Silicon-based negative electrode material for a battery and secondary battery

Abstract

The application provides a silicon-based battery negative electrode material and a secondary battery. The negative electrode material comprises a negative electrode active material, a conductive agent and a binder. The negative electrode active material comprises 0.1wt%-30wt% of a silicon material and the rest is a carbon material in terms of the mass percentage of the negative electrode active material. The secondary battery comprises a negative electrode, a positive electrode and a separator arranged between the negative electrode and the positive electrode, and the negative electrode is prepared by using the silicon-based battery negative electrode material. According to the adding amount of the silicon material, the carbon material with different particle size distributions is screened, the appropriate silicon-based battery negative electrode active material is obtained, the initial coulomb efficiency of the secondary battery is improved, the service life of the secondary battery in the long-term charging process is ensured, and the safety of the secondary battery and even the charging process is improved.

Description

Technical Field

[0001] This invention relates primarily to the field of secondary batteries, and in particular to a silicon-based battery anode material and a secondary battery. Background Technology

[0002] Secondary batteries have been widely used due to their advantages such as high terminal voltage, high specific energy, long charge-discharge life, stable discharge performance, low self-discharge rate, and no pollution. Traditional graphite anode materials have a small coefficient of expansion (about 10%), but their energy density is too low (theoretical specific capacity is 372 mAh / g). Although graphite is an ideal anode material for batteries, the energy density of batteries of the same volume is too low to meet the needs of use. However, after adding silicon to graphite anode materials, theoretically, the storage capacity of the battery will be 10 times that of lithium-ion batteries using traditional graphite materials, while also having extremely high charging efficiency, making the battery energy density sufficient to meet the requirements.

[0003] However, during lithium-ion insertion and extraction, silicon undergoes volume expansion, ranging from 100% to 300%, generating significant internal stress. This causes the SEI film on the silicon surface to repeatedly form, break, and re-form, reducing the electrode's conductivity and cycle stability. Furthermore, silicon's conductivity is much lower than graphite, leading to greater irreversibility during lithium-ion insertion and extraction, further reducing its initial coulombic efficiency.

[0004] With the introduction of silicon anode materials, the coulombic efficiency and cycle life of secondary batteries have become major obstacles. The strategies proposed so far include: (1) synthesizing amorphous silicon at the hundred-nanometer scale; (2) developing suitable polymer binders; (3) synthesizing special multi-level buffer / confined structures. However, these strategies have disadvantages such as long development cycles, high usage costs, and difficulties in practical application. In the process of use, inappropriate material selection will affect the performance of the battery and even affect the safety of the battery.

[0005] Therefore, there is a need to provide an improved technical solution that addresses the shortcomings of the existing technology. Summary of the Invention

[0006] In view of the shortcomings of the prior art described above, the purpose of this invention is to provide a silicon-based battery anode material and a secondary battery. By determining the appropriate carbon material to match the silicon material addition ratio, and rationally selecting battery materials from aspects such as particle size distribution, the coulombic efficiency and cycle performance of the secondary battery can be improved.

[0007] To achieve the above and other related objectives, the present invention provides a silicon-based battery anode material, the silicon-based battery anode material comprising: an anode active material, a conductive agent, and a binder;

[0008] The negative electrode active material comprises carbon material and silicon material; based on the mass percentage of the negative electrode active material, the negative electrode active material comprises 0.1wt% to 30wt% silicon material, with the balance being carbon material.

[0009] It should be noted that the carbon material in this application is a compound containing carbon, and the silicon material in this application is a compound containing silicon. Preferably, the carbon material includes one or more combinations of natural graphite, artificial graphite, soft carbon, hard carbon, and doped carbon; preferably, the silicon material includes one or more combinations of silicon-carbon, silicon-oxygen, elemental silicon, and nano-silicon materials, wherein silicon-carbon is usually SiC, and silicon-oxygen is usually SiO2.

[0010] Preferably, the negative electrode active material comprises 2 wt% to 20 wt% silicon material, with the balance being carbon material, based on the mass percentage of the negative electrode active material.

[0011] Preferably, the volumetric particle size distribution Dv50 of the carbon material is 3μm to 25μm, where Dv50 is the particle size corresponding to the cumulative volumetric distribution percentage of the carbon material reaching 50%.

[0012] Preferably, the volumetric particle size distribution of the carbon material is Dvmax ≤ 48 μm, where Dvmax is the particle size corresponding to a cumulative volumetric distribution percentage of 99% for the carbon material.

[0013] Preferably, the volumetric particle size distribution of the carbon material satisfies the following condition: 0.5≤(Dvmax-Dvmin) / Dv50≤3; where Dvmax is the particle size corresponding to a cumulative volumetric distribution percentage of 99% for the carbon material, and Dvmin is the particle size corresponding to a cumulative volumetric distribution percentage of less than 1% for the carbon material.

[0014] Preferably, based on the mass percentage of the negative electrode active material, when the negative electrode active material includes 0.1wt% to 10wt% silicon material, the volume particle size distribution of the carbon material satisfies the following condition: 0.5≤(Dvmax-Dvmin) / Dv50≤1.2;

[0015] and / or;

[0016] Based on the mass percentage of the negative electrode active material, when the content of silicon material is 10wt% < 30wt% in the negative electrode active material, the volume particle size distribution of the carbon material satisfies the following condition: 1.2 < (Dvmax - Dvmin) / Dv50 ≤ 3.

[0017] Preferably, the specific surface area of ​​the carbon material is 0.5 m². 2 / g~18m 2 / g.

[0018] Preferably, the tap density of the carbon material is 0.6 g / cm³. 3 ~1.4g / cm 3 .

[0019] Preferably, the volumetric particle size distribution Dv50 of the silicon material is 3μm to 8μm; wherein, the Dv50 of the silicon material is the particle size corresponding to the cumulative volumetric distribution percentage of the silicon material reaching 50%.

[0020] Preferably, the volumetric particle size distribution of the silicon material is Dvmax ≤ 15 μm; wherein, Dvmax is the particle size corresponding to a cumulative volumetric distribution percentage of 99% for the silicon material.

[0021] Preferably, the specific surface area of ​​the silicon material is 1.5 m². 2 / g~2.2m 2 / g.

[0022] Preferably, the volumetric particle size distribution of the silicon material satisfies the following condition: 1.1≤(Dvmax-Dvmin) / Dv50≤2.6; where Dvmax is the particle size corresponding to a cumulative volumetric distribution percentage of 99% for the silicon material, and Dvmin is the particle size corresponding to a cumulative volumetric distribution percentage of less than 1% for the silicon material.

[0023] The present invention provides a secondary battery, which includes a negative electrode, a positive electrode and a separator disposed between the negative electrode and the positive electrode, wherein the negative electrode is made of the aforementioned silicon-based battery negative electrode material.

[0024] As described above, the silicon-based battery anode material and secondary battery of the present invention have the following beneficial effects:

[0025] The silicon-based battery anode material of this invention includes an anode active material, which comprises carbon and silicon materials. By controlling the amount of silicon material added and the particle size and distribution of the carbon material, a suitable anode active material is obtained, thereby improving the initial coulombic efficiency of the secondary battery. Using the silicon-based battery anode material of this invention to form a secondary battery ensures its lifespan during long-term charging, significantly improving its cycle life. Furthermore, the selection of secondary battery materials according to this invention allows for the rapid determination of silicon-based battery anode materials, greatly reducing development time and costs. The technical solution of this invention is also simple to apply in practice. Detailed Implementation

[0026] The following specific examples illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention.

[0027] This invention provides a silicon-based battery anode material, which includes: an anode active material, a conductive agent, and a binder; wherein the anode active material includes carbon material and silicon material; based on the mass percentage of the anode active material, the anode active material includes 0.1 wt% to 30 wt% silicon material, with the balance being carbon material.

[0028] Specifically, the mass percentage of silicon material in the negative electrode active material can be any value within a range such as 0.1wt%, 0.5wt%, 1wt%, 5wt%, 10wt%, 20wt%, 25wt%, 28wt%, 30wt%, etc., and should be adjusted according to the actual situation.

[0029] As an example, the negative electrode active material comprises 2 wt% to 20 wt% silicon material and the balance is carbon material, based on the mass percentage of the negative electrode active material.

[0030] Specifically, the negative electrode active material includes silicon materials in any range such as 2wt%, 5wt%, 10wt%, 15wt%, 20wt%, etc., with the balance being carbon materials.

[0031] As examples, carbon materials include one or more combinations of natural graphite, artificial graphite, soft carbon, hard carbon, and doped carbon; silicon materials include one or more combinations of silicon-carbon, silicon-oxygen, elemental silicon, and nano-silicon materials, wherein silicon-carbon is typically SiC and silicon-oxygen is typically SiO2; conductive agents include one or more combinations of carbon black and carbon nanotubes; and binders include one or more combinations of carboxymethyl cellulose (CMC), polyacrylic acid (PAA), and styrene-butadiene rubber (SBR).

[0032] As an example, the volumetric particle size distribution Dv50 of carbon materials ranges from 3 μm to 25 μm, where Dv50 is the particle size corresponding to a cumulative volumetric distribution percentage of 50% for carbon materials.

[0033] Specifically, the volumetric particle size distribution Dv50 of the carbon material can include values ​​within any range such as 3μm, 6μm, 9μm, 16μm, 22μm, 25μm, etc., and can be adjusted according to actual conditions; preferably, the volumetric particle size distribution Dv50 of the carbon material is 4μm to 20μm (e.g., 4μm, 8μm, 12μm, 16μm, 18μm, 20μm, etc.).

[0034] As an example, the volumetric particle size distribution of carbon materials is Dvmax≤48μm, where Dvmax is the particle size corresponding to a cumulative volumetric distribution percentage of 99% for carbon materials.

[0035] Specifically, the volumetric particle size distribution Dvmax of the carbon material can include values ​​in any range such as 15μm, 20μm, 25μm, 30μm, and 48μm. Preferably, the volumetric particle size distribution Dvmax of the carbon material is 20μm to 35μm (e.g., 20μm, 23μm, 25μm, 27μm, 30μm, and 35μm), and can be adjusted according to actual conditions.

[0036] As an example, the volumetric particle size distribution of carbon materials satisfies the following condition: 0.5≤(Dvmax-Dvmin) / Dv50≤3; where Dvmax is the particle size corresponding to a cumulative volumetric distribution percentage of 99% for carbon materials, and Dvmin is the particle size corresponding to a cumulative volumetric distribution percentage of less than 1% for carbon materials.

[0037] Specifically, the volumetric particle size distribution of carbon materials satisfies the following condition: 0.5≤(Dvmax-Dvmin) / Dv50≤3, where (Dvmax-Dvmin) / Dv50 can include any value within the range of 0.5, 0.8, 1, 1.2, 2, 3, etc., and can be adjusted according to actual conditions.

[0038] As an example, based on the mass percentage of the negative electrode active material, when the negative electrode active material includes 0.1 wt% to 10 wt% silicon material, the volumetric particle size distribution of the carbon material satisfies the following condition: 0.5 ≤ (Dvmax - Dvmin) / Dv50 ≤ 1.2;

[0039] And / or; based on the mass percentage of the negative electrode active material, when the content of silicon material in the negative electrode active material is 10wt% < 30wt%, the volume particle size distribution of the carbon material satisfies the following condition: 1.2 < (Dvmax - Dvmin) / Dv50 ≤ 3.

[0040] Specifically, based on the mass percentage of the negative electrode active material, when the negative electrode active material includes 0.1wt% to 10wt% silicon material, (Dvmax - Dvmin) / Dv50 can include values ​​in any range such as 0.5, 0.8, 1, 1.2, etc., and should be adjusted according to the actual situation; when the content of silicon material in the negative electrode active material is less than 10wt% and less than 30wt%, (Dvmax - Dvmin) / Dv50 can include values ​​in any range such as 1.3, 1.5, 2.0, 2.5, 3, etc., and should be adjusted according to the actual situation.

[0041] As an example, the specific surface area of ​​carbon materials is 0.5 m².2 / g~18m 2 / g.

[0042] Specifically, the specific surface area of ​​carbon materials can include 0.5 m². 2 / g, 5.0m 2 / g, 6.5m 2 / g、18m 2 The value can be within any range such as / g, but preferably, the specific surface area of ​​the carbon material is 0.9m². 2 / g~2.0m 2 / g (e.g., 0.9m) 2 / g, 1.0m 2 / g, 1.2m 2 / g, 1.5m 2 / g, 1.8m 2 / g, 2.0m 2 / g, etc., can be adjusted according to actual conditions.

[0043] As an example, the tap density of carbon materials is 0.6 g / cm³. 3 ~1.4g / cm 3 .

[0044] Specifically, the tap density of carbon materials can include 0.6 g / cm³. 3 0.8g / cm 3 1.0g / cm 3 1.2g / cm 3 1.4g / cm 3 The values ​​are within any range, but preferably, the tap density of the carbon material is 0.9 g / cm³. 3 ~1.2g / cm 3 (e.g., 0.9g / cm) 3 1.0g / cm 3 1.2g / cm 3 (etc.), the specifics can be adjusted according to the actual situation.

[0045] As an example, the volumetric particle size distribution Dv50 of the silicon material is 3μm to 8μm; wherein, the Dv50 of the silicon material is the particle size corresponding to the cumulative volumetric distribution percentage of the silicon material reaching 50%.

[0046] Specifically, the volumetric particle size distribution Dv50 of silicon materials can include values ​​within any range such as 3μm, 4μm, 5μm, 6μm, 7μm, and 8μm, and can be adjusted according to actual conditions.

[0047] As an example, the volumetric particle size distribution of silicon material is Dvmax≤15μm; where Dvmax is the particle size corresponding to the cumulative volumetric distribution percentage of silicon material reaching 99%.

[0048] Specifically, the volumetric particle size distribution Dvmax of the silicon material can include values ​​in any range such as 5μm, 7μm, 10μm, 12μm, 14μm, and 15μm. Preferably, the volumetric particle size distribution of the silicon material is 10μm≤Dvmax≤15μm (e.g., 10μm, 11μm, 12μm, 13μm, 14μm, 15μm, etc.), and can be adjusted according to actual conditions.

[0049] As an example, the specific surface area of ​​silicon material is 1.5 m². 2 / g~2.2m 2 / g.

[0050] Specifically, the specific surface area of ​​silicon materials can include 1.5m². 2 / g, 1.7m 2 / g, 1.9m 2 / g, 2.0m 2 / g、2.1m 2 / g, 2.2m 2 / g, etc., preferably, the specific surface area of ​​the silicon material is 1.7m². 2 / g~2.0m 2 / g (e.g., 1.7m) 2 / g, 1.8m 2 / g, 1.9m 2 / g, 2.0m 2 / g, etc., can be adjusted according to actual conditions.

[0051] As an example, the volumetric particle size distribution of silicon material satisfies the following condition: 1.1≤(Dvmax-Dvmin) / Dv50≤2.6; where Dvmax is the particle size corresponding to the cumulative volumetric distribution percentage of silicon material reaching 99%, and Dvmin is the particle size corresponding to the cumulative volumetric distribution percentage of silicon material being less than 1%.

[0052] Specifically, the volumetric particle size distribution of silicon material satisfies the condition that (Dvmax - Dvmin) / Dv50 can include values ​​in any range such as 1.1, 1.3, 1.5, 1.7, 2.0, 2.3, 2.6, etc. Preferably, 1.8 ≤ (Dvmax - Dvmin) / Dv50 ≤ 2.2 (e.g., 1.8, 1.9, 2.0, 2.1, 2.2, etc.), which can be adjusted according to actual conditions.

[0053] The present invention also provides a secondary battery, which includes a negative electrode, a positive electrode and a separator disposed between the negative electrode and the positive electrode, wherein the negative electrode is made of the aforementioned silicon-based battery negative electrode material.

[0054] The silicon-based battery anode material and secondary battery of the present invention will be described below with reference to specific embodiments. It should be noted that these embodiments are merely descriptive and do not limit the present invention in any way.

[0055] Examples 1-10

[0056] Examples 1-10 provide a silicon-based battery anode material, comprising an anode active material, a conductive agent, and a binder. The mass percentages of silicon and carbon materials in the anode active material are shown in Table 1. The carbon material is artificial graphite, the silicon material is silicon-carbon (SiC), the conductive agent is a mixture of carbon black and single-walled carbon nanotubes, and the binder is polyacrylic acid. The volumetric particle size distribution (Dv50), Dvmax, (Dvmax-Dvmin) / Dv50, specific surface area, and tap density of the carbon material are all shown in Table 1. The volumetric particle size distribution (Dv50), Dvmax, specific surface area, and (Dvmax-Dvmin) / Dv50 of the silicon material are also shown in Table 1.

[0057] Various embodiments also provide a secondary battery prepared using conventional methods in the prior art.

[0058] Performance testing:

[0059] The secondary batteries in Examples 1-10 were subjected to performance tests, including initial coulombic efficiency tests and cycle life tests, as detailed below:

[0060] Initial coulombic efficiency test: The negative electrode sheet (the negative electrode made of the silicon-based battery negative electrode material in the corresponding embodiment), lithium sheet (positive electrode), and separator in each embodiment are assembled into a button cell. After standing for 3 hours, the cell is tested on the Blue Battery system. Lithium insertion is performed at a constant current of 0.05C until the cutoff voltage is 5mV. The specific capacity of lithium insertion at this time is recorded as C0. After standing for 5 minutes, lithium extraction is performed at a constant current of 0.05C until the cutoff voltage is 2.0V. The specific capacity of lithium extraction at this time is recorded as C1. The initial coulombic efficiency = C1 / C0*100%.

[0061] Cycle life test: The secondary batteries prepared in each embodiment were charged at a constant current of 1C to the rated charging voltage, then charged at a constant voltage to a current of 0.05C, allowed to stand for 10 minutes, and then discharged at a constant current of 1C to the rated discharge voltage. The initial capacity was recorded as C0. Then, the batteries were charged at a constant current of 1C0 to the rated charging voltage, then charged at a constant voltage to a current of 0.05C, allowed to stand for 10 minutes, and then discharged at 1C0. The discharge capacity Cn of each cycle was recorded until the cycle capacity retention rate (Cn / C0×100%) reached 80%. The number of cycles was recorded. The more cycles, the higher the cycle life of the battery. The results of the initial coulombic efficiency test and the cycle life test are shown in Table 2.

[0062] Comparative Examples 1-5

[0063] Comparative Examples 1-5 provide a silicon-based battery anode material, comprising an anode active material, a conductive agent, and a binder. The mass percentages of silicon and carbon materials in the anode active material are shown in Table 2. The carbon material is artificial graphite, the silicon material is silicon-carbon, the conductive agent is a mixture of carbon black and single-walled carbon nanotubes, and the binder is polyacrylic acid. The volumetric particle size distribution (Dv50), Dvmax, (Dvmax-Dvmin) / Dv50, specific surface area, (Dvmax-Dvmin) / Dv50, and tap density of the carbon material are as listed in Table 1. The volumetric particle size distribution (Dv50), Dvmax, specific surface area, and (Dvmax-Dvmin) / Dv50 of the silicon material are also as listed in Table 1.

[0064] Each comparative example also provides a secondary battery, which includes a negative electrode, a positive electrode, and a separator disposed between the negative electrode and the positive electrode. The negative electrode is made of the silicon-based battery negative electrode material in this comparative example. The preparation method of the secondary battery is the same as that in Examples 1 to 10.

[0065] Performance testing:

[0066] The secondary battery in this comparative example underwent performance testing, including an initial coulombic efficiency test and a cycle life test. The specific steps and methods were the same as those in Examples 1-10, and will not be repeated here. The results of the initial coulombic efficiency test and the cycle life test are shown in Table 2.

[0067] Table 1. Parameters of the negative electrode active materials in Examples 1-10 and Comparative Examples 1-5

[0068]

[0069]

[0070] Table 2 shows the initial coulombic efficiency test and cycle life test results of the secondary batteries in Examples 1-10 and Comparative Examples 1-5.

[0071]

[0072]

[0073] As can be seen from the comparison between Example 6 and Comparative Example 3, when the amount of silicon material added is too large, the initial coulombic efficiency and cycle performance of the battery will drop sharply.

[0074] A comparison of Comparative Example 1 and Example 3 shows that when the Dv50 of the carbon material is not within the range defined in this application, (Dvmax-Dvmin) / Dv50 is also not within the defined range; thus, the initial coulombic efficiency and cycle performance of the battery will also decrease.

[0075] By comparing Comparative Example 2 and Example 8, it can be seen that when the Dvmax of the carbon material is not within the range defined in this application, the specific surface area of ​​the carbon material is also not within the defined range, which leads to a decrease in the first coulombic efficiency and cycle performance of the battery.

[0076] By comparing Comparative Example 4 and Example 9, it can be seen that when the content of silicon material in the negative electrode active material is 10wt% < 30wt%, the corresponding carbon material volume particle size distribution does not meet the following condition: 1.2 < (Dvmax - Dvmin) / Dv50 ≤ 3, which will result in a low stacking efficiency of silicon particles in the electrode and uneven distribution of the negative electrode active material; silicon particles tend to form large agglomerates, and silicon clusters cause local stress hot spots in the electrode, leading to material expansion and damage, and affecting the continuity of electron and ion transport.

[0077] As shown in Comparative Example 5, when the negative electrode active material includes 0.1wt% to 10wt% silicon material, the corresponding carbon material's volume particle size distribution does not meet the following condition: 0.5≤(Dvmax-Dvmin) / Dv50≤1.2, which will reduce the initial coulombic efficiency of the secondary battery.

[0078] In summary, the silicon-based battery anode material of this invention includes an active anode material, which comprises carbon and silicon materials. By controlling the amount of silicon material added and the particle size and distribution of the carbon material, a suitable active anode material is obtained, thereby improving the initial coulombic efficiency of the secondary battery. Using the silicon-based battery anode material of this invention to form a secondary battery ensures its lifespan during long-term charging, significantly improving its cycle life. Furthermore, the selection of secondary battery materials according to this invention allows for the rapid determination of silicon-based battery anode materials, greatly reducing research and development time. Therefore, this invention effectively overcomes the various shortcomings of existing technologies and has high industrial application value.

[0079] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the invention. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in the present invention should still be covered by the claims of the present invention.

Claims

1. A silicon-based battery anode material, characterized in that, The negative electrode material includes: a negative electrode active material, a conductive agent, and a binder; The negative electrode active material includes carbon material and silicon material; based on the mass percentage of the negative electrode active material, the negative electrode active material includes 0.1wt% to 30wt% silicon material, with the balance being carbon material; The volumetric particle size distribution of the carbon material satisfies the following condition: 0.5 ≤ (Dvmax - Dvmin) / Dv50 ≤ 3; where Dvmax is the particle size corresponding to a cumulative volumetric particle size distribution percentage of 99% for the carbon material, and Dvmin is the particle size corresponding to a cumulative volumetric particle size distribution percentage of less than 1% for the carbon material; the volumetric particle size distribution Dv50 of the carbon material is 3 μm to 25 μm, and the volumetric particle size distribution Dvmax ≤ 48 μm for the carbon material, where Dv50 is the particle size corresponding to a cumulative volumetric particle size distribution percentage of 50% for the carbon material; The volumetric particle size distribution Dv50 of the silicon material is 3μm~8μm, and the volumetric particle size distribution Dvmax of the silicon material is ≤15μm; wherein, Dv50 of the silicon material is the particle size corresponding to when the cumulative volumetric distribution percentage of the silicon material reaches 50%, and Dvmax is the particle size corresponding to when the cumulative volumetric distribution percentage of the silicon material reaches 99%. Based on the mass percentage of the negative electrode active material, when the negative electrode active material includes 0.1wt% to 10wt% silicon material, the volume particle size distribution of the carbon material satisfies the following condition: 0.5≤(Dvmax-Dvmin) / Dv50≤1.2; or; Based on the mass percentage of the negative electrode active material, when the content of silicon material is 10wt% < 30wt% in the negative electrode active material, the volume particle size distribution of the carbon material satisfies the following condition: 1.2 < (Dvmax - Dvmin) / Dv50 ≤ 3.

2. The silicon-based battery anode material according to claim 1, characterized in that: The carbon material includes one or more of the following conditions: The specific surface area of ​​the carbon material is 0.5 m². 2 / g~18m 2 / g; The tap density of the carbon material is 0.6 g / cm³. 3 ~1.4g / cm 3 .

3. The silicon-based battery anode material according to claim 1, characterized in that: The specific surface area of ​​the silicon material is 1.5 m². 2 / g~2.2m 2 / g.

4. The silicon-based battery anode material according to claim 1, characterized in that: The volumetric particle size distribution of the silicon material satisfies the following condition: 1.1≤(Dvmax-Dvmin) / Dv50≤2.6; where Dvmax is the particle size corresponding to a cumulative volumetric distribution percentage of 99% for the silicon material, and Dvmin is the particle size corresponding to a cumulative volumetric distribution percentage of less than 1% for the silicon material.

5. A secondary battery, the secondary battery comprising a negative electrode, a positive electrode, and a separator disposed between the negative electrode and the positive electrode, characterized in that, The negative electrode is prepared from any one of the silicon-based battery negative electrode materials described in claims 1 to 4.

Images