Foamed nickel positive electrode material for nickel-hydrogen battery and preparation method of foamed nickel positive electrode material
By preparing NiMoO4-graphene modified nickel foam positive electrode material, the performance problem of nickel-hydrogen battery positive electrode material is solved, and high discharge capacity, long life and good cycle stability are achieved, which is suitable for the industrial production of nickel-hydrogen batteries.
Patent Information
- Application Number
- CN202510840434.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-06-23
- Publication Date
- 2025-09-12
AI Technical Summary
The existing nickel foam positive electrode material of nickel-hydrogen batteries has problems such as complex production process, rapid electrode capacity decay, low discharge efficiency, and poor electrode performance balance, which limits its widespread application in fields such as electric vehicles.
By preparing Ni-NiO heterostructured nano-foam nickel sheets and growing three-dimensional graphene on their surface, they are then immersed in a mixture of molybdenum source and nickel source to form NiMoO4-graphene-modified foam nickel positive electrode materials. The process parameters are optimized to increase the contact area and conductivity between the electrode and the electrolyte.
It significantly improves the discharge capacity, coulombic efficiency and cycle stability of nickel-hydrogen batteries, prolongs the electrode life, improves the overall electrochemical performance, and facilitates industrial production.
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Figure BDA0005461931180000071
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of nickel-hydrogen batteries, and in particular to a foamed nickel positive electrode material for nickel-hydrogen batteries and a preparation method thereof. Background Art
[0002] Currently, the most widely used chemical power sources include lithium-ion batteries, lead-acid batteries, fuel cells, nickel-cadmium batteries, and nickel-zinc batteries. These chemical power sources have certain disadvantages, such as the poor safety of lithium-ion batteries; lead-acid batteries are heavy and bulky, with a relatively low specific energy density and environmental pollution; fuel cells are expensive and the technology is not yet mature; nickel-cadmium batteries have a memory effect, are highly polluting, and are difficult to meet the requirements of contemporary sustainable development; and the formation of zinc dendrites at the negative electrode and the poor cycling stability caused by the irreversibility of nickel-based cathodes, as well as the low capacity of nickel-based cathode materials, limit the further widespread application of nickel-zinc batteries.
[0003] Nickel-metal hydride batteries have the excellent performance of low cost and high power, and are considered to be one of the most promising power batteries for use in electric vehicles. Foamed nickel electrodes have become the main development direction of nickel electrodes due to their excellent comprehensive performance. Their main advantages are high specific capacity, simple electrode manufacturing process, short production cycle and low cost. However, the foamed nickel electrodes produced in the existing technology still have problems such as complex production process, rapid electrode capacity decay, low discharge efficiency and poor electrode performance balance.
[0004] In recent years, ternary metal oxides containing two different metal ions have attracted widespread attention due to their rich redox reactions and high electronic conductivity. For example, ternary metal molybdates such as MnMoO4, CoMoO4, and NiMoO4 have also attracted increasing attention in recent years. Due to the high electrochemical activity of nickel ions, NiMoO4 is expected to become an ideal electrode material for high-performance supercapacitors and batteries. Although NiMoO4 with different structures has been developed for energy storage applications, its practical application in this field is still limited due to its poor conductivity.
[0005] Therefore, it is of great significance to study and obtain a NiMoO4-modified nickel foam positive electrode material to improve the discharge capacity, coulombic efficiency and cycle stability of nickel-hydrogen batteries. Summary of the Invention
[0006] The object of the present invention is to provide a foam nickel positive electrode material for nickel-hydrogen batteries and a preparation method thereof in view of the deficiencies in the prior art.
[0007] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions:
[0008] The present invention provides a method for preparing a foamed nickel positive electrode material for a nickel-hydrogen battery, comprising the following steps:
[0009] 1) placing a nickel foam sheet in a Ni-NiO precursor solution for post-reaction annealing to obtain a Ni-NiO heterostructured nano-nickel foam sheet;
[0010] 2) A Ni-NiO heterostructured nano-foamed nickel sheet is introduced into a protective gas and hydrogen atmosphere to obtain a Ni-NiO heterostructured nano-foamed nickel sheet with three-dimensional graphene grown on the surface;
[0011] 3) The Ni-NiO heterostructured nano-foam nickel sheet with three-dimensional graphene grown on the surface is immersed in a mixture of a molybdenum source and a nickel source for reaction and then dried to obtain a NiMoO4-graphene modified foam nickel positive electrode material.
[0012] Preferably, the Ni-NiO precursor solution in step 1) comprises oxalic acid, hexamethylenetetramine, nickel nitrate hexahydrate and water, wherein the concentration of oxalic acid in the Ni-NiO precursor solution is 0.15 to 0.35 mol / L, the concentration of hexamethylenetetramine is 0.8 to 1.5 mol / L, and the concentration of nickel nitrate hexahydrate is 0.1 to 0.2 mol / L.
[0013] Preferably, the reaction temperature in step 1) is 100-120° C., and the reaction time is 2-4 h; the annealing temperature is 280-320° C., and the annealing time is 1-3 h, and the annealing is carried out under a nitrogen atmosphere.
[0014] Preferably, in step 2), the carbon source gas is introduced for 8 to 12 minutes at a flow rate of 3 to 7 sccm, and the carbon source gas is methanol or methane.
[0015] Preferably, in step 2), the temperature of the protective gas and hydrogen is 700-900° C., the protective gas is argon, the flow rate of the protective gas is 200-300 sccm, and the flow rate of the hydrogen is 100-150 sccm.
[0016] Preferably, the molybdenum source and nickel source mixed solution in step 3) comprises polyvinyl pyrrolidone, a nickel source, a molybdenum source and water; the nickel source is one or more of nickel nitrate hexahydrate, nickel chloride and nickel acetate, and the molybdenum source is ammonium molybdate and / or sodium molybdate.
[0017] Preferably, in the mixed solution of the molybdenum source and nickel source in step 3), the concentration of polyvinyl pyrrolidone is 0.02-0.05 mol / L, the concentration of the nickel source is 0.1-0.2 mol / L, and the concentration of the molybdenum source is 0.1-0.2 mol / L.
[0018] Preferably, the reaction temperature in step 3) is 120-150° C., and the reaction time is 3-5 h.
[0019] The present invention also provides a foamed nickel positive electrode material for a nickel-hydrogen battery prepared by the preparation method.
[0020] The beneficial effects of the present invention include the following:
[0021] 1) The Ni-NiO heterostructure and graphene of the present invention have excellent energy storage performance. By combining the Ni-NiO heterostructure, three-dimensional graphene and NiMoO4 and rationally controlling the process parameters, the contact area between the electrode and the electrolyte is increased, the conductivity and ion diffusion rate of the nickel foam positive electrode material are significantly improved, and the discharge capacity, coulombic efficiency and cycle stability of the nickel-hydrogen battery are significantly improved, the service life is extended, and the overall electrochemical performance is improved.
[0022] 2) The method for preparing NiMoO4-graphene-modified nickel foam positive electrode material of the present invention has low energy consumption and is environmentally friendly. It can reduce the expansion, deformation and aging of the electrode, extend the electrode life, and is easy to realize industrial production. It provides a good positive electrode material for nickel-hydrogen batteries and has great application prospects. DETAILED DESCRIPTION
[0023] The present invention provides a method for preparing a foamed nickel positive electrode material for a nickel-hydrogen battery, comprising the following steps:
[0024] 1) placing a nickel foam sheet in a Ni-NiO precursor solution for post-reaction annealing to obtain a Ni-NiO heterostructured nano-nickel foam sheet;
[0025] 2) A Ni-NiO heterostructured nano-foamed nickel sheet is introduced into a protective gas and hydrogen atmosphere to obtain a Ni-NiO heterostructured nano-foamed nickel sheet with three-dimensional graphene grown on the surface;
[0026] 3) The Ni-NiO heterostructured nano-foam nickel sheet with three-dimensional graphene grown on the surface is immersed in a mixture of a molybdenum source and a nickel source for reaction and then dried to obtain a NiMoO4-graphene modified foam nickel positive electrode material.
[0027] In the present invention, the Ni-NiO precursor solution in step 1) preferably comprises oxalic acid, hexamethylenetetramine, nickel nitrate hexahydrate and water. In the Ni-NiO precursor solution, the concentration of oxalic acid is preferably 0.15 to 0.35 mol / L, more preferably 0.2 to 0.3 mol / L, more preferably 0.25 mol / L, the concentration of hexamethylenetetramine is preferably 0.8 to 1.5 mol / L, more preferably 1 to 1.3 mol / L, more preferably 1.1 to 1.2 mol / L, and the concentration of nickel nitrate hexahydrate is preferably 0.1 to 0.2 mol / L, more preferably 0.12 to 0.18 mol / L, more preferably 0.14 to 0.15 mol / L.
[0028] In the present invention, the reaction temperature in step 1) is preferably 100-120°C, more preferably 105-115°C, more preferably 110°C, and the reaction time is preferably 2-4h, more preferably 2.5-3.5h, more preferably 3h; the annealing temperature is preferably 280-320°C, more preferably 290-310°C, more preferably 300-305°C, and the annealing time is preferably 1-3h, more preferably 1.5-2.5h, more preferably 2h, and the annealing is preferably carried out under a nitrogen atmosphere.
[0029] In the present invention, after the reaction in step 1) is completed, drying is performed first and then annealing is performed; the drying temperature is preferably 70-85° C., more preferably 75-80° C., and the drying time is preferably 1-2 h, more preferably 1.5 h.
[0030] In the present invention, the introduction time of the carbon source gas in step 2) is preferably 8 to 12 minutes, more preferably 9 to 11 minutes, and more preferably 10 minutes. The flow rate of the carbon source gas is preferably 3 to 7 sccm, more preferably 4 to 6 sccm, and more preferably 5 sccm. The carbon source gas is preferably methanol or methane.
[0031] In the present invention, the temperature of the protective gas and hydrogen in step 2) is preferably 700-900°C, more preferably 750-850°C, and more preferably 800-820°C. The protective gas is preferably argon, and the flow rate of the protective gas is preferably 200-300 sccm, more preferably 220-280 sccm, and more preferably 250-260 sccm. The flow rate of hydrogen is preferably 100-150 sccm, more preferably 110-140 sccm, and more preferably 120-130 sccm.
[0032] In the present invention, after the carbon source gas in step 2) is stopped from being introduced, the mixture is cooled to room temperature at a rate of 150-200° C. / min, and the protective gas and hydrogen are turned off.
[0033] In the present invention, the mixed solution of molybdenum source and nickel source in step 3) preferably comprises polyvinyl pyrrolidone, nickel source, molybdenum source and water; the nickel source is preferably one or more of nickel nitrate hexahydrate, nickel chloride and nickel acetate, and the molybdenum source is preferably ammonium molybdate and / or sodium molybdate.
[0034] In the present invention, in the mixed solution of the molybdenum source and the nickel source in step 3), the concentration of polyvinyl pyrrolidone is preferably 0.02-0.05 mol / L, more preferably 0.03-0.04 mol / L, more preferably 0.035 mol / L, the concentration of the nickel source is preferably 0.1-0.2 mol / L, more preferably 0.12-0.18 mol / L, more preferably 0.14-0.15 mol / L, and the concentration of the molybdenum source is preferably 0.1-0.2 mol / L, more preferably 0.12-0.18 mol / L, more preferably 0.14-0.15 mol / L.
[0035] In the present invention, the reaction temperature in step 3) is preferably 120-150°C, more preferably 125-145°C, more preferably 135-140°C, and the reaction time is preferably 3-5h, more preferably 3.5-4.5h, more preferably 4h.
[0036] In the present invention, the drying temperature in step 3) is preferably 60-70°C, more preferably 62-68°C, more preferably 64-65°C, and the drying time is preferably 5-7h, more preferably 5.5-6.5h, more preferably 6h.
[0037] The present invention also provides a foamed nickel positive electrode material for a nickel-hydrogen battery prepared by the preparation method.
[0038] The technical solutions provided by the present invention are described in detail below with reference to the embodiments, but they should not be construed as limiting the scope of protection of the present invention.
[0039] In the embodiment, the nickel foam sheet is an activated nickel foam sheet, and the activation treatment process is: the original nickel foam sheet is activated in 2 mol / L hydrochloric acid for 10 minutes.
[0040] Example 1
[0041] The Ni-NiO precursor solution consists of oxalic acid, hexamethylenetetramine, nickel nitrate hexahydrate and deionized water, with the concentration of oxalic acid being 0.2 mol / L, the concentration of hexamethylenetetramine being 1 mol / L, and the concentration of nickel nitrate hexahydrate being 0.12 mol / L; the foam nickel sheet is placed in the Ni-NiO precursor solution, reacted at 105°C for 4 hours, dried at 75°C for 2 hours, and then annealed at 290°C in a nitrogen atmosphere for 3 hours to obtain a Ni-NiO heterostructured nano-foam nickel sheet.
[0042] Argon was introduced at a flow rate of 220 sccm, and hydrogen was introduced at a flow rate of 100 sccm. The temperature of the argon and hydrogen was 750°C. In the argon and hydrogen atmosphere, methanol was introduced at a flow rate of 3 sccm for 12 minutes. After the introduction of methanol was stopped, the sample was cooled to room temperature at a rate of 180°C / min. The argon and hydrogen were turned off to obtain a Ni-NiO heterostructured nano-foam nickel sheet with three-dimensional graphene grown on its surface.
[0043] The molybdenum source and nickel source mixture consists of polyvinyl pyrrolidone, nickel nitrate hexahydrate, ammonium molybdate and deionized water. In the molybdenum source and nickel source mixture, the concentration of polyvinyl pyrrolidone is 0.02 mol / L, the concentration of nickel nitrate hexahydrate is 0.12 mol / L, and the concentration of ammonium molybdate is 0.12 mol / L. Ni-NiO heterostructured nano-foam nickel sheets with three-dimensional graphene grown on the surface are immersed in the molybdenum source and nickel source mixture, reacted at 125°C for 5 hours, and then dried at 60°C for 7 hours to obtain a NiMoO4-graphene modified foam nickel positive electrode material.
[0044] Example 2
[0045] The Ni-NiO precursor solution consists of oxalic acid, hexamethylenetetramine, nickel nitrate hexahydrate and deionized water, with the concentration of oxalic acid being 0.3 mol / L, the concentration of hexamethylenetetramine being 1.3 mol / L, and the concentration of nickel nitrate hexahydrate being 0.18 mol / L; the foam nickel sheet is placed in the Ni-NiO precursor solution, reacted at 115°C for 2 hours, dried at 85°C for 1 hour, and then annealed at 310°C in a nitrogen atmosphere for 1.5 hours to obtain a Ni-NiO heterostructured nano-foam nickel sheet.
[0046] Argon was introduced at a flow rate of 280 sccm, and hydrogen was introduced at a flow rate of 150 sccm. The temperature of the argon and hydrogen was 850°C. In the argon and hydrogen atmosphere, methane was introduced at a flow rate of 6 sccm for 9 minutes. After the introduction of methane was stopped, the sample was cooled to room temperature at a rate of 160°C / min, and the argon and hydrogen were turned off to obtain a Ni-NiO heterostructured nano-foam nickel sheet with three-dimensional graphene grown on its surface.
[0047] The molybdenum source and nickel source mixture consists of polyvinyl pyrrolidone, nickel acetate, sodium molybdate and deionized water. In the molybdenum source and nickel source mixture, the concentration of polyvinyl pyrrolidone is 0.05 mol / L, the concentration of nickel acetate is 0.18 mol / L, and the concentration of sodium molybdate is 0.18 mol / L. A Ni-NiO heterostructured nano-foam nickel sheet with three-dimensional graphene grown on the surface is immersed in the molybdenum source and nickel source mixture, reacted at 145°C for 3 hours, and then dried at 70°C for 5 hours to obtain a NiMoO4-graphene-modified foam nickel positive electrode material.
[0048] Example 3
[0049] The Ni-NiO precursor solution consists of oxalic acid, hexamethylenetetramine, nickel nitrate hexahydrate and deionized water, with the concentration of oxalic acid being 0.25 mol / L, the concentration of hexamethylenetetramine being 1.2 mol / L and the concentration of nickel nitrate hexahydrate being 0.15 mol / L; the foam nickel sheet is placed in the Ni-NiO precursor solution, reacted at 110°C for 3 hours and then dried at 80°C for 1.5 hours, and then annealed at 300°C in a nitrogen atmosphere for 2 hours to obtain a Ni-NiO heterostructured nano-foam nickel sheet.
[0050] Argon was introduced at a flow rate of 260 sccm, and hydrogen was introduced at a flow rate of 130 sccm. The temperature of the argon and hydrogen was 800°C. Methanol was introduced under the argon and hydrogen atmosphere at a flow rate of 5 sccm for 10 minutes. After the introduction of methanol was stopped, the sample was cooled to room temperature at a rate of 190°C / min. The argon and hydrogen were turned off to obtain a Ni-NiO heterostructured nano-foam nickel sheet with three-dimensional graphene grown on its surface.
[0051] The molybdenum source and nickel source mixture consists of polyvinyl pyrrolidone, nickel nitrate hexahydrate, sodium molybdate and deionized water. In the molybdenum source and nickel source mixture, the concentration of polyvinyl pyrrolidone is 0.04 mol / L, the concentration of nickel nitrate hexahydrate is 0.15 mol / L, and the concentration of sodium molybdate is 0.15 mol / L. Ni-NiO heterostructured nano-foam nickel sheets with three-dimensional graphene grown on the surface are immersed in the molybdenum source and nickel source mixture, reacted at 135°C for 4 hours, and then dried at 65°C for 6 hours to obtain a NiMoO4-graphene modified foam nickel positive electrode material.
[0052] Comparative Example 1
[0053] On the basis of Example 3, the Ni-NiO precursor solution was omitted and three-dimensional graphene was grown directly on the surface of the nickel foam sheet. The flow rate of methanol was 10 sccm, and the reaction temperature in the molybdenum source and nickel source mixture was 100°C; other process conditions were the same as in Example 3.
[0054] Comparative Example 2
[0055] On the basis of Example 3, the step of growing three-dimensional graphene on the surface was omitted, and the Ni-NiO heterostructure nano-foam nickel sheet was directly immersed in a mixture of a molybdenum source and a nickel source; in the mixture of the molybdenum source and the nickel source, the concentration of polyvinyl pyrrolidone was 0.1 mol / L, the concentration of nickel nitrate hexahydrate was 0.05 mol / L, and the concentration of sodium molybdate was 0.05 mol / L; the other process conditions were the same as those in Example 3.
[0056] The nickel foam positive electrode material of the embodiment or comparative example was used as the battery positive electrode, nickel hydride metal was used as the battery negative electrode, a polypropylene separator was placed between the positive and negative electrodes, and a 30 wt % KOH aqueous solution was used as the electrolyte. A nickel-hydrogen battery was prepared according to conventional methods in the art. The discharge capacity, coulombic efficiency, and cycle stability of the nickel-hydrogen battery were tested at a current of 10 mA. The results are shown in Table 1.
[0057] Table 1 Performance test results of nickel-hydrogen batteries prepared from positive electrode materials of Examples and Comparative Examples
[0058]
[0059] As can be seen from Table 1, the present invention combines Ni-NiO heterostructure, three-dimensional graphene and NiMoO4, and reasonably controls the process parameters to increase the contact area between the electrode and the electrolyte, thereby improving the performance of the nickel foam positive electrode material. The nickel-hydrogen battery prepared with the nickel foam positive electrode material has a high discharge capacity. The battery discharge capacity retention rate of the nickel-hydrogen battery is more than 91% after 500 cycles, and the discharge capacity retention rate is more than 86% after 1000 cycles. There is no obvious attenuation of the discharge capacity. The initial coulomb efficiency is more than 98.5%, and the coulomb efficiency is more than 97.0% after 500 cycles, and the service life is significantly extended.
[0060] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as within the scope of protection of the present invention.
Claims
1. A method for preparing a foamed nickel positive electrode material for a nickel-hydrogen battery, characterized in that: The following steps are included: 1) placing a nickel foam sheet in a Ni-NiO precursor solution for post-reaction annealing to obtain a Ni-NiO heterostructured nano-nickel foam sheet; 2) A Ni-NiO heterostructured nano-foamed nickel sheet is introduced into a protective gas and hydrogen atmosphere to obtain a Ni-NiO heterostructured nano-foamed nickel sheet with three-dimensional graphene grown on the surface; 3) The Ni-NiO heterostructured nano-foam nickel sheet with three-dimensional graphene grown on the surface is immersed in a mixture of a molybdenum source and a nickel source for reaction and then dried to obtain a NiMoO4-graphene modified foam nickel positive electrode material.
2. The preparation method according to claim 1, characterized in that Step 1) The Ni-NiO precursor solution comprises oxalic acid, hexamethylenetetramine, nickel nitrate hexahydrate and water. In the Ni-NiO precursor solution, the concentration of oxalic acid is 0.15-0.35 mol / L, the concentration of hexamethylenetetramine is 0.8-1.5 mol / L, and the concentration of nickel nitrate hexahydrate is 0.1-0.2 mol / L.
3. The preparation method according to claim 1 or 2, characterized in that Step 1) The reaction temperature is 100-120° C., and the reaction time is 2-4 hours; the annealing temperature is 280-320° C., and the annealing time is 1-3 hours. The annealing is carried out under a nitrogen atmosphere.
4. The preparation method according to claim 3, characterized in that In step 2), the carbon source gas is introduced for 8 to 12 minutes at a flow rate of 3 to 7 sccm. The carbon source gas is methanol or methane.
5. The preparation method according to claim 3, characterized in that Step 2) The temperature of the protective gas and hydrogen is 700-900° C., the protective gas is argon, the flow rate of the protective gas is 200-300 sccm, and the flow rate of the hydrogen is 100-150 sccm.
6. The preparation method according to claim 4 or 5, characterized in that In step 3), the molybdenum source and nickel source mixed solution comprises polyvinyl pyrrolidone, a nickel source, a molybdenum source and water; the nickel source is one or more of nickel nitrate hexahydrate, nickel chloride and nickel acetate, and the molybdenum source is ammonium molybdate and / or sodium molybdate.
7. The preparation method according to claim 6, characterized in that In step 3), in the mixed solution of the molybdenum source and the nickel source, the concentration of polyvinyl pyrrolidone is 0.02-0.05 mol / L, the concentration of the nickel source is 0.1-0.2 mol / L, and the concentration of the molybdenum source is 0.1-0.2 mol / L.
8. The preparation method according to claim 7, characterized in that Step 3) The reaction temperature is 120-150° C., and the reaction time is 3-5 h.
9. A foamed nickel positive electrode material for nickel-hydrogen batteries prepared by the preparation method according to any one of claims 1 to 8.