Aluminum negative electrode based on mof interface modification and preparation method thereof

Abstract

The present application relates to an aluminum negative electrode based on MOF interface modification and a preparation method thereof, and belongs to the technical field of batteries, and specifically relates to an interface modification technology based on MOF, which is used for realizing a stable long-cycle aluminum negative electrode. The method of the present application successfully improves the negative electrode performance of an aluminum secondary battery by in-situ synthesizing a modification layer on the surface of an aluminum foil through a hydrothermal method. The modification layer not only increases the active site density of the surface of the aluminum negative electrode, optimizes the electrode reaction interface structure, significantly improves the cycle performance and safety of the battery, but also successfully suppresses the generation of aluminum dendrites and reduces the short circuit risk in the cycle process of the battery. In addition, the modification layer serves as a protective layer, effectively prevents the corrosion of aluminum in the electrolyte, prolongs the service life of the aluminum foil, and reduces the maintenance cost of the battery.

Description

Technical Field

[0001] This invention relates to aluminum anodes based on MOF interface modification and their preparation methods, belonging to the field of battery technology. Specifically, it relates to an interface modification technology based on MOF for achieving stable long-cycle aluminum anodes. Background Technology

[0002] With the development of the electrochemical energy storage field, the research and development of battery materials has become increasingly important. Aluminum secondary batteries, as a novel electrochemical energy storage device, offer advantages such as low cost, environmental friendliness, and high safety. The aluminum anode is a crucial component of aluminum secondary batteries, and its performance directly affects the battery's cycle life and safety. During cycling, the aluminum anode is prone to problems such as aluminum corrosion and aluminum dendrite formation, leading to a decline in battery performance. However, aluminum secondary batteries face several challenges in practical applications, primarily including aluminum anode corrosion and aluminum dendrite formation, which limit their cycle life and safety.

[0003] While the importance of aluminum anodes in aluminum secondary batteries is widely recognized, current protection technologies still have many shortcomings. Existing aluminum anode protection methods mainly include surface coating and alloying. However, each of these methods has certain limitations. Surface coating technology often faces the problem of insufficient adhesion between the coating and the aluminum substrate, making it prone to peeling off during cycling, leading to a gradual weakening of the protective effect. Although alloying can improve the corrosion resistance of aluminum anodes, the complex alloy preparation process and high material cost limit its large-scale application. Summary of the Invention

[0004] The technical problem solved by this invention is to overcome the shortcomings of the prior art and propose an aluminum anode based on MOF interface modification and its preparation method.

[0005] The technical solution of this invention is:

[0006] The aluminum anode based on MOF interface modification includes an aluminum metal matrix and a MOF particle layer located on the surface of the aluminum metal matrix, or it can be an aluminum metal matrix and a MOF-C particle layer located on the surface of the aluminum metal matrix. The stability and durability of the aluminum anode based on MOF interface modification are improved, and stable long-term cycling is achieved.

[0007] The technical solution of this invention is:

[0008] A method for preparing an aluminum anode based on MOF interface modification, wherein the prepared aluminum anode comprises an aluminum metal substrate and a MOF particle layer located on the surface of the aluminum metal substrate, and the specific steps are as follows:

[0009] The first step is to mix water, nitric acid and coordination material to obtain a mixture with a mass ratio of 200:5-20:2-5.

[0010] The second step is to perform surface pretreatment on the aluminum metal substrate. Surface pretreatment refers to removing the oxide film on the surface of the aluminum metal substrate by using alkaline or acidic reagents; NaOH solution is preferred as the alkaline reagent, and hydrochloric acid is preferred as the acidic reagent.

[0011] The third step involves hydrothermal synthesis of the aluminum metal substrate after surface pretreatment in the second step and the mixture obtained in the first step in a hydrothermal reactor. The hydrothermal synthesis temperature is 160-200℃ and the hydrothermal synthesis time is 10-16h.

[0012] The fourth step involves washing and drying the hydrothermal synthesis product from the third step to obtain an aluminum anode based on MOF interface modification.

[0013] A method for preparing an aluminum anode based on MOF interface modification, wherein the prepared aluminum anode comprises an aluminum metal matrix and a MOF-C particle layer located on the surface of the aluminum metal matrix, and the specific steps are as follows:

[0014] The first step is to mix water, nitric acid and coordination material to obtain a mixture with a mass ratio of 200:5-20:2-5.

[0015] The second step is to perform surface pretreatment on the aluminum metal substrate. Surface pretreatment refers to removing the oxide film on the surface of the aluminum metal substrate by using alkaline or acidic reagents; NaOH solution is preferred as the alkaline reagent, and hydrochloric acid is preferred as the acidic reagent.

[0016] The third step involves hydrothermal synthesis of the aluminum metal substrate after surface pretreatment in the second step and the mixture obtained in the first step in a hydrothermal reactor. The hydrothermal synthesis temperature is 160-200℃ and the hydrothermal synthesis time is 10-16h.

[0017] The fourth step involves washing, drying, and heating the hydrothermal synthesis product from the third step to obtain an aluminum anode based on MOF-C interface modification. The heating temperature is 550-600℃, and the heating time is 12-16h.

[0018] The application of MOF-modified aluminum anodes in aluminum secondary batteries can improve the cycle performance and safety of aluminum secondary batteries.

[0019] The coordinating material is one of the following: benzoic acid, aromatic amine, aromatic diketone, aromatic triketone, pyridine, amino acid, ether, nitro compound, and heterocyclic compound;

[0020] The benzoic acids include benzoic acid, phthalic acid, and tribenzoic acid;

[0021] The aromatic amines include p-phenylenediamine and p-hydroxyaniline;

[0022] The aromatic diketones include m-phenylenedione and p-phenylenedione;

[0023] The aromatic triketones include phenyltriketone and m-phenyltriketone;

[0024] The pyridines include pyridine, para-dipyridine, and pyridinone;

[0025] The amino acids include aminoacetic acid and aminopropionic acid;

[0026] The ethers include ethylene glycol and glycine ethyl ester;

[0027] The nitro compounds include nitrobenzene and nitrobenzene;

[0028] The MOF is an aluminum-based MOF, such as at least one of MIL-96, MIL-100, MIL-110, MIL-53, CAU-10, MOF-74, NOTT-300, MIL-68, PCN-333, MOF-177, CAU-17, MIL-125, NU-1000, DUT-5, MMPF-12, MIL-160, CPO-27, and NU-901.

[0029] The thickness of the MOF particle layer located on the surface of the aluminum metal substrate is 10-20 μm;

[0030] The thickness of the MOF-C particle layer located on the surface of the aluminum metal substrate is 10-20 μm;

[0031] During drying, the drying temperature is 80-200℃ and the drying time is 10-24h.

[0032] Beneficial effects

[0033] (1) The method of the present invention effectively increases the active sites on the negative electrode surface by forming a modification layer on the surface of the aluminum metal substrate, which is beneficial to reducing the polarization voltage of the battery electrode;

[0034] (2) The method of the present invention can improve the cycle performance of aluminum secondary batteries and suppress the formation of aluminum dendrites and corrosion by forming a modification layer on the surface of aluminum metal substrate, thereby significantly improving the cycle performance of the battery.

[0035] (3) This invention relates to an interface modification technology based on metal-organic framework (MOF) materials, aiming to solve problems existing in aluminum anodes in aluminum secondary batteries, such as aluminum corrosion and aluminum dendrite formation, to improve the cycle life and safety of the battery. This technology improves the interaction between the anode surface and the electrolyte by forming a uniform and dense MOF modification layer on the surface of the aluminum anode, thereby enhancing the stability and durability of the aluminum anode. This invention provides detailed implementation steps, including the preparation of a precursor solution, treatment of the aluminum substrate, hydrothermal synthesis, drying, and heat treatment. Experimental results show that this technology can effectively improve the cycle performance of aluminum secondary batteries and has good industrial application prospects. This invention, through the method of synthesizing a MOF modification layer on the aluminum surface in situ, enables aluminum metal to cycle stably in an ionic liquid electrolyte system, inhibiting aluminum metal corrosion and dendrite growth, preventing battery failure, and effectively improving the cycle stability of aluminum secondary batteries. The technical solution of this invention is simple and feasible, can effectively improve the cycle life and safety of aluminum secondary batteries, and has good application prospects.

[0036] (4) The method of the present invention successfully improves the negative electrode performance of aluminum secondary batteries by synthesizing a MIL-96-C modification layer in situ on the surface of aluminum foil using a hydrothermal method. This modification layer not only increases the density of active sites on the surface of the aluminum negative electrode and optimizes the electrode reaction interface structure, significantly improving the cycle performance and safety of the battery, but also successfully inhibits the formation of aluminum dendrites, reducing the risk of short circuits during battery cycling. In addition, the MIL-96-C modification layer, as a protective layer, effectively prevents the corrosion of aluminum in the electrolyte, extends the service life of the aluminum foil, and reduces the maintenance cost of the battery.

[0037] (5) The preparation process of this invention is simple and efficient, requiring no complex preparation steps or expensive raw materials, which helps reduce preparation costs and is suitable for industrial production. Furthermore, the hydrothermal synthesis method for the MIL-96-C modified layer does not require large amounts of organic solvents and toxic reagents, exhibiting good environmental friendliness and effectively utilizing raw materials while saving energy. Overall, this invention not only improves the cycle life and safety of aluminum secondary batteries but also has good environmental and energy-saving effects, providing greater possibilities for the optimization of aluminum secondary batteries.

[0038] (6) The method for preparing aluminum anodes based on MOF interface modification proposed in this invention has significant advantages. By synthesizing MOF materials in situ on the surface of aluminum foil, a uniform and robust protective layer can be formed on the surface of the aluminum anode. Due to its unique porous structure and tunable chemical properties, MOF materials can not only effectively inhibit the formation of aluminum dendrites but also significantly reduce the corrosion of aluminum metal. In addition, the in-situ synthesis technology ensures a tight bond between the MOF layer and the aluminum substrate, improving the stability of the interface and thus extending the cycle life of the battery. Compared with traditional coating and alloying methods, the MOF modification technology in this patent is more cost-effective and provides reliable technical support for the practical application of aluminum secondary batteries. Attached Figure Description

[0039] Figure 1 SEM image of the MIL-96-C modified layer;

[0040] Figure 2 Electrochemical performance diagram of a symmetric cell assembled with an aluminum layer modified with MIL-96-C. Detailed Implementation

[0041] The following provides a detailed description of specific embodiments of the present invention. It should be understood that the specific embodiments described herein are for illustrative and explanatory purposes only and are not intended to limit the scope of the invention.

[0042] The present invention discloses a method for processing the aluminum negative electrode in an aluminum secondary battery, the method comprising the following steps:

[0043] I. Preparation of precursor solution:

[0044] a. Weigh out an appropriate amount of M in a clean container.

[0045] b. Add an appropriate amount of N to the container.

[0046] c. Stir the mixture thoroughly with a glass rod or magnetic stirrer to obtain a homogeneous mixture.

[0047] II. Treatment of the aluminum substrate:

[0048] a. Place the aluminum foil in solution L to ensure that the oxide film on the surface of the aluminum foil is completely removed.

[0049] b. Remove the processed aluminum foil and clean it with alcohol.

[0050] III. Hydrothermal Synthesis:

[0051] a. Place the treated aluminum foil and precursor solution in a hydrothermal reactor.

[0052] b. Heat the reaction vessel.

[0053] c. After the reaction is complete, remove the reactor from the heating source and allow it to cool to room temperature.

[0054] d. Open the reactor, remove the aluminum foil, and thoroughly wash it with deionized water or other solvents to remove unreacted substances and residual solvents.

[0055] IV. Drying:

[0056] a. Place the treated aluminum foil in a vacuum drying oven to dry it completely.

[0057] V. Heat Treatment:

[0058] a. Place the dried aluminum foil into a heating device protected by an inert gas.

[0059] b. Heat the heating device and keep the temperature stable.

[0060] c. Heat the aluminum foil for a certain period of time to convert the MIL-96 on the surface of the aluminum foil into MIL-96-C.

[0061] d. After the heat treatment is completed, cool the heating device to room temperature.

[0062] VI. Collect and test samples:

[0063] a. Store the heated aluminum foil in a sealed container to prevent the aluminum foil from reacting with air and forming an oxide film.

[0064] b. Characterize and analyze the prepared aluminum foil sheets, such as by scanning electron microscopy (SEM) and by assembling them into symmetrical cells in an ionic liquid system.

[0065] In step one, the raw materials for the precursor solution are: M is HNO3, and N is Me3BTC (trimethyl 1,3,5-benzenetricarboxylic acid). The aluminum foil is an aluminum sheet that can be used as the negative electrode of an aluminum secondary battery.

[0066] In step two, the L solution used to treat the aluminum substrate is an acidic or alkaline reagent, preferably a NaOH solution.

[0067] In step three, the hydrothermal treatment time is 12 hours and the heating temperature is 180°C.

[0068] In step five, the heating time is 12 hours and the heating temperature is 600℃.

[0069] In step six, the raw materials for the ionic liquid are 1-ethyl-3-methylimidazolium chloride and aluminum chloride powder, with a molar ratio of EMIC:AlCl3 = 1:1.3.

[0070] The controllable diameter of MIL-96 on the surface of the high-purity aluminum sheet is 10-20μm, occupying 100% of the surface of the high-purity aluminum sheet.

[0071] Example 1

[0072] The preparation method of aluminum anode based on MOF interface modification includes the following steps:

[0073] I. Preparation of precursor solution:

[0074] Take 0.8g of nitric acid (HNO3) in a clean container.

[0075] Add 1.5g of Me3BTC (trimethyl 1,3,5-benzenetricarboxylate) to the container.

[0076] Add 100ml of water to a container and use a glass rod or magnetic stirrer to stir the mixture thoroughly until a homogeneous mixture is obtained.

[0077] II. Treatment of the aluminum substrate:

[0078] Place a 5cm x 5cm piece of aluminum foil into a container containing 100mL of 10% NaOH solution (L) to ensure that the oxide film on the surface of the aluminum foil is completely removed.

[0079] Remove the treated aluminum foil and wash it with 75% ethanol to remove surface impurities.

[0080] III. Hydrothermal Synthesis:

[0081] The treated aluminum foil and precursor solution were placed in a 500 mL hydrothermal reactor.

[0082] The reactor was heated to 180°C and kept at that temperature for 12 hours.

[0083] After the reaction is complete, remove the reactor from the heating source and allow it to cool to room temperature.

[0084] Open the reaction vessel, remove the aluminum foil, and thoroughly wash it with deionized water or other solvents to remove unreacted substances and residual solvents.

[0085] IV. Drying:

[0086] The treated aluminum foil was placed in a vacuum drying oven and dried at 80°C for 24 hours.

[0087] V. Collect and test samples:

[0088] The aluminum foil modified with the MIL-96 modification layer prepared by the above steps should be stored in a sealed container to prevent the aluminum foil from reacting with air and forming an oxide film.

[0089] Example 2

[0090] The preparation method of aluminum anode based on MOF interface modification includes the following steps:

[0091] I. Preparation of precursor solution:

[0092] Take 0.8g of nitric acid (HNO3) in a clean container.

[0093] Add 1.5g of Me3BTC (trimethyl 1,3,5-benzenetricarboxylate) to the container.

[0094] Add 100ml of water to a container and use a glass rod or magnetic stirrer to stir the mixture thoroughly until a homogeneous mixture is obtained.

[0095] II. Treatment of the aluminum substrate:

[0096] Place a 5cm x 5cm piece of aluminum foil into a container containing 100mL of 10% NaOH solution (L) to ensure that the oxide film on the surface of the aluminum foil is completely removed.

[0097] Remove the treated aluminum foil and wash it with 75% ethanol to remove surface impurities.

[0098] III. Hydrothermal Synthesis:

[0099] The treated aluminum foil and precursor solution were placed in a 500 mL hydrothermal reactor.

[0100] The reactor was heated to 180°C and kept at that temperature for 12 hours.

[0101] After the reaction is complete, remove the reactor from the heating source and allow it to cool to room temperature.

[0102] Open the reaction vessel, remove the aluminum foil, and thoroughly wash it with deionized water or other solvents to remove unreacted substances and residual solvents.

[0103] IV. Drying:

[0104] The treated aluminum foil was placed in a vacuum drying oven and dried at 80°C for 24 hours.

[0105] V. Heat Treatment:

[0106] Place the dried aluminum foil into the heating device.

[0107] Heat the heating device to 600℃ and maintain the temperature for 12 hours.

[0108] The aluminum foil was heated at 600°C for 12 hours. After the heat treatment was completed, the heating device was cooled to room temperature.

[0109] VI. Collect samples and test:

[0110] Store the heated aluminum foil in a sealed container to prevent it from reacting with air and forming an oxide film.

[0111] The above steps prepare aluminum foil modified with the MIL-96-C modification layer, which is used to assemble aluminum secondary batteries.

[0112] SEM images of the aluminum foil modified with the MIL-96-C modification layer are shown below. Figure 1 As shown, by Figure 1 It can be seen that the synthesized MIL-96-C material has good particle morphology and high crystallinity, exhibiting a dense and uniform hexagonal bitruxed granular structure with uniform particle distribution and a particle size of about 15 micrometers.

[0113] Electrochemical tests were performed on the assembled aluminum symmetric cell, and the results are as follows: Figure 2 As shown, by Figure 2 It can be seen that the aluminum symmetric cell assembled with aluminum foil modified by MIL-96-C has a deposition / dissolution overpotential of 15mV and a cycle time of 7800 hours, exhibiting excellent stability and long cycle performance.

[0114] Example 3

[0115] The method described in Example 1 is different, except that the mixture consists of 3g of terephthalic acid, 2g of sodium oxalate, and 100mL of deionized water, which are added sequentially to a clean container. The mixture is thoroughly stirred using a glass rod or magnetic stirrer, transferred to a hydrothermal reactor, and an aluminum substrate is placed inside. The reactor is heated to 180°C and maintained at a constant temperature for 12 hours. After the reaction is complete, the reactor is removed from the heat source and cooled to room temperature. An aluminum foil with a CAU-10 modified layer is obtained.

[0116] Example 4

[0117] The method described in Example 1 is different, except that the mixture consists of 2g of tricresylbenzene, 1g of lithium fluoride, and 100mL of deionized water, which are added sequentially to a clean container. The mixture is thoroughly stirred using a glass rod or magnetic stirrer, transferred to a hydrothermal reactor, and an aluminum substrate is placed inside. The reactor is heated to 180°C and maintained at a constant temperature for 12 hours. After the reaction is complete, the reactor is removed from the heat source and cooled to room temperature. An aluminum foil with a NOTT-300 modified layer is obtained.

[0118] Example 5

[0119] The method described in Example 1 is different, except that the mixture consists of 1.5 g phthalic acid, 1 g lithium fluoride, and 100 mL deionized water, which are added sequentially to a clean container. The mixture is thoroughly stirred using a glass rod or magnetic stirrer, transferred to a hydrothermal reactor, and an aluminum substrate is placed inside. The reactor is heated to 180°C and maintained at a constant temperature for 12 hours. After the reaction is complete, the reactor is removed from the heat source and cooled to room temperature. An aluminum foil with a PCN-333 modified layer is obtained.

[0120] Example 6

[0121] The method described in Example 1 is different, except that the mixture consists of 2.5 g benzoic acid, 1.8 g potassium chloride, and 100 mL deionized water, which are added sequentially to a clean container. The mixture is thoroughly stirred using a glass rod or magnetic stirrer, transferred to a hydrothermal reactor, and an aluminum substrate is placed inside. The reactor is heated to 180°C and maintained at a constant temperature for 12 hours. After the reaction is complete, the reactor is removed from the heat source and cooled to room temperature. An aluminum foil with a CPM-800 modified layer is obtained.

[0122] Comparative example: Aluminum foil was used directly to assemble aluminum secondary batteries.

[0123] Table 1: Comparison of overpotentials after stabilization of metal-symmetric cells in the examples and comparative examples

[0124]

[0125]

[0126] The results from Examples 1-6 and Comparative Example 1 show that the aluminum-pair batteries assembled with the optimized aluminum sheets in Examples 1-6 of the present invention have significantly better cycle life than the aluminum-pair batteries assembled with untreated aluminum sheets, which can significantly improve the stability of the batteries.

[0127] The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited to the specific details in the above embodiments. Within the scope of the technical concept of the present invention, various simple modifications can be made to the technical solution of the present invention, and these simple modifications all fall within the protection scope of the present invention.

[0128] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present invention will not describe the various possible combinations separately.

[0129] Furthermore, various different embodiments of the present invention can be combined in any way, as long as they do not violate the spirit of the present invention, they should also be regarded as the content disclosed by the present invention.

[0130] In summary, the above are merely preferred embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for preparing an aluminum anode based on MOF interface modification, characterized in that... The specific steps are as follows: The first step is to mix water, nitric acid, and the coordination material to obtain a mixture; The second step is to perform surface pretreatment on the aluminum metal substrate; The third step involves hydrothermal synthesis of the aluminum metal substrate that has undergone surface pretreatment in the second step and the mixture obtained in the first step in a hydrothermal reactor. The fourth step involves washing and drying the hydrothermal synthesis product from the third step to obtain an aluminum anode based on MOF interface modification. The obtained aluminum anode based on MOF interface modification was heated in an inert gas protective atmosphere to obtain an aluminum anode based on MOF-C interface modification. The heating temperature is 550-600℃, the heating time is 12-16h, and the inert gas is one of helium, neon, argon, krypton, xenon and nitrogen. The MOF is at least one of MIL-96, MIL-100, MIL-110, MIL-53, CAU-10, MOF-74, NOTT-300, MIL-68, PCN-333, MOF-177, CAU-17, MIL-125, NU-1000, DUT-5, MMPF-12, MIL-160, CPO-27, and NU-901. The thickness of the MOF particle layer located on the surface of the aluminum metal substrate is 10-20 μm; The thickness of the MOF-C particle layer on the surface of the aluminum metal substrate is 10-20 μm.

2. The method for preparing an aluminum anode based on MOF interface modification according to claim 1, characterized in that: In the first step, the mass ratio of water, nitric acid, and coordination material is 200:5-20:2-5.

3. The method for preparing an aluminum anode based on MOF interface modification according to claim 1, characterized in that: In the second step, surface pretreatment refers to removing the oxide film on the surface of the aluminum metal substrate by using alkaline or acidic reagents; the alkaline reagent is NaOH solution, and the acidic reagent is hydrochloric acid.

4. The method for preparing an aluminum anode based on MOF interface modification according to claim 1, characterized in that: In the third step, the hydrothermal synthesis temperature is 160-200℃, and the hydrothermal synthesis time is 10-16h; In the fourth step, the drying temperature is 80-200℃ and the drying time is 10-24h.

5. The method for preparing an aluminum anode based on MOF interface modification according to claim 1, characterized in that: In the third step, the coordinating material is one of the following: benzoic acid, aromatic amine, aromatic diketone, aromatic triketone, pyridine, amino acid, ether, nitro compound, and heterocyclic compound; The benzoic acid is benzoic acid, phthalic acid, or tribenzoic acid; The aromatic amine is p-phenylenediamine or p-hydroxyaniline; The aromatic diketones are m-phenylenedione or p-phenylenedione; The aromatic triketones are phenyltriketones or m-phenyltriketones; The pyridines are pyridine, para-dipyridine, or pyridinone; The amino acid is aminoacetic acid or aminopropionic acid; The ether is ethylene glycol or glycine ethyl ester; The nitro compound is nitrobenzene or nitrobenzene; The MOF is an aluminum-based MOF.

6. An application of the aluminum anode based on MOF interface modification as described in claim 1, characterized in that: Applying MOF-based aluminum anodes to aluminum secondary batteries can improve their cycle performance and safety.

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