A manganese sulfide-iron-based prussian blue composite electrode material, a preparation method thereof and application thereof in sodium ion batteries
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- LIAONING UNIVERSITY
- Filing Date
- 2026-03-02
- Publication Date
- 2026-06-02
AI Technical Summary
The structural stability and conductivity of manganese-iron-based Prussian blue materials are not ideal during charge and discharge, and the dissolution of manganese ions leads to rapid capacity decay, which limits their application in sodium-ion batteries.
By introducing sulfides into manganese-iron-based Prussian blue materials and treating them under an inert atmosphere using vapor deposition, a manganese-iron-based Prussian blue sulfide composite electrode material was prepared, which improved the conductivity of the material and inhibited manganese dissolution.
It significantly improves the redox activity and conductivity of the material, enhances structural stability, and improves the energy density and cycle life of sodium-ion batteries.
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Abstract
Description
Technical Field
[0001] This invention belongs to the field of electrode material technology, specifically relating to a manganese iron sulfide-based Prussian blue composite electrode material, its preparation method, and its application in sodium-ion batteries. Background Technology
[0002] Given the global warming caused by fossil fuel combustion, the efficient utilization of renewable and clean energy sources (such as wind and solar power) has become extremely urgent. Electrochemical energy storage technology has attracted widespread attention due to its advantages such as long cycle life and environmental friendliness. As a typical electrochemical energy storage technology, lithium-ion batteries (LIBs) dominate the portable electronic device and electric vehicle markets due to their high energy density; however, the scarcity of lithium resources limits their application in large-scale energy storage systems. Sodium-ion batteries, due to their lower cost, abundant natural sodium reserves, and better safety, show broad application prospects in the field of large-scale energy storage. Among many cathode materials, Prussian blue and its analogues are environmentally friendly and possess a three-dimensional open lattice structure (beneficial to Na+). + Its characteristics, such as reversible insertion / extraction and compositional flexibility (tunable capacity and discharge platform), have led to extensive research. Among them, manganese-iron-based Prussian blue (MnHCF) possesses two redox active metals, Mn and Fe, and theoretically can store two Na atoms per unit molecular weight. + Thus reaching 170 mAh·g -1 High theoretical capacity. However, interstitial water and lattice vacancies in MnHCF lead to suboptimal structural stability and electrochemical activity during charge and discharge, and the inherently low conductivity of Prussian blue further limits its reversible capacity and cycle stability. More importantly, the Jahn-Teller effect induces manganese ion dissolution, causing rapid capacity decay. Therefore, effective strategies need to be designed to improve the structural stability and conductivity of manganese-based Prussian blue cathodes, thereby constructing sodium-ion batteries with high specific capacity and long-term cycle stability. Summary of the Invention
[0003] To address the aforementioned problems, one objective of this invention is to provide a MnHCF-S composite electrode material and its preparation method.
[0004] The second objective of this invention is to provide the application of MnHCF-S composite electrode material as a positive electrode material in sodium-ion batteries.
[0005] To achieve the above-mentioned objectives, the technical solution adopted by this invention is as follows: a manganese iron sulfide-based Prussian blue composite electrode material, the preparation method of which includes: dissolving manganese acetate and dipotassium ethylenediaminetetraacetate in deionized water to obtain solution A, dissolving potassium ferrocyanide in deionized water to obtain solution B, adding solution A dropwise to solution B under stirring conditions, aging for 4-5 hours, centrifuging and washing, and vacuum drying to obtain manganese iron sulfide-based Prussian blue MnHCF; mixing and grinding sulfur powder with manganese iron sulfide-based Prussian blue MnHCF, placing it in a tube furnace, and performing vapor deposition under an inert atmosphere to obtain manganese iron sulfide-based Prussian blue composite electrode material MnHCF-S.
[0006] Furthermore, in a molar ratio, dipotassium ethylenediaminetetraacetate: manganese acetate: potassium ferrocyanide = 1:(1-1.5):1.
[0007] Furthermore, by mass ratio, MnHCF:sulfur powder = 10:(0.35-1).
[0008] Furthermore, the vapor deposition refers to heating to 200 ℃-300 ℃ at a heating rate of 5 ℃ / min-10 ℃ / min under an inert atmosphere, and calcining for 100 min-200 min.
[0009] This invention provides the application of a manganese iron sulfide-based Prussian blue composite electrode material as a positive electrode material in sodium-ion batteries.
[0010] A sodium-ion battery, using the aforementioned manganese iron sulfide-based Prussian blue composite electrode material MnHCF-S as the positive electrode material, is prepared by the following method:
[0011] (1) After the manganese iron sulfide-based Prussian blue composite electrode material MnHCF-S is mixed evenly with binder and conductive material, a small amount of NMP is added as a solvent. After mixing evenly, it is directly coated on the substrate, dried in a vacuum drying oven, and taken out to obtain a positive electrode sheet coated with manganese iron sulfide-based Prussian blue composite electrode material MnHCF-S.
[0012] (2) Using sodium sheet as negative electrode;
[0013] (3) Using the positive electrode obtained in step (1) as the positive electrode and the negative electrode obtained in step (2) as the negative electrode, and NaPF6 as the electrolyte, a sodium-ion battery is obtained.
[0014] Furthermore, the adhesive is PVDF.
[0015] Furthermore, the conductive material is Super-p.
[0016] The beneficial effects of this invention are:
[0017] 1. This invention significantly enhances the redox activity of the material by introducing sulfur during the synthesis process, effectively improves the conductivity of MnHCF, and also helps to suppress manganese dissolution, thereby preparing an advanced Prussian blue cathode material for sodium-ion batteries, improving the energy density and cycle life of the material.
[0018] 2. This invention has the characteristics of low cost, environmental friendliness and high safety.
[0019] 3. The synthesis and assembly processes of this invention are simple, easy to operate and control, and suitable for continuous large-scale production.
[0020] 4. After modification, this invention is available in 0.02 A g. -1 At a current density of [value missing], the specific capacity of the electrode material increased from the previous 99 mAh·g [value missing]. -1 Increased to 118 mAh·g -1 . Attached Figure Description
[0021] Figure 1 This is the XRD pattern of the MnHCF-S composite electrode material prepared in Example 3.
[0022] Figure 2 This is a TEM image of the MnHCF-S composite electrode material prepared in Example 3.
[0023] Figure 3 This is a specific capacity diagram of the MnHCF-S composite electrode material prepared in Example 3.
[0024] Figure 4 This is a cycle diagram of the MnHCF-S composite electrode material prepared in Example 3. Detailed Implementation
[0025] The technical solution of the present invention will be further described below, but the present invention is not limited thereto. Any modifications or equivalent substitutions to the technical solution of the present invention that do not depart from the spirit and scope of the technical solution of the present invention should be covered within the protection scope of the present invention.
[0026] Example 1: Manganese sulfide iron-based Prussian blue composite electrode material (MnHCF-S)
[0027] Preparation method:
[0028] 1. Preparation of MnHCF:
[0029] Manganese acetate (0.98 g, 5 mmol) and dipotassium ethylenediaminetetraacetate (1.61 g, 4 mmol) were weighed and dissolved in 50 mL of deionized water to obtain solution A. Potassium ferrocyanide (1.66 g, 4 mmol) was weighed and dissolved in 50 mL of deionized water to obtain solution B. Solution A was added dropwise to solution B under stirring. After aging the mixture for 4 h, centrifugation was performed. The precipitate was washed three times with deionized water, and finally, the product was vacuum dried at 60 °C for 12 h to obtain MnHCF.
[0030] 2. Preparation of MnHCF-S:
[0031] Take 3.5 mg of sulfur powder and 100 mg of MnHCF, mix and grind them evenly, and place them in a tube furnace. Under an argon atmosphere, heat the mixture to 250 °C at a heating rate of 5 °C / min and hold for 150 min to obtain MnHCF-S.
[0032] Example 2: Manganese sulfide iron-based Prussian blue composite electrode material (MnHCF-S)
[0033] Preparation method:
[0034] 1. Preparation of MnHCF:
[0035] Manganese acetate (0.98 g, 5 mmol) and dipotassium ethylenediaminetetraacetate (1.61 g, 4 mmol) were weighed and dissolved in 50 mL of deionized water to obtain solution A. Potassium ferrocyanide (1.66 g, 4 mmol) was weighed and dissolved in 50 mL of deionized water to obtain solution B. Solution A was added dropwise to solution B under stirring. After aging the mixture for 4 h, centrifugation was performed. The precipitate was washed three times with deionized water, and finally, the product was vacuum dried at 60 °C for 12 h to obtain MnHCF.
[0036] 2. Preparation of MnHCF-S:
[0037] Take 5.0 mg of sulfur powder and 100 mg of MnHCF, mix and grind them evenly, and place them in a tube furnace. Under an argon atmosphere, heat the mixture to 250 °C at a heating rate of 5 °C / min and hold for 150 min to obtain MnHCF-S.
[0038] Example 3: Manganese sulfide iron-based Prussian blue composite electrode material (MnHCF-S)
[0039] (a) Preparation method:
[0040] 1. Preparation of MnHCF:
[0041] Manganese acetate (0.98 g, 5 mmol) and dipotassium ethylenediaminetetraacetate (1.61 g, 4 mmol) were weighed and dissolved in 50 mL of deionized water to obtain solution A. Potassium ferrocyanide (1.66 g, 4 mmol) was weighed and dissolved in 50 mL of deionized water to obtain solution B. Solution A was added dropwise to solution B under stirring. After aging the mixture for 4 h, centrifugation was performed. The precipitate was washed three times with deionized water, and finally, the product was vacuum dried at 60 °C for 12 h to obtain MnHCF.
[0042] 2. Preparation of MnHCF-S:
[0043] Take 7.5 mg of sulfur powder and 100 mg of MnHCF, mix and grind them evenly, and place them in a tube furnace. Under an argon atmosphere, heat the mixture to 250 °C at a heating rate of 5 °C / min and hold for 150 min to obtain MnHCF-S.
[0044] (II) Testing
[0045] Figure 1 This is the XRD pattern of MnHCF-S prepared in this embodiment. Figure 1 It is evident that sulfur did not affect the crystal form of Prussian blue.
[0046] Figure 2 This is the TEM image of MnHCF-S prepared in this embodiment. Figure 2 It is evident that the prepared MnHCF-S exhibits a typical cubic structure.
[0047] Example 4: Manganese sulfide iron-based Prussian blue composite electrode material (MnHCF-S)
[0048] Preparation method:
[0049] 1. Preparation of MnHCF:
[0050] Manganese acetate (0.98 g, 5 mmol) and dipotassium ethylenediaminetetraacetate (1.61 g, 4 mmol) were weighed and dissolved in 50 mL of deionized water to obtain solution A. Potassium ferrocyanide (1.66 g, 4 mmol) was weighed and dissolved in 50 mL of deionized water to obtain solution B. Solution A was added dropwise to solution B under stirring. After aging the mixture for 4 h, centrifugation was performed. The precipitate was washed three times with deionized water, and finally, the product was vacuum dried at 60 °C for 12 h to obtain MnHCF.
[0051] 2. Preparation of MnHCF-S:
[0052] Take 10.0 mg of sulfur powder and 100 mg of MnHCF, mix and grind them evenly, and place them in a tube furnace. Under an argon atmosphere, heat the mixture to 250 °C at a heating rate of 5 °C / min and hold for 150 min to obtain MnHCF-S.
[0053] Example 5: Application of manganese iron sulfide-based Prussian blue composite electrode material MnHCF-S as a positive electrode material in sodium-ion batteries.
[0054] (I) Preparation of sodium-ion batteries
[0055] 1. Preparation of the positive electrode:
[0056] After mixing 70 mg of the MnHCF-S composite electrode material prepared in Example 3 with 20 mg of Super-p and 10 mg of PVDF, a small amount of NMP was added as a solvent. After mixing evenly, the mixture was directly coated onto a titanium foil substrate, dried in a vacuum drying oven, and removed to obtain a positive electrode sheet coated with MnHCF-S.
[0057] 2. Preparation of the negative electrode:
[0058] Commercially available circular sodium sheets with a diameter of 12 mm were purchased as the negative electrode.
[0059] 3. Assembly
[0060] Using the positive electrode sheet prepared in step 1 as the positive electrode and the negative electrode sheet prepared in step 2 as the negative electrode, and selecting NaPF6 electrolyte (NP-005) as the electrolyte, a sodium-ion battery was obtained and electrochemical tests were performed.
[0061] Figure 3 This is the specific capacity diagram of MnHCF-S. (From...) Figure 3 It is evident that the specific capacitance of MnHCF-S is significantly higher than that of MnHCF. At a current density of 0.02 A·g -1 The specific capacity is 118 mAh·g -1 .
[0062] Figure 4 This is a circulation diagram of MnHCF-S. (From...) Figure 4 It is evident that MnHCF-S exhibits superior cycle stability compared to MnHCF. This is achieved at a current density of 0.1 A·g. -1 At that time, MnHCF-S still maintained a capacity retention of 83.3% after 283 cycles.
[0063] (II) Effect of MnHCF-S composite electrode materials prepared with different mass ratios of MnHCF to sulfur powder on the electrochemical performance of sodium-ion batteries
[0064] 1. Preparation of the positive electrode:
[0065] 70 mg of the MnHCF-S composite electrode material prepared in Examples 1-4 were mixed evenly with 20 mg of Super-p and 10 mg of PVDF, and a small amount of NMP was added as a solvent. After mixing evenly, the mixture was directly coated onto the substrate titanium foil, dried in a vacuum drying oven, and removed to obtain positive electrode sheets coated with MnHCF-S.
[0066] 2. Preparation of the negative electrode:
[0067] Commercially available circular sodium sheets with a diameter of 12 mm were purchased as the negative electrode.
[0068] 3. Assembly
[0069] Using the positive electrode sheet prepared in step 1 as the positive electrode and the negative electrode sheet prepared in step 2 as the negative electrode, and selecting NaPF6 electrolyte (NP-005) as the electrolyte, four types of sodium-ion batteries were obtained.
[0070] Electrochemical tests were conducted on the four sodium-ion batteries prepared above. We found that the sodium-ion battery assembled using the MnHCF-S composite electrode material with a mass ratio of MnHCF to sulfur powder of 10:0.75 exhibited the best electrochemical performance. At different current densities, the specific capacity of MnHCF-S was consistently higher than that of MnHCF (e.g., ...). Figure 3 (As shown). At a current density of 0.1 A·g -1 At that time, the specific capacity was 87.6 mAh·g -1 And after 283 cycles, the capacity retention rate still reached 83.3% (e.g. Figure 4 (As shown). This is because in the MnHCF-S composite material formed when the mass ratio of MnHCF to sulfur powder is 10:0.75, sulfur is more uniformly and orderly distributed on the surface of MnHCF, and the Prussian blue is not completely coated, thus affecting the insertion / extraction of sodium ions. By improving the conductivity, reducing the volume expansion of MnHCF during the redox reaction and inhibiting the dissolution of manganese, a sodium-ion battery with high rate performance and long cycle performance is achieved.
Claims
1. A manganese sulfide iron-based Prussian blue composite electrode material, characterized in that, The preparation method includes: dissolving manganese acetate and dipotassium ethylenediaminetetraacetate in deionized water to obtain solution A, dissolving potassium ferrocyanide in deionized water to obtain solution B, adding solution A dropwise to solution B under stirring, aging for 4-5 hours, centrifuging and washing, and vacuum drying to obtain manganese-iron-based Prussian blue (MnHCF); mixing and grinding sulfur powder with manganese-iron-based Prussian blue (MnHCF), placing it in a tube furnace, and performing vapor deposition under an inert atmosphere to obtain manganese-iron-based Prussian blue sulfide composite electrode material MnHCF-S.
2. The manganese sulfide iron-based Prussian blue composite electrode material according to claim 1, characterized in that, The molar ratio is: dipotassium ethylenediaminetetraacetate: manganese acetate: potassium ferrocyanide = 1:(1-1.5):
1.
3. The manganese sulfide iron-based Prussian blue composite electrode material according to claim 1, characterized in that, By mass ratio, MnHCF:sulfur powder = 10:(0.35-1).
4. The manganese sulfide iron-based Prussian blue composite electrode material according to claim 1, characterized in that, The vapor deposition refers to heating to 200 ℃-300 ℃ at a heating rate of 5 ℃ / min-10 ℃ / min under an inert atmosphere, and calcining for 100 min-200 min.
5. The application of the manganese sulfide iron-based Prussian blue composite electrode material as described in any one of claims 1-4 as a positive electrode material in sodium-ion batteries.
6. A sodium-ion battery, characterized in that, Using the manganese iron sulfide-based Prussian blue composite electrode material MnHCF-S as described in any one of claims 1-4 as the positive electrode material, the preparation method includes: (1) After the manganese iron sulfide-based Prussian blue composite electrode material MnHCF-S is mixed evenly with binder and conductive material, a small amount of NMP is added as a solvent. After mixing evenly, it is directly coated on the substrate, dried in a vacuum drying oven, and taken out to obtain a positive electrode sheet coated with manganese iron sulfide-based Prussian blue composite electrode material MnHCF-S. (2) Using sodium sheet as negative electrode; (3) Using the positive electrode obtained in step (1) as the positive electrode and the negative electrode obtained in step (2) as the negative electrode, and NaPF6 as the electrolyte, a sodium-ion battery is obtained.
7. A sodium-ion battery according to claim 6, characterized in that, The adhesive is PVDF.
8. A sodium-ion battery according to claim 6, characterized in that, The conductive material is Super-p.