (5854 mAh cm⁻¹). -3 and 820mAh g -1 Aqueous zinc-ion batteries possess advantages such as abundant reserves and low cost. These advantages make them a promising candidate for large-scale energy storage systems in the future. Currently, a major obstacle to the large-scale application of aqueous zinc-ion batteries is the lack of suitable cathode materials. Therefore, exploring new and efficient cathode materials is of great significance for the development of aqueous zinc-ion batteries.
[0004] Prussian blue analogues (PBAs) with three-dimensional open framework structures have attracted widespread attention from researchers due to their tunable composition and simple synthesis. However, PBAs suffer from low specific capacity and poor cycle stability when used as cathodes in aqueous zinc-ion batteries. The electrochemical energy storage properties of PBAs can be attributed to the redox behavior of transition metal ions; by changing the transition metal ions, the energy storage performance of PBAs can be adjusted. Furthermore, current research on PBA cathode materials mainly focuses on first-transition metals, while second-transition metals have not yet been explored. Metallic octacyanomolybdenum compounds, like PBAs, belong to the cyano-bridged three-dimensional structure compounds, but their framework crystal structures are quite different from those of PBAs. Due to the large radius of the second-transition metal molybdenum, these compounds possess more abundant ion diffusion channels than PBAs, showing potential as cathodes for aqueous zinc-ion batteries. Unfortunately, however, the application of these materials as cathode materials for aqueous zinc-ion batteries has not yet been reported. Manganese octacyanomolybdate (Mn2[Mo(CN)8]) is a typical representative of metallic octacyanomolybdenum compounds, while carbon nanotubes (CNTs) possess advantages such as excellent conductivity, high electrochemical stability, and large specific surface area. Combining (Mn2[Mo(CN)8]) with carbon nanotubes to prepare composite electrode materials can overcome problems such as structural collapse and poor conductivity during charge and discharge processes, potentially providing a new approach for designing and developing high-performance aqueous zinc-ion battery cathode materials. Summary of the Invention
[0005] To address the shortcomings of the existing technology, the present invention aims to provide a method for preparing a composite material of manganese octacyanomolybdate nanoparticles / carbon nanotubes (Mn2[Mo(CN)8] / CNTs).
[0006] Technical solution
[0007] A method for preparing a manganese octacyanomolybdate nanoparticle / carbon nanotube (Mn2[Mo(CN)8] / CNTs) composite material includes the following steps:
[0008] (1) Carboxylated multi-walled carbon nanotubes are stirred and ultrasonically dispersed in deionized water to obtain a carbon nanotube (CNTs) dispersion, referred to as solution A, wherein the mass-volume ratio of carbon nanotubes to deionized water is 5-40 mg: 5-40 mL, preferably 20 mg: 20 mL.
[0009] (2) Dissolve the manganese source in deionized water, which is called solution B. The molar volume ratio of the manganese source to the deionized water is 0.5-2 mmol: 5-20 mL, preferably 1 mmol: 10 mL. The manganese source is manganese chloride, manganese sulfate, manganese acetate or manganese nitrate, preferably manganese chloride. Add solution B to solution A at a volume ratio of 1:2, and stir evenly at room temperature by sonication to obtain a mixed solution.
[0010] (3) Prepare a deionized aqueous solution of potassium octacyanomolybdate(IV), referred to as solution C, wherein the mass-volume ratio of potassium octacyanomolybdate(IV) to deionized water is 115-460 mg: 10-30 mL, preferably 230 mg: 20 mL;
[0011] (4) Add solution C to the mixed solution obtained in step (2) at a volume ratio of 2:3, add isopropanol, wherein the volume ratio of isopropanol to solution C is 2.5-7.5 mL: 10-30 mL, preferably 5 mL: 20 mL, let stand for 3 days, centrifuge the obtained precipitate, wash with deionized water and ethanol, and then vacuum dry at 60°C to obtain manganese octacyanomolybdate nanoparticles / carbon nanotubes (Mn2[Mo(CN)8] / CNTs) composite material.
[0012] The product obtained by this invention has the morphology of Mn2[Mo(CN)8] nanoparticles with a size of 30±10nm, which are attached to the surface of the carbon nanotube conductive framework.
[0013] The second objective of this invention is to apply the prepared composite material to the cathode material of aqueous zinc-ion batteries.
[0014] The experimental steps are as follows:
[0015] The prepared manganese octacyanomolybdate nanoparticles / carbon nanotubes (Mn2[Mo(CN)8] / CNTs) composite material, acetylene black, and polyvinylidene fluoride (PVDF) were mixed together in a mass ratio of 7:2:1. After thorough grinding, the mixture was dispersed in N-methylpyrrolidone and stirred for 12 hours. The resulting slurry was then uniformly coated onto the surface of current collector graphite paper to a certain thickness. The N-methylpyrrolidone solvent was removed by vacuum drying at 60°C. After drying, the graphite paper was cut into electrode sheets for later use. Battery assembly was carried out at room temperature and atmospheric environment, with a zinc sheet as the negative electrode and a 3M ZnSO4 + 0.1M MnSO4 aqueous solution as the electrolyte.
[0016] This invention combines nanoscale Mn2[Mo(CN)8] with carbon nanotubes to prepare Mn2[Mo(CN)8] / CNTs composite materials, which have the following advantages:
[0017] (1) The Mn2[Mo(CN)8] prepared by this invention has a three-dimensional channel structure that can accommodate the insertion / extraction of zinc ions;
[0018] (2) The high manganese content in Mn2[Mo(CN)8] can provide redox behavior with multiple electron transfer during charge and discharge, ensuring high specific capacity and working voltage;
[0019] (3) Compared with traditional bulk materials, nanomaterials have the advantages of small size and high specific surface area, which allows the electrode material to fully contact the electrolyte and shorten the diffusion distance of zinc ions.
[0020] (4) The introduction of carbon nanotubes can improve the conductivity of the composite material, prevent the aggregation of nanoparticles, and effectively buffer the structural collapse of the electrode material during charge and discharge. These advantages enable the composite material to exhibit superior electrochemical performance and show a high specific capacity (200 mAg) when used as a cathode material for aqueous zinc-ion batteries. -1 The initial discharge specific capacity reached 333 mAh g. -1 ) and good cycling stability (at 2000 mA g) -1 After 2000 cycles at a current density, the capacity retention is close to 100%.
[0021] Beneficial effects
[0022] This invention employs an in-situ self-assembly method, firstly by combining Mn... 2+ The material is adsorbed onto carboxylated carbon nanotubes via electrostatic interactions, and then [Mo(CN)8] is added. 4- A composite cathode material of Mn2[Mo(CN)8] nanoparticles and carbon nanotubes was prepared by co-precipitation. This material exhibited excellent zinc storage performance and has potential application prospects. This method is simple, feasible, has good composite effect, and is suitable for large-scale production. Attached Figure Description
[0023] Figure 1 X-ray diffraction (XRD) pattern of Mn2[Mo(CN)8] / CNTs nanocomposite prepared in Example 1, where the horizontal axis is the diffraction angle (2θ) in degrees; and the vertical axis is the diffraction intensity in cps.
[0024] Figure 2 Scanning electron microscope (SEM) image of the Mn2[Mo(CN)8] / CNTs nanocomposite material prepared in Example 1;
[0025] Figure 3 The Mn2[Mo(CN)8] / CNTs nanocomposite material prepared in Example 1 was used as a cathode material for an aqueous zinc-ion battery at a current density of 2000 mAg. -1 The following is a graph showing the cyclic performance and the corresponding coulombic efficiency. Detailed Implementation
[0026] The present invention will be described in detail below with reference to embodiments, so that those skilled in the art can better understand the present invention, but the present invention is not limited to the following embodiments.
[0027] Example 1
[0028] A method for preparing a manganese octacyanomolybdate nanoparticle / carbon nanotube composite material includes the following steps:
[0029] (1) 20 mg of carboxylated multi-walled carbon nanotubes were ultrasonically dispersed in 20 ml of deionized water, ultrasonicated for 1 h, and stirred at room temperature for 30 min to obtain a carbon nanotube dispersion.
[0030] (2) Add 10 ml of MnCl2·4H2O solution (containing 198 mg of MnCl2·4H2O), sonicate for 30 min, stir at room temperature for 1 h, then add 20 ml of K4[Mo(CN)8] solution (containing 230 mg of K4[Mo(CN)8]), and add 5 mL of isopropanol. Let stand for 3 days.
[0031] (3) The precipitate was separated by centrifugation, washed with deionized water and ethanol, and then dried under vacuum at 60°C to obtain manganese octacyanomolybdate nanoparticles / carbon nanotube composite material (Mn2[Mo(CN)8] / CNTs).
[0032] The prepared composite material, when used as a cathode material in an aqueous zinc-ion battery, showed performance at 200 mA g. -1 The initial discharge specific capacity was 333.27 mAh g. -1 .
[0033] Figure 1 The image shows the XRD pattern of the product prepared in this embodiment. All diffraction peaks in the image correspond to Mn2[Mo(CN)8], indicating that the Mn2[Mo(CN)8] / CNTs composite material was successfully prepared.
[0034] Figure 2 The image shows a SEM image of the product prepared in this embodiment. It can be seen that manganese octacyanomolybdate nanoparticles are attached to the surface of the carbon nanotube conductive framework, and the size of the nanoparticles is about 30 nm.
[0035] Figure 3 The manganese octacyanomolybdate nanoparticle / carbon nanotube composite material prepared in this embodiment was used as a positive electrode material for an aqueous zinc-ion battery at a current density of 2000 mA g. -1 Cyclic performance graph at 2000 mA g. -1 It can provide up to 72mAh g -1 Its specific capacity is such that after 2000 cycles, its capacity retention rate is almost 100%.
[0036] Example 2
[0037] A method for preparing a manganese octacyanomolybdate nanoparticle / carbon nanotube composite material includes the following steps:
[0038] (1) 20 mg of carboxylated multi-walled carbon nanotubes were ultrasonically dispersed in 20 ml of deionized water, ultrasonicated for 1 h, and stirred at room temperature for 30 min to obtain a carbon nanotube dispersion.
[0039] (2) Add 10 ml of MnCl2·4H2O solution (containing 198 mg of MnCl2·4H2O), sonicate for 30 min, stir at room temperature for 1 h, then add 20 ml of K4[Mo(CN)8] solution (containing 230 mg of K4[Mo(CN)8]), and add 5 mL of isopropanol. Let stand for 3 days.
[0040] (3) The precipitate was separated by centrifugation, washed with deionized water and ethanol, and then dried under vacuum at 60°C to obtain manganese octacyanomolybdate nanoparticles / carbon nanotube composite material (Mn2[Mo(CN)8] / CNTs).
[0041] The prepared composite material, when used as a cathode material in an aqueous zinc-ion battery, showed performance at 200 mA g. -1 The initial discharge specific capacity was 327.24 mAh g. -1 .
[0042] Example 3
[0043] A method for preparing a manganese octacyanomolybdate nanoparticle / carbon nanotube composite material includes the following steps:
[0044] (1) 20 mg of carboxylated multi-walled carbon nanotubes were ultrasonically dispersed in 20 ml of deionized water, ultrasonicated for 1 h, and stirred at room temperature for 30 min to obtain a carbon nanotube dispersion.
[0045] (2) Add 10 ml of MnCl2·4H2O solution (containing 198 mg of MnCl2·4H2O), sonicate for 30 min, stir at room temperature for 1 h, then add 20 ml of K4[Mo(CN)8] solution (containing 230 mg of K4[Mo(CN)8]), and add 5 mL of isopropanol. Let stand for 3 days.
[0046] (3) The precipitate was separated by centrifugation, washed with deionized water and ethanol, and then dried under vacuum at 60°C to obtain manganese octacyanomolybdate nanoparticles / carbon nanotube composite material (Mn2[Mo(CN)8] / CNTs).
[0047] The prepared composite material, when used as a cathode material in an aqueous zinc-ion battery, showed performance at 200 mA g. -1 The initial discharge specific capacity was 342.77 mAh g. -1 .
[0048] Example 4
[0049] A method for preparing a manganese octacyanomolybdate nanoparticle / carbon nanotube composite material includes the following steps:
[0050] (1) 20 mg of carboxylated multi-walled carbon nanotubes were ultrasonically dispersed in 20 ml of deionized water, ultrasonicated for 1 h, and stirred at room temperature for 30 min to obtain a carbon nanotube dispersion.
[0051] (2) Add 10 ml of MnSO4·H2O solution (containing 169 mg of MnSO4·H2O), sonicate for 30 min, stir at room temperature for 1 h, then add 20 ml of K4[Mo(CN)8] solution (containing 230 mg of K4[Mo(CN)8]), and add 5 mL of isopropanol. Let stand for 3 days.
[0052] (3) The precipitate was separated by centrifugation, washed with deionized water and ethanol, and then dried under vacuum at 60°C to obtain manganese octacyanomolybdate nanoparticles / carbon nanotube composite material (Mn2[Mo(CN)8] / CNTs).
[0053] The prepared composite material, when used as a cathode material in an aqueous zinc-ion battery, showed performance at 200 mA g. -1 The initial discharge specific capacity was 319.36 mAh g. -1 .
[0054] Example 5
[0055] A method for preparing a manganese octacyanomolybdate nanoparticle / carbon nanotube composite material includes the following steps:
[0056] (1) 20 mg of carboxylated multi-walled carbon nanotubes were ultrasonically dispersed in 20 ml of deionized water, ultrasonicated for 1 h, and stirred at room temperature for 30 min to obtain a carbon nanotube dispersion.
[0057] (2) Add 10 ml of Mn(NO3)2·4H2O solution (containing 251 mg of Mn(NO3)2·4H2O), sonicate for 30 min, stir at room temperature for 1 h, then add 20 ml of K4[Mo(CN)8] solution (containing 230 mg of K4[Mo(CN)8]), and add 5 mL of isopropanol, and let stand for 3 days;
[0058] (3) The precipitate was separated by centrifugation, washed with deionized water and ethanol, and then dried under vacuum at 60°C to obtain manganese octacyanomolybdate nanoparticles / carbon nanotube composite material (Mn2[Mo(CN)8] / CNTs).
[0059] The prepared composite material, when used as a cathode material in an aqueous zinc-ion battery, showed performance at 200 mA g. -1 The initial discharge specific capacity was 307.24 mAh g. -1 .
[0060] Example 6
[0061] A method for preparing a manganese octacyanomolybdate nanoparticle / carbon nanotube composite material includes the following steps:
[0062] (1) 20 mg of carboxylated multi-walled carbon nanotubes were ultrasonically dispersed in 20 ml of deionized water, ultrasonicated for 1 h, and stirred at room temperature for 30 min to obtain a carbon nanotube dispersion.
[0063] (2) Add 10 ml of Mn(CH3COO)2·4H2O solution (containing 245 mg of Mn(CH3COO)2·4H2O), sonicate for 30 min, stir at room temperature for 1 h, then add 20 ml of K4[Mo(CN)8] solution (containing 230 mg of K4[Mo(CN)8]), and add 5 mL of isopropanol. Let stand for 3 days.
[0064] (3) The precipitate was separated by centrifugation, washed with deionized water and ethanol, and then dried under vacuum at 60°C to obtain manganese octacyanomolybdate nanoparticles / carbon nanotube composite material (Mn2[Mo(CN)8] / CNTs).
[0065] The prepared composite material, when used as a cathode material in an aqueous zinc-ion battery, showed performance at 200 mA g. -1 The initial discharge specific capacity was 323.19 mAh g. -1 .
[0066] Example 7
[0067] A method for preparing a manganese octacyanomolybdate nanoparticle / carbon nanotube composite material includes the following steps:
[0068] (1) 20 mg of carboxylated multi-walled carbon nanotubes were ultrasonically dispersed in 20 ml of deionized water, ultrasonicated for 1 h, and stirred at room temperature for 30 min to obtain a carbon nanotube dispersion.
[0069] (2) Add 10 ml of MnSO4·H2O solution (containing 169 mg of MnSO4·H2O), sonicate for 30 min, stir at room temperature for 1 h, then add 20 ml of K4[Mo(CN)8] solution (containing 230 mg of K4[Mo(CN)8]), and add 5 mL of isopropanol. Let stand for 3 days.
[0070] (3) The precipitate was separated by centrifugation, washed with deionized water and ethanol, and then dried under vacuum at 60°C to obtain manganese octacyanomolybdate nanoparticles / carbon nanotube composite material (Mn2[Mo(CN)8] / CNTs).
[0071] The prepared composite material, when used as a cathode material in an aqueous zinc-ion battery, showed a performance of 200 mAg. -1 The initial discharge specific capacity was 316.58 mAh g. -1 .
[0072] The above description is merely an embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural or procedural transformations made using the present invention specification, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of the present invention.
Claims
1. A method for preparing a manganese octacyanomolybdate nanoparticle / carbon nanotube composite material, characterized in that, Includes the following steps: (1) Carboxylated multi-walled carbon nanotubes are stirred and ultrasonically dispersed in deionized water to obtain a carbon nanotube dispersion, referred to as solution A, wherein the mass-volume ratio of carbon nanotubes to deionized water is 5-40 mg: 5-40 mL. (2) Dissolve the manganese source in deionized water, which is called solution B. The molar volume ratio of manganese source to deionized water is 0.5-2 mmol: 5-20 mL. The manganese source is manganese chloride, manganese sulfate, manganese acetate or manganese nitrate. Add solution B to solution A at a volume ratio of 1:
2. After sonication and stirring at room temperature, a mixed solution is obtained. (3) Prepare a deionized aqueous solution of potassium octacyanomolybdate, referred to as solution C, wherein the mass-volume ratio of potassium octacyanomolybdate to deionized water is 115-460 mg: 10-30 mL. (4) Add solution C to the mixed solution obtained in step (2) at a volume ratio of 2:3, add isopropanol, wherein the volume ratio of isopropanol to solution C is 2.5-7.5 mL: 10-30 mL, let stand for 3 days, centrifuge the precipitate, wash with deionized water and ethanol, and then vacuum dry at 60°C to obtain manganese octacyanomolybdate nanoparticles / carbon nanotube composite material.
2. The method for preparing the manganese octacyanomolybdate nanoparticle / carbon nanotube composite material according to claim 1, characterized in that: In step (1), the mass-to-volume ratio of carbon nanotubes to deionized water is 20 mg: 20 mL.
3. The method for preparing the manganese octacyanomolybdate nanoparticle / carbon nanotube composite material according to claim 1, characterized in that: In step (2), the molar volume ratio of the manganese source to deionized water is 1 mmol: 10 mL.
4. The method for preparing the manganese octacyanomolybdate nanoparticle / carbon nanotube composite material according to claim 1, characterized in that: In step (2), the manganese source is manganese chloride.
5. The method for preparing the manganese octacyanomolybdate nanoparticle / carbon nanotube composite material according to claim 1, characterized in that: In step (3), the mass-to-volume ratio of potassium octacyanomolybdate to deionized water is 230 mg: 20 mL.
6. The method for preparing the manganese octacyanomolybdate nanoparticle / carbon nanotube composite material according to claim 1, characterized in that: In step (4), the volume ratio of isopropanol to solution C is 5 mL: 20 mL.
7. The manganese octacyanomolybdate nanoparticle / carbon nanotube composite material prepared by any one of the methods described in claims 1-6.
8. The manganese octacyanomolybdate nanoparticle / carbon nanotube composite material according to claim 7, characterized in that: The Mn2[Mo(CN)8] nanoparticles have a size of 30±10 nm and are attached to the surface of the carbon nanotube conductive framework.
9. An application of the manganese octacyanomolybdate nanoparticle / carbon nanotube composite material as described in claim 7 or 8, characterized in that: It was applied to the cathode material of aqueous zinc-ion batteries.