Na2mnfe(cn)6 material, preparation and application thereof

Abstract

The application discloses a novel Na2MnFe(CN)6 material and application thereof as a lithium ion battery, a sodium ion battery, a potassium ion battery, a magnesium ion battery, a zinc ion battery and a zinc-sodium dual-ion battery positive electrode material, wherein the Na2MnFe(CN)6 material is an inorganic material. The excellent electrochemical performance of the novel Na2MnFe(CN)6 material in the application indicates that the novel Na2MnFe(CN)6 material has a very large application prospect as the lithium ion battery, the sodium ion battery, the magnesium ion battery, the zinc ion battery and the zinc-sodium dual-ion battery positive electrode material. Meanwhile, the novel Na2MnFe(CN)6 material has a simple and controllable preparation process, and a simple device, and is a method easy to mass produce.

Description

TECHNICAL FIELD

[0001] The application relates to a novel Na2MnFe(CN)6 material and application, and belongs to the inorganic material preparation and electrochemical technical field. BACKGROUND

[0002] Prussian blue (PB) and its analogues have a general formula of A x PR(CN)6.yH2O, have an open framework structure, and a crystal structure similar to ABX3 perovskite, and are particularly favorable to Li + , Na + , K + , Mg 2+ and other ion intercalation / deintercalation. Among them, Prussian white (Na2MnFe(CN)6) has stable crystal structure, high theoretical cycle performance, and a three-dimensional space structure, which is favorable to the transmission of large-size ions such as Na + , Mg 2+ and other ions, and the material has excellent rate discharge performance, so it has recently attracted much attention of researchers. At the same time, the precursor of the Prussian blue material is cheap, and the preparation process is relatively simple, and is particularly favorable to large-scale production. Itaya et al. have proved that the electrodeposited Prussian blue thin film material can reversibly intercalate / deintercalate potassium ions in an aqueous solution; recently, Prussian blue (PB) and its analogues have been widely explored for monovalent, divalent and even trivalent ion batteries. However, in actual production, Prussian blue (PB) and its analogues often contain crystal water, which reduces the cycle life of the material; at the same time, lattice defects are easily generated in the material during the preparation process, and the crystal is not easy to grow (the particle size is usually only a few hundred nanometers), resulting in low tap density and short cycle life of the material. In order to solve this problem, most researchers focus on coating carbon materials or some oxides / carbides on the surface of the material, or compounding with other materials, such as graphene material. However, this not only increases the preparation cost of the material, but also reduces the specific capacity of the material due to the additional coating or compounding components. SUMMARY

[0003] The application aims to avoid the deficiencies of the prior art, and provides a novel Na2MnFe(CN)6 material.

[0004] According to one aspect of the application, a preparation method of a Na2MnFe(CN)6 material is provided. The novel Na2MnFe(CN)6 material is a high-sodium manganese-based Prussian blue analogue, and has a block structure with a length of 3-5 um (microns), a width of 2-3 um, and a height of 2-3 um; the material has a core-shell structure with an internal hollow, and the internal cavity has a diameter of about 300-400 nm.

[0005] The novel Na2MnFe(CN)6 material is prepared by a hard template method; the hard template is SiO2 or Al(OH)3 with a diameter of about 300-400 nm. The specific preparation method is as follows:

[0006] At least one of sodium chloride, sodium sulfate and sodium citrate is dissolved in deionized water, and then at least one of sodium ferrocyanide and potassium ferrocyanide is added, stirred to completely dissolve to form solution A; manganese chloride and manganese sulfate are dissolved in deionized water to form solution B; SiO2 or Al(OH)3 is dispersed in deionized water to form solution C. Under the condition of vigorous stirring, solution A and solution B are simultaneously added to solution C at a drop rate of about 1 mL / min to 2 mL / min, and after stirring for 10-30 minutes, the mixed solution is transferred to a reaction kettle with polytetrafluoroethylene as the inner liner. Reaction is carried out at 80-120°C for 6-10h. After that, when the temperature drops to room temperature, the white precipitate is collected using a centrifuge. Then, the obtained product is dispersed in HF for etching for 12h-24h. Then, the precipitate is collected by washing 3-4 times with deionized water using a centrifuge, and dried at 60-80°C for 6-10h to obtain the Na2MnFe(CN)6 material in the application.

[0007] The concentration of the sodium salt solution in the solution A is 1 mg mL -1 -500 mg mL -1 , and the molar concentration ratio of the sodium salt to the ferrocyanide is 1:0.01-1:2;

[0008] The concentration of the manganese salt in the solution B is 1 mg mL -1 -100 mg mL -1 ;

[0009] The concentration of SiO2 or Al(OH)3 in the solution C is 0.01 mg mL -1 -10 mg mL -1 .

[0010] The mass ratio of the ferrocyanide to the manganese salt is 3:1-1:2;

[0011] The mass ratio of the ferrocyanide to SiO2 or Al(OH)3 is 10:1-2:1.

[0012] The concentration of the HF is 1M-3M.

[0013] Optionally, the concentration of the sodium salt solution in the solution A is selected from 1 mg mL -1 , 50 mg mL -1 , 120 mg mL -1 , 200 mg mL -1 , and 350 mg mL-1 450mg / mL -1 500mg / mL -1 any two of the above; and the molar concentration ratio of the sodium salt to ferrocyanide is selected from any of 1:0.01, 1:0.2, 1:0.5, 1:1, 1:1.5, 1:2 or a range between any two of the above.

[0014] Optionally, the concentration of the manganese salt in the solution B is selected from any of 1 mg / mL -1 20mg / mL -1 50mg / mL -1 80mg / mL -1 100mg / mL -1 or a range between any two of the above.

[0015] Optionally, the concentration of SiO2 or Al(OH)3 in the solution C is selected from any of 0.01 mg / mL -1 0.1mg / mL -1 0.5mg / mL -1 1mg / mL -1 2mg / mL -1 6mg / mL -1 10mg / mL -1 or a range between any two of the above.

[0016] Optionally, the concentration of HF is selected from any of 1M, 1.5M, 2M, 2.2M, 3M or a range between any two of the above.

[0017] According to another aspect of the present application, the material prepared by the present application is applied as a positive electrode material of lithium ion battery, sodium ion battery, potassium ion battery, magnesium ion battery, zinc ion battery, zinc-sodium dual-ion battery, and a method for preparing an electrode with the material as a positive electrode active material is provided. The specific preparation method is as follows:

[0018] A certain amount of the prepared Na2MnFe(CN)6 material is weighed, mixed with conductive carbon black and polyvinylidene fluoride at a mass ratio of 8:1:1 to 7:1.5:1.5, and fully ground. Then, an appropriate amount of N-methyl-2-pyrrolidone is added dropwise with a dropper, and after fully stirring, the mixed electrode material is coated on a foamed nickel, and then dried in a blast drying oven at a temperature of 60-80°C for 4-6h. Then, the electrode is used to assemble lithium ion batteries, sodium ion batteries, potassium ion batteries, magnesium ion batteries, zinc ion batteries, and zinc-sodium dual-ion batteries, respectively. Then, the prepared batteries are tested for electrochemical performance using a LAND-CT2001A battery test system.

[0019] Test results show that batteries using Na2MnFe(CN)6 as the positive electrode active material exhibit excellent electrochemical performance. When used as the positive electrode material in lithium-ion batteries, the battery discharge voltage plateau reaches 3.6V, and the discharge specific capacity is 145mAhg. -1 When used as a cathode material in sodium-ion batteries, the battery's discharge specific capacity is 150.1 mAh g. -1 When used as a positive electrode material in potassium-ion batteries, the battery's discharge specific capacity is 141 mAh g. -1 When used as a positive electrode material in zinc-ion batteries, the battery's discharge specific capacity is 85 mAh g. -1 When used as a positive electrode material in magnesium-ion batteries, the battery's discharge specific capacity is 95 mAh g. -1 When used as the positive electrode material in a zinc-sodium dual-ion battery, the battery's discharge specific capacity is 147.2 mAh g. -1 Its excellent electrochemical performance indicates its great application potential. Furthermore, the preparation process is simple and controllable, requiring only basic equipment, making it an easy method for large-scale production.

[0020] The beneficial effects that this application can produce include:

[0021] 1) The raw materials used in this invention are inexpensive materials such as sodium chloride (NaCl), potassium ferrocyanide (K4Fe(CN)6), MnSO4 (MnSO4), and silicon dioxide (SiO2). The materials are widely available, green and safe, and have low cost.

[0022] 2) The preparation method of this invention is simple and can be mass-produced.

[0023] 3) The novel Na2MnFe(CN)6 material obtained by this invention has broad application prospects and can be used as a cathode material for lithium-ion batteries, sodium-ion batteries, potassium-ion batteries, magnesium-ion batteries, zinc-ion batteries, and zinc-sodium dual-ion batteries, exhibiting excellent electrochemical performance. Attached Figure Description

[0024] Figure 1 This is a SEM image of the Na2MnFe(CN)6 material of this application.

[0025] Figure 2 The discharge voltage plateau diagram of the Na2MnFe(CN)6 material prepared in this application as the positive electrode of a magnesium-ion battery at a current density of 0.2C.

[0026] Figure 3 When the Na2MnFe(CN)6 material prepared in this application is used as the positive electrode of a zinc-sodium dual-ion battery, it achieves a performance of 50 mA g. -1 Charge-discharge cycle curves at current density.

[0027] Figure 4 The Na2MnFe(CN)6 material prepared in the application has a discharge voltage plateau of 50mA g-1 -1 The discharge voltage plateau diagram at a current density. DETAILED DESCRIPTION

[0028] The application will be described in detail below with reference to examples, but the application is not limited to these examples.

[0029] The raw materials in the examples of the application are all purchased through commercial channels unless otherwise specified.

[0030] The AZ61 is scanned by using a JSM-7800F scanning electron microscope.

[0031] The electrochemical performance test is carried out by using a blue electric battery test system.

[0032] The application is a preparation method of a Na2MnFe(CN)6 material, comprising the following steps:

[0033] At least one of sodium chloride, sodium sulfate and sodium citrate is dissolved in deionized water, and then at least one of sodium ferrocyanide and potassium ferrocyanide is added, stirred to completely dissolve to form a solution A; manganese chloride and manganese sulfate are dissolved in deionized water to form a solution B; SiO2 or Al(OH)3 is dispersed in deionized water to form a solution C. Under the condition of vigorous stirring, solution A and solution B are simultaneously added to solution C at a drop rate of about 1mL / min to 2mL / min, and after stirring for 10 to 30 minutes, the mixed solution is transferred to a reaction kettle with polytetrafluoroethylene as the inner liner. Reaction is carried out at 80 to 120℃ for 6 to 10h. Then, after the temperature drops to room temperature, the white precipitate is collected using a centrifuge. Then, the obtained product is dispersed in HF for etching for 12h to 24h. Then, the precipitate is collected by washing 3 to 4 times with deionized water using a centrifuge, and dried at 60 to 80℃ for 6 to 10h to obtain the Na2MnFe(CN)6 material in the application.

[0034] A certain amount of the prepared Na2MnFe(CN)6 material is weighed, mixed with conductive carbon black and polyvinylidene fluoride at a mass ratio of 8:1:1 to 7:1.5:1.5, and fully ground, then an appropriate amount of N-methyl-2-pyrrolidone is added dropwise using a dropper, and after fully stirring, the mixed electrode material is coated on a foamed nickel, and then a forced air drying oven is used for drying at a temperature of 60 to 80℃ for 4 to 6h. Then, the electrode is used to assemble into lithium ion batteries, sodium ion batteries, potassium ion batteries, magnesium ion batteries, zinc ion batteries and zinc-sodium dual-ion batteries, respectively. Then, the prepared batteries are subjected to electrochemical performance test by using a LAND-CT2001A battery test system.

[0035] Preparation Example 1

[0036] 1 g of the prepared Na2MnFe(CN)6 material was weighed out and mixed with conductive carbon black and polyvinylidene fluoride in a mass ratio of 8:1:1 and ground thoroughly, then 2 mL of N-methyl-2-pyrrolidone was added dropwise using a dropper, and after stirring thoroughly, the mixed electrode material was coated on a 200-400 cm2 2 (Here, 300 cm2 2 One side surface of the nickel foam sheet was then coated with the electrode material, and then dried at a temperature of 60-80°C (here, 70°C) for 4-6 h (here, 6 h) using a blast drying oven. The electrode was then used to assemble lithium ion batteries (lithium sheet as the negative electrode, Celgard 2400 as the separator, 1M LiPF6 dissolved in a mixed solution of EC:DEC:DMC at a ratio of 1:1:1 as the electrolyte), sodium ion batteries (hard carbon as the negative electrode, GF / C glass fiber membrane as the separator, 1M NaClO4 dissolved in a mixed solution of EC:DEC:DMC at a ratio of 1:1:1 as the electrolyte), potassium ion batteries (potassium foil as the negative electrode, GF / C glass fiber membrane as the separator, 0.8M KPF4 dissolved in a mixed solution of EC:DEC at a ratio of 1:1 as the electrolyte), magnesium ion batteries (AZ61 alloy as the negative electrode, sodium alginate / magnesium chloride solid-state electrolyte as the separator and electrolyte), zinc ion batteries (zinc foil as the negative electrode, GF / C glass fiber membrane as the separator, 1M ZnSO4 aqueous solution as the electrolyte), and zinc-sodium dual-ion batteries (zinc foil as the negative electrode, GF / C glass fiber membrane as the separator, 1M ZnSO4+1M Na2SO4 aqueous solution as the electrolyte). The prepared batteries were then subjected to electrochemical performance testing using a LAND-CT2001A battery testing system.

[0037] Example 1

[0038] 5 g of sodium chloride was dissolved in 50 mL of deionized water, then 1.1 g of sodium ferrocyanide was added and stirred until completely dissolved to form solution A; 2.4 g of manganese chloride was dissolved in 50 mL of deionized water to form solution B; 0.1 g of SiO2 with a particle size of 300 nm was dispersed in 20 mL of deionized water to form solution C. Under vigorous stirring, solutions A and B were simultaneously added to solution C at a rate of 1 mL / min, and after stirring for 10 minutes, the mixed solution was transferred to a reaction kettle lined with polytetrafluoroethylene. The reaction was carried out at 100°C for 6 h. After the temperature dropped to room temperature, the white precipitate was collected using a centrifuge. The resulting product was then dispersed in 1.5M HF for etching for 12 h. After centrifugation using a centrifuge and washing with deionized water three times, the precipitate was collected and dried at 80°C for 8 h to obtain the Na2MnFe(CN)6 material.

[0039] The Na2MnFe(CN)6 material prepared according to the above steps was used as the active material, and the electrode prepared in Preparation Example 1 was used as the positive electrode, and lithium ion batteries, sodium ion batteries, potassium ion batteries, magnesium ion batteries, zinc ion batteries, and zinc-sodium dual-ion batteries were assembled, respectively. Then, the prepared batteries were subjected to electrochemical performance test using a blue battery test system.

[0040] Figure 1 The SEM image of the prepared Na2MnFe(CN)6 material. As can be seen from the figure, the material is a block structure with a particle size of 3-5 um in length, 2-3 um in width, and 2-3 um in height, and has good crystallinity, and is a core-shell structure with an internal cavity of about 300 nm in diameter.

[0041] Figure 2 The discharge voltage platform graph of the Na2MnFe(CN)6 material prepared in the present application as the positive electrode of the magnesium ion battery at a current density of 0.2C. As can be clearly seen from the figure, Figure 2 the discharge voltage of the battery can reach 2.8V, and the discharge voltage of the battery reaches 2.2V.

[0042] Figure 3 The charge-discharge cycle curve graph of the Na2MnFe(CN)6 material prepared in the present application as the positive electrode of the zinc-sodium dual-ion battery at a current density of 50mA g -1 As can be seen from the figure, Figure 3 the specific discharge capacity of the battery can still reach 147.2mAh g -1 after 100 cycles of charge-discharge cycle life.

[0043] Figure 4 The discharge voltage platform graph of the Na2MnFe(CN)6 material prepared in the present application as the positive electrode of the zinc-sodium dual-ion battery at a current density of 50mA g -1 As can be seen from the figure, Figure 4 the discharge voltage platform of the battery reaches 1.85V, and the average discharge voltage is 1.65V.

[0044] Example 2

[0045] Sodium sulfate 6 g was dissolved in 50 mL of deionized water, then 1.5 g of potassium ferrocyanide was added, stirred to completely dissolve to form solution A; 3.2 g of manganese sulfate was dissolved in 50 mL of deionized water to form solution B; 0.2 g of Al(OH)3 with a particle size of 400 nm was dispersed into 20 mL of deionized water to form solution C. Under the condition of vigorous stirring, solution A and solution B were added to solution C at the same time, and the dropping rate of solution A and B was 1 mL / min, and after stirring for 10 minutes, the mixed solution was transferred to a reaction kettle with a polytetrafluoroethylene lining. Reaction at 90℃ for 6h. Then, after the temperature dropped to room temperature, the white precipitate was collected using a centrifuge. Then, the obtained product was dispersed in 2M HF for etching for 12h. Then, the precipitate was collected after centrifugation using a centrifuge and washing with deionized water 3 times, and dried at 80℃ for 8h to obtain a Na2MnFe(CN)6 material.

[0046] The Na2MnFe(CN)6 material prepared according to the above steps was used as an active material, and the electrode prepared in Preparation Example 1 was used as a positive electrode, and lithium ion batteries, sodium ion batteries, potassium ion batteries, magnesium ion batteries, zinc ion batteries, and zinc-sodium dual-ion batteries were assembled respectively. Then, the prepared batteries were subjected to electrochemical performance test using a blue battery test system.

[0047] The method adopted in Example 2 is basically the same as that in Example 1, except that sodium chloride in solution A is replaced by sodium sulfate, and the concentration is changed from 100 mg mL -1 to 120 mg mL -1 ; sodium ferrocyanide is replaced by potassium ferrocyanide, and the concentration is changed from 22 mg mL -1 to 30 mg mL -1 ; manganese chloride in solution B is replaced by manganese sulfate, and the concentration is changed from 48 mg mL -1 to 64 mg mL -1 ; SiO2 in solution C is replaced by Al(OH)3, and the concentration is changed from 5 mg mL -1 to 10 mg mL -1 ; and the reaction temperature is changed from 100℃ to 90℃.

[0048] The prepared material is a block structure with a block structure of a particle size of 3-5um in length, 2-3um in width, and 2-3um in height, and has good crystallinity, and is a core-shell structure with an internal hollow cavity with a diameter of about 400nm.

[0049] The electrochemical test results show that the performance of the Na2MnFe(CN)6 material prepared by the method is basically the same as that in Example 1 (the voltage platform is the same, the discharge performance is basically the same, Figure 2 , Figure 3 , Figure 4 , and the specific capacity difference is about 1-2 mAh / g.-1 ). This is because, within a certain range, the Na2MnFe(CN)6 material performance is independent of the type of sodium salt, manganese salt, and hard template agent.

[0050] Comparative Example

[0051] Dissolve 5 g of sodium chloride in 50 mL of deionized water, then add 1.1 g of sodium ferrocyanide, stir to dissolve completely to form solution A; dissolve 2.4 g of manganese chloride in 50 mL of deionized water to form solution B. Under the condition of vigorous stirring, add solution B dropwise to solution A at a rate of 1 mL / min, and after stirring for 10 minutes, transfer the mixed solution to a reaction kettle lined with polytetrafluoroethylene. React at 100°C for 6 h. After the temperature drops to room temperature, use a centrifuge to collect the white precipitate. Then, disperse the obtained product in HF for etching for 12 h. Then, use a centrifuge to collect the precipitate after washing with deionized water 3 times, and dry at 80°C for 8 h to obtain the Na2MnFe(CN)6 material in this application.

[0052] Use the Na2MnFe(CN)6 material prepared according to the above steps as the active material, and use the electrode prepared in Preparation Example 1 as the positive electrode, to assemble into lithium ion batteries, sodium ion batteries, potassium ion batteries, magnesium ion batteries, zinc ion batteries, and zinc-sodium dual-ion batteries, respectively. Then, use the prepared batteries to perform electrochemical performance tests using a blue battery test system.

[0053] The method used in Comparative Example is basically the same as that in Example 1, except that no hard template agent is added. The material prepared has a block structure with a particle size of 3-5 um in length, 2-3 um in width, and 2-3 um in height, and has good crystallinity, and is a solid structure inside.

[0054] The electrochemical test results show that the Na2MnFe(CN)6 material prepared by this method has poorer performance than that of Example 1. (The voltage plateau is 0.1 V lower than that of Figure 2 The discharge performance is 10-15 mAh g Figure 3 , Figure 4 The specific capacity is 10-15 mAh g -1 ). This is because the solid structure increases the ion transport distance, causing increased polarization, resulting in a decrease in the voltage plateau and a decrease in the specific capacity.

[0055] The above is only a few embodiments of the present application, and does not limit the present application in any form. Although the present application is disclosed with the preferred embodiments as above, it is not intended to limit the present application. Any skilled person in the art can make some changes or modifications to the above disclosed technical content without departing from the scope of the technical solution of the present application, which are equivalent to equivalent embodiments, and are within the scope of the technical solution.

Claims

1. A Na2MnFe(CN)6 material, characterized in that, The Na2MnFe(CN)6 material is a high-sodium manganese-based Prussian blue analogue; The Na2MnFe(CN)6 material is a block structure with a length of 3-5 um, a width of 2-3 um, and a height of 2-3 um. The Na2MnFe(CN)6 material is a shell structure with an internal hollow, and the internal cavity has a diameter of 300-400 nm.

2. The Na2MnFe(CN)6 material of claim 1, wherein, The material is prepared by a hard template method; the hard template is SiO2 and / or Al(OH)3 with a diameter of 300-400 nm.

3. A preparation method of the Na2MnFe(CN)6 material according to any one of claims 1-2, characterized in that: at least one or two or more of sodium chloride, sodium sulfate, and sodium citrate are dissolved in deionized water, then at least one or two of sodium ferrocyanide and potassium ferrocyanide is added, stirred to completely dissolve to form solution A; at least one or two of manganese chloride and manganese sulfate is dissolved in deionized water to form solution B; SiO2 and / or Al(OH)3 with a diameter of 300-400 nm is dispersed in deionized water to form solution C; Under stirring conditions, solution A and solution B are simultaneously added to solution C at a drop rate of 1 mL / min to 2 mL / min, and after stirring for 10-30 minutes, the mixed solution is transferred to a reaction kettle; the reaction is carried out at 80-120 °C for 6-10 hours; then, after the temperature drops to room temperature, the precipitate is collected by centrifugation; then, the obtained precipitate is dispersed in an HF solution for etching for 12-24 hours; then, the precipitate is collected by centrifugation after being washed with deionized water for 3-4 times, and dried at 60-80 °C for 6-10 hours to obtain the Na2MnFe(CN)6 material.

4. The preparation method according to claim 3, characterized in that: The concentration of sodium salt in the solution A is 1 mg / mL -1 500 mg / mL -1 The molar concentration ratio of the sodium salt to ferrocyanide is 1:0.01 to 1:2, and the sodium salt is at least one or more than two of sodium chloride, sodium sulfate, and sodium citrate. The concentration of the manganese salt in the solution B is 1 mg mL -1 ~100 mg mL -1 ; The concentration of Si02and / or Al(OH)3in the solution C is 0.01 mg mL -1 10 mg mL -1 ; the mass ratio of the ferrocyanide to the manganese salt is 3:1 to 1:5; the mass ratio of the ferrocyanide to SiO2 and / or Al(OH)3 is 10:1 to 2:

1.

5. The preparation method according to claim 4, characterized in that: the concentration of the sodium salt in the solution A is 20 mg / mL -1 450 mg / mL -1 the molar concentration ratio of the sodium salt to ferrocyanide is 1:0.08 to 1:1.8; The concentration of the manganese salt in the solution B is 5 mg mL -1 ~90 mg mL -1 ; The concentration of Si02and / or Al(OH)3in the solution C is 0.05 mg mL -1 9 mg mL -1 ; the mass ratio of the ferrocyanide to the manganese salt is 2:1 to 1:4.5; the mass ratio of the ferrocyanide to SiO2 and / or Al(OH)3 is 9:1 to 2.5:

1.

6. The preparation method according to claim 3, characterized in that, The concentration of the HF solution is 1 M to 3 M.

7. The preparation method according to claim 3, characterized in that, The concentration of the HF solution is 1.2 M to 2.8 M.

8. Application of the Na2MnFe(CN)6 material according to any one of claims 1-2 as a positive electrode active material in a battery.

9. Use according to claim 8, characterized in that, The Na2MnFe(CN)6 material is applied as a positive electrode active material of a lithium ion battery, a sodium ion battery, a potassium ion battery, a magnesium ion battery, a zinc ion battery, or a zinc-sodium dual-ion battery.

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