A long-life mesoporous carbon / nickel-cobalt-manganese hydrotalcite supercapacitor material, its preparation method and application
The Ni2Co1-xMnx water slide stone and mesoporous carbon composite addresses the stability and lifespan issues of supercapacitor materials, offering enhanced performance and durability for high-energy density applications.
Patent Information
- Application Number
- CN202211370219.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2022-11-03
- Publication Date
- 2025-07-11
- Estimated Expiration
- 2042-11-03
AI Technical Summary
Existing supercapacitor materials face limitations in cycle stability and lifespan, restricting their practical application, especially in fields requiring high performance and durability.
A composite material of Ni2Co1-xMnx water slide stone and mesoporous carbon is developed, with a specific molar ratio, prepared via a solvothermal method, enhancing the electrochemical properties of the supercapacitor.
The composite material exhibits improved lifespan, high energy density, power density, and excellent cycle stability, with a capacity retention of over 80% after 50,000 cycles, suitable for high-energy density supercapacitor applications.
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Figure CN115692035B_ABST
Abstract
Description
Technical Field
[0001] The present invention belongs to the technical field of preparing positive electrode materials for supercapacitors, and relates to a long-life mesoporous carbon / nickel cobalt manganese hydrotalcite supercapacitor material, a preparation method thereof and an application thereof. Background Art
[0002] With the continuous development of human society, the development and utilization of energy resources have attracted more and more attention. At present, fossil fuels are still the main source of energy. However, due to their limited reserves, serious pollution and conflict with the global carbon-free concept, more and more scientific researchers have focused on developing recyclable and environmentally friendly new energy sources.
[0003] Currently, the new energy sources that have been utilized include solar energy, wind energy, tidal energy, etc. Although these energy sources are inexhaustible, they are easily affected by conditions such as weather and geographical location. And if these energy sources are not stored in time, it is easy to cause waste of resources. Therefore, in order not to cause waste of new energy and achieve the effect of using it as needed, these new energy sources are often used in combination with electrochemical energy storage devices. Since the power generation outputs of solar energy, wind energy and tidal energy are unstable, if they are directly connected to the power grid or battery energy storage devices, it will cause impact and damage to them. Although traditional capacitor elements combined with batteries can solve the problem of unstable output of new energy, their capacity is too small, and the comprehensive application cost is high and the efficiency is low.
[0004] Supercapacitors have become one of the best energy storage devices in new energy due to their advantages such as high charging rate, high power density, environmental friendliness and good safety. In recent years, hybrid power systems composed of batteries and supercapacitors have been applied in fields such as wearable electronic devices, new energy vehicles, and key equipment of spacecraft. Supercapacitors mainly consist of capacitive materials, diaphragms, current collectors, electrolytes, etc. Among them, common capacitive materials include carbon, transition metal oxides, hydroxides, sulfides, phosphides, etc. In practical applications, supercapacitors should have properties such as high discharge specific capacity, good rate performance, good cycle stability, high energy density and long service life. And the performance of these properties is closely related to the structural characteristics of the capacitive materials. Since the performance requirements for supercapacitors in actual use are very strict, currently only carbon materials are put into production. Among many properties, especially the cycle stability and service life greatly limit the use of capacitive materials. Therefore, in order to expand the types of capacitive materials actually applied in supercapacitors, it is necessary to develop a capacitive material with excellent cycle stability and service life. Summary of the Invention
[0005] In view of this, one of the objectives of the present invention is to provide a long-life mesoporous carbon / nickel cobalt manganese hydrotalcite supercapacitor material; another objective of the present invention is to provide a preparation method of a long-life mesoporous carbon / nickel cobalt manganese hydrotalcite supercapacitor material; and a third objective of the present invention is to provide an application of a long-life mesoporous carbon / nickel cobalt manganese hydrotalcite supercapacitor material in supercapacitors.
[0006] To achieve the above objectives, the present invention provides the following technical solutions:
[0007] 1. A long-life mesoporous carbon / nickel cobalt manganese hydrotalcite supercapacitor material, wherein the capacitor material is composed of Ni2Co 1-x Mn x hydrotalcite and mesoporous carbon;
[0008] The molar mass ratio of the Ni2Co 1-x Mn x hydrotalcite to mesoporous carbon is: 1:8 - 12; mmol: mg, where the value range of x is 0.025 to 0.4.
[0009] Preferably, the value of x is any one of 0.025, 0.05, 0.075, 0.1, 0.2, 0.3, 0.4.
[0010] 2. The preparation method of the long-life mesoporous carbon / nickel cobalt manganese hydrotalcite supercapacitor material as described above, and the method is as follows:
[0011] Put divalent soluble cobalt salt, divalent soluble nickel salt, divalent soluble manganese salt and hexamethylenetetramine into a mesoporous carbon solution, mix evenly and then place it in a tetrafluoroethylene reaction kettle, and then place the reaction kettle in a constant temperature air blast oven and react at 120 - 160 °C for 4 - 8 h. After the reaction, centrifuge and filter the product to obtain a precipitate, wash it with deionized water and dry it for more than 24 h.
[0012] Preferably, the divalent soluble cobalt salt is any one or several of cobalt chloride, cobalt sulfate, cobalt carbonate, cobalt nitrate; the divalent soluble nickel salt is any one or several of nickel chloride, nickel sulfate, nickel carbonate, nickel nitrate; the divalent soluble manganese salt is any one or several of manganese chloride, manganese sulfate, manganese carbonate, manganese nitrate.
[0013] Preferably, the molar ratio of the divalent soluble cobalt salt, divalent soluble nickel salt, divalent soluble manganese salt and hexamethylenetetramine is 1 - x:2:x:3, where the value range of x is 0.025 to 0.4; the molar mass ratio of the mixture formed by the divalent soluble cobalt salt and the divalent soluble manganese salt to the mesoporous carbon is 1:8 - 1:12, mmol: mg.
[0014] Preferably, the solvent of the mesoporous carbon solution is any one or more of water, methanol, ethanol or acetone; the mass-volume concentration of mesoporous carbon in the mesoporous carbon solution is 1.5-2.5 mg / ml.
[0015] Preferably, the mesoporous carbon is prepared by the following method:
[0016] Add acetone, furfuryl alcohol and p-toluenesulfonic acid to mesoporous silica, stir at 10-35 °C to form a mixture, dry the mixture at 140-160 °C, place the dried mixture in a muffle furnace and react at 150 °C for 2 h to obtain a solid sample, then place the solid sample in a tube furnace and carbonize at 900 °C for 5 h in a nitrogen atmosphere to obtain a carbide, add 1 mol / L NaOH solution to the carbide and stir for more than 24 h to obtain a stirred solution, centrifuge the stirred solution to remove the supernatant, wash and dry the remaining solid to obtain mesoporous carbon.
[0017] Preferably, the mass-volume ratio of the mesoporous silica, acetone, furfuryl alcohol and p-toluenesulfonic acid is: 100:0.6:100:5, mg:ml:mg:mg; the mass-volume ratio of the carbide to the NaOH solution is: 100:1, mg:L.
[0018] Preferably, the rotation speed of the centrifugation is 4500-6000 rpm, the time is more than 5 min; the number of centrifugation operations is 4-6 times.
[0019] 3. Application of the long-life mesoporous carbon / nickel-cobalt-manganese hydrotalcite supercapacitor material in a supercapacitor.
[0020] The beneficial effect of the present invention is that the present invention discloses a long-life mesoporous carbon / nickel-cobalt-manganese hydrotalcite supercapacitor material. This material is composed of Ni2Co 1-x Mn x hydrotalcite and mesoporous carbon are compounded, and through mesoporous carbon on Ni2Co 1-x Mn xThe electrochemical properties of the hydrotalcite material are modified. Compared with traditional hydrotalcite capacitive materials, the modified material has the characteristics of long service life, high energy density, high power density, high voltage window, high discharge specific capacity, and good cycle stability. When the current density is 1 A / g, the discharge specific capacity of the composite material is 247 - 312.61 F / g. After the composite material undergoes 50,000 cycles, its capacity retention rate is above 80%, and the impedance change is small. Therefore, the composite material has the characteristic of long service life. The improvement of cycle stability and service life makes the material have great practical value and broad application prospects. When the mesoporous carbon / nickel cobalt manganese hydrotalcite composite material is used as the positive electrode material and combined with a commercial activated carbon negative electrode material to prepare a two-electrode device, the energy density of the device can reach more than 20 kWh / kg, greatly promoting the practical application of supercapacitors.
[0021] The present invention also discloses a preparation method of a long-life mesoporous carbon / nickel cobalt manganese hydrotalcite supercapacitor material. This material is prepared by a hydrothermal or solvothermal method. The preparation method is simple in operation, low in cost, and easy to scale up production. In the material prepared by this method, the combination of mesoporous carbon and nickel cobalt manganese talc is very good, which helps to improve the capacitive performance of the material based on pseudocapacitance.
[0022] Other advantages, objectives, and features of the present invention will be described to some extent in the subsequent specification, and to some extent, will be obvious to those skilled in the art based on the study of the following text, or can be taught from the practice of the present invention. The objectives and other advantages of the present invention can be achieved and obtained through the following specification. BRIEF DESCRIPTION OF THE DRAWINGS
[0023] In order to make the objectives, technical solutions, and advantages of the present invention clearer, the present invention will be described in detail preferably with reference to the accompanying drawings, where:
[0024] Figure 1 are the morphology diagrams of common nickel cobalt manganese hydrotalcite at different sizes;
[0025] Figure 2 is the morphology diagram of the mesoporous carbon / Ni2Co 0.925 Mn 0.075 nickel cobalt manganese hydrotalcite composite material at different sizes;
[0026] Figure 3 is the mesoporous carbon / Ni2Co in Example 1 0.925 Mn 0.075 nickel cobalt manganese hydrotalcite composite material at scanning rates of 10 mV / s -1 、20 mV / s -1 、30 mV / s -1 、40 mV / s -1, 50 mVs -1 Cyclic voltammogram under the condition;
[0027] Figure 4 is the mesoporous carbon / Ni2Co in Example 1 0.925 Mn 0.075 Galvanostatic charge-discharge curves of the nickel cobalt manganese hydrotalcite composite material at current densities of 1 A / g, 2 A / g, 3 A / g, 4 A / g, and 5 A / g respectively;
[0028] Figure 5 is the mesoporous carbon / Ni2Co in Example 1 0.925 Mn 0.075 Comparison chart of charge-discharge curves and capacity retention rate comparison chart of the nickel cobalt manganese hydrotalcite composite material at different cycle numbers when the current density is 10 A / g;
[0029] Figure 6 is the mesoporous carbon / Ni2Co in Example 1 0.925 Mn 0.075 Impedance comparison chart of the nickel cobalt manganese hydrotalcite composite material at 0 cycles, 20,000 cycles, and 50,000 cycles respectively;
[0030] Figure 7 Comparison chart of cyclic voltammograms of the mesoporous carbon / nickel cobalt manganese hydrotalcite composite materials in Examples 2 to 7;
[0031] Figure 8 Comparison chart of galvanostatic charge-discharge curves of the mesoporous carbon / nickel cobalt manganese hydrotalcite composite materials in Examples 2 to 7 under the condition of a current density of 1 A / g;
[0032] Figure 9 Discharge specific capacity comparison chart of the mesoporous carbon / nickel cobalt manganese hydrotalcite composite materials in Examples 2 to 7 at different current densities. Detailed implementation manners
[0033] The following illustrates the implementation manners of the present invention through specific specific examples. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific implementation manners. Various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the diagrams provided in the following examples only illustrate the basic concept of the present invention schematically. Under the condition of no conflict, the following examples and the features in the examples can be combined with each other.
[0034] Example 1
[0035] A long-life mesoporous carbon / nickel cobalt manganese hydrotalcite supercapacitor material, which is composed of Ni2Co0.925 Mn 0.075 composed of hydrotalcite and mesoporous carbon, where Ni2Co 0.925 Mn 0.075 The molar ratio of hydrotalcite to the mass of mesoporous carbon is 1:12, mmol:mg. The specific preparation method is as follows:
[0036] (1) Add 0.6 mL of acetone, 100 mg of furfuryl alcohol, and 5 mg of p-toluenesulfonic acid to 100 mg of commercial mesoporous silica, stir at 10 °C to form a mixture, dry the mixture at 160 °C, place the dried mixture in a muffle furnace and react at 150 °C for 2 h to obtain a solid sample, then place the solid sample in a tube furnace and carbonize at 900 °C in a nitrogen atmosphere for 5 h to obtain a carbide. Add 1 L of 1 mol / L NaOH solution to the carbide and stir for 28 h to obtain a stirred solution. Centrifuge the stirred solution at 4800 r for 5 min, then remove the supernatant. Repeat the operation 5 times, wash and dry the remaining solid to obtain mesoporous carbon;
[0037] (2) Weigh CoCl2, Ni(SO4)2, Mn(CO3)2, and hexamethylenetetramine according to the molar ratio of 0.925:2:0.075:3; weigh mesoporous carbon according to the molar ratio of the sum of the amounts of CoCl2 and Mn(CO3)2 to the mass of mesoporous carbon of 1:12, mmol:mg; place CoCl2, Ni(SO4)2, Mn(CO3)2, and hexamethylenetetramine in an aqueous solution of mesoporous carbon with a concentration of 2 mg / ml and stir evenly to obtain a mixed solution; place the mixed solution in a Teflon reaction kettle, and then place the reaction kettle in a constant temperature air blast oven and react at 160 °C for 4 h; load it into a centrifuge tube and centrifuge at 6000 r for 8 min, filter off the supernatant to leave the precipitate, wash the precipitate with deionized water. Repeat the centrifugation and washing process 5 times, then freeze-dry the obtained precipitate for more than 24 h, and collect mesoporous carbon / Ni2Co 0.925 Mn 0.075 Nickel-cobalt-manganese hydrotalcite capacitive material.
[0038] Example 2
[0039] A long-life mesoporous carbon / nickel-cobalt-manganese hydrotalcite supercapacitor material, which is composed of Ni2Co 0.975 Mn 0.025 composed of hydrotalcite and mesoporous carbon, where Ni2Co 0.975 Mn 0.025 The molar ratio of hydrotalcite to the mass of mesoporous carbon is 1:8, mmol:mg. The specific preparation method is as follows:
[0040] (1) 0.6 mL of acetone, 100 mg of furfuryl alcohol, and 5 mg of p-toluenesulfonic acid were added to 100 mg of commercial mesoporous silica, and the mixture was stirred at 25 °C to form a mixture. The mixture was dried at 150 °C, and the dried mixture was placed in a muffle furnace and reacted at 150 °C for 2 h to obtain a solid sample. Then, the solid sample was placed in a tube furnace and carbonized at 900 °C for 5 h under a nitrogen atmosphere to obtain a carbide. 1 L of 1 mol / L NaOH solution was added to the carbide and stirred for 28 h to obtain a stirred solution. The stirred solution was centrifuged at 4800 r for 5 min, and the supernatant was removed. After repeating the operation 5 times, the remaining solid was washed and dried to obtain mesoporous carbon;
[0041] (2) Co(SO4)2, Ni(NO3)2·6H2O, MnCl2, and hexamethylenetetramine were weighed according to the molar ratio of 0.975:2:0.025:3; mesoporous carbon was weighed according to the mass ratio of the sum of the amounts of Co(SO4)2 and MnCl2 to mesoporous carbon of 1:8, mmol:mg; Co(SO4)2, Ni(NO3)2·6H2O, Mn(NO3)2, and hexamethylenetetramine were placed in an aqueous solution of mesoporous carbon with a concentration of 2 mg / ml and stirred to obtain a mixed solution; the mixed solution was loaded into a Teflon reaction kettle, and then the reaction kettle was placed in a constant temperature air blast oven and reacted at 120 °C for 8 h; it was loaded into a centrifuge tube and centrifuged at 6000 r for 5 min, the supernatant was filtered off to leave the precipitate, the precipitate was washed with deionized water, and the centrifugation and washing process was repeated 4 times. The obtained precipitate was freeze-dried for more than 24 h, and mesoporous carbon / Ni2Co 0.975 Mn 0.025 Nickel-cobalt-manganese hydrotalcite capacitive material.
[0042] Example 3
[0043] A long-life mesoporous carbon / nickel-cobalt-manganese hydrotalcite supercapacitor material, which is composed of Ni2Co 0.95 Mn 0.05 Hydrotalcite and mesoporous carbon are composite, and the molar ratio of Ni2Co 0.95 Mn 0.05 The amount of hydrotalcite to the mass of mesoporous carbon is 1:10, mmol:mg. The specific preparation method is as follows:
[0044] (1) Add 0.6 mL of acetone, 100 mg of furfuryl alcohol, and 5 mg of p-toluenesulfonic acid to 100 mg of commercial mesoporous silica, stir to form a mixture at 35 °C, dry the mixture at 140 °C, place the dried mixture in a muffle furnace and react at 150 °C for 2 h to obtain a solid sample, then place the solid sample in a tube furnace and carbonize at 900 °C for 5 h under a nitrogen atmosphere to obtain a carbide. Add 1 L of 1 mol / L NaOH solution to the carbide and stir for 25 h to obtain a stirred solution. Centrifuge the stirred solution at 4500 r for 6 min and then remove the supernatant. Repeat the operation 4 times, wash and dry the remaining solid to obtain mesoporous carbon;
[0045] (2) Mesoporous carbon / Ni2Co 0.95 Mn 0.05 Preparation of nickel-cobalt-manganese hydrotalcite composite material: Weigh Co(NO3)2·6H2O, Ni(NO3)2·6H2O, Mn(NO3)2, and hexamethylenetetramine according to the molar ratio of 0.95:2:0.05:3; Weigh mesoporous carbon according to the mass ratio of the sum of the amounts of substance of Co(NO3)2·6H2O and Mn(NO3)2 to the mass of mesoporous carbon of 1:10, mmol:mg; Place Co(NO3)2·6H2O, Ni(NO3)2·6H2O, Mn(NO3)2, and hexamethylenetetramine in an aqueous solution of mesoporous carbon with a concentration of 2 mg / ml and ultrasonicate to obtain a mixed solution; Put the mixed solution into a Teflon reaction kettle, and then place the reaction kettle in a constant temperature air blast oven and react at 140 °C for 6 h; Load it into a centrifuge tube and centrifuge at 4500 r for 5 min, filter off the supernatant to leave the precipitate, wash the precipitate with deionized water, repeat the centrifugation and washing process 5 times, and then freeze-dry the obtained precipitate for more than 24 h to collect mesoporous carbon / Ni2Co 0.95 Mn 0.05 Nickel-cobalt-manganese hydrotalcite capacitive material.
[0046] Example 4
[0047] A long-life mesoporous carbon / nickel-cobalt-manganese hydrotalcite supercapacitor material, which is composed of Ni2Co 0.9 Mn 0.1 Hydrotalcite and mesoporous carbon are composite, in which the molar ratio of Ni2Co 0.9 Mn 0.1 Hydrotalcite to the mass of mesoporous carbon is 1:8, mmol:mg, and its specific preparation method is as follows:
[0048] (1) 0.6 mL of acetone, 100 mg of furfuryl alcohol, and 5 mg of p-toluenesulfonic acid were added to 100 mg of commercial mesoporous silica, and stirred at 10 °C to form a mixture. The mixture was dried at 160 °C, and the dried mixture was placed in a muffle furnace and reacted at 150 °C for 2 h to obtain a solid sample. Then, the solid sample was placed in a tube furnace and carbonized at 900 °C for 5 h under a nitrogen atmosphere to obtain a carbide. 1 L of 1 mol / L NaOH solution was added to the carbide and stirred for 28 h to obtain a stirred solution. The stirred solution was centrifuged at 4800 r for 5 min, and the supernatant was removed. After repeating the operation 5 times, the remaining solid was washed and dried to obtain mesoporous carbon;
[0049] (2) Co(CO3)2, NiCl2, Mn(NO3)2, and hexamethylenetetramine were weighed according to the molar ratio of 0.9:2:0.1:3; Mesoporous carbon was weighed according to the mass ratio of the sum of the amounts of Co(CO3)2 and Mn(NO3)2 to mesoporous carbon of 1:8, mmol:mg; Co(CO3)2, NiCl2, Mn(NO3)2, and hexamethylenetetramine were placed in a methanol solution of mesoporous carbon with a concentration of 2 mg / ml and stirred to obtain a mixed solution; The mixed solution was loaded into a Teflon reaction kettle, and the reaction kettle was placed in a constant temperature air blast oven and reacted at 150 °C for 5 h; It was loaded into a centrifuge tube and centrifuged at 4500 r for 6 min, the supernatant was filtered off to leave the precipitate, and the precipitate was washed with deionized water. After repeating the centrifugation and washing process 5 times, the obtained precipitate was freeze-dried for more than 24 h, and mesoporous carbon / Ni2Co 0.9 Mn 0.1 Nickel-cobalt-manganese hydrotalcite capacitive material.
[0050] Example 5
[0051] A long-life mesoporous carbon / nickel-cobalt-manganese hydrotalcite supercapacitor material, which is composed of Ni2Co 0.8 Mn 0.2 Hydrotalcite and mesoporous carbon are composite, and the molar ratio of Ni2Co 0.8 Mn 0.2 The amount of hydrotalcite to the mass of mesoporous carbon is 1:9, mmol:mg. The specific preparation method is as follows:
[0052] (1) 0.6 mL of acetone, 100 mg of furfuryl alcohol, and 5 mg of p-toluenesulfonic acid were added to 100 mg of commercial mesoporous silica, and stirred at 15 °C to form a mixture. The mixture was dried at 160 °C, and the dried mixture was placed in a muffle furnace and reacted at 150 °C for 2 h to obtain a solid sample. Then, the solid sample was placed in a tube furnace and carbonized at 900 °C for 5 h under a nitrogen atmosphere to obtain a carbide. 1 L of 1 mol / L NaOH solution was added to the carbide and stirred for 25 h to obtain a stirred solution. The stirred solution was centrifuged at 4800 r for 6 min, and the supernatant was removed. After repeating the operation 6 times, the remaining solid was washed and dried to obtain mesoporous carbon;
[0053] (2) Co(NO3)2·6H2O, Ni(SO4)2, Mn(NO3)2, and hexamethylenetetramine were weighed according to the molar ratio of 0.8:2:0.2:3; mesoporous carbon was weighed according to the mass ratio of the sum of the amounts of substances of Co(NO3)2·6H2O and Mn(NO3)2 to mesoporous carbon of 1:9, mmol:mg; Co(NO3)2·6H2O, Ni(SO4)2, Mn(NO3)2, and hexamethylenetetramine were placed in an ethanol solution of mesoporous carbon with a concentration of 2 mg / ml and stirred to obtain a mixed solution; the mixed solution was loaded into a Teflon reaction kettle, and then the reaction kettle was placed in a constant temperature air blast oven and reacted at 130 °C for 8 h; it was loaded into a centrifuge tube and centrifuged at 4500 r for 6 min, the supernatant was filtered off to leave a precipitate, the precipitate was washed with deionized water, and the centrifugation and washing process was repeated 5 times. The obtained precipitate was freeze-dried for more than 24 h, and mesoporous carbon / Ni2Co 0.8 Mn 0.1 Nickel-cobalt-manganese hydrotalcite capacitive material.
[0054] Example 6
[0055] A long-life mesoporous carbon / nickel-cobalt-manganese hydrotalcite supercapacitor material, which is composed of Ni2Co 0.7 Mn 0.3 Hydrotalcite and mesoporous carbon are composite, and the molar ratio of Ni2Co 0.7 Mn 0.3 The amount of hydrotalcite to the mass of mesoporous carbon is 1:11, mmol:mg. The specific preparation method is as follows:
[0056] (1) 0.6 mL of acetone, 100 mg of furfuryl alcohol, and 5 mg of p-toluenesulfonic acid were added to 100 mg of commercial mesoporous silica, and stirred at 35 °C to form a mixture. The mixture was dried at 150 °C, and the dried mixture was placed in a muffle furnace and reacted at 150 °C for 2 h to obtain a solid sample. Then, the solid sample was placed in a tube furnace and carbonized at 900 °C for 5 h under a nitrogen atmosphere. 1 L of 1 mol / L NaOH solution was added to the carbide and stirred for 26 h to obtain a stirred solution. The stirred solution was centrifuged at 4500 r for 6 min, and the supernatant was removed. After repeating the operation 5 times, the remaining solid was washed and dried to obtain mesoporous carbon;
[0057] (2) CoCl2, Ni(NO3)2·6H2O, Mn(SO4)2, and hexamethylenetetramine were weighed according to the molar ratio of 0.7:2:0.3:3; mesoporous carbon was weighed according to the mass ratio of the sum of the amounts of CoCl2 and Mn(SO4)2 to mesoporous carbon of 1:11, mmol:mg; CoCl2, Ni(NO3)2·6H2O, Mn(SO4)2, and hexamethylenetetramine were placed in an acetone solution of mesoporous carbon with a concentration of 2 mg / ml and stirred to obtain a mixed solution; the mixed solution was loaded into a Teflon reaction kettle, and then the reaction kettle was placed in a constant temperature blast oven and reacted at 130 °C for 8 h; it was loaded into a centrifuge tube and centrifuged at 4500 r for 6 min, the supernatant was filtered off to leave the precipitate, and the precipitate was washed with deionized water. After repeating the centrifugation and washing process 5 times, the obtained precipitate was freeze-dried for more than 24 h, and mesoporous carbon / Ni2Co was collected 0.7 Mn 0.3 Nickel-cobalt-manganese hydrotalcite capacitive material.
[0058] Example 7
[0059] A long-life mesoporous carbon / nickel-cobalt-manganese hydrotalcite supercapacitor material, which is composed of Ni2Co 0.6 Mn 0.4 hydrotalcite and mesoporous carbon composites, where the molar ratio of Ni2Co 0.6 Mn 0.4 hydrotalcite to the mass of mesoporous carbon is 1:10, mmol:mg, and its specific preparation method is as follows:
[0060] (1) 0.6 mL of acetone, 100 mg of furfuryl alcohol, and 5 mg of p-toluenesulfonic acid were added to 100 mg of commercial mesoporous silica, and stirred at 15 °C to form a mixture. The mixture was dried at 160 °C, and the dried mixture was placed in a muffle furnace and reacted at 150 °C for 2 h to obtain a solid sample. Then, the solid sample was placed in a tube furnace and carbonized at 900 °C for 5 h under a nitrogen atmosphere to obtain a carbide. 1 L of 1 mol / L NaOH solution was added to the carbide and stirred for 25 h to obtain a stirred solution. The stirred solution was centrifuged at 4500 r for 8 min to remove the supernatant, and the operation was repeated 4 times. The remaining solid was washed and dried to obtain mesoporous carbon;
[0061] (2) Co(NO3)2·6H2O, Ni(NO3)2·6H2O, Mn(NO3)2, and hexamethylenetetramine were weighed according to the molar ratio of 0.6:2:0.4:3; mesoporous carbon was weighed according to the mass ratio of the sum of the amounts of Co(NO3)2·6H2O and Mn(NO3)2 to mesoporous carbon of 1:10, mmol:mg; Co(NO3)2·6H2O, Ni(NO3)2·6H2O, Mn(NO3)2, and hexamethylenetetramine were placed in an aqueous solution of mesoporous carbon with a concentration of 2 mg / ml and stirred to obtain a mixed solution; the mixed solution was loaded into a Teflon reaction kettle, and the reaction kettle was placed in a constant temperature air blast oven and reacted at 150 °C for 5 h; it was loaded into a centrifuge tube and centrifuged at 4500 r for 5 min, the supernatant was filtered off to leave the precipitate, and the precipitate was washed with deionized water. After the centrifugal washing process was repeated 5 times, the obtained precipitate was freeze-dried for more than 24 h, and mesoporous carbon / Ni2Co 0.6 Mn 0.4 Nickel-cobalt-manganese hydrotalcite capacitive material.
[0062] Figure 1 are the morphology diagrams of common nickel-cobalt-manganese hydrotalcite at different sizes. The morphology of the nickel-cobalt-manganese hydrotalcite was tested at 5 μm, 4 μm, and 1 μm respectively. From Figure 1 it can be seen that the nickel-cobalt-manganese hydrotalcite material has a good morphology and a relatively large specific surface area. Figure 2 is the mesoporous carbon / Ni2Co in Example 1 0.925 Mn 0.075 Morphology diagrams of nickel-cobalt-manganese hydrotalcite composite materials at different sizes. The morphology of the composite material was tested at 5 μm, 4 μm, and 1 μm respectively. Figure 1 and Figure 2 were compared, and it can be seen that mesoporous carbon and nickel-cobalt-manganese hydrotalcite are closely combined, indicating that mesoporous carbon and nickel-cobalt-manganese hydrotalcite are very well combined in the materials prepared by hydrothermal or solvothermal methods.
[0063] Figure 3 is the mesoporous carbon / Ni2Co in Example 10.925 Mn 0.075 The cyclic voltammograms of the nickel-cobalt-manganese hydrotalcite composite material at scanning rates of 10 mV s -1 , 20 mV s -1 , 30 mV s -1 , 40 mV s -1 , 50 mV s -1 respectively. It can be seen from Figure 3 that as the scanning rate increases, the symmetry of the cyclic voltammogram becomes lower and lower, but the shape of the cyclic voltammogram becomes more and more stable. This shows that the prepared mesoporous carbon / Ni2Co 0.925 Mn 0.075 nickel-cobalt-manganese hydrotalcite composite material has high purity and good stability.
[0064] Figure 4 The galvanostatic charge-discharge curves of the mesoporous carbon / Ni2Co 0.925 Mn 0.075 nickel-cobalt-manganese hydrotalcite composite material in Example 1 at current densities of 1 A / g, 2 A / g, 3 A / g, 4 A / g, and 5 A / g respectively. It can be seen from Figure 4 that as the current density increases, although the capacitance performance of the mesoporous carbon / Ni2Co 0.95 Mn 0.05 nickel-cobalt-manganese hydrotalcite composite material decreases, the shape of the charge-discharge curve does not change significantly. This indicates that the material still shows good stability at high current densities.
[0065] Figure 5 The comparison diagrams of the charge-discharge curves and the capacitance retention rate of the mesoporous carbon / Ni2Co 0.925 Mn 0.075 nickel-cobalt-manganese hydrotalcite composite material in Example 1 at a current density of 10 A / g under different numbers of cycles. Among them, it can be seen from the comparison diagram of the charge-discharge curves that the charge-discharge curves of the composite material change little under different numbers of cycles. This shows that the composite material has the advantages of good cycle stability and long service life; it can be seen from the comparison diagram of the capacitance retention rate that the material still retains 83.76% of its capacitance performance after 50,000 cycles. This also fully demonstrates the excellent cycle stability of the material.
[0066] Figure 6 The impedance comparison diagrams of the mesoporous carbon / Ni2Co 0.925 Mn 0.075 nickel-cobalt-manganese hydrotalcite composite material in Example 1 at 0 cycles, 20,000 cycles, and 50,000 cycles respectively. It can be seen from Figure 6 that as the number of cycles increases, the impedance of the material increases. However, the increase in impedance is not significant, indicating that the material has good cycle stability and is suitable as the positive electrode of a practical capacitor.
[0067] Similarly, the mesoporous carbon / nickel cobalt manganese hydrotalcite composites in Examples 2-7 were tested for their morphology, electrochemical properties, and impedance as in Example 1 above. The results of the morphology test showed that the binding degree between mesoporous carbon and nickel cobalt manganese hydrotalcite in the mesoporous carbon / nickel cobalt manganese hydrotalcite composites with different Co and Mn content ratios prepared by hydrothermal or solvothermal methods was very tight; the composite materials in each example were tested for cyclic voltammetry curves at different scan rates, and all had the same trend as the composite material in Example 1, that is, as the scan rate increased, although the symmetry of the cyclic voltammetry curve became lower, the shape of the cyclic voltammetry curve became more and more stable, indicating that the composite materials in each example had high purity and good stability; by testing the charge and discharge performance of each composite material in Examples 2-7 at different current densities, the stability of each composite material was good at high current densities; when testing the capacity retention rate of each composite material in each example under different cycle numbers, the experimental results showed that the capacity retention rate of each composite material was above 80%.
[0068] Figure 7 It is a comparative diagram of cyclic voltammetry curves of the mesoporous carbon / nickel cobalt manganese hydrotalcite composites in Examples 2 to 7. From Figure 7 it can be seen that the oxidation-reduction peaks of the composite materials in different examples are close, that is, the properties of the materials are close, so it can be shown that the composite materials in Examples 2-7 all exhibit excellent cyclic stability.
[0069] Figure 8 It is a comparative diagram of galvanostatic charge-discharge curves of the mesoporous carbon / nickel cobalt manganese hydrotalcite composites in Examples 2 to 7 under the condition of a current density of 1 A / g. From Figure 8 it can be seen that the charge and discharge performance of the composite materials in Examples 2-7 is close at a current density of 1 A / g.
[0070] Figure 9 It is a comparative diagram of discharge specific capacities of the mesoporous carbon / nickel cobalt manganese hydrotalcite composites in Examples 2 to 7 at different current densities. From Figure 9 it can be seen that the charge-discharge specific capacities and rate performance of the composite materials in Examples 2-7 are similar at different current densities.
[0071] In summary, the present invention discloses a long-life mesoporous carbon / nickel cobalt manganese hydrotalcite supercapacitor material, its preparation method and application. Through mesoporous carbon on Ni2Co 1-x Mn xThe electrochemical properties of the hydrotalcite material are modified. Compared with traditional hydrotalcite capacitive materials, the modified material has outstanding advantages in service life and cycle stability. After 50,000 cycles, the capacity retention rate of the material is above 80% and the impedance change is small. When this composite material is used as the positive electrode material and combined with a commercial activated carbon negative electrode material to prepare a two-electrode device, the energy density of the device can reach above 20 kWh / kg. In the material prepared by the hydrothermal or solvothermal method, the combination of mesoporous carbon and nickel-cobalt-manganese talc is very good. This method is simple to operate and low in cost, and is suitable for large-scale production.
[0072] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that the technical solutions of the present invention can be modified or equivalently replaced without departing from the purpose and scope of the present technical solution, and they should all be covered within the scope of the claims of the present invention.
Claims
1. A long - life mesoporous carbon / nickel - cobalt - manganese hydrotalcite supercapacitor material, characterized in that: The capacitive material is composed of Ni2Co 1-x Mn x hydrotalcite and mesoporous carbon; The Ni2Co 1-x Mn x The molar mass ratio of the hydrotalcite and the mesoporous carbon is 1:8 - 12; mmol: mg, where the value range of x is 0.025 to 0.4, The preparation method of the supercapacitor material is as follows: Put divalent soluble cobalt salt, divalent soluble nickel salt, divalent soluble manganese salt and hexamethylenetetramine into the mesoporous carbon solution. After mixing evenly, place it in a tetrafluoroethylene reaction kettle. Then place the reaction kettle in a constant temperature air blast oven and react at 120~160 °C for 4~8 h. After the reaction is completed, centrifuge and filter the product to obtain a precipitate. After washing with deionized water, dry it for more than 24 h.
2. A long - life mesoporous carbon / nickel - cobalt - manganese hydrotalcite supercapacitor material according to claim 1, characterized in that: The value of x is any one of 0.025, 0.05, 0.075, 0.1, 0.2, 0.3, 0.
4.
3. A long-life mesoporous carbon / nickel cobalt manganese hydrotalcite supercapacitor material according to claim 2, characterized in that: The divalent soluble cobalt salt is any one or several of cobalt chloride, cobalt sulfate, cobalt carbonate, cobalt nitrate; the divalent soluble nickel salt is any one or several of nickel chloride, nickel sulfate, nickel carbonate, nickel nitrate; the divalent soluble manganese salt is any one or several of manganese chloride, manganese sulfate, manganese carbonate, manganese nitrate.
4. A long - life mesoporous carbon / nickel - cobalt - manganese hydrotalcite supercapacitor material according to claim 3, wherein: The molar ratio of the divalent soluble cobalt salt, divalent soluble nickel salt, divalent soluble manganese salt and hexamethylenetetramine is 1 - x:2:x:3, where the value range of x is 0.025~0.4; the molar mass ratio of the mixture formed by the divalent soluble cobalt salt and the divalent soluble manganese salt to the mesoporous carbon is 1:8~1:12, mmol:mg.
5. The long-life mesoporous carbon / nickel cobalt manganese hydrotalcite supercapacitor material according to claim 3, characterized in that: The solvent of the mesoporous carbon solution is any one or several of water, methanol, ethanol or acetone; the mass volume concentration of mesoporous carbon in the mesoporous carbon solution is 1.5~2.5 mg / ml.
6. The long-life mesoporous carbon / nickel cobalt manganese hydrotalcite supercapacitor material according to claim 3, characterized in that: The mesoporous carbon is prepared as follows: Add acetone, furfuryl alcohol and p-toluenesulfonic acid to mesoporous silica, stir at 10~35 °C to form a mixture. Dry the mixture at 140~160 °C. Place the dried mixture in a muffle furnace and react at 150 °C for 2 h to obtain a solid sample. Then place the solid sample in a tube furnace and carbonize it at 900 °C in a nitrogen atmosphere for 5 h to obtain a carbide. Add 1 mol / L NaOH solution to the carbide and stir for more than 24 h to obtain a stirred solution. Centrifuge the stirred solution to remove the supernatant, wash and dry the remaining solid to obtain mesoporous carbon.
7. A long-life mesoporous carbon / nickel cobalt manganese hydrotalcite supercapacitor material according to claim 6, characterized in that: The mass volume ratio of the mesoporous silica, acetone, furfuryl alcohol and p-toluenesulfonic acid is: 100:0.6:100:5, mg:ml:mg:mg; the mass volume ratio of the carbide to the NaOH solution is: 100:1, mg:L.
8. A long - life mesoporous carbon / nickel - cobalt - manganese hydrotalcite supercapacitor material according to claim 6, characterized in that: The rotation speed of the centrifugation is 4500~6000 rpm, the time is more than 5 min; the number of centrifugation operations is 4~6 times.
9. Application of the long-life mesoporous carbon / nickel cobalt manganese hydrotalcite supercapacitor material according to any one of claims 1~8 in a supercapacitor.