A flower ball-shaped bismuth disulfide / tungsten disulfide composite material, a preparation method and application thereof
By preparing flower-shaped bismuth disulfide/tungsten disulfide composite materials, the problems of unstable structure and poor conductivity in potassium-ion batteries were solved, enabling efficient application and low-cost production of the materials.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2023-09-20
- Publication Date
- 2026-03-17
AI Technical Summary
The low availability of lithium on Earth limits the large-scale application of lithium-ion batteries. Potassium-ion batteries suffer from structural instability and poor conductivity during charging and discharging, resulting in capacity decay and poor cycle stability.
Using bismuth nitrate pentahydrate, tungsten hexachloride, and thioacetamide as raw materials, a flower-shaped bismuth disulfide/tungsten disulfide composite material was prepared through homogeneous reaction, forming a self-assembled nanoflower structure with vertically grown nanosheets, which improves the structural stability and conductivity of the material.
The prepared composite material has a more stable structure and better conductivity, which significantly improves the electrochemical performance of potassium-ion battery anode materials. It is suitable for large-scale production and has low cost.
Smart Images
Figure CN117228722B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the preparation of functional materials, specifically to a flower-shaped bismuth disulfide / tungsten disulfide composite material, its preparation method, and its application. Background Technology
[0002] As a mature and commercially viable energy storage system, lithium-ion batteries have been widely used in various electronic devices and electric vehicles due to their high energy density and environmental friendliness. However, the limited reserves of lithium on Earth significantly restrict its application in large-scale energy storage systems. Benefiting from the abundant and widely distributed nature of potassium and its similar physicochemical properties to lithium, potassium-ion batteries are considered the most likely next-generation battery product to replace lithium-ion batteries.
[0003] As a typical transition metal disulfide, WS2 (tungsten disulfide) is characterized by SWS covalent bonds within the layers and van der Waals forces between the layers, exhibiting a large interlayer spacing (0.64 nm) and weak interlayer interactions, thus providing abundant K-retaining capacity. + (Potassium ion) active sites and unobstructed K+ + Insertion / extraction channel. However, during charging and discharging, K... + The repeated insertion / extraction and WS2-W transformations lead to excessive expansion / contraction of WS2, causing WS2 active material to pulverize and resulting in structural instability, leading to capacity decay and poor cycle stability. Furthermore, as an intrinsic semiconductor, WS2 has poor conductivity and slow charge transport in the electrodes, resulting in slower electrochemical reactions during charge and discharge and exhibiting poor rate capability. To address these issues, most researchers have attempted to improve its structural stability and conductivity through four main approaches: optimizing the WS2 crystal structure, compositing with carbon materials, nanoengineering WS2, and constructing WS2 heterojunctions. Summary of the Invention
[0004] The purpose of this invention is to provide a flower-shaped bismuth disulfide / tungsten disulfide composite material, its preparation method and application. The preparation method of this invention has the characteristics of low cost, high yield, low pollution and suitability for large-scale production. The composite material obtained by this invention can improve the volume expansion problem of tungsten disulfide anode material during charge and discharge process and enhance its conductivity, thereby improving its electrochemical performance.
[0005] To achieve the above objectives, the preparation method of the present invention is as follows:
[0006] Step 1: Take 0.4-0.9g of analytical grade tungsten hexachloride and add it to 50ml of anhydrous ethanol solution, stir well to obtain solution A;
[0007] Step 2: Add 0.04-0.15g of bismuth nitrate pentahydrate to solution A and stir until homogeneous to obtain solution B;
[0008] Step 3: Add 0.5-2.0g of thioacetamide to solution B and stir until homogeneous to obtain solution C;
[0009] Step 4: Transfer solution C into the reaction vessel, seal it, and place it in a homogeneous reactor. React fully at 180-240℃.
[0010] Step 5: After the reaction is complete, remove the product, wash it, and dry it thoroughly in a vacuum oven to obtain a flower-shaped bismuth disulfide / tungsten disulfide composite material.
[0011] The stirring speed is 200-500 r / min.
[0012] The reaction time in the homogeneous reactor in step 4 is 1-5 hours.
[0013] The vacuum oven drying temperature in step 5 is 60°C.
[0014] The flower-shaped bismuth disulfide / tungsten disulfide composite material prepared by the above method consists of a self-assembled flower-shaped structure with a diameter of 350-400 nm and vertically grown nanosheets with a thickness of 20-30 nm.
[0015] The application of the flower-shaped bismuth disulfide / tungsten disulfide composite material of the present invention in the preparation of potassium-ion battery anode materials.
[0016] The advantages of this invention compared to the prior art are as follows:
[0017] (1) The present invention uses bismuth nitrate pentahydrate, tungsten hexachloride and thioacetamide as raw materials. The raw materials are all common materials, cheap and easy to obtain, low cost, high yield, easy to control reaction, no need for post-processing, environmentally friendly, can significantly reduce the preparation cost of the material reported in the existing literature, and can be suitable for large-scale production.
[0018] (2) The preparation method adopted in this invention has the characteristics of simple process, short preparation cycle and easy control of reaction conditions. The reaction process is controlled by adjusting the temperature. It overcomes the disadvantages of traditional preparation processes such as complex process, expensive equipment and low yield. It has the advantages of simple synthesis route, no need for large equipment and easy to achieve reaction conditions.
[0019] (3) The flower-shaped bismuth disulfide / tungsten disulfide composite material obtained by the present invention has a more stable structure, better conductivity, and can significantly improve the theoretical capacity of the material.
[0020] (4) The flower-shaped bismuth disulfide / tungsten disulfide composite material obtained by the present invention has a unique micro and crystal structure, which can greatly improve its electrochemical performance as a negative electrode material for potassium-ion batteries. Attached Figure Description
[0021] Figure 1 The XRD pattern of the flower-shaped bismuth disulfide / tungsten disulfide composite material prepared in Example 3 of this invention;
[0022] Figure 2 The SEM image of the flower-shaped bismuth disulfide / tungsten disulfide composite material prepared in Example 3 of this invention;
[0023] Figure 3 This is a cycle performance diagram of the flower-shaped bismuth disulfide / tungsten disulfide composite material prepared in Example 3 of the present invention;
[0024] Figure 4 This is a rate performance diagram of the flower-shaped bismuth disulfide / tungsten disulfide composite material prepared in Example 3 of the present invention. Detailed Implementation
[0025] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments.
[0026] Example 1:
[0027] Step 1: Take 0.4g of analytical grade tungsten hexachloride and add it to 50ml of anhydrous ethanol solution. Stir at 200r / min until homogeneous to obtain solution A.
[0028] Step 2: Add 0.08g of bismuth nitrate pentahydrate to solution A and stir at 200r / min until homogeneous to obtain solution B;
[0029] Step 3: Add 1.0g of thioacetamide to solution B and stir at 200r / min until homogeneous to obtain solution C;
[0030] Step 4: Transfer solution C into the reaction vessel, seal it, and place it in a homogeneous reactor. React at 180°C for 5 hours.
[0031] Step 5: After the reaction is complete, remove the product, wash it, and dry it thoroughly in a vacuum oven at 60°C to obtain a flower-shaped bismuth disulfide / tungsten disulfide composite material.
[0032] Example 2:
[0033] Step 1: Take 0.6g of analytical grade tungsten hexachloride and add it to 50ml of anhydrous ethanol solution. Stir at 400r / min until homogeneous to obtain solution A.
[0034] Step 2: Add 0.04g of bismuth nitrate pentahydrate to solution A and stir at 400r / min until homogeneous to obtain solution B;
[0035] Step 3: Add 0.5g of thioacetamide to solution B and stir at 400r / min until homogeneous to obtain solution C;
[0036] Step 4: Transfer solution C into the reaction vessel, seal it, and place it in a homogeneous reactor. React at 200°C for 3 hours.
[0037] Step 5: After the reaction is complete, remove the product, wash it, and dry it thoroughly in a vacuum oven at 60°C to obtain a flower-shaped bismuth disulfide / tungsten disulfide composite material.
[0038] Example 3:
[0039] Step 1: Take 0.4958g of analytical grade tungsten hexachloride and add it to 50ml of anhydrous ethanol solution. Stir at 300r / min until homogeneous to obtain solution A.
[0040] Step 2: Add 0.9735g of bismuth nitrate pentahydrate to solution A and stir at 300r / min until homogeneous to obtain solution B;
[0041] Step 3: Add 0.061g of thioacetamide to solution B and stir at 300r / min until homogeneous to obtain solution C;
[0042] Step 4: Transfer solution C into the reaction vessel, seal it, and place it in a homogeneous reactor. React at 220°C for 2 hours.
[0043] Step 5: After the reaction is complete, remove the product, wash it, and dry it thoroughly in a vacuum oven at 60°C to obtain a flower-shaped bismuth disulfide / tungsten disulfide composite material.
[0044] Example 4:
[0045] Step 1: Take 0.5g of analytical grade tungsten hexachloride and add it to 50ml of anhydrous ethanol solution. Stir at 500r / min until homogeneous to obtain solution A.
[0046] Step 2: Add 0.1g of bismuth nitrate pentahydrate to solution A and stir at 500r / min until homogeneous to obtain solution B;
[0047] Step 3: Add 1.5g of thioacetamide to solution B and stir at 500r / min until homogeneous to obtain solution C;
[0048] Step 4: Transfer solution C into the reaction vessel, seal it, and place it in a homogeneous reactor. React at 190°C for 4 hours.
[0049] Step 5: After the reaction is complete, remove the product, wash it, and dry it thoroughly in a vacuum oven at 60°C to obtain a flower-shaped bismuth disulfide / tungsten disulfide composite material.
[0050] Example 5:
[0051] Step 1: Take 0.9g of analytical grade tungsten hexachloride and add it to 50ml of anhydrous ethanol solution. Stir at 300r / min until homogeneous to obtain solution A.
[0052] Step 2: Add 0.13g of bismuth nitrate pentahydrate to solution A and stir at 300r / min until homogeneous to obtain solution B;
[0053] Step 3: Add 1.8g of thioacetamide to solution B and stir at 300r / min until homogeneous to obtain solution C;
[0054] Step 4: Transfer solution C into the reaction vessel, seal it, and place it in a homogeneous reactor. React at 230°C for 1 hour.
[0055] Step 5: After the reaction is complete, remove the product, wash it, and dry it thoroughly in a vacuum oven at 60°C to obtain a flower-shaped bismuth disulfide / tungsten disulfide composite material.
[0056] Example 6:
[0057] Step 1: Take 0.8g of analytical grade tungsten hexachloride and add it to 50ml of anhydrous ethanol solution. Stir at 400r / min until homogeneous to obtain solution A.
[0058] Step 2: Add 0.15g of bismuth nitrate pentahydrate to solution A and stir at 400r / min until homogeneous to obtain solution B;
[0059] Step 3: Add 2.0g of thioacetamide to solution B and stir at 400r / min until homogeneous to obtain solution C;
[0060] Step 4: Transfer solution C into the reaction vessel, seal it, and place it in a homogeneous reactor. React at 240°C for 1 hour.
[0061] Step 5: After the reaction is complete, remove the product, wash it, and dry it thoroughly in a vacuum oven at 60°C to obtain a flower-shaped bismuth disulfide / tungsten disulfide composite material.
[0062] The flower-shaped bismuth disulfide / tungsten disulfide composite material prepared by the above method consists of a self-assembled flower-shaped structure with a diameter of 350-400 nm and vertically grown nanosheets with a thickness of 20-30 nm.
[0063] The following is an application analysis of this embodiment:
[0064] like Figure 1 As shown, the product obtained in Example 3 was analyzed using a Rigaku D / max2000PC X-ray diffractometer, and the XRD pattern of the composite material was obtained. The diffraction peaks of the obtained product are consistent with the standard cards for bismuth disulfide (PDF#17-0267) and tungsten disulfide (PDF#08-0237), indicating that the bismuth disulfide / tungsten disulfide composite material was successfully prepared. The broad diffraction peaks indicate that its crystallinity is low.
[0065] like Figure 2 As shown, the product obtained in Example 3 was observed under a scanning electron microscope. The composite material exhibits a nano-flower-shaped structure with numerous nanosheets on its surface. The obtained product was then used to prepare a button-type sodium-ion battery. The specific encapsulation steps are as follows: The flower-shaped bismuth disulfide / tungsten disulfide composite material prepared in Example 3, the conductive agent (Super P), and the binder (carboxymethyl cellulose CMC) were ground uniformly in a mass ratio of 7:2:1 to form a slurry. The slurry was then uniformly coated onto copper foil using a coating applicator and dried in a vacuum drying oven at 70°C for 12 hours. Afterward, the electrode sheets were assembled into a potassium-ion half-cell. A constant current charge-discharge test was performed on the battery using a Xinwei electrochemical workstation, with a test voltage of 0.01V-3.0V. The resulting material was then assembled into a button cell to test its potassium-ion battery negative electrode material performance. Figure 3 As shown, at a current density of 100 mA / g, the initial capacity of the bismuth disulfide / tungsten disulfide composite material is approximately 400 mAh / g, while the initial capacity of pure tungsten disulfide is approximately 200 mAh / g. This demonstrates a significant improvement in the capacity of the composite material, and the bismuth disulfide / tungsten disulfide composite material exhibits slower capacity decay and better cycle performance. Figure 4 As shown, the comparison between the bismuth disulfide / tungsten disulfide composite material and pure tungsten disulfide shows that the capacity of the bismuth disulfide / tungsten disulfide composite material is significantly improved at current densities of 0.2 A / g, 0.5 A / g, 1 A / g, 2 A / g, and 5 A / g, respectively.
[0066] The composite material obtained by the preparation method of this invention has a self-assembled hydrangea-like structure with a diameter of 350-400 nm on which nanosheets with a thickness of 20-30 nm are vertically grown. The obtained composite material can be used in the preparation of potassium-ion battery anode materials, making the structure more stable, the conductivity better, and greatly improving the electrochemical performance.
Claims
1. A method for preparing a flower ball-shaped bismuth disulfide / tungsten disulfide composite material, characterized by, The method comprises the following steps: Step 1: 0.4-0.9 g of analysis pure tungsten hexachloride is added to 50 ml of anhydrous ethanol solution, and stirred to obtain solution A; Step 2: 0.04-0.15 g of bismuth nitrate pentahydrate is added to solution A, and stirred to obtain solution B; Step 3: 0.5-2.0 g of thioacetamide is added to solution B, and stirred to obtain solution C; Step 4: Solution C is moved into a reaction kettle, sealed and placed in a homogeneous reactor, and reacted at 180-240 DEG C for 1-5 h; Step 5: After the reaction is completed, the product is taken out, washed and dried in a vacuum oven to obtain flower ball-shaped bismuth disulfide / tungsten disulfide composite material.
2. The method for preparing the flower-shaped bismuth disulfide / tungsten disulfide composite material as described in claim 1, characterized in that, The stirring speed is 200-500 r / min.
3. The method for preparing the flower-shaped bismuth disulfide / tungsten disulfide composite material as described in claim 1, characterized in that, The drying temperature of the vacuum oven in step 5 is 60 DEG C.
4. A flower-ball-shaped BiS2 / TiS2 composite material obtained by the production method according to any one of claims 1 to 3, characterized in that, The composite material is a flower ball-shaped structure with a diameter of 350-400 nm, and nanosheets with a thickness of 20-30 nm are vertically grown on the flower ball-shaped structure.
5. Use of the flower ball-shaped bismuth disulfide / tungsten disulfide composite material in claim 4 in the preparation of a potassium ion battery negative electrode material.