A sodium-ion battery negative electrode material, a preparation method thereof, and a negative electrode sheet and a sodium-ion secondary battery comprising the negative electrode material
Hard carbon materials were prepared by pre-oxidation and carbonization of biomass sulfonated lignin and pitch, which solved the problems of low carbon production rate and insufficient sodium storage capacity of sodium-ion battery electrode materials, thereby improving battery performance and reducing costs.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- CHINA PETROLEUM & CHEMICAL CORP
- Filing Date
- 2023-10-18
- Publication Date
- 2026-06-16
AI Technical Summary
The electrochemical performance and production cost of existing sodium-ion batteries are mainly limited by the development of electrode materials. Biomass and asphalt, as precursors, have problems with low carbon production rate and insufficient sodium storage capacity.
Hard carbon materials are prepared by mixing biomass sulfonated lignin with asphalt and then performing pre-oxidation and carbonization treatments, which improves carbon production rate and enhances the reversible capacity and cycle stability of batteries.
This improves the reversible capacity and cycle stability of sodium-ion batteries, reduces production costs, and offers better economic benefits.
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Figure CN119841300B_ABST
Abstract
Description
Technical Field
[0001] This disclosure relates to the field of sodium-ion battery anode material technology, specifically to a sodium-ion battery anode material and its preparation method, as well as an anode electrode sheet containing the anode material and a sodium-ion secondary battery. Background Technology
[0002] Sodium is abundant and relatively inexpensive, making it a suitable complement to lithium-ion batteries in large-scale energy storage systems. However, the electrochemical performance and production cost of sodium-ion batteries are primarily limited by the development of electrode materials; therefore, the rational design of electrode material structures is a crucial research area.
[0003] Biomass is a suitable precursor for sodium storage materials due to its natural porous structure, large interlayer spacing, and high sodium storage capacity, but its carbon yield is relatively low. Asphalt, as a petrochemical product, is abundant, low in cost, and has a high carbon yield, but after calcination, it produces soft carbon with a low sodium storage capacity. Summary of the Invention
[0004] The purpose of this disclosure is to provide a sodium-ion battery anode material and its preparation method, as well as an anode sheet containing the anode material and a sodium-ion secondary battery. The method has a simple process, low raw material cost, and can effectively improve carbon production rate, improve the reversible capacity and cycle stability of the battery, thus having better economic benefits.
[0005] To achieve the above objectives, the first aspect of this disclosure provides a method for preparing a sodium-ion battery anode material, the method comprising the following steps:
[0006] S1: After mixing the biomass precursor with asphalt, the mixture is placed in an oxygen-containing atmosphere for pre-oxidation treatment to obtain a pre-oxidized precursor.
[0007] S2: The pre-oxidized precursor is carbonized under an inert atmosphere;
[0008] In S1, the pre-oxidation treatment conditions include: a temperature of 150–350°C and a time of 12–48 h; the biomass precursor includes sulfonated lignin; in S2, the carbonization treatment conditions include: a carbonization temperature of 1000–1600°C and a carbonization time of 1–6 h.
[0009] Optionally, in S1, the pre-oxidation treatment conditions include: a temperature of 200–300°C and a time of 20–30 h; the oxygen volume fraction in the oxygen-containing atmosphere is 21% or more.
[0010] Optionally, in S1, the sulfonated lignin is selected from one or more of sodium lignin sulfonate, calcium lignin sulfonate, and magnesium lignin sulfonate; the asphalt is selected from one or more of natural asphalt, petroleum asphalt, sulfonated asphalt, and coal tar.
[0011] The mass ratio of the biomass precursor to the asphalt is 1:(0.1-9), preferably 1:(0.2-5).
[0012] Optionally, in S2, the carbonization conditions include: a carbonization temperature of 1200–1600°C and a carbonization time of 2–4 hours.
[0013] The carbonization process is carried out under an inert atmosphere, which includes one or more of nitrogen, helium, and argon; the flow rate of the inert atmosphere is 50-300 mL / min, preferably 50-150 mL / min.
[0014] Optionally, the method further includes: sequentially acid washing, water washing and drying of the carbonized product.
[0015] Optionally, the pickling includes mixing the carbonized product with an inorganic acid; the inorganic acid is selected from hydrochloric acid, sulfuric acid, and acetic acid; the concentration of the inorganic acid is 1-12 mol / L, preferably 4-12 mol / L.
[0016] Optionally, the washing process includes washing the acid-washed product with water until the pH of the filtrate is 6.5 to 7.5, followed by filtration, and drying the filtered solid.
[0017] The drying process is carried out at a temperature of 80–110°C for 12–24 hours.
[0018] The second aspect of this disclosure provides a sodium-ion battery anode material prepared by the method described in the first aspect of this disclosure.
[0019] Optionally, the oxygen content of the negative electrode material is 1-25 wt%.
[0020] The third aspect of this disclosure provides a sodium-ion battery negative electrode sheet, the negative electrode sheet comprising: a current collector, a binder, and the sodium-ion battery negative electrode material described in the second aspect of this disclosure.
[0021] This disclosure provides a fourth aspect of a sodium-ion secondary battery, comprising the negative electrode, positive electrode, electrolyte, and separator between the positive electrode and the negative electrode as described in the third aspect of this disclosure.
[0022] The positive electrode is one of sodium manganate, sodium cobaltate, sodium vanadium phosphate, or sodium iron phosphate.
[0023] Through the above technical solution, the method disclosed herein uses low-cost sulfonated lignin as a precursor for sodium storage materials. By mixing biomass sulfonated lignin with pitch and subjecting it to pre-oxidation and carbonization treatment, a cross-linking reaction between biomass molecules and pitch molecules is promoted to obtain hard carbon materials. This preparation method can improve the carbon yield of the precursor, and the prepared negative electrode material can improve the reversible capacity and cycle stability of sodium-ion batteries. The method disclosed herein is simple in process, has low raw material costs, and offers better economic benefits.
[0024] Other features and advantages of this disclosure will be described in detail in the following detailed description section. Attached Figure Description
[0025] The accompanying drawings are provided to further illustrate the present disclosure and form part of the specification. They are used together with the following detailed description to explain the present disclosure, but do not constitute a limitation thereof. In the drawings:
[0026] Figure 1 This is the XRD pattern of the negative electrode material in Embodiment 1 of this disclosure.
[0027] Figure 2 This is a charge-discharge curve of the negative electrode material in Embodiment 1 of this disclosure for the first three weeks. Detailed Implementation
[0028] The specific embodiments of this disclosure will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustration and explanation only and are not intended to limit this disclosure.
[0029] The first aspect of this disclosure provides a method for preparing a sodium-ion battery anode material, the method comprising the following steps:
[0030] S1: After mixing the biomass precursor with asphalt, the mixture is placed in an oxygen-containing atmosphere for pre-oxidation treatment to obtain a pre-oxidized precursor.
[0031] S2: The pre-oxidized precursor is carbonized under an inert atmosphere;
[0032] In S1, the pre-oxidation treatment conditions include: a temperature of 150–350°C and a time of 12–48 h; the biomass precursor includes sulfonated lignin; in S2, the carbonization treatment conditions include: a carbonization temperature of 1000–1600°C and a carbonization time of 1–6 h.
[0033] The method disclosed herein uses inexpensive sulfonated lignin to mix with pitch, and performs pre-oxidation treatment in an oxygen-containing atmosphere at a specific temperature. After the hard carbon precursor and soft carbon precursor are introduced with oxygen-containing functional groups through pre-oxidation treatment, they undergo cross-linking reaction, avoiding the occurrence of the soft carbon precursor in a molten state. Then, carbonization treatment is carried out under specific conditions to obtain hard carbon material, which improves the feasibility of the preparation process, effectively increases the sodium storage capacity of the battery, and at the same time increases the carbon production rate and reduces the production cost.
[0034] According to one embodiment of this disclosure, the mixing in S1 includes grinding mixing and ball milling mixing; the grinding mixing time is 20-40 min; the ball milling mixing time is 2-8 h, the rotation speed is 300-600 r / min, and the ball-to-material ratio is 5-8:1.
[0035] According to one embodiment of this disclosure, in step S1, the pre-oxidation treatment conditions include: a temperature of 200–300°C and a time of 20–30 hours; the oxygen volume fraction in the oxygen-containing atmosphere is 21% or higher. This embodiment is beneficial for improving the reversible capacity and cycle stability of the battery.
[0036] According to one embodiment of this disclosure, in S1, the sulfonated lignin is selected from one or more of sodium lignin sulfonate, calcium lignin sulfonate, and magnesium lignin sulfonate; the asphalt is selected from one or more of natural asphalt, petroleum asphalt, sulfonated asphalt, and coal tar pitch; the mass ratio of the biomass precursor to the asphalt is 1:(0.1-9), preferably 1:(0.2-5). The above embodiment is beneficial for improving the reversible capacity and cycle stability of the battery.
[0037] According to one embodiment of this disclosure, in step S2, the carbonization treatment conditions include: a carbonization temperature of 1200–1600°C and a carbonization time of 2–4 hours; the carbonization treatment is carried out under an inert atmosphere, which includes one or more of nitrogen, helium, and argon; the flow rate of the inert atmosphere is 50–300 mL / min, preferably 50–150 mL / min. The above embodiment is beneficial for improving the reversible capacity and cycle stability of the battery.
[0038] According to one embodiment of this disclosure, the method further includes: sequentially subjecting the carbonized product to acid washing, water washing, and drying treatment.
[0039] According to one embodiment of this disclosure, the pickling includes mixing the carbonized product with an inorganic acid; the inorganic acid is selected from hydrochloric acid, sulfuric acid, and acetic acid; the concentration of the inorganic acid is 1 to 12 mol / L, preferably 4 to 12 mol / L.
[0040] According to one embodiment of this disclosure, the water washing includes washing the acid-washed product with water until the pH of the filtrate is 6.5 to 7.5, followed by filtration, and drying the filtered solid; the drying process is carried out at a temperature of 80 to 110°C for 12 to 24 hours.
[0041] The second aspect of this disclosure provides a sodium-ion battery anode material prepared by the method described in the first aspect of this disclosure.
[0042] According to one embodiment of this disclosure, the oxygen content of the negative electrode material is 1-25 wt%, preferably 5-20 wt%. In this disclosure, the oxygen content of the negative electrode material is based on the oxygen content on the surface of the negative electrode material measured by XPS.
[0043] The third aspect of this disclosure provides a sodium-ion battery negative electrode sheet, the negative electrode sheet comprising: a current collector, a binder, and the sodium-ion battery negative electrode material described in the second aspect of this disclosure.
[0044] This disclosure provides a fourth aspect of a sodium-ion secondary battery, comprising the negative electrode, positive electrode, electrolyte, and separator between the positive electrode and the negative electrode as described in the third aspect of this disclosure; the positive electrode is one of sodium manganate, sodium cobaltate, sodium vanadium phosphate, or sodium iron phosphate.
[0045] According to one embodiment of this disclosure, the electrolyte can be a conventional electrolyte in the art, such as the electrolyte salt being one of sodium hexafluorophosphate, sodium perchlorate, sodium bis(trifluoromethanesulfonyl)imide, or sodium bis(trifluoromethanesulfonyl)imide, and the electrolyte solvent being one or more of ethylene carbonate (EC), diethyl carbonate (DEC), dimethyl carbonate (DMC), ethylene glycol dimethyl ether (DME), diethylene glycol dimethyl ether (DEGDME), and methyl ethyl carbonate (EMC); the diaphragm can be a conventional diaphragm in the art, such as a glass fiber diaphragm or a polyolefin porous membrane.
[0046] The specific embodiments of this disclosure will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustration and explanation only and are not intended to limit this disclosure.
[0047] In the following embodiments of this disclosure, the X-ray scanning diffractometer (XRD) used is an X-ray powder diffractometer from Philips Corporation, USA. The method uses a Cu target anode Kα radiation source, with a step width of 0.02°, a scanning speed of 2° / min, and 2θ = 10°-80°.
[0048] In the following embodiments of this disclosure, the electrochemical performance tests were performed on a CT3001A1U-5V 5mA instrument from Wuhan Landian Company.
[0049] XPS was performed on a Thermo Fisher Thermo ESCALAB 250 instrument.
[0050] Sodium lignosulfonate was purchased from Beijing Innochem Technology Co., Ltd.
[0051] The electrolyte was a sodium-ion battery-specific electrolyte purchased from Suzhou Duoduo Reagent Co., Ltd.
[0052] The adhesive is a product of Beijing Innochem Technology Co., Ltd.;
[0053] All raw materials and reagents used in the following examples and comparative examples are battery grade;
[0054] Unless otherwise specified, the chemical reagents used in the following examples and comparative examples are commercially available products.
[0055] Example 1
[0056] (1) Take 4g of sodium lignosulfonate and 4g of petroleum asphalt powder, mix them evenly, place them in a corundum boat, put them in a muffle furnace, and pre-oxidize them for 24h in an air atmosphere at a temperature of 250℃ to obtain the pre-oxidized precursor, which is denoted as M11-250.
[0057] (2) The above-mentioned pre-oxidized precursor was evenly placed in a corundum boat, placed in a tube furnace, and nitrogen was introduced. The carbonization was carried out at 1300℃ for 2 hours. The carbonized product was acid washed and water washed with 2 mol / L HCl until the pH of the filtrate was about 7. Then it was filtered, and the filtered solid was dried at 110℃ for 24 hours to obtain the composite hard carbon material, which is denoted as M11-250-1300.
[0058] (3) Preparation of sodium-ion battery negative electrode sheet. The above-mentioned sodium-ion battery negative electrode material and 20% sodium alginate binder were weighed at a mass ratio of 9:1. The mixture was stirred magnetically for 6 hours to ensure thorough mixing. The mixture was then coated onto copper foil using a 150 μm thick scraper. The coated copper foil was dried in an 80°C oven for 12 hours. Subsequently, the coated copper foil was cut into electrode sheets with a diameter of 12 mm using a die-cutting machine. Electrode sheets with uniform coating and similar mass were selected using a microbalance to obtain the sodium-ion battery negative electrode. The sodium alginate binder was prepared by first placing sodium alginate powder into a 25*25 mm weighing bottle, adding an appropriate amount of deionized water, and then stirring the sodium alginate and deionized water under magnetic stirring to form a uniform gel-like solution.
[0059] (4) Assembly of sodium-ion half-cells. Using metallic sodium as the counter electrode, 1 mol / L NaPF6-DEGDME as the electrolyte, the aforementioned sodium-ion negative electrode sheet as the working electrode, and a Whatman GF / D glass fiber membrane as the battery separator, a CR2032 experimental button-shaped symmetrical cell was assembled in a glove box filled with argon atmosphere to evaluate the electrochemical performance of the aforementioned sodium-ion battery negative electrode material.
[0060] Example 2
[0061] (1) Take 4g of sodium lignosulfonate and 4g of petroleum asphalt powder, mix them evenly, place them in a corundum boat, put them in a muffle furnace, and pre-oxidize them for 24h in an air atmosphere at a temperature of 150℃ to obtain the pre-oxidized precursor, which is denoted as M11-150.
[0062] (2) Take the above pre-oxidized precursor and place it evenly in a corundum boat. Place it in a tube furnace, introduce nitrogen gas, and carbonize it at 1300℃ for 2 hours to obtain a composite hard carbon material, denoted as M11-150-1300.
[0063] The preparation of the negative electrode sheet for the sodium-ion battery and the assembly of the sodium-ion half-cell are the same as in Example 1.
[0064] Example 3
[0065] (1) Take 4g of sodium lignosulfonate and 4g of petroleum asphalt powder, mix them evenly, place them in a corundum boat, put them in a muffle furnace, and pre-oxidize them for 24h in an air atmosphere at a temperature of 250℃ to obtain the pre-oxidized precursor, which is denoted as M11-250.
[0066] (2) Take the above pre-oxidized precursor and place it evenly in a corundum boat, put it in a tube furnace, introduce nitrogen gas, and carbonize it at 1000℃ for 2 hours to obtain a composite hard carbon material, denoted as M11-250-1000.
[0067] The preparation of the negative electrode sheet for the sodium-ion battery and the assembly of the sodium-ion half-cell are the same as in Example 1.
[0068] Example 4
[0069] (1) Take 9g of sodium lignosulfonate and 1g of petroleum asphalt powder, mix them evenly, place them in a corundum boat, put them in a muffle furnace, and pre-oxidize them for 24h in an air atmosphere at a temperature of 250℃ to obtain the pre-oxidized precursor, which is denoted as M91-250.
[0070] (2) Take the above pre-oxidized precursor and place it evenly in a corundum boat. Place it in a tube furnace, introduce nitrogen gas, and carbonize it at 1300℃ for 2 hours to obtain a composite hard carbon material, denoted as M91-250-1300.
[0071] The preparation of the negative electrode sheet for the sodium-ion battery and the assembly of the sodium-ion half-cell are the same as in Example 1.
[0072] Example 5
[0073] (1) Take 3g of sodium lignosulfonate and 2g of petroleum asphalt powder, mix them evenly, place them in a corundum boat, put them in a muffle furnace, and pre-oxidize them for 24h in an air atmosphere at a temperature of 250℃ to obtain the pre-oxidized precursor, which is denoted as M32-250.
[0074] (2) Take the above pre-oxidized precursor and place it evenly in a corundum boat. Place it in a tube furnace, introduce nitrogen, and carbonize it at 1300℃ for 2 hours to obtain a composite hard carbon material, denoted as M32-250-1300.
[0075] The preparation of the negative electrode sheet for the sodium-ion battery and the assembly of the sodium-ion half-cell are the same as in Example 1.
[0076] Comparative Example 1
[0077] (1) Take 4g of sodium lignosulfonate and 4g of petroleum asphalt powder, mix them evenly, place them in a corundum boat, put them in a tube furnace, introduce nitrogen gas, set a segmented calcination program, calcine at 250℃ for 24h, then raise the temperature to 1300℃ and calcine again for 2h to obtain composite hard carbon material, denoted as D11-250-1300.
[0078] The preparation of the negative electrode sheet for the sodium-ion battery and the assembly of the sodium-ion half-cell are the same as in Example 1.
[0079] Comparative Example 2
[0080] (1) Take 4g of sodium lignosulfonate and 4g of petroleum asphalt powder, mix them evenly, place them in a corundum boat, put them in a muffle furnace, and pre-oxidize them for 24h in an air atmosphere at a temperature of 100℃ to obtain the pre-oxidized precursor, denoted as D11-100.
[0081] (2) Take the above pre-oxidized precursor and place it evenly in the corundum boat, put it in the tube furnace, introduce nitrogen, set the segmented calcination program, calcinate at 1000℃ for 2 hours to obtain the composite hard carbon material, denoted as D11-100-1000.
[0082] Comparative Example 3
[0083] (1) Take 4g of sodium lignosulfonate and 4g of petroleum asphalt powder, mix them evenly, place them in a corundum boat, put them in a tube furnace, introduce nitrogen gas, and calcine at 1000℃ for 2 hours to obtain composite hard carbon material, denoted as D11-1000.
[0084] The preparation of the negative electrode sheet for the sodium-ion battery and the assembly of the sodium-ion half-cell are the same as in Example 1.
[0085] Test Example 1
[0086] The oxygen content of the negative electrode materials of Examples 1-5 and Comparative Examples 1-3 was tested by XPS, and the carbon production rate was calculated. The results are shown in Table 1.
[0087] Table 1
[0088]
[0089]
[0090] The negative electrode material disclosed herein has an oxygen content of 5–20 wt% and a carbon yield of 57–65%. The negative electrode material disclosed herein has a high carbon yield and low cost.
[0091] Test Example 2
[0092] The electrochemical performance of the solar cells from Examples 1-5 and Comparative Examples 1-3 was tested under the following conditions: 0.1C (1C = 300 mAg). -1 Under the given rate, constant current charging and discharging was performed within a cutoff voltage range of 0.01V to 3V. The test results are shown in Table 2.
[0093] Table 2
[0094]
[0095] As shown in Table 2, the method of this disclosure has simple process conditions and effectively improves the electrochemical performance, reversible capacity, and cycle stability of the battery. A comparison of Examples 1 and 2 shows that the negative electrode material prepared by the method of this disclosure has better electrochemical performance within the preferred pre-oxidation temperature range of this disclosure. A comparison of Examples 1 and 3 shows that the negative electrode material prepared by the method of this disclosure has better electrochemical performance within the preferred carbonization temperature range of this disclosure. A comparison of Examples 1 and 4 shows that the negative electrode material prepared by the method of this disclosure has better electrochemical performance within the mass ratio range of biomass precursor to asphalt disclosed in this disclosure.
[0096] The preferred embodiments of this disclosure have been described in detail above with reference to the accompanying drawings. However, this disclosure is not limited to the specific details of the above embodiments. Within the scope of the technical concept of this disclosure, various simple modifications can be made to the technical solutions of this disclosure, and these simple modifications all fall within the protection scope of this disclosure.
[0097] It should also be noted that the various specific technical features described in the above embodiments can be combined in any suitable manner without contradiction. To avoid unnecessary repetition, this disclosure will not describe the various possible combinations separately.
[0098] Furthermore, various different embodiments of this disclosure can be combined in any way, as long as they do not violate the spirit of this disclosure, they should also be regarded as the content disclosed in this disclosure.
Claims
1. A method for preparing a sodium-ion battery anode material, characterized in that, The method includes the following steps: S1: After mixing the biomass precursor with asphalt, the mixture is placed in an oxygen-containing atmosphere for pre-oxidation treatment to obtain a pre-oxidized precursor. S2: The pre-oxidized precursor is carbonized under an inert atmosphere; In S1, the pre-oxidation treatment conditions include: a temperature of 150~350℃ and a time of 12~48h; the mass ratio of the biomass precursor to the asphalt is 1:(0.1~9); the biomass precursor includes sulfonated lignin; in S2, the carbonization treatment conditions include: a carbonization temperature of 1000~1600℃ and a carbonization time of 1~6h.
2. The method according to claim 1, wherein, In S1, the pre-oxidation treatment conditions include: a temperature of 200~300℃ and a time of 20~30h; the volume fraction of oxygen in the oxygen-containing atmosphere is 21% or more.
3. The method according to claim 1, wherein, In S1, the sulfonated lignin is selected from one or more of sodium lignin sulfonate, calcium lignin sulfonate, and magnesium lignin sulfonate; the asphalt is selected from one or more of natural asphalt, petroleum asphalt, sulfonated asphalt, and coal tar pitch. The mass ratio of the biomass precursor to the asphalt is 1:(0.2~5).
4. The method according to claim 1, wherein, In S2, the carbonization conditions include: a carbonization temperature of 1200~1600℃ and a carbonization time of 2~4h; The carbonization process is carried out under an inert atmosphere, which includes one or more of nitrogen, helium, and argon; the flow rate of the inert atmosphere is 50~300 mL / min.
5. The method according to claim 4, wherein, In S2, the flow rate of the inert atmosphere is 50~150 mL / min.
6. The method according to claim 1, wherein, The method further includes: sequentially acid washing, water washing and drying of the carbonized product.
7. The method according to claim 6, wherein, The pickling process involves mixing the carbonized product with an inorganic acid; the inorganic acid is selected from hydrochloric acid, sulfuric acid, and acetic acid; and the concentration of the inorganic acid is 1~12 mol / L.
8. The method according to claim 7, wherein, The concentration of the inorganic acid is 4~12 mol / L.
9. The method according to claim 6, wherein, The water washing includes washing the acid-washed product with water until the pH of the filtrate is 6.5-7.5, followed by filtration, and drying the filtered solid. The drying process is carried out at a temperature of 80~110℃ for 12~24 hours.
10. A sodium-ion battery anode material prepared by the method according to any one of claims 1 to 9, wherein the oxygen content of the anode material is 1 to 25 wt%.
11. A sodium-ion battery negative electrode sheet, characterized in that, The negative electrode sheet includes: a current collector, a binder, and the sodium-ion battery negative electrode material as described in claim 10.
12. A sodium-ion secondary battery, characterized in that, Includes the negative electrode, positive electrode, electrolyte, and separator between the positive electrode and the negative electrode as described in claim 11; The positive electrode is one of sodium manganate, sodium cobaltate, sodium vanadium phosphate, or sodium iron phosphate.