A porous phosphorus-based sodium-ion battery alloy negative electrode material and a preparation method thereof

Abstract

The application discloses a kind of porous phosphorus-based sodium-ion battery alloy negative materials and preparation method thereof, comprising the following steps: S1, raw material mixing: red phosphorus and sodium-embedded metal powder are mixed uniformly according to proportion, to obtain raw material powder;S2, alloying treatment: raw material powder is ball milled in protective atmosphere and alloyed, to form phosphorus-based alloy powder;S3, calcination pore-forming: phosphorus-based alloy powder is high-temperature calcined pore-forming in protective atmosphere, to form porous phosphorus-based alloy powder, after cooling, porous phosphorus-based sodium-ion battery alloy negative material can be obtained.The preparation method of the porous phosphorus-based sodium-ion battery alloy negative material of the application has the characteristics of adjustable material structure and morphology, high porosity and excellent electrochemical performance.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of sodium ion battery materials, in particular to a porous phosphorus-based sodium ion battery alloy negative electrode material and a preparation method thereof. BACKGROUND

[0002] Lithium ion batteries have been the dominant technology in the field of energy storage due to their excellent energy density and relatively stable cycle performance. However, the scarcity and uneven distribution of lithium resources limit its potential in large-scale applications and cost control. At the same time, sodium ion batteries have attracted attention due to their similar physical and chemical properties to lithium ion batteries. Sodium is abundant in the earth's crust, widely distributed, and relatively low in cost, which makes sodium ion batteries exhibit obvious advantages in the sustainable use of resources.

[0003] Although sodium ion batteries have great potential in theory, many challenges still need to be overcome in practical applications. Currently, significant progress has been made in the research of sodium ion battery cathode materials, and a variety of materials with excellent electrochemical performance have been developed.

[0004] In contrast, the research of sodium ion battery anode materials has been slower. The performance of anode materials has a direct impact on the capacity, cycle stability and charging efficiency of the battery. An ideal anode material should have a low charge-discharge voltage platform, high specific capacity and good cycle stability. Although hard carbon materials have been commercialized, there are still some challenges, such as lower capacity (usually less than 350 mAh / g), low initial coulombic efficiency and poor rate performance.

[0005] Phosphorus-based materials are considered an important candidate for sodium ion battery anode materials due to their high theoretical specific capacity (2596 mAh / g) and abundant reserves, low price, etc. However, phosphorus-based materials face challenges such as poor conductivity and large volume expansion in practical applications, which limit their performance as anode materials. The combination of phosphorus-based materials with other metals can alleviate this problem to some extent. However, when combined with sodium-embedded metals, the sodium-embedded metals themselves also have a large volume expansion, leading to the collapse of the material structure. SUMMARY

[0006] The purpose of the present application is to provide a porous phosphorus-based sodium ion battery alloy negative electrode material and a preparation method thereof, which has the characteristics of adjustable material structure and morphology, high porosity and excellent electrochemical performance.

[0007] The present application can be realized by the following technical solutions:

[0008] The present application discloses a preparation method of a porous phosphorus-based sodium ion battery alloy negative electrode material, comprising the following steps:

[0009] S1, raw material mixing: red phosphorus and sodium-embedded metal powder are weighed and mixed uniformly according to the proportion to obtain raw material powder;

[0010] S2, alloying treatment: the raw material powder is ball milled for alloying under a protective atmosphere to form phosphorus-based alloy powder;

[0011] S3, calcination and pore formation: the phosphorus-based alloy powder is calcined and pore-formed at high temperature under a protective atmosphere to form porous phosphorus-based alloy powder, and the porous phosphorus-based sodium-ion battery alloy negative electrode material can be obtained after cooling.

[0012] The present application now synthesizes an alloy material with a porous structure. The presence of pores can provide expansion space for phosphorus and composite metals, and the porous structure can increase the specific surface area of the material, thereby providing more active sites, which helps to improve the transmission rate of electrons and ions. This structural characteristic is crucial for improving the energy density and power density of the battery.

[0013] Further, in step S3, the calcination temperature is 590-690 DEG C, the calcination time is 1-4 h, and the heating rate is 5-10 DEG C / min. Specifically, adjusting the calcination temperature, calcination time and heating rate can optimize the size and distribution of the pores, and a porous phosphorus-based alloy material with a gradient structure can be obtained. When the calcination temperature is low, red phosphorus does not sublimate, and when the calcination temperature is too high, the size of the pores is uneven due to the violent sublimation of phosphorus. During the sublimation of phosphorus, the phosphorus distributed on the outer layer of the powder sublimates first, so controlling the calcination time can control the position of the red phosphorus pores, thereby adjusting the physical and chemical properties of the material. Too little sublimated phosphorus results in insufficient pores and insufficient expansion space, while too much sublimated red phosphorus leads to a decrease in the capacity of the phosphorus-based alloy powder.

[0014] Further, in step S2, the mass ratio of the raw material powder to the grinding balls is 1:10-1:20. Specifically, the grinding balls function to impact and grind the raw material, and are chemically inert and do not react with the raw material. Therefore, the material type of the grinding balls is rich, and grinding balls made of materials such as hard alloy, silicon oxide, zirconium oxide, aluminum oxide, zirconium silicate, stainless steel, agate and ceramic can be used to achieve the purpose of ball milling.

[0015] Further, in the ball milling process, the grinding balls are graded in five levels with diameters of 12 mm, 10 mm, 8 mm, 6 mm and 4 mm; the grinding balls with diameters of 12 mm and 10 mm account for 30%-40% by mass percentage, the grinding balls with a diameter of 8 mm account for 30%-40%, and the grinding balls with diameters of 6 mm and 4 mm account for 30% in total.

[0016] Further, in step S2, the ball milling time is 4-12h, and the ball milling frequency is 40-50Hz. Specifically, in the ball milling process, because of the high-speed vibration of the ball milling tank, the grinding balls in the ball milling tank exert strong mechanical force on the powder raw materials, which can make the powder particles repeatedly experience compression, shearing and impact. These mechanical forces increase the contact interface between different powder raw materials, promoting the mixing between the raw materials. During the ball milling process, the powder particles will be cold-welded under high-energy impact, that is, the particle surfaces will contact and bond together under high pressure. Subsequently, these cold-welded particles are broken in subsequent impact, forming smaller particles. This process is repeated, so that the raw material powder is gradually mixed and forms an alloy. The mechanical force of ball milling can cause the lattice of the powder particles to deform and dislocate, and even cause grain refinement and amorphization. This change in microstructure promotes mixing at the atomic scale, allowing different elements to be uniformly distributed in the lattice to form an alloy. Therefore, the phosphorus in the obtained phosphorus-based alloy powder is uniformly distributed in the powder, and the in-situ formed pores are also uniformly distributed.

[0017] Further, in step S1, the mixing method of the raw materials is one or more of ball milling, grinding and stirring. The uniform mixing by means such as grinding facilitates the subsequent ball milling process. The uniform grinding operation can be changed according to the actual process conditions, for example, in laboratory conditions, a small grinding machine or a mortar can be used to complete the process; while in industrial processing conditions, a large grinding machine or grinding equipment can also achieve the same purpose.

[0018] Further, the sodium-embedded metal powder is antimony powder and / or tin powder. Specifically, antimony and tin themselves have sodium-embedding activity and can provide more capacity, and the obtained phosphorus-based alloy powder has the advantage of high capacity.

[0019] Further, in step S1, the molar ratio of red phosphorus to antimony powder is 1-2, and the molar ratio of red phosphorus to tin powder is 0.75-4. Specifically, phosphorus itself can provide sodium-embedding capacity, and the sublimation of phosphorus during subsequent calcination will also reduce the capacity of the porous phosphorus-based alloy material, so the proportion of phosphorus has a great influence on the cycle stability and capacity of the porous phosphorus-based alloy material. On the basis of ensuring the molar ratio of the target phosphorus-based alloy material, increasing the proportion of phosphorus as a pore-forming agent can retain the capacity of the material while obtaining a porous structure, but because the conductivity of phosphorus is not good, too large a proportion of phosphorus will cause the overall conductivity of the phosphorus-based alloy material to decrease.

[0020] Further, in steps S2 and S3, the protective atmosphere is argon and / or nitrogen.

[0021] Another aspect of the present application is to protect the porous phosphorus-based sodium ion battery alloy anode material, which is prepared by the above preparation method.

[0022] The application is a kind of porous phosphorus-based sodium ion battery alloy negative electrode material and its preparation method, which has the following beneficial effects:

[0023] First, the material structure and morphology can be adjusted. The pore size and distribution can be optimized by adjusting the calcination temperature, calcination time and heating rate through calcination pore forming. The porous phosphorus-based alloy material with gradient structure can be obtained. In the process of phosphorus sublimation, the phosphorus distributed in the outer layer of the powder sublimates first. Therefore, by controlling the calcination temperature, calcination time and heating rate, the position of the red phosphorus pore can be controlled, thereby adjusting the physical and chemical properties of the material.

[0024] Second, the porosity is high. In the calcination pore forming process, due to the sublimation of phosphorus, more pore structures are formed in situ, avoiding the additional pore forming step, simplifying the production process, and improving the porosity and specific surface area of the material, which has potential advantages in improving the electrochemical performance of the material.

[0025] Third, the electrochemical performance is excellent. The pore structure can provide a buffer space for the volume expansion of the phosphorus-based alloy negative electrode material during cycling, which is beneficial to maintaining the integrity of the material structure. Therefore, the cycle stability of the material is improved. In addition, the porous material usually has a large specific surface area, which provides more active sites for electrochemical reactions, thereby exhibiting higher specific capacity. The porous structure with interconnected channels can establish a continuous charge transport path in the electrochemical reaction, shorten the ion diffusion path, and promote the achievement of high capacity at high current density. BRIEF DESCRIPTION OF DRAWINGS

[0026] Figure 1 The cycle performance curve of application example 1 and comparative example 1 at 1000 mA / g is shown in the following table:

[0027] Figure 2 The specific surface area test curve of application example 2 and comparative example 2 is shown in the following table:

[0028] Figure 3 The scanning electron microscope image of application example 3 is shown in the following table:

[0029] Figure 4 The transmission electron microscope image of application example 4 is shown in the following table. DETAILED DESCRIPTION

[0030] In order to make the person skilled in the art better understand the technical solutions of the present application, the product of the present application will be further described in detail below in combination with application examples.

[0031] The application discloses a kind of porous phosphorus-based sodium ion battery alloy negative electrode material and its preparation method, comprising the following steps:

[0032] S1, raw material mixing: red phosphorus and sodium-embedded metal powder are weighed and mixed uniformly according to the proportion to obtain raw material powder;

[0033] S2, alloying treatment: the raw material powder is ball milled under a protective atmosphere for alloying to form a phosphorus-based alloy powder;

[0034] S3, calcination and pore forming: the phosphorus-based alloy powder is high-temperature calcined and pore formed under a protective atmosphere to form a porous phosphorus-based alloy powder, and the porous phosphorus-based sodium-ion battery alloy negative electrode material can be obtained after cooling.

[0035] Further, in step S3, the calcination temperature is 590-690℃, the calcination time is 1-4h, and the heating rate is 5-10℃ / min.

[0036] Further, in step S2, the mass ratio of the raw material powder to the grinding ball is 1:10-1:20.

[0037] Further, in step S2, the ball milling time is 4-12h, and the ball milling frequency is 40-50Hz.

[0038] Further, in step S1, the raw material mixing method is one or more of ball milling, grinding, and stirring.

[0039] Further, the sodium-embedded metal powder is antimony powder and / or tin powder.

[0040] Further, in step S1, the molar ratio of red phosphorus to antimony powder is 1-2, and the molar ratio of red phosphorus to tin powder is 0.75-4.

[0041] Further, in steps S2 and S3, the protective atmosphere is argon and / or nitrogen.

[0042] Another aspect of the present application is to protect the porous phosphorus-based sodium-ion battery alloy negative electrode material, which is prepared by the above preparation method.

[0043] Example 1

[0044] This embodiment relates to a porous phosphorus-based sodium-ion battery alloy negative electrode material, and the preparation method thereof comprises the following steps:

[0045] S1, raw material mixing: red phosphorus and sodium-embedded metal powder are mixed in proportion to obtain a raw material powder. Specifically, the raw material mixing method is ball milling, and the molar ratio of red phosphorus to antimony powder is 2.

[0046] S2, alloying treatment: the raw material powder is ball milled under a protective atmosphere for alloying to form a phosphorus-based alloy powder. Specifically, the mass ratio of the raw material powder to the grinding ball is 1:15, the ball milling time is 4h, and the ball milling frequency is 50Hz; the protective atmosphere is argon.

[0047] S3, pore forming by calcination: the phosphorus-based alloy powder is high-temperature calcined to form pores under a protective atmosphere to form a porous phosphorus-based alloy powder, and the porous phosphorus-based sodium-ion battery alloy negative electrode material can be obtained after cooling. Specifically, the calcination temperature is 590℃, the calcination time is 2h, and the heating rate is 5℃ / min; the protective atmosphere is nitrogen.

[0048] Example 2

[0049] This embodiment relates to a porous phosphorus-based sodium-ion battery alloy negative electrode material, and a preparation method thereof includes the following steps:

[0050] S1, raw material mixing: red phosphorus and sodium-embedded metal powder are weighed and mixed uniformly according to the proportion to obtain raw material powder. Specifically, the raw material mixing method is grinding; the molar ratio of red phosphorus to antimony powder is 1.5.

[0051] S2, alloying treatment: the raw material powder is ball milled for alloying under a protective atmosphere to form a phosphorus-based alloy powder. Specifically, the mass ratio of the raw material powder to the grinding ball is 1:10, the ball milling time is 12h, and the ball milling frequency is 45Hz; the protective atmosphere is nitrogen.

[0052] S3, pore forming by calcination: the phosphorus-based alloy powder is high-temperature calcined to form pores under a protective atmosphere to form a porous phosphorus-based alloy powder, and the porous phosphorus-based sodium-ion battery alloy negative electrode material can be obtained after cooling. Specifically, the calcination temperature is 650℃, the calcination time is 1h, and the heating rate is 10℃ / min; the protective atmosphere is nitrogen.

[0053] Example 3

[0054] This embodiment relates to a porous phosphorus-based sodium-ion battery alloy negative electrode material, and a preparation method thereof includes the following steps:

[0055] S1, raw material mixing: red phosphorus and sodium-embedded metal powder are weighed and mixed uniformly according to the proportion to obtain raw material powder. Specifically, the raw material mixing method is stirring; the molar ratio of red phosphorus to tin powder is 0.75.

[0056] S2, alloying treatment: the raw material powder is ball milled for alloying under a protective atmosphere to form a phosphorus-based alloy powder. Specifically, the mass ratio of the raw material powder to the grinding ball is 1:20, the ball milling time is 8h, and the ball milling frequency is 40Hz; the protective atmosphere is argon and nitrogen.

[0057] S3, pore forming by calcination: the phosphorus-based alloy powder is high-temperature calcined to form pores under a protective atmosphere to form a porous phosphorus-based alloy powder, and the porous phosphorus-based sodium-ion battery alloy negative electrode material can be obtained after cooling. Specifically, the calcination temperature is 690℃, the calcination time is 4h, and the heating rate is 8℃ / min; the protective atmosphere is argon and nitrogen.

[0058] Example 4

[0059] The embodiment relates to a porous phosphorus-based sodium ion battery alloy negative electrode material, and a preparation method thereof.

[0060] S1, raw material mixing: red phosphorus and sodium-embedded metal powder are weighed and uniformly mixed according to a proportion to obtain raw material powder. Specifically, the raw material mixing is performed by ball milling; the molar ratio of the red phosphorus to the tin powder is 2.

[0061] S2, alloying treatment: the raw material powder is ball milled under a protective atmosphere to perform alloying, so as to form phosphorus-based alloy powder. Specifically, the mass ratio of the raw material powder to the grinding ball is 1:12, the ball milling time is 6h, and the ball milling frequency is 40Hz; the protective atmosphere is argon and nitrogen.

[0062] S3, calcination and pore forming: the phosphorus-based alloy powder is high-temperature calcined and pore-formed under a protective atmosphere, so as to form porous phosphorus-based alloy powder, and the porous phosphorus-based sodium ion battery alloy negative electrode material can be obtained after cooling. Specifically, the calcination temperature is 640 DEG C, the calcination time is 2h, and the heating rate is 6 DEG C / min; the protective atmosphere is argon and nitrogen.

[0063] Embodiment 5

[0064] The embodiment relates to a porous phosphorus-based sodium ion battery alloy negative electrode material, and a preparation method thereof.

[0065] S1, raw material mixing: red phosphorus and sodium-embedded metal powder are weighed and uniformly mixed according to a proportion to obtain raw material powder. Specifically, the raw material mixing is performed by ball milling; the molar ratio of the red phosphorus to the tin powder is 2.

[0066] S2, alloying treatment: the raw material powder is ball milled under a protective atmosphere to perform alloying, so as to form phosphorus-based alloy powder. Specifically, the mass ratio of the raw material powder to the grinding ball is 1:12, the ball milling time is 6h, and the ball milling frequency is 40Hz; the protective atmosphere is argon and nitrogen.

[0067] S3, calcination and pore forming: the phosphorus-based alloy powder is high-temperature calcined and pore-formed under a protective atmosphere, so as to form porous phosphorus-based alloy powder, and the porous phosphorus-based sodium ion battery alloy negative electrode material can be obtained after cooling. Specifically, the calcination temperature is 640 DEG C, the calcination time is 2h, and the heating rate is 6 DEG C / min; the protective atmosphere is argon and nitrogen.

[0068] Application embodiment 1

[0069] The embodiment relates to a porous phosphorus-based sodium ion battery alloy negative electrode material, and a preparation method thereof.

[0070] S1, raw material mixing: red phosphorus and sodium-embedded metal powder are weighed and uniformly mixed according to a proportion to obtain raw material powder. Specifically, the raw material mixing is performed by ball milling; the molar ratio of the red phosphorus to the tin powder is 2.

[0071] S2, alloying treatment: Put the raw material powder into a ball milling jar, and add a total of 55 g of milling balls. Mill under an argon atmosphere at 45 Hz for 4 h until tin and phosphorus are fully alloyed to form the raw material powder.

[0072] S3, calcination for porosity: The raw material powder is calcined under an argon atmosphere, during which a porous tin-phosphorus alloy powder material is formed. The calcination temperature is 590°C, the heating rate is 5°C / min, and the holding time is 2 h. After calcination is complete, the material is naturally cooled to room temperature to obtain a porous tin-phosphorus alloy (Sn4P3) material.

[0073] Comparative Example 1

[0074] This example relates to a phosphorus-based sodium-ion battery alloy anode material, and the preparation method thereof comprises the following steps:

[0075] S1, raw material mixing: Take 1 g of red phosphorus and 4.18 g of tin powder and grind them uniformly to obtain a raw material powder.

[0076] S2, alloying treatment: Put the raw material powder into a ball milling jar, and add a total of 55 g of milling balls. Mill under an argon atmosphere at 45 Hz for 4 h until tin and phosphorus are fully alloyed to form the raw material powder.

[0077] Application Example 2

[0078] This example relates to a porous phosphorus-based sodium-ion battery alloy anode material, and the preparation method thereof comprises the following steps:

[0079] S1, raw material mixing: Take 2.5 g of red phosphorus and 2.8 g of tin powder and grind them uniformly to obtain a raw material powder.

[0080] S2, alloying treatment: Put the raw material powder into a ball milling jar, and add a total of 100 g of milling balls. Mill under an argon atmosphere at 50 Hz for 6 h until tin and phosphorus are fully alloyed to form the raw material powder.

[0081] S3, calcination for porosity: The raw material powder is calcined under an argon atmosphere, during which a porous tin-phosphorus alloy powder material is formed. The calcination temperature is 600°C, the heating rate is 10°C / min, and the holding time is 1 h. After calcination is complete, the material is naturally cooled to room temperature to obtain a porous tin-phosphorus alloy (SnP3) material

[0082] Comparative Example 2

[0083] This example relates to a phosphorus-based sodium-ion battery alloy anode material, and the preparation method thereof comprises the following steps:

[0084] S1, raw material mixing: Take 2.5 g of red phosphorus and 2.8 g of tin powder and grind them uniformly to obtain a raw material powder.

[0085] S2, alloying treatment: Put the raw material powder into a ball milling tank, and add a total of 100 g of grinding balls. Mill at 50 Hz for 6 h under an argon atmosphere until tin and phosphorus are fully alloyed to form the raw material powder.

[0086] Application Example 3

[0087] This example relates to a porous phosphorus-based sodium-ion battery alloy anode material, and the preparation method thereof comprises the following steps:

[0088] S1, raw material mixing: Take 3 g of red phosphorus and 2.39 g of antimony powder and grind them uniformly to obtain a raw material powder.

[0089] S2, alloying treatment: Put the raw material powder into a ball milling tank, and add a total of 65 g of grinding balls. Mill at 40 Hz for 6 h under an argon atmosphere until antimony and phosphorus are fully alloyed to form an antimony-phosphorus alloy powder B.

[0090] S3, calcination for pore formation: The antimony-phosphorus alloy powder B is calcined under an argon atmosphere, and in this process, a porous antimony-phosphorus alloy powder material is formed. The calcination temperature is 650°C, the heating rate is 8°C / min, and the holding time is 3 h. After calcination is completed, it is naturally cooled to room temperature to obtain a porous antimony-phosphorus alloy (SbP) material.

[0091] Application Example 4

[0092] This example relates to a porous phosphorus-based sodium-ion battery alloy anode material, and the preparation method thereof comprises the following steps:

[0093] S1, raw material mixing: Take 1.5 g of red phosphorus and 3.97 g of tin powder and grind them uniformly to obtain a raw material powder.

[0094] S2, alloying treatment: Put the raw material powder into a ball milling tank, and add a total of 80 g of grinding balls. Mill at 45 Hz for 4 h under an argon atmosphere until tin and phosphorus are fully alloyed to form the raw material powder.

[0095] S3, calcination for pore formation: The raw material powder is calcined under an argon atmosphere, and in this process, a porous tin-phosphorus alloy powder material is formed. The calcination temperature is 630°C, the heating rate is 10°C / min, and the holding time is 4 h. After calcination is completed, it is naturally cooled to room temperature to obtain a porous tin-phosphorus alloy (SnP) material.

[0096] The porous phosphorus-based alloy materials obtained in the above-mentioned four application examples and the phosphorus-based alloy materials obtained in the two comparative examples are subjected to different characterizations, which are as follows:

[0097] The porous phosphorus-based alloy material, carboxymethyl cellulose CMC and conductive carbon black Super P obtained by application example 1 were uniformly grinded in a ratio of 7:2:1, and coated, and the phosphorus-based alloy material, carboxymethyl cellulose CMC and conductive carbon black Super P obtained by comparative example 1 were uniformly grinded in a ratio of 7:2:1, and coated. The pole pieces obtained by the two were assembled with sodium sheets in a glove box with a water oxygen value of less than 0.01 ppm to obtain a sodium ion half battery, and the electrochemical performance was measured on a Neware. Specifically, the cycle was carried out at a current density of 1000 mA / g, and the related data was obtained and the cycle performance of the two was compared.

[0098] Application example 2 and comparative example 2 were subjected to N2-adsorption and desorption test, and the surface area data of the two were obtained, and the specific surface area was compared.

[0099] Application example 3 was subjected to SEM characterization, and SEM data was obtained;

[0100] Application example 4 was subjected to TEM characterization, and TEM data was obtained;

[0101] Figure 1 It can be seen that the porous tin-phosphorus alloy material carbon composite negative electrode obtained by application example 1 has better cycle stability, and there is almost no attenuation in the 200 cycle process, while the capacity of comparative example 1 rapidly attenuates. This is because the pores provide a buffer space for the volume expansion of the porous tin-phosphorus alloy material, inhibit the crushing and pulverization of the material, thereby having good cycle performance.

[0102] Figure 2 It can be seen that the specific surface area of application example 2 is greater than that of comparative example 2, because the pore structure is formed in situ during the calcination of the material. The existence of the pore structure increases the specific surface area of the material, thereby increasing the sodium intercalation active site.

[0103] Figure 3 The SEM image of application example 3 can be seen to have obvious pore structure, because the pores are formed in situ during the calcination of the material.

[0104] Figure 4 The TEM image of application example 4 can be seen to have obvious pore structure, because the pore structure is formed in situ during the calcination of the material.

[0105] The above examples are only specific embodiments of the present application, which are described in more detail and in detail, but should not be construed as limiting the scope of the present patent. It should be noted that for those skilled in the art, without departing from the concept of the present application, a number of modifications and improvements can be made, and these obvious alternative forms all belong to the protection scope of the present application.

Claims

1. A method for preparing a porous phosphorus-based sodium-ion battery alloy anode material, characterized by: The method comprises the following steps: S1, raw material mixing: red phosphorus and sodium-embedded metal powder are weighed and mixed according to a proportion to obtain raw material powder, the sodium-embedded metal powder being antimony powder and / or tin powder; S2, alloying treatment: the raw material powder is ball-milled in a protective atmosphere to form phosphorus-based alloy powder; S3, calcination and pore forming: the phosphorus-based alloy powder is calcined at high temperature in a protective atmosphere to form porous phosphorus-based alloy powder, and the porous phosphorus-based sodium-ion battery alloy negative electrode material is obtained after cooling; the calcination temperature is 590-690 DEG C, the calcination time is 1-4h, and the heating rate is 5-10 DEG C / min.

2. The method of claim 1, wherein the method further comprises: In step S2, the mass ratio of the raw material powder to the grinding balls is 1:10-1:

20. ​ 3. The method of claim 2, wherein the method further comprises: In the ball milling process, the grinding balls are graded in five levels, i.e., 12mm, 10mm, 8mm, 6mm and 4mm; the grinding balls with diameters of 12mm and 10mm account for 30%-40% in mass percentage, the grinding balls with a diameter of 8mm account for 30%-40%, and the grinding balls with diameters of 6mm and 4mm account for 30% in total.

4. The method of claim 1, wherein the method further comprises: In step S2, the ball milling time is 4-12h, and the ball milling frequency is 40-50Hz.

5. The method of claim 1, wherein the method further comprises: In step S1, the raw material mixing is performed by one or more than two of ball milling, grinding and stirring.

6. The method of claim 1, wherein the method further comprises: In step S1, the molar ratio of red phosphorus to antimony powder is 1-2, and the molar ratio of red phosphorus to tin powder is 0.75-4.

7. The method of claim 6, wherein the method further comprises: In steps S2 and S3, the protective atmosphere is argon and / or nitrogen.

8. A porous phosphorus-based sodium-ion battery alloy anode material, characterized in that: The porous phosphorus-based sodium-ion battery alloy negative electrode material is prepared by the method according to any one of claims 1-7.

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