P / CNT self-supporting electrode material and preparation method and application thereof
The P/CNT self-supporting electrode material, which forms chemical bonds between red phosphorus and carbon nanotubes, solves the structural instability problem caused by volume changes during sodium insertion/extraction in sodium-ion battery anode materials, achieving high-efficiency electrochemical performance and an environmentally friendly preparation process.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- CHINA PETROLEUM & CHEMICAL CORP
- Filing Date
- 2024-11-08
- Publication Date
- 2026-05-12
AI Technical Summary
Existing sodium-ion battery anode materials, such as red phosphorus, exhibit large volume changes during sodium insertion/extraction, resulting in poor structural stability, rapid capacity decay, and unsatisfactory initial coulombic efficiency and long-term cycle stability.
P/CNT self-supporting electrode materials, which form phosphorus-carbon chemical bonds with red phosphorus and carbon nanotubes, are prepared by blending, grinding and filtering to prevent phosphorus from falling off the surface of carbon materials and improve bonding strength and conductivity.
It improves the cycle stability and initial coulombic efficiency of electrode materials, enhances conductivity, reduces battery volume expansion, exhibits good electrochemical performance, and has a simple and environmentally friendly process that reduces resource consumption.
Smart Images
Figure CN122025565A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of battery energy storage, specifically relating to a P / CNT self-supporting electrode material and its preparation method, as well as the application of the P / CNT self-supporting electrode material in the preparation of sodium-ion battery anode materials. Background Technology
[0002] Lithium-ion batteries are widely used in energy storage, but the lithium resources used in them are limited in quantity on Earth. Therefore, it is necessary to develop other battery systems to partially replace lithium-ion batteries. Sodium resources are more abundant on Earth than lithium, have lower costs, and have similar electrochemical properties to lithium. Therefore, sodium-ion batteries are the optimal choice to replace lithium-ion batteries in some applications.
[0003] To date, various anode materials for sodium-ion batteries have been reported, such as carbon materials, alloy materials, organic compounds, and transition metal oxides. Among them, carbon materials are inexpensive and possess good cycle life, showing promising prospects for industrial applications. However, carbon anode materials, represented by hard carbon, have relatively low reversible specific capacity. Therefore, developing sodium-ion battery anode materials with high specific capacity and long lifespan is of significant application importance. Phosphorus anode materials for sodium-ion batteries have the highest theoretical capacity (2596 mAh g⁻¹). -1 Phosphorus (P) has attracted widespread attention due to its suitable sodium storage potential. It exists primarily in three allotropes: white phosphorus, red phosphorus, and black phosphorus. White phosphorus is toxic and unstable in air, making it unsuitable as an electrode material. Red and black phosphorus are relatively stable and can be used as sodium storage electrode materials. However, the sodium insertion / extraction process of P involves a significant volume change (approximately 400%), leading to poor structural stability, rapid capacity decay, and poor initial coulombic efficiency and long-term cycle stability. Therefore, most researchers have focused on improving the sodium storage performance of P as a sodium-ion battery material through methods such as reducing P size, combining it with carbon materials, alloying it with other metal materials, and coating it with conductive polymer films. Carbon nanotubes possess excellent flexibility, mechanical properties, and conductivity, and are often used to improve the volume expansion and conductivity of electrode materials. Summary of the Invention
[0004] The purpose of this invention is to provide a P-based self-supporting electrode material and its preparation method. This material exhibits good electrochemical performance and has great application potential in the field of battery energy storage. Its preparation method is characterized by simple process, green and environmentally friendly, energy saving and high efficiency.
[0005] To achieve the above objectives, a first aspect of the present invention provides a P / CNT self-supporting electrode material, the P / CNT self-supporting electrode material comprising red phosphorus (red P) and carbon nanotubes.
[0006] Optionally, based on the weight of the P / CNT self-supporting electrode material, the content of red phosphorus is 20-70% by weight, preferably 30-60% by weight, and the content of carbon nanotubes is 30-80% by weight, preferably 40-70% by weight.
[0007] In this invention, a phosphorus-carbon chemical bond is formed between the red phosphorus and the carbon nanotube.
[0008] Optionally, the thickness of the P / CNT self-supporting electrode material is 10–500 μm, preferably 50–200 μm.
[0009] Optionally, the P / CNT self-supporting electrode material of the present invention does not contain conductive agents and binders.
[0010] Optionally, the P / CNT self-supporting electrode material is prepared by blending, grinding and filtering red phosphorus and carbon nanotubes.
[0011] A second aspect of the present invention provides a method for preparing the above-mentioned P / CNT self-supporting electrode material, comprising the following steps:
[0012] (1) Mix red phosphorus and carbon nanotube solution and grind them to obtain P / CNT electrode material precursor solution;
[0013] (2) Filter the P / CNT electrode material precursor solution to obtain the P / CNT self-supporting electrode material.
[0014] Optionally, step (1) includes:
[0015] Red phosphorus was added to an aqueous solution of carbon nanotubes and stirred to form a uniform P / CNT solution. The P / CNT solution was then milled to obtain a P / CNT electrode material precursor solution.
[0016] Optionally, the red phosphorus is in the form of powder with a particle size of 0.1–2 μm.
[0017] Optionally, the grinding time is 5 to 10 hours.
[0018] Optionally, step (2) may also include drying the filtered product.
[0019] A third aspect of the present invention provides the application of the above-mentioned P / CNT self-supporting electrode material in the preparation of sodium-ion battery anode materials.
[0020] Compared with the prior art, the present invention has the following beneficial effects:
[0021] (1) In the P / CNT self-supporting electrode material provided by the present invention, the excellent physical properties of carbon nanotubes are beneficial to reducing the breakage of the electrode material, improving cycle stability, improving the first coulombic efficiency and fast charging performance.
[0022] (2) In the P / CNT self-supporting electrode material provided by this invention, red P and carbon materials exist in the form of phosphorus-carbon chemical bonds, which greatly improves the bonding force of the P / CNT electrode material, prevents P from falling off the surface of the carbon material, and is beneficial to improving the stability of the electrode material and improving the conductivity of red P. When this material was tested as a negative electrode material for sodium-ion batteries, it showed good electrochemical performance.
[0023] (3) The present invention uses a simple grinding (such as sand milling) and filtration (such as vacuum filtration) method to prepare P / CNT self-supporting electrode material. The reaction conditions are mild, the operation is simple, the equipment is simple, and the process eliminates the dangers and use of toxic solutions and solvents associated with traditional lithium-ion battery production. These features not only reduce the consumption of natural resources, but also promote the environmental protection and economy of batteries.
[0024] Other features and advantages of the present invention will be described in detail in the following detailed description section. Attached Figure Description
[0025] Exemplary embodiments of the present invention will be described in more detail with reference to the accompanying drawings.
[0026] Figure 1 This is a digital photograph of the P / CNT self-supporting electrode material prepared in one embodiment of the present invention.
[0027] Figure 2 This is a scanning electron microscope image of the P / CNT self-supporting electrode material prepared in one embodiment of the present invention.
[0028] Figure 3 This is the XPS:P 2p spectrum of the P / CNT self-supporting electrode material prepared in one embodiment of the present invention.
[0029] Figure 4 This is a cyclic voltammetry curve of the P / CNT self-supporting electrode material prepared in one embodiment of the present invention.
[0030] Figure 5 This is a charge-discharge test diagram of the P / CNT self-supporting electrode material prepared in one embodiment of the present invention. Detailed Implementation
[0031] The following provides a detailed description of specific embodiments of the present invention. It should be understood that the specific embodiments described herein are for illustrative and explanatory purposes only and are not intended to limit the scope of the invention.
[0032] This invention provides a P / CNT self-supporting electrode material, which includes red phosphorus (red P) and carbon nanotubes.
[0033] In the P / CNT self-supporting electrode material of the present invention, based on the weight of the P / CNT self-supporting electrode material, the content of red phosphorus is 20-70% by weight, preferably 30-60% by weight, and the content of carbon nanotubes is 30-80% by weight, preferably 40-70% by weight.
[0034] Specifically, the mass ratio of red phosphorus to carbon nanotubes can be varied within the range of 3:7 to 6:4, specifically any one of the ratios of 3:7, 4:6, 5:5, and 6:4, or any ratio between any two of the above ranges.
[0035] In this invention, the thickness of the P / CNT self-supporting electrode material can be determined as needed, depending on the amount of filter material taken during filtration. This invention does not have a particular limitation on this. Typically, the thickness of the P / CNT self-supporting electrode material is 10 to 500 μm, preferably 50 to 200 μm.
[0036] This invention does not have any special requirements on the form of carbon nanotubes. Various types of carbon nanotubes can be used to realize this invention, such as conventional single-walled or multi-walled carbon nanotube powders, which can be commercially available or prepared according to known methods.
[0037] The P / CNT self-supporting electrode material of the present invention does not contain conductive agents and binders. The meaning of conductive agents and binders is known to those skilled in the art, referring to conventional components that are mixed with active components to form electrode slurry.
[0038] The P / CNT self-supporting electrode material of the present invention can be prepared by blending, grinding, and filtering red phosphorus and carbon nanotubes. The grinding includes, but is not limited to, sand milling, and the filtering includes, but is not limited to, vacuum filtration.
[0039] During the grinding process, phosphorus forms PC bonds with carbon nanotubes, thereby alleviating the volume effect of phosphorus during lithiation / delithiation and maintaining its cycle stability.
[0040] This invention also provides a method for preparing the above-mentioned P / CNT self-supporting electrode material, comprising the following steps:
[0041] (1) Mix red phosphorus and carbon nanotube solution and grind them to obtain P / CNT electrode material precursor solution;
[0042] (2) Filter the P / CNT electrode material precursor solution to obtain the P / CNT self-supporting electrode material.
[0043] According to a specific embodiment of the present invention, step (1) includes:
[0044] Red phosphorus was added to an aqueous solution of carbon nanotubes and stirred to form a uniform P / CNT solution. The P / CNT solution was then milled to obtain a P / CNT electrode material precursor solution.
[0045] In the preparation method of the present invention, the red phosphorus is preferably a micro-nano powder, specifically, its particle size is 0.1 to 2 μm.
[0046] The sand milling can be carried out using conventional equipment in the field, such as a sand mill. The sand milling time can also be determined as needed, preferably 5 to 10 hours.
[0047] According to a preferred embodiment of the present invention, step (2) further includes drying the filtered product. The drying can also be performed using various methods conventional in the art, such as drying in an oven for several hours.
[0048] The P / CNT self-supporting electrode material of the present invention can be used to prepare sodium-ion battery anode materials.
[0049] The present invention will be further described below with reference to the embodiments, but the scope of the present invention is not limited to these embodiments.
[0050] In the following examples, red P was purchased from Aladdin Company, and the powder particle size was 0.5–1 μm. Carbon nanotubes (CNTs) were multi-walled carbon nanotube powder.
[0051] Example 1
[0052] (1) Preparation of P / CNT electrode material precursor solution by sand milling method
[0053] Red P was added to a 500 mL, 2 g / mL CNT aqueous solution (with a mass ratio of red P to CNT of 3:7) and magnetically stirred to form a uniformly dispersed P / CNT solution. The P / CNT solution was then added to a sand mill and milled for 5 hours to obtain a P / CNT electrode material precursor solution.
[0054] (2) Preparation of P / CNT self-supporting electrode material by vacuum filtration method
[0055] The filtrate was extracted from 50 mL of the P / CNT precursor solution by vacuum filtration. The filtered product was then dried in an oven for several hours to finally obtain a self-supporting P / CNT electrode material with a thickness of 120 μm.
[0056] Example 2
[0057] (1) Preparation of P / CNT electrode material precursor solution by sand milling method
[0058] Red P was added to a 1000 mL CNT aqueous solution with a concentration of 1.8 g / mL (the mass ratio of red P to CNT was 4:6), and the solution was magnetically stirred to form a uniformly dispersed P / CNT solution. The P / CNT solution was then added to a sand mill and milled for 6 hours to obtain a P / CNT electrode material precursor solution.
[0059] (2) Preparation of P / CNT self-supporting electrode material by vacuum filtration method
[0060] By using a vacuum filtration method, 80 mL of the P / CNT precursor solution was extracted to obtain the filtrate. The filtered product was then placed in an oven and dried for several hours to finally obtain a self-supporting P / CNT electrode material with a thickness of 180 μm.
[0061] Example 3
[0062] (1) Preparation of P / CNT electrode material precursor solution by sand milling method
[0063] Red P was added to a 1000 mL, 1.1 g / mL CNT aqueous solution (with a mass ratio of red P to CNT of 6:4), and the solution was magnetically stirred to form a uniformly dispersed P / CNT solution. The P / CNT solution was then added to a sand mill and milled for 6 hours to obtain a P / CNT electrode material precursor solution.
[0064] (2) Preparation of P / CNT self-supporting electrode material by vacuum filtration method
[0065] The filtrate was extracted from 50 mL of the P / CNT precursor solution by vacuum filtration. The filtered product was then dried in an oven for several hours to finally obtain a self-supporting P / CNT electrode material with a thickness of 110 μm.
[0066] Test case
[0067] The P / CNT self-supporting electrode material prepared in Example 1 was photographed, as shown below. Figure 1 As shown.
[0068] The P / CNT self-supporting electrode material prepared in Example 1 was subjected to scanning electron microscopy (SEM) testing, and the results are as follows: Figure 2 As shown, CNTs are uniformly coated around P, which helps improve the conductivity of the P electrode material, alleviates the stress generated during cycling, forms a stable solid electrolyte film, and thus improves the electrochemical performance of the electrode material.
[0069] The P / CNT self-supporting electrode material prepared in Example 1 was subjected to XPS testing, and the obtained XPS:P 2p spectrum is shown below. Figure 3As shown, red phosphorus (P) mainly exists in the form of elemental phosphorus (P), and phosphorus-carbon chemical bonds are formed between red phosphorus and carbon nanotubes.
[0070] The P / CNT self-supporting electrode material prepared in Example 1 was subjected to cyclic voltammetry testing, and the results are as follows: Figure 4 As shown, the electrode material exhibits a distinct redox peak for P, demonstrating the feasibility of this P / CNT self-supporting electrode material as a negative electrode material for sodium-ion batteries.
[0071] The P / CNT self-supporting electrode material prepared in Example 1 was subjected to charge-discharge tests. The results for the first three cycles are as follows: Figure 5 As shown in the figure, the P / CNT self-supporting electrode material exhibits high electrochemical performance.
[0072] The various embodiments of the present invention have been described above. These descriptions are exemplary and not exhaustive, nor are they limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments.
[0073] The endpoints and any values of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values should be understood to include values close to these ranges or values. For numerical ranges, the endpoint values of the various ranges, the endpoint values of the various ranges and individual point values, and individual point values can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.
Claims
1. A P / CNT self-supporting electrode material, characterized in that, The P / CNT self-supporting electrode material includes red phosphorus and carbon nanotubes.
2. The P / CNT self-supporting electrode material according to claim 1, characterized in that, Based on the weight of the P / CNT self-supporting electrode material, the content of red phosphorus is 20-70% by weight, preferably 30-60% by weight, and the content of carbon nanotubes is 30-80% by weight, preferably 40-70% by weight.
3. The P / CNT self-supporting electrode material according to claim 1, characterized in that, The red phosphorus forms phosphorus-carbon chemical bonds with the carbon nanotubes.
4. The P / CNT self-supporting electrode material according to claim 1, characterized in that, The thickness of the P / CNT self-supporting electrode material is 10–500 μm, preferably 50–200 μm.
5. The P / CNT self-supporting electrode material according to claim 1, characterized in that, The P / CNT self-supporting electrode material does not contain conductive agents or binders.
6. The P / CNT self-supporting electrode material according to any one of claims 1-5, characterized in that, The P / CNT self-supporting electrode material is prepared by blending, grinding and filtering red phosphorus and carbon nanotubes.
7. A method for preparing the P / CNT self-supporting electrode material according to any one of claims 1-6, comprising the following steps: (1) Mix red phosphorus and carbon nanotube solution and grind them to obtain P / CNT electrode material precursor solution; (2) Filter the P / CNT electrode material precursor solution to obtain the P / CNT self-supporting electrode material.
8. The preparation method according to claim 7, characterized in that, Step (1) includes: Red phosphorus was added to an aqueous solution of carbon nanotubes and stirred to form a uniform P / CNT solution. The P / CNT solution was then milled to obtain a P / CNT electrode material precursor solution.
9. The preparation method according to claim 7 or 8, characterized in that, The red phosphorus is in powder form with a particle size of 0.1–2 μm.
10. The preparation method according to claim 8, characterized in that, The grinding time is 5 to 10 hours.
11. The preparation method according to claim 7, characterized in that, Step (2) also includes drying the filtered product.
12. The application of the P / CNT self-supporting electrode material according to any one of claims 1-6 in the preparation of sodium-ion battery anode materials.