Electrode material preparation method, battery negative electrode sheet, and sodium ion battery
By preparing a hollow carbon-encapsulated cobalt-doped nickel tetraselenide electrode material, the problem of structural collapse of sodium-ion battery anode materials during charge and discharge was solved, and the stability and cycle performance were improved. The method is simple and low in cost.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- GUANGDONG ELECTRIC POWER DEV CO LTD
- Filing Date
- 2024-03-27
- Publication Date
- 2026-05-15
AI Technical Summary
The existing sodium-ion battery anode material Ni3Se4 suffers from poor stability and cycle performance due to the large volume change of Na+ ions during charging and discharging, which makes the structure prone to collapse.
The carbon-encapsulated cobalt-doped nickel tetraselenide (Co/Ni3Se4) electrode material is prepared with a hollow structure. By grinding the hollow LDH structure with selenium powder and then selenizing it, an electrode material with a hollow frame is formed, which buffers the stress and structural collapse caused by volume changes.
It improves the stability and cycle performance of sodium-ion batteries, exhibiting good rate performance and capacity retention, while the preparation method is simple, low-cost, and yields high output.
Smart Images
Figure CN118405667B_ABST
Abstract
Description
Technical Field
[0001] This application belongs to the field of composite material preparation technology, and particularly relates to electrode material preparation methods, battery negative electrode sheets and sodium-ion batteries. Background Technology
[0002] Lithium-ion batteries (LIBs) have advantages such as long lifespan, environmental friendliness, and no memory effect, and are widely used in smart electronic devices and electric vehicles. However, current lithium-ion batteries face many challenges, such as limited capacity, poor rate capability, and the limitation of asymmetrical lithium resource distribution. Sodium-ion batteries (SIBs) are considered ideal candidate materials for lithium-ion batteries due to their abundant sodium resources and similar ion storage mechanism. However, due to the large radius of sodium ions (…),… The slow reaction kinetics of the anode material still hinders the development of SIBs.
[0003] Compared to metal sulfides and oxides, metal selenides exhibit higher conductivity, and the M-Se bond is weaker than the MS bond, which is beneficial for the conversion reaction. Therefore, metal selenides can be considered very promising anode materials. Ni3Se4 has a large lattice spacing, which facilitates sodium ion insertion and stripping without causing excessive damage to the material structure, making it an excellent anode material for sodium-ion batteries.
[0004] However, there are currently few reports on Ni3Se4 in sodium-ion batteries, mainly because its synthesis is quite difficult; generally, NiSe and NiSe2 are synthesized instead. Furthermore, the material's structure significantly impacts its performance. Na+ ions are relatively large, leading to significant volume changes during charge and discharge, and the electrode material structure is prone to collapse, resulting in poor stability and ultimately reduced cycle performance. Summary of the Invention
[0005] This application provides an electrode material preparation method, a battery negative electrode sheet, and a sodium-ion battery to overcome the stress and structural collapse problems caused by sodium ion volume changes, accelerate sodium ion insertion and stripping, and ensure stability and cycle performance.
[0006] This application is achieved through the following technical solution:
[0007] In a first aspect, embodiments of this application provide a method for preparing an electrode material, including:
[0008] Dimethylimidazole and cobalt salt were dissolved in a solvent and stirred, followed by centrifugation, washing and drying to obtain the ZIF-67 purple sample.
[0009] The ZIF-67 purple sample was dispersed in a mixed solution of ethanol and deionized water, and tris(hydroxymethyl)aminomethane was added. After the tris(hydroxymethyl)aminomethane was completely dissolved, dopamine hydrochloride was added. Then, the mixture was stirred, centrifuged, washed, and dried to obtain the precursor.
[0010] The precursor was uniformly dispersed in an ethanol solution, and a nickel salt solution was added and stirred. Then, the mixture was filtered and dried to obtain a hollow LDH structure.
[0011] Hollow LDH structures are ground evenly with selenium powder and placed in a reaction vessel. Selenization is then carried out under the first preset conditions to obtain electrode materials.
[0012] In conjunction with the first aspect, in some possible implementations, dimethylimidazole and cobalt salt are dissolved in a solvent and stirred, followed by centrifugation, washing, and drying to obtain a ZIF-67 purple sample, including:
[0013] Dimethylimidazole was dissolved in methanol to obtain a first solution; wherein each 13.14 g of dimethylimidazole corresponds to 500 ml of methanol.
[0014] The cobalt salt was dissolved in methanol to obtain a second solution; wherein the cobalt salt was cobalt nitrate hexahydrate, and each 11.64 g of cobalt nitrate hexahydrate corresponded to 500 ml of methanol.
[0015] Add the first solution to the second solution and stir for at least 2 hours, then let stand for at least 2 hours.
[0016] Centrifugation and washing were performed sequentially, and the samples were dried in a forced-air drying oven at 30°C to 60°C for 12 to 24 hours to obtain ZIF-67 purple samples.
[0017] In conjunction with the first aspect, in some possible implementations, the ZIF-67 purple sample is dispersed in a mixed solution of ethanol and deionized water, tris(hydroxymethyl)aminomethane is added, and after the tris(hydroxymethyl)aminomethane is completely dissolved, dopamine hydrochloride is added. Following this, stirring, centrifugation, washing, and drying are performed to obtain the precursor, comprising:
[0018] The ZIF-67 purple sample was dispersed in a mixed solution of ethanol and deionized water with a volume ratio of 1:1.
[0019] Add tris(hydroxymethyl)aminomethane and stir for at least 2 hours.
[0020] After the tris(hydroxymethyl)aminomethane is completely dissolved, dopamine hydrochloride is added; wherein the concentration of the dissolved tris(hydroxymethyl)aminomethane is 1-2 mmol / 200 ml.
[0021] The precursor is obtained by stirring, centrifuging, washing and drying.
[0022] In conjunction with the first aspect, in some possible implementations, the mass ratio of dopamine hydrochloride to the ZIF-67 purple sample is 1:2.
[0023] In conjunction with the first aspect, in some possible implementations, the precursor is uniformly dispersed in an ethanol solution, a nickel salt solution is added thereto and stirred, including:
[0024] The precursor was uniformly dispersed in an ethanol solution to obtain a third solution.
[0025] Add the nickel salt solution to the third solution and stir for 1 to 6 hours; wherein the nickel salt solution is nickel nitrate hexahydrate solution.
[0026] In conjunction with the first aspect, in some possible implementations, filtration and drying operations are performed to obtain a hollow LDH structure, including:
[0027] The mixture was filtered and washed with ethanol, then dried in a forced-air drying oven at 30°C to 60°C for 12 to 24 hours to obtain a hollow LDH structure.
[0028] In conjunction with the first aspect, in some possible implementations, the hollow LDH structure is ground uniformly with selenium powder and placed in a reaction vessel, where selenization is performed under first preset conditions to obtain an electrode material, including:
[0029] Hollow LDH structures are ground evenly with selenium powder and placed in a ceramic boat. The reaction is carried out at a temperature of 300–800°C for 1 to 6 hours with an inert gas purging to obtain the electrode material.
[0030] In conjunction with the first aspect, in some possible implementations, the mass ratio of hollow LDH structure to selenium powder ranges from 1:1 to 1:1.5.
[0031] Secondly, embodiments of this application provide a battery negative electrode sheet, wherein the active material of the battery negative electrode sheet is an electrode material prepared by the preparation method described in any one of the first aspects.
[0032] Thirdly, embodiments of this application provide a sodium-ion battery, including the battery negative electrode sheet as described in the second aspect.
[0033] It is understood that the beneficial effects of the second and third aspects mentioned above can be found in the relevant descriptions in the first aspect mentioned above, and will not be repeated here.
[0034] The beneficial effects of the embodiments in this application compared with the prior art are:
[0035] The carbon-encapsulated cobalt-doped nickel tetraselenide (Co / Ni3Se4) electrode material prepared in this application has a hollow structure, which can mitigate the problem of excessive volume expansion during sodium insertion and extraction of metal phosphides. Using this material as the anode material for sodium-ion batteries exhibits excellent cycle performance and rate capability, and also improves the stability of sodium-ion batteries. Furthermore, this method is simpler than traditional preparation methods, yields a pure phase, and is low-cost, high-yield, and highly efficient.
[0036] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and are not intended to limit this specification. Attached Figure Description
[0037] To more clearly illustrate the technical solutions in the embodiments of this application, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0038] Figure 1 This is a schematic flowchart of an embodiment of the electrode material preparation method provided in this application;
[0039] Figure 2 This is an XRD pattern of the electrode material prepared by the method according to an embodiment of this application;
[0040] Figure 3 This is a TEM image of the electrode material prepared by the method according to an embodiment of this application;
[0041] Figure 4 This is a rate performance diagram of a sodium-ion battery at different current densities, using the electrode material prepared by this method as the negative electrode material according to an embodiment of this application.
[0042] Figure 5 This is a graph showing the long-cycle performance of an electrode material prepared by the method provided in an embodiment of this application as a negative electrode material in a sodium-ion battery with a current density of 1 A / g. Detailed Implementation
[0043] In the following description, specific details such as particular system architectures and techniques are set forth for illustrative purposes and not for limitation, in order to provide a thorough understanding of the embodiments of this application. However, those skilled in the art will understand that this application may also be implemented in other embodiments without these specific details. In other instances, detailed descriptions of well-known systems, apparatuses, circuits, and methods have been omitted so as not to obscure the description of this application with unnecessary detail.
[0044] It should be understood that, when used in this application specification and the appended claims, the term "comprising" indicates the presence of the described features, integrals, steps, operations, elements and / or components, but does not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components and / or a collection thereof.
[0045] It should also be understood that the term “and / or” as used in this application specification and the appended claims means any combination of one or more of the associated listed items and all possible combinations, and includes such combinations.
[0046] As used in this application specification and the appended claims, the term "if" may be interpreted, depending on the context, as "when," "once," "in response to determination," or "in response to detection." Similarly, the phrase "if determined" or "if detected [the described condition or event]" may be interpreted, depending on the context, as meaning "once determined," "in response to determination," "once detected [the described condition or event]," or "in response to detection [the described condition or event]."
[0047] Furthermore, in the description of this application and the appended claims, the terms "first," "second," "third," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.
[0048] References to "one embodiment" or "some embodiments" as described in this specification mean that one or more embodiments of this application include a specific feature, structure, or characteristic described in connection with that embodiment. Therefore, the phrases "in one embodiment," "in some embodiments," "in other embodiments," "in still other embodiments," etc., appearing in different parts of this specification do not necessarily refer to the same embodiment, but rather mean "one or more, but not all, embodiments," unless otherwise specifically emphasized. The terms "comprising," "including," "having," and variations thereof mean "including but not limited to," unless otherwise specifically emphasized.
[0049] Na+ ions are relatively large, which can lead to problems such as large volume changes and easy collapse of electrode material structure during charging and discharging, resulting in poor stability and ultimately reduced cycle performance.
[0050] To address the aforementioned issues, the electrode material preparation method in this application involves fabricating the electrode material into a hollow structure, thereby ensuring stability and cycling performance. The hollow structure effectively buffers stress and structural collapse caused by volume changes. Furthermore, its internal hollowness allows for more rapid insertion and removal of Na+ ions, thus resolving the poor cycling performance.
[0051] Figure 1 This is a schematic flowchart of an embodiment of the electrode material preparation method provided in this application, with reference to... Figure 1 The preparation method of this electrode material is described in detail below:
[0052] Step 101: Dissolve dimethylimidazole and cobalt salt in a solvent and stir, then centrifuge, wash and dry to obtain ZIF-67 purple sample.
[0053] For example, step 101 may include:
[0054] Dimethylimidazole was dissolved in methanol to obtain a first solution; wherein each 13.14 g of dimethylimidazole corresponds to 500 ml of methanol.
[0055] The cobalt salt was dissolved in methanol to obtain a second solution; wherein the cobalt salt was cobalt nitrate hexahydrate, and each 11.64 g of cobalt nitrate hexahydrate corresponded to 500 ml of methanol.
[0056] Add the first solution to the second solution and stir for at least 2 hours, then let stand for at least 2 hours.
[0057] Centrifugation and washing were performed sequentially, and the samples were dried in a forced-air drying oven at 30°C to 60°C for 12 to 24 hours to obtain ZIF-67 purple samples.
[0058] Specifically, the sample is first centrifuged, then washed with methanol, and finally dried in a forced-air drying oven at 30°C to 60°C for 12 to 24 hours to obtain the ZIF-67 purple sample.
[0059] Specifically, the first solution is added to the second solution and stirred for at least 2 hours, and then left to stand for at least 2 hours to ensure that the solution reacts fully and facilitates subsequent centrifugation.
[0060] Step 102: Disperse the ZIF-67 purple sample in a mixed solution of ethanol and deionized water, add tris(hydroxymethyl)aminomethane, and after the tris(hydroxymethyl)aminomethane is completely dissolved, add dopamine hydrochloride. Then, stir, centrifuge, wash and dry to obtain the precursor.
[0061] For example, step 102 may include:
[0062] The ZIF-67 purple sample was dispersed in a mixed solution of ethanol and deionized water with a volume ratio of 1:1.
[0063] Add tris(hydroxymethyl)aminomethane and stir for at least 2 hours.
[0064] After the tris(hydroxymethyl)aminomethane is completely dissolved, dopamine hydrochloride is added; wherein the concentration of the dissolved tris(hydroxymethyl)aminomethane is 1-2 mmol / 200 ml.
[0065] The precursor is obtained by stirring, centrifuging, washing and drying.
[0066] For example, the mass ratio of dopamine hydrochloride to the ZIF-67 purple sample was 1:2.
[0067] Step 103: The precursor is uniformly dispersed in an ethanol solution, a nickel salt solution is added and stirred, followed by filtration and drying to obtain a hollow LDH structure.
[0068] For example, the precursor is uniformly dispersed in an ethanol solution, a nickel salt solution is added thereto and stirred, including:
[0069] The precursor was uniformly dispersed in an ethanol solution to obtain a third solution.
[0070] Add the nickel salt solution to the third solution and stir for 1 to 6 hours; wherein the nickel salt solution is nickel nitrate hexahydrate solution.
[0071] For example, a vacuum filtration and drying process is performed to obtain a hollow LDH structure, comprising:
[0072] The mixture was filtered and washed with ethanol, then dried in a forced-air drying oven at 30°C to 60°C for 12 to 24 hours to obtain a hollow LDH structure.
[0073] Step 104: After grinding the hollow LDH structure and selenium powder evenly, place them in a reaction vessel and perform selenization under the first preset conditions to obtain the electrode material.
[0074] Specifically, the electrode material generated according to steps 101-104 is a carbon-encapsulated cobalt-doped nickel tetraselenide electrode material (Co / Ni3Se4). This electrode material has a hollow structure with a frame size of 500-800 nanometers and a wall thickness of approximately 10-50 nanometers.
[0075] For example, step 104 may include:
[0076] Hollow LDH structures are ground evenly with selenium powder and placed in a ceramic boat. The reaction is carried out at a temperature of 300–800°C for 1 to 6 hours with an inert gas purging to obtain the electrode material.
[0077] For example, the mass ratio of hollow LDH structure to selenium powder ranges from 1:1 to 1:1.5.
[0078] Specifically, the selenization process ensures the structural stability of the hollow structure, and the carbonization after dopamine encapsulation to obtain a carbon layer is crucial for battery performance. The hollow structure overcomes the problem of structural collapse caused by volume expansion during the charge and discharge of metal selenide electrode materials in sodium-ion batteries. Metal composites are beneficial for increasing the heterojunction interface and promoting the driving force for ion migration within the electrode phase. This material was used for the first time as the anode material in a sodium-ion battery, achieving a capacity of 290 mAh / g at a current of 5 A / g, and maintaining a capacity of 240 mAh / g after 300 cycles at a current of 1 A / g, demonstrating excellent cycle performance and rate performance.
[0079] The electrode material prepared by the above method produces a carbon-encapsulated cobalt-doped nickel tetraselenide (Co / Ni3Se4) electrode material with a hollow structure, which can mitigate the problem of excessive volume expansion during sodium insertion and extraction of metal phosphides. Using this material as the anode material for sodium-ion batteries exhibits excellent cycle performance and rate capability, and also improves the stability of sodium-ion batteries. Furthermore, this method is simpler than traditional preparation methods, yields a pure phase, and is low-cost, high-yield, and highly efficient.
[0080] For ease of understanding, this application provides specific embodiments for preparing carbon-encapsulated cobalt-doped nickel tetraselenide electrode materials (Co / Ni3Se4):
[0081] Two 500ml portions of methanol were measured separately. 11.64g of cobalt nitrate hexahydrate was weighed and mixed thoroughly with 500ml of methanol in beaker 1 to obtain a purple-pink solution, which was designated solution A. Separately, 13.14g of dimethylimidazole was weighed and mixed thoroughly with 500ml of methanol in beaker 2 to obtain a clear solution, designated solution B. Solution A was added to solution B, and the mixture was stirred for 12 hours. After standing for 12 hours, it was centrifuged, washed, and dried in a 60℃ oven for 12–24 hours to obtain the ZIF-67 purple sample.
[0082] 0.3 g of the purple ZIF-67 sample was dispersed in 100 ml of a 1:1 mixture of ethanol and deionized water until homogeneous. 0.121 g of tris(hydroxymethyl)aminomethane (Tris) was weighed and added to the above solution, and the mixture was stirred for 2 hours. 0.15 g of dopamine hydrochloride (DAH) was then added to obtain the blackish-gray precursor ZIF-67@DHA.
[0083] 0.3 g of ZIF-67@DHA was dispersed in 50 ml of ethanol, denoted as solution C; 0.34 g of nickel nitrate hexahydrate was dissolved in 50 ml of ethanol, denoted as solution D. After stirring evenly, solution D was added to solution C, and after stirring for 2 hours, the mixture was filtered and washed three times with ethanol. It was then dried in a 60°C oven for 12–24 hours to obtain hollow LDH structure CoNi-LDH@DHA.
[0084] 0.1g of the prepared hollow LDH structure CoNi-LDH@DHA and 0.1g of selenium powder (Se) were ground evenly in a mortar and then placed in a porcelain boat or tubular furnace. After heating at 700℃ for 3 hours under an Ar gas flow, the electrode material Co / Ni3Se4@NC was obtained.
[0085] like Figure 1 The image shows the XRD pattern of Co / Ni3Se4@NC prepared in this embodiment. Comparison with the standard card shows that the diffraction peaks of the synthesized material are completely consistent with those of Ni3Se4 (PDF#18-0890), indicating that Ni3Se4 has been synthesized. It is evident from the image that the Ni3Se4 peaks have shifted to the right, indicating the presence of the Co phase.
[0086] like Figure 2 As shown, transmission electron microscopy (TEM) reveals that the above method successfully prepared the hollow electrode material Co / Ni3Se4@NC.
[0087] The electrode material in the example was ground into powder, and Super P, sodium alginate and deionized water were added and ground into a slurry. The slurry was coated onto copper foil, and the battery was installed in a glove box. The sodium-ion battery cycle performance was tested using the Blue Electric System.
[0088] like Figure 3 As shown in the figure, the cycling performance of the Co / Ni3Se4@NC prepared in the example is shown at different current densities. It can be seen from the figure that the Co / Ni3Se4@NC has excellent performance at different current densities, exhibiting excellent rate performance.
[0089] like Figure 4 As shown in the figure, the Co / Ni3Se4@NC composite material prepared in the example has good cycling performance at a current of 1A / g. It can be seen that Co / Ni3Se4@NC has good cycling stability, indicating that the hollow structure with carbon coating helps to improve the conductivity of the material and alleviate the problem of volume expansion during cycling.
[0090] This application also provides a battery negative electrode sheet, wherein the active material of the battery negative electrode sheet is an electrode material prepared by any of the preparation methods described above.
[0091] This application also provides a sodium-ion battery, including the aforementioned battery negative electrode sheet.
[0092] It should be understood that the sequence number of each step in the above embodiments does not imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this application.
[0093] The above-described embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application, and should all be included within the protection scope of this application.
Claims
1. A method for preparing an electrode material, characterized in that, include: Dimethylimidazole and cobalt salt were dissolved in a solvent and stirred, followed by centrifugation, washing and drying to obtain the ZIF-67 purple sample; The ZIF-67 purple sample was dispersed in a mixed solution of ethanol and deionized water, and tris(hydroxymethyl)aminomethane was added. After the tris(hydroxymethyl)aminomethane was completely dissolved, dopamine hydrochloride was added. Then, the mixture was stirred, centrifuged, washed and dried to obtain the precursor. The precursor was uniformly dispersed in an ethanol solution, a nickel salt solution was added and stirred, and then filtered and dried to obtain a hollow LDH structure. The hollow LDH structure is ground evenly with selenium powder and placed in a reaction vessel. Selenization is carried out under the first preset conditions to obtain the electrode material.
2. The electrode material preparation method according to claim 1, characterized in that, The process involves dissolving dimethylimidazole and cobalt salt in a solvent and stirring, followed by centrifugation, washing, and drying to obtain a ZIF-67 purple sample, comprising: Dimethylimidazole was dissolved in methanol to obtain the first solution; wherein, each 13.14 g of dimethylimidazole corresponds to 500 ml of methanol. The cobalt salt is dissolved in methanol to obtain a second solution; wherein the cobalt salt is cobalt nitrate hexahydrate, and each 11.64 g of cobalt nitrate hexahydrate corresponds to 500 ml of methanol solvent; Add the first solution to the second solution and stir for at least 2 hours, then let stand for at least 2 hours; The samples were centrifuged and washed sequentially, and then dried in a forced-air drying oven at 30°C to 60°C for 12 to 24 hours to obtain the ZIF-67 purple sample.
3. The electrode material preparation method according to claim 1, characterized in that, The ZIF-67 purple sample was dispersed in a mixed solution of ethanol and deionized water, and tris(hydroxymethyl)aminomethane was added. After the tris(hydroxymethyl)aminomethane was completely dissolved, dopamine hydrochloride was added. The mixture was then stirred, centrifuged, washed, and dried to obtain the precursor, comprising: The ZIF-67 purple sample was dispersed in a mixed solution of ethanol and deionized water with a volume ratio of 1:
1. Add the tris(hydroxymethyl)aminomethane and stir for at least 2 hours; After the tris(hydroxymethyl)aminomethane is completely dissolved, dopamine hydrochloride is added; wherein the concentration of the dissolved tris(hydroxymethyl)aminomethane is 1-2 mmol / 200 ml; The precursor is obtained by stirring, centrifuging, washing and drying.
4. The electrode material preparation method according to claim 1, characterized in that, The mass ratio of dopamine hydrochloride to the ZIF-67 purple sample is 1:
2.
5. The electrode material preparation method according to claim 1, characterized in that, The step of uniformly dispersing the precursor in an ethanol solution, adding a nickel salt solution therein, and stirring includes: The precursor was uniformly dispersed in an ethanol solution to obtain a third solution; A nickel salt solution is added to the third solution and stirred for 1 to 6 hours; wherein the nickel salt solution is a nickel nitrate hexahydrate solution.
6. The method for preparing electrode material according to claim 1, characterized in that, The process of filtration and drying yields a hollow LDH structure, including: The material was filtered and washed with ethanol, then dried in a forced-air drying oven at 30°C to 60°C for 12 to 24 hours to obtain the hollow LDH structure.
7. The method for preparing electrode material according to claim 1, characterized in that, The hollow LDH structure is ground evenly with selenium powder and placed in a reaction vessel, where it is selenized under first preset conditions to obtain the electrode material, comprising: The hollow LDH structure is ground evenly with selenium powder and placed in a ceramic boat. The reaction is carried out at a temperature of 300-800℃ with an inert gas for 1 to 6 hours to obtain the electrode material.
8. The method for preparing electrode material as described in claim 1, characterized in that, Among them The mass ratio of the hollow LDH structure to the selenium powder ranges from 1:1 to 1:1.
5.
9. A battery negative electrode sheet, characterized in that, The active material of the battery negative electrode sheet is an electrode material prepared by the preparation method according to any one of claims 1 to 8.
10. A sodium-ion battery, characterized in that, The sodium-ion battery includes the negative electrode sheet as described in claim 9.