In-situ synthesized aqueous magnesium ion battery organic composite negative electrode material, preparation method and negative electrode
By synthesizing an organic composite anode material for aqueous magnesium-ion batteries in situ, a special structure was constructed using a quinone aldehyde condensation reaction, which solved the problem of low performance of magnesium-ion battery electrode materials and achieved improvements in high capacity, long cycle life, and high power performance.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- SUN YAT SEN UNIV
- Filing Date
- 2025-11-10
- Publication Date
- 2026-05-01
AI Technical Summary
Existing magnesium-ion battery electrode materials have relatively low performance, especially in terms of capacity, power and cycle life, which limits their large-scale application.
PDBM@KB anode material was prepared by in-situ synthesis of 2,5-dihydroxy-1,4-benzoquinone and conductive carbon, followed by quinone aldehyde polycondensation reaction with formaldehyde solution. A special structure was constructed to shorten the ion diffusion distance and improve conductivity.
It significantly improves the capacity, cycle life, and power performance of magnesium-ion batteries, achieving high capacity, high rate performance, and high power performance.
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Figure CN121964560A_ABST
Abstract
Description
An in-situ synthesized organic composite anode material for aqueous magnesium-ion batteries, its preparation method, and the anode itself. Technical Field
[0001] This application belongs to the field of magnesium-ion battery technology, and particularly relates to an in-situ synthesized aqueous magnesium-ion battery organic composite negative electrode material, its preparation method, and the negative electrode. Background Technology
[0002] With the grid connection of renewable energy power generation such as wind and solar power, and the electrification of transportation vehicles such as automobiles, the demand for energy storage and power batteries is increasing. This places comprehensive demands on batteries in terms of environmental protection, safety, affordability, and durability. Currently, mainstream lithium-ion batteries usually use volatile organic electrolytes, which pose safety hazards such as fire and even explosion, and often require battery thermal management systems for protection. At the same time, lithium mines have the disadvantages of insufficient resources and uneven distribution, which makes lithium-ion batteries more expensive. Therefore, it is necessary to develop new types of lithium-ion batteries.
[0003] Water-based rechargeable batteries are inherently safe due to their low cost and non-flammable water-based electrolyte, and do not heavily rely on complex battery management systems for protection. Meanwhile, magnesium metal is abundant, has high volumetric capacity, and is environmentally friendly. Magnesium is a plentiful resource (its atomic abundance in the Earth's crust is approximately 10⁴ times that of Li), and is a non-toxic element. Furthermore, magnesium provides two electrons per redox center, compared to Li metal (2046 mAh / cm³). 3 ) and commercial graphite anodes (760mAh / cm) 3 It has a higher theoretical volumetric capacity (3833mAh / cm³). 3 Magnesium has many advantages, making it the preferred choice for developing environmentally friendly, safe, inexpensive, and durable aqueous magnesium-ion batteries. However, aqueous ion batteries have drawbacks such as short cycle life and the need for frequent battery replacements, which limit their large-scale application. Electrode active materials are the key to battery performance. It is urgent for researchers to develop an aqueous ion battery with high capacity, high power, and long cycle life based on material innovation and improvements in electrode materials.
[0004] Among existing electrode materials, inorganic crystalline materials have relatively low theoretical specific capacities, generally less than 150 mAh / g. 1 Moreover, most of them can only accommodate Li ions with smaller ionic radii. + Na + or Zn 2+When intercalation and deintercalation occur within its crystal, it exhibits strong cation selectivity. These performance defects of inorganic crystalline materials will, to some extent, limit the performance of aqueous rechargeable batteries (ARBs). To further improve the electrochemical performance of aqueous rechargeable batteries (ARBs), it is necessary to research and develop electrode materials with novel structural characteristics and electrochemical energy storage mechanisms. Organic compounds, mainly composed of elements such as C, H, N, and O, are green and environmentally friendly, and contain a large number of unsaturated C=O and C=N active functional groups. They can undergo reversible "enol" coordination reactions with metal ions, theoretically possessing a high theoretical specific capacity. In addition, some polymers not only have low solubility in aqueous solutions, but also have structural units stacked together by weak van der Waals forces, exhibiting an amorphous form and large spacing between active molecules. Therefore, not only Li + Na + These monovalent metal cations with relatively small ionic radii can pass through the gaps between active molecules, and Zn 2+ Mg 2+ Ca 2+ Al 3+ Some divalent or trivalent metal cations with larger ionic radii can also diffuse through the gaps between structural units to the carbonyl active sites of organic molecules in the structural units to participate in electrochemical reactions, showing broad adaptability to various metal cations. However, they also have defects such as high solubility of small molecules and poor conductivity, which adversely affect the capacity, power and cycle life of ion batteries. Solubility can be improved by selecting some specific polymers and organic compounds with specific groups and structures. However, the conductivity of organic compounds is difficult to improve. For organic compounds with low conductivity, on the one hand, the ion diffusion rate is slow during charging and discharging, and some ions may accumulate on the surface of the electrode material to form metal dendrites. The ion diffusion rate is too slow and the active sites of the electrode material cannot be effectively utilized, affecting the capacity, rate performance and cycle performance of the electrode material. This makes the current performance of magnesium ion battery electrode materials based on organic compounds relatively low. Summary of the Invention
[0005] In view of this, this application provides an in-situ synthesized aqueous magnesium-ion battery organic composite anode material, its preparation method, and the anode itself, to solve the technical problem of low performance of existing magnesium-ion battery electrode materials.
[0006] The first aspect of this application provides an in-situ synthesized organic composite anode material for aqueous magnesium-ion batteries, which is synthesized in situ by a quinone aldehyde condensation reaction of a uniformly mixed suspension of 2,5-dihydroxy-1,4-benzoquinone and conductive carbon with a formaldehyde solution.
[0007] Preferably, the amount of conductive carbon doped in the in-situ synthesized organic composite anode material for aqueous magnesium-ion batteries is 10wt%~30wt%.
[0008] Preferably, the conductive carbon is selected from at least one of Ketjen black, carbon nanotubes, carbon nanofibers, carbon black, and graphene.
[0009] The second aspect of this application provides a method for preparing an in-situ synthesized organic composite anode material for aqueous magnesium-ion batteries, which can prepare the in-situ synthesized organic composite anode material for aqueous magnesium-ion batteries described in the first aspect, comprising the following steps:
[0010] The steps for preparing the suspension are as follows: add conductive carbon to a glacial acetic acid solution containing 2,5-dihydroxy-1,4-benzoquinone, and then perform ultrasonic dispersion and vacuum impregnation treatment in sequence to obtain a uniformly mixed suspension of 2,5-dihydroxy-1,4-benzoquinone and conductive carbon.
[0011] The in-situ synthesis steps are as follows: Formaldehyde solution is slowly added to a uniformly mixed suspension of 2,5-dihydroxy-1,4-benzoquinone and conductive carbon under vigorous stirring. The quinone aldehyde condensation reaction is carried out at 35~40℃ for 24~72h under a protective atmosphere to obtain the in-situ synthesized organic composite anode material for aqueous magnesium-ion batteries.
[0012] Preferably, in the step of preparing the suspension, the ultrasonic dispersion time is 1~3 hours and the power is 300W.
[0013] Preferably, in the step of preparing the suspension, the vacuum impregnation treatment time is 1-3 hours, the pressure is 0.001 MPa, and the number of times is 1-3.
[0014] Preferably, in the in-situ synthesis step, the formaldehyde solution is slowly added at a rate of 5~50 μL / min.
[0015] Preferably, in the in-situ synthesis step, the mass ratio of 2,5-dihydroxy-1,4-benzoquinone, conductive carbon, and formaldehyde in the formaldehyde solution and the uniformly mixed suspension of 2,5-dihydroxy-1,4-benzoquinone and conductive carbon is 1:0.11~0.43:1.2, while the volume ratio of the formaldehyde solution to the suspension of 2,5-dihydroxy-1,4-benzoquinone and conductive carbon is 2~4:50.
[0016] Preferably, the post-processing after the quinone aldehyde polycondensation reaction is as follows: sequential filtration, washing, and freeze-drying.
[0017] The third aspect of this application provides an organic composite anode for an aqueous magnesium-ion battery, wherein the current collector of the organic composite anode for the aqueous magnesium-ion battery is loaded with the in-situ synthesized organic composite anode material for an aqueous magnesium-ion battery described in the first aspect.
[0018] The current collector is selected from any one of copper current collectors, aluminum current collectors, and stainless steel current collectors.
[0019] The fourth aspect of this application provides an aqueous magnesium-ion battery, including an aqueous electrolyte, a separator, a positive electrode, and an organic composite negative electrode for an aqueous magnesium-ion battery as described in the third aspect.
[0020] Compared with the prior art, the in-situ synthesized organic composite anode material for aqueous magnesium-ion batteries provided in this application has at least the following beneficial effects:
[0021] 1. As can be seen from the structural characterization and performance testing of the anode materials provided in Examples 1 and 6, the in-situ synthesized organic composite anode material PDBM@KB for aqueous magnesium-ion batteries provided in Example 1, due to the uniform mixing of 2,5-dihydroxy-1,4-benzoquinone and conductive carbon followed by the introduction of formaldehyde for quinone aldehyde condensation reaction, PDBM@KB was synthesized in situ. This resulted in KB being uniformly distributed in the synthesized PDBM sheets, constructing a special structure, shortening the diffusion distance of cations to PDBM, constructing a fast ion transport channel, and significantly improving the utilization rate of PDBM active material. As a result, the aqueous magnesium-ion battery with PDBM / KB as the anode exhibits high capacity, long cycle life, high rate performance, and high power performance.
[0022] 2. As can be seen from the performance tests of the negative electrode materials provided in Examples 1 and 7-8, this application achieves uniform mixing of 2,5-dihydroxy-1,4-benzoquinone and conductive carbon through ultrasonic dispersion and vacuum impregnation. 2,5-dihydroxy-1,4-benzoquinone penetrates into the porous structure of KB conductive carbon, making the distribution of KB conductive carbon in PDBM@KB more uniform, further optimizing the ion transport rate, improving the utilization rate of PDBM active material, and further enhancing the performance of PDBM@KB.
[0023] 3. As can be seen from the performance tests of the negative electrode materials provided in Examples 1, 4-5 and 8-10, this application further improves the performance of aqueous magnesium-ion batteries with PDBM / KB as the negative electrode by optimizing reaction process parameters such as formaldehyde addition rate, reaction temperature or protective atmosphere. Attached Figure Description
[0024] To more clearly illustrate the technical solutions in the specific embodiments of this application or the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.
[0025] Figure 1 is a schematic flowchart of a method for preparing an in-situ synthesized organic composite anode material for an aqueous magnesium-ion battery according to Embodiment 1 of this application.
[0026] Figure 2 shows the FT-IR spectra of the PDBM@KB anode material prepared in Example 1, the PDBM anode material prepared in Example 6, and the synthetic raw material DHBQ.
[0027] Figure 3 shows the XRD patterns of the PDBM@KB anode material prepared in Example 1, the PDBM anode material prepared in Example 6, and the synthetic raw material DHBQ.
[0028] Figure 4 is a SEM image of the PDBM@KB anode material prepared in Example 1 of this application;
[0029] Figure 5 is a SEM image of the PDBM@KB anode material prepared in Example 6 of this application;
[0030] Figure 6 shows the EDS energy spectrum of the PDBM@KB anode material prepared in Example 1 and the PDBM anode material prepared in Example 6 of this application.
[0031] Figure 7 shows the long-cycle performance of PDBM@KB prepared in Example 1 of this application at a 4C rate. Detailed Implementation
[0032] This application provides an in-situ synthesized aqueous magnesium-ion battery organic composite anode material, its preparation method, and the anode itself, which addresses the technical problem of low performance of existing magnesium-ion battery electrode materials.
[0033] The technical solutions of this application will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this application. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.
[0034] Example 1
[0035] This embodiment provides a method for preparing an organic composite anode material for an aqueous magnesium-ion battery through in-situ synthesis. The schematic flowchart of the preparation method is shown in Figure 1, which includes the steps of preparing a suspension, in-situ synthesis, and post-processing.
[0036] The steps for preparing a suspension include:
[0037] Weigh 1g of 2,5-dihydroxy-1,4-benzoquinone (DHBQ) and slowly add it to 50mL of glacial acetic acid solution under magnetic stirring (20~30min) until it is completely dissolved, to obtain a glacial acetic acid solution containing 2,5-dihydroxy-1,4-benzoquinone.
[0038] 0.43 g of Ketjen Black (KB) was added to a glacial acetic acid solution containing dissolved 2,5-dihydroxy-1,4-benzoquinone (DHBQ) at a ratio of 30 wt% of the combined mass of 2,5-dihydroxy-1,4-benzoquinone.
[0039] Next, the mixture was transferred to an ultrasonic instrument and ultrasonically dispersed at 100% power (300W) for 2 hours, and then placed under vacuum conditions (0.001MPa) for 1.5 hours to allow the DHBQ solution to fully penetrate the pores of Ketjen black, resulting in a uniformly mixed suspension of 2,5-dihydroxy-1,4-benzoquinone and conductive carbon.
[0040] The steps of in-situ synthesis include:
[0041] 3 mL of 37% formaldehyde solution was slowly added to a well-mixed suspension of 2,5-dihydroxy-1,4-benzoquinone and conductive carbon at a rate of 5 μL / min using a microsyringe.
[0042] After the formaldehyde solution was added dropwise, the sample was transferred to an oil bath and reacted at 38°C for 48 hours under Ar gas protection to carry out quinone aldehyde condensation reaction, resulting in a suspension containing the in-situ synthesized aqueous magnesium-ion battery organic composite negative electrode material.
[0043] Post-processing steps include:
[0044] The suspension containing the in-situ synthesized aqueous magnesium-ion battery organic composite anode material was filtered through a 0.22 μm organic filter membrane, washed thoroughly with a large amount of deionized water and anhydrous ethanol (6-9 times), and freeze-dried for 48 h to obtain the in-situ synthesized aqueous magnesium-ion battery organic composite anode material (PDBM@KB) for later use.
[0045] Example 2
[0046] This embodiment provides a method for preparing an organic composite anode material for an aqueous magnesium-ion battery synthesized in situ. The difference from Embodiment 1 is that the doping ratio of conductive carbon is adjusted. The preparation method includes the steps of preparing a suspension, in-situ synthesis, and post-processing.
[0047] The steps for preparing a suspension include:
[0048] Weigh 1g of 2,5-dihydroxy-1,4-benzoquinone (DHBQ) and slowly add it to 50mL of glacial acetic acid solution under magnetic stirring (20~30min) until it is completely dissolved, to obtain a glacial acetic acid solution containing 2,5-dihydroxy-1,4-benzoquinone.
[0049] According to a 20wt% ratio of the combined mass of 2,5-dihydroxy-1,4-benzoquinone (DHBQ) and conductive carbon, 0.25g of Ketjen black (KB) was added to a glacial acetic acid solution containing dissolved 2,5-dihydroxy-1,4-benzoquinone. The solution was then transferred to an ultrasonic instrument and ultrasonically dispersed at 100% power (300W) for 2 hours. Afterward, it was placed under vacuum (0.001MPa) for 1.5 hours to allow the DHBQ solution to fully penetrate the pores of the Ketjen black, resulting in a uniformly mixed suspension of 2,5-dihydroxy-1,4-benzoquinone and conductive carbon.
[0050] The steps of in-situ synthesis include:
[0051] 3 mL of 37% formaldehyde solution was slowly added to a well-mixed suspension of 2,5-dihydroxy-1,4-benzoquinone and conductive carbon at a rate of 5 μL / min using a microsyringe.
[0052] After the formaldehyde solution was added dropwise, the sample was transferred to an oil bath and reacted at 38°C for 48 hours under Ar gas protection to carry out quinone aldehyde condensation reaction, resulting in a suspension containing the in-situ synthesized aqueous magnesium-ion battery organic composite negative electrode material.
[0053] Post-processing steps include:
[0054] The suspension containing the in-situ synthesized aqueous magnesium-ion battery organic composite anode material was filtered through a 0.22 μm organic filter membrane, washed thoroughly with a large amount of deionized water and anhydrous ethanol (6-9 times), and freeze-dried for 48 h to obtain the in-situ synthesized aqueous magnesium-ion battery organic composite anode material for later use.
[0055] Example 3
[0056] This embodiment provides a method for preparing an organic composite anode material for an aqueous magnesium-ion battery synthesized in situ. The difference from Embodiment 1 is that the doping ratio of conductive carbon is adjusted. The preparation method includes the steps of preparing a suspension, in-situ synthesis, and post-processing.
[0057] The steps for preparing a suspension include:
[0058] Weigh 1g of 2,5-dihydroxy-1,4-benzoquinone (DHBQ) and slowly add it to 50mL of glacial acetic acid solution under magnetic stirring (20~30min) until it is completely dissolved, to obtain a glacial acetic acid solution containing 2,5-dihydroxy-1,4-benzoquinone.
[0059] According to a 10wt% ratio of the combined mass of 2,5-dihydroxy-1,4-benzoquinone (DHBQ) and conductive carbon, 0.11g of Ketjen black (KB) was added to a glacial acetic acid solution containing dissolved 2,5-dihydroxy-1,4-benzoquinone. The solution was then transferred to an ultrasonic instrument and ultrasonically dispersed at 100% power (300W) for 2 hours. Afterward, it was placed under vacuum (0.001MPa) for 1.5 hours to allow the DHBQ solution to fully penetrate the pores of the Ketjen black, resulting in a uniformly mixed suspension of 2,5-dihydroxy-1,4-benzoquinone and conductive carbon.
[0060] The steps of in-situ synthesis include:
[0061] 3 mL of 37% formaldehyde solution was slowly added to a well-mixed suspension of 2,5-dihydroxy-1,4-benzoquinone and conductive carbon at a rate of 5 μL / min using a microsyringe.
[0062] After the formaldehyde solution was added dropwise, the sample was transferred to an oil bath and reacted at 38°C for 48 hours under Ar gas protection to carry out quinone aldehyde condensation reaction, resulting in a suspension containing the in-situ synthesized aqueous magnesium-ion battery organic composite negative electrode material.
[0063] Post-processing steps include:
[0064] The suspension containing the in-situ synthesized aqueous magnesium-ion battery organic composite anode material was filtered through a 0.22 μm organic filter membrane, washed thoroughly with a large amount of deionized water and anhydrous ethanol (6-9 times), and freeze-dried for 48 h to obtain the in-situ synthesized aqueous magnesium-ion battery organic composite anode material for later use.
[0065] Example 4
[0066] This embodiment provides a method for preparing an organic composite anode material for an aqueous magnesium-ion battery through in-situ synthesis. The preparation method includes steps of preparing a suspension, in-situ synthesis, and post-processing.
[0067] The steps for preparing a suspension include:
[0068] Weigh 1g of 2,5-dihydroxy-1,4-benzoquinone (DHBQ) and slowly add it to 50mL of glacial acetic acid solution under magnetic stirring (20~30min) until it is completely dissolved, to obtain a glacial acetic acid solution containing 2,5-dihydroxy-1,4-benzoquinone.
[0069] 0.43 g of Ketjen Black (KB) was added to a glacial acetic acid solution containing dissolved 2,5-dihydroxy-1,4-benzoquinone (DHBQ) at a ratio of 30 wt% of the combined mass of 2,5-dihydroxy-1,4-benzoquinone.
[0070] Next, the mixture was transferred to an ultrasonic instrument and ultrasonically dispersed at 100% power (300W) for 2 hours, and then placed under vacuum conditions (0.001MPa) for 1.5 hours to allow the DHBQ solution to fully penetrate the pores of Ketjen black, resulting in a uniformly mixed suspension of 2,5-dihydroxy-1,4-benzoquinone and conductive carbon.
[0071] The steps of in-situ synthesis include:
[0072] 3 mL of 37% formaldehyde solution was slowly added to a well-mixed suspension of 2,5-dihydroxy-1,4-benzoquinone and conductive carbon at a rate of 10 μL / min using a microsyringe.
[0073] After the formaldehyde solution was added dropwise, the sample was transferred to an oil bath and reacted at 38°C for 48 hours under Ar gas protection to carry out quinone aldehyde condensation reaction, resulting in a suspension containing the in-situ synthesized aqueous magnesium-ion battery organic composite negative electrode material.
[0074] Post-processing steps include:
[0075] The suspension containing the in-situ synthesized aqueous magnesium-ion battery organic composite anode material was filtered through a 0.22 μm organic filter membrane, washed thoroughly with a large amount of deionized water and anhydrous ethanol (6-9 times), and freeze-dried for 48 h to obtain the in-situ synthesized aqueous magnesium-ion battery organic composite anode material for later use.
[0076] Example 5
[0077] This embodiment provides a method for preparing an organic composite anode material for an aqueous magnesium-ion battery through in-situ synthesis. The preparation method includes steps of preparing a suspension, in-situ synthesis, and post-processing.
[0078] The steps for preparing a suspension include:
[0079] Weigh 1g of 2,5-dihydroxy-1,4-benzoquinone (DHBQ) and slowly add it to 50mL of glacial acetic acid solution under magnetic stirring (20~30min) until it is completely dissolved, to obtain a glacial acetic acid solution containing 2,5-dihydroxy-1,4-benzoquinone.
[0080] 0.43 g of Ketjen Black (KB) was added to a glacial acetic acid solution containing dissolved 2,5-dihydroxy-1,4-benzoquinone (DHBQ) at a ratio of 30 wt% of the combined mass of 2,5-dihydroxy-1,4-benzoquinone.
[0081] Next, the mixture was transferred to an ultrasonic instrument and ultrasonically dispersed at 100% power (300W) for 2 hours, and then placed under vacuum conditions (0.001MPa) for 1.5 hours to allow the DHBQ solution to fully penetrate the pores of Ketjen black, resulting in a uniformly mixed suspension of 2,5-dihydroxy-1,4-benzoquinone and conductive carbon.
[0082] The steps of in-situ synthesis include:
[0083] 3 mL of 37% formaldehyde solution was slowly added to a well-mixed suspension of 2,5-dihydroxy-1,4-benzoquinone and conductive carbon at a rate of 50 μL / min using a microsyringe.
[0084] After the formaldehyde solution was added dropwise, the sample was transferred to an oil bath and reacted at 38°C for 48 hours under Ar gas protection to carry out quinone aldehyde condensation reaction, resulting in a suspension containing the in-situ synthesized aqueous magnesium-ion battery organic composite negative electrode material.
[0085] Post-processing steps include:
[0086] The suspension containing the in-situ synthesized aqueous magnesium-ion battery organic composite anode material was filtered through a 0.22 μm organic filter membrane, washed thoroughly with a large amount of deionized water and anhydrous ethanol (6-9 times), and freeze-dried for 48 h to obtain the in-situ synthesized aqueous magnesium-ion battery organic composite anode material for later use.
[0087] Example 6
[0088] This embodiment provides a method for preparing a negative electrode material for aqueous magnesium-ion batteries. The preparation method includes a solution preparation step, a quinone aldehyde condensation reaction step, and a post-treatment step.
[0089] The steps for preparing the solution include:
[0090] Weigh 1g of 2,5-dihydroxy-1,4-benzoquinone (DHBQ) and slowly add it to 50mL of glacial acetic acid solution (20~30min) under magnetic stirring until it is completely dissolved, to obtain a glacial acetic acid solution containing dissolved 2,5-dihydroxy-1,4-benzoquinone.
[0091] The steps of the quinone aldehyde condensation reaction include:
[0092] 3 mL of 37% formaldehyde solution was slowly added to a solution of glacial acetic acid containing 2,5-dihydroxy-1,4-benzoquinone using a microsyringe at a rate of 50 μL / min.
[0093] After the formaldehyde solution was added dropwise, the sample was transferred to an oil bath and reacted at 38°C for 48 hours under Ar gas protection to carry out quinone aldehyde condensation reaction, resulting in a suspension containing aqueous magnesium ion battery negative electrode material.
[0094] Post-processing steps include:
[0095] The suspension containing the aqueous magnesium-ion battery anode material was filtered through a 0.22 μm organic filter membrane, washed thoroughly with a large amount of deionized water and anhydrous ethanol (6-9 times), and freeze-dried for 48 h to obtain the aqueous magnesium-ion battery anode material (PDBM) for later use.
[0096] Example 7
[0097] This embodiment provides a method for preparing an organic composite anode material for an aqueous magnesium-ion battery through in-situ synthesis. As a first comparative embodiment, the preparation method includes the steps of preparing a suspension, in-situ synthesis, and post-processing.
[0098] The steps for preparing a suspension include:
[0099] Weigh 1g of 2,5-dihydroxy-1,4-benzoquinone (DHBQ) and slowly add it to 50mL of glacial acetic acid solution under magnetic stirring (20~30min) until it is completely dissolved, to obtain a glacial acetic acid solution containing 2,5-dihydroxy-1,4-benzoquinone.
[0100] 0.43 g of Ketjen Black (KB) was added to a glacial acetic acid solution containing dissolved 2,5-dihydroxy-1,4-benzoquinone (DHBQ) at a ratio of 30 wt% of the combined mass of 2,5-dihydroxy-1,4-benzoquinone.
[0101] Next, the mixture was kept under vacuum (0.001 MPa) for 1.5 hours to allow the DHBQ solution to fully penetrate the pores of Ketjen black, resulting in a uniformly mixed suspension of 2,5-dihydroxy-1,4-benzoquinone and conductive carbon.
[0102] The steps of in-situ synthesis include:
[0103] 3 mL of 37% formaldehyde solution was slowly added to a well-mixed suspension of 2,5-dihydroxy-1,4-benzoquinone and conductive carbon at a rate of 5 μL / min using a microsyringe.
[0104] After the formaldehyde solution was added dropwise, the sample was transferred to an oil bath and reacted at 38°C for 48 hours under Ar gas protection to carry out quinone aldehyde condensation reaction, resulting in a suspension containing the in-situ synthesized aqueous magnesium-ion battery organic composite negative electrode material.
[0105] Post-processing steps include:
[0106] The suspension containing the in-situ synthesized aqueous magnesium-ion battery organic composite anode material was filtered through a 0.22 μm organic filter membrane, washed thoroughly with a large amount of deionized water and anhydrous ethanol (6-9 times), and freeze-dried for 48 h to obtain the in-situ synthesized aqueous magnesium-ion battery organic composite anode material for later use.
[0107] Example 8
[0108] This embodiment provides a method for preparing an organic composite anode material for an aqueous magnesium-ion battery through in-situ synthesis. As a second comparative embodiment, the preparation method includes the steps of preparing a suspension, in-situ synthesis, and post-processing.
[0109] The steps for preparing a suspension include:
[0110] Weigh 1g of 2,5-dihydroxy-1,4-benzoquinone (DHBQ) and slowly add it to 50mL of glacial acetic acid solution under magnetic stirring (20~30min) until it is completely dissolved, to obtain a glacial acetic acid solution containing 2,5-dihydroxy-1,4-benzoquinone.
[0111] 0.43 g of Ketjen Black (KB) was added to a glacial acetic acid solution containing dissolved 2,5-dihydroxy-1,4-benzoquinone (DHBQ) at a ratio of 30 wt% of the combined mass of 2,5-dihydroxy-1,4-benzoquinone.
[0112] Next, the mixture was transferred to an ultrasonic instrument and ultrasonically dispersed at 100% power (300 W) for 2 hours, so that the DHBQ solution could fully penetrate into the pores of Ketjen black, resulting in a uniformly mixed suspension of 2,5-dihydroxy-1,4-benzoquinone and conductive carbon.
[0113] The steps of in-situ synthesis include:
[0114] 3 mL of 37% formaldehyde solution was slowly added to a well-mixed suspension of 2,5-dihydroxy-1,4-benzoquinone and conductive carbon at a rate of 5 μL / min using a microsyringe.
[0115] After the formaldehyde solution was added dropwise, the sample was transferred to an oil bath and reacted at 38°C for 48 hours under Ar gas protection to carry out quinone aldehyde condensation reaction, resulting in a suspension containing the in-situ synthesized aqueous magnesium-ion battery organic composite negative electrode material.
[0116] Post-processing steps include:
[0117] The suspension containing the in-situ synthesized aqueous magnesium-ion battery organic composite anode material was filtered through a 0.22 μm organic filter membrane, washed thoroughly with a large amount of deionized water and anhydrous ethanol (6-9 times), and freeze-dried for 48 h to obtain the in-situ synthesized aqueous magnesium-ion battery organic composite anode material for later use.
[0118] Example 9
[0119] This embodiment provides a method for preparing an organic composite anode material for an aqueous magnesium-ion battery through in-situ synthesis. As a third comparative embodiment, the preparation method includes the steps of preparing a suspension, in-situ synthesis, and post-processing.
[0120] The steps for preparing a suspension include:
[0121] Weigh 1g of 2,5-dihydroxy-1,4-benzoquinone (DHBQ) and slowly add it to 50mL of glacial acetic acid solution under magnetic stirring (20~30min) until it is completely dissolved, to obtain a glacial acetic acid solution containing 2,5-dihydroxy-1,4-benzoquinone.
[0122] According to a 30wt% ratio of the combined mass of 2,5-dihydroxy-1,4-benzoquinone (DHBQ) and conductive carbon, 0.43g of Ketjen black (KB) was added to a glacial acetic acid solution containing dissolved 2,5-dihydroxy-1,4-benzoquinone. The solution was then transferred to an ultrasonic instrument and ultrasonically dispersed at 100% power (300W) for 2 hours. Afterward, it was placed under vacuum (0.001MPa) for 1.5 hours to allow the DHBQ solution to fully penetrate the pores of the Ketjen black, resulting in a uniformly mixed suspension of 2,5-dihydroxy-1,4-benzoquinone and conductive carbon.
[0123] The steps of in-situ synthesis include:
[0124] 3 mL of 37% formaldehyde solution was slowly added to a well-mixed suspension of 2,5-dihydroxy-1,4-benzoquinone and conductive carbon at a rate of 5 μL / min using a microsyringe.
[0125] After the formaldehyde solution was added, the sample was transferred to an oil bath and reacted at 38°C for 48 hours to carry out the quinone aldehyde condensation reaction, resulting in a suspension containing the in-situ synthesized aqueous magnesium-ion battery organic composite negative electrode material.
[0126] Post-processing steps include:
[0127] The suspension containing the in-situ synthesized aqueous magnesium-ion battery organic composite anode material was filtered through a 0.22 μm organic filter membrane, washed thoroughly with a large amount of deionized water and anhydrous ethanol (6-9 times), and freeze-dried for 48 h to obtain the in-situ synthesized aqueous magnesium-ion battery organic composite anode material for later use.
[0128] Example 10
[0129] This embodiment provides a method for preparing an organic composite anode material for an aqueous magnesium-ion battery through in-situ synthesis. As a fourth comparative embodiment, the preparation method includes the steps of preparing a suspension, in-situ synthesis, and post-processing.
[0130] The steps for preparing a suspension include:
[0131] Weigh 1g of 2,5-dihydroxy-1,4-benzoquinone (DHBQ) and slowly add it to 50mL of glacial acetic acid solution under magnetic stirring (20~30min) until it is completely dissolved, to obtain a glacial acetic acid solution containing 2,5-dihydroxy-1,4-benzoquinone.
[0132] 0.43 g of Ketjen Black (KB) was added to a glacial acetic acid solution containing dissolved 2,5-dihydroxy-1,4-benzoquinone (DHBQ) at a ratio of 30 wt% of the combined mass of 2,5-dihydroxy-1,4-benzoquinone.
[0133] Next, the mixture was transferred to an ultrasonic instrument and ultrasonically dispersed at 100% power (300W) for 2 hours, and then kept under vacuum for 1.5 hours to allow the DHBQ solution to fully penetrate the pores of Ketjen black, resulting in a uniformly mixed suspension of 2,5-dihydroxy-1,4-benzoquinone and conductive carbon.
[0134] The steps of in-situ synthesis include:
[0135] 3 mL of 37% formaldehyde solution was slowly added to a well-mixed suspension of 2,5-dihydroxy-1,4-benzoquinone and conductive carbon at a rate of 5 μL / min using a microsyringe.
[0136] After the formaldehyde solution was added, the sample was transferred to an oil bath and reacted at room temperature for 48 hours under Ar gas protection to carry out quinone aldehyde condensation reaction, resulting in a suspension containing the in-situ synthesized aqueous magnesium-ion battery organic composite negative electrode material.
[0137] Post-processing steps include:
[0138] The suspension containing the in-situ synthesized aqueous magnesium-ion battery organic composite anode material was filtered through a 0.22 μm organic filter membrane, washed thoroughly with a large amount of deionized water and anhydrous ethanol (6-9 times), and freeze-dried for 48 h to obtain the in-situ synthesized aqueous magnesium-ion battery organic composite anode material for later use.
[0139] Example 11
[0140] This embodiment provides an aqueous magnesium-ion battery anode, including a thin-film preparation step and a loading step.
[0141] The preparation steps of the thin film include:
[0142] The organic composite anode material for aqueous magnesium-ion batteries synthesized in situ in Examples 1-5 and 7-10 was placed in a mortar with a 60% PTFE emulsion binder at a mass ratio of 95:5. Then, an appropriate amount of anhydrous ethanol was added until it was ground into a clay-like state as the anode slurry. The slurry was then rolled into a thin sheet of PDBM@KB anode material.
[0143] Alternatively, the aqueous magnesium-ion battery anode material provided in Example 6 and Ketjen Black (KB) can be mixed in a 7:3 mass ratio, and then placed in a mortar with a 60% PTFE emulsion binder in a 95:5 mass ratio. An appropriate amount of anhydrous ethanol can be added, and the mixture can be ground until it reaches a putty-like consistency to form an anode slurry. This slurry can then be rolled into a thin sheet of PDBM / KB anode material.
[0144] The load process includes:
[0145] Cut the resulting thin sheet into 1×1cm pieces. 2 The electrode sheet is pressed onto a stainless steel mesh current collector (30MPa). The electrode pressed onto the stainless steel current collector is thoroughly dried in a drying oven and weighed. The mass of the active material in the electrode sheet can then be calculated, thus obtaining the PDBM@KB or PDBM / KB electrode sheet.
[0146] Example 12
[0147] This embodiment provides an aqueous magnesium-ion battery, including a negative electrode, a positive electrode, a separator, and an electrolyte; wherein the negative electrode is the PDBM@KB or PDBM / KB electrode sheet provided in Example 11, the positive electrode is an activated carbon electrode, the separator is an aqueous separator (Whatman GF / D), and the electrolyte is 1M Mg(CH2OOH)2.
[0148] Experimental Example 1
[0149] This experiment characterizes the structure of the negative electrode materials provided in Examples 1 and 6, and performs performance tests on the negative electrode materials provided in Examples 1-10. The structural characterization includes the use of instruments and equipment such as infrared spectrometer, X-ray diffractometer, scanning electron microscope, and EDS energy dispersive spectroscopy. The performance tests are performed after the aqueous magnesium ion battery is fabricated.
[0150] The structural characterization results are shown in Figures 2-6. As can be seen from the infrared spectrum in Figure 2, the anode materials provided in Examples 1 and 6 exhibit good performance at 3200 cm⁻¹. -1 2900cm -1 1600cm -1The presence of absorption peaks at positions such as OH, CH, and C=O indicates that the anode materials provided in Examples 1 and 6 have the same basic chemical framework. However, the transmittance of the anode material PDBM@KB provided in Example 1 is significantly higher than that of the anode material PDBM provided in Example 6. This may be because the addition of KB affects its absorption of infrared light, resulting in a stronger final transmittance signal. As shown in Figure 3, the X-ray diffraction pattern shows that the diffraction peaks of the anode material PDBM@KB provided in Example 1 are further broadened, with almost no sharp peaks, indicating that the introduction of KB further enhances its amorphousness. Combining Figures 4-5 and 6, it can be seen that the energy spectrum shown in Figure 6 also shows that the carbon distribution of the anode material PDBM@KB provided in Example 1 is denser and the color is darker, indicating the introduction of KB. Comparing Figures 4-5, it can be seen that the PDBM@KB shown in Figure 5 has KB uniformly distributed in the synthesized PDBM sheets due to the in-situ synthesis of PDBM.
[0151] The performance testing process includes: using a Newway battery performance tester to perform charge / discharge rate tests (4~110 C, 1C=352.5mAh / g). -1 The test included a long-cycle test (3500 cycles); the first cycle involved constant current discharge at a current density of 4 C to a cutoff voltage of 0.01V, followed by constant current charging at a current density of 4C to 1.2V for the second cycle, with both discharge and charge current densities at 4C. The test results for the first charge / discharge capacity, first coulombic efficiency, cycle life, and capacity retention are shown in Table 1 and Figure 7.
[0152] As shown in Table 1, the performance test results indicate that the PDBM@KB anode materials with different KB doping amounts provided in Examples 1-3 exhibit different performance characteristics. As the KB doping amount increases from 10% to 30%, the performance of the aqueous magnesium-ion battery made from the PDBM@KB anode material is improved in terms of initial coulombic efficiency, cycle life, and capacity retention. This demonstrates that introducing the conductive material KB into the 2,5-dihydroxy-1,4-benzoquinone-3,6-methylene polymer (PDBM) enhances the conductivity of PDBM, allowing magnesium ions to be effectively intercalated and deintercalated during charging and discharging, thereby improving the utilization rate of PDBM and ultimately enhancing the coulombic efficiency, cycle life, and capacity retention of the aqueous magnesium-ion battery.
[0153] Table 1 also shows that, compared with the PDBM@KB anode materials provided in Examples 1-3, the performance of the aqueous magnesium-ion battery made with PDBM provided in Example 6 is reduced in all aspects. This is because the PDBM@KB anode materials provided in Examples 1-3 are synthesized by in-situ reaction of 2,5-dihydroxy-1,4-benzoquinone and conductive carbon mixed evenly with formaldehyde solution. This allows KB to be uniformly distributed in the synthesized PDBM sheets, constructing a three-dimensional conductive network. This special structure not only introduces conductive components to enhance the conductivity of PDBM itself, but more importantly, it gives the PDBM@KB anode material a richer electron transport channel, shortens the distance of cation diffusion to PDBM, constructs a fast ion transport channel for the aqueous battery, promotes ion diffusion during charging and discharging, and significantly improves the utilization rate of PDBM active material. As a result, the aqueous magnesium-ion battery with PDBM / KB as the anode exhibits high capacity, long cycle life, high rate performance, and high power performance. As shown in Table 1 and Figure 7, the aqueous magnesium-ion battery with PDBM@KB as the anode provided in Examples 1-3 exhibits lower performance in the range of 4 C to 110 C. Within a wide current density range of C, the specific capacity remains stable between 100.93 and 120.74 mAh / g. At a high rate of 110 C, the capacity retention rate can reach 83.59%, showing excellent rate performance. After 3500 cycles at a current density of 4 C, the capacity retention rate can still reach 42.42%, and the coulombic efficiency is always close to 100%.
[0154] Table 1 also shows that, compared with Examples 4-5 and 7-10, the PDBM@KB anode material provided in Example 1 has better performance when the KB doping amount is 30%. This is because the anode material preparation method provided in Examples 4-5 introduced formaldehyde solution for quinone aldehyde condensation reaction to synthesize PDBM@KB, resulting in a decrease in the performance of the PDBM@KB anode material due to the excessively rapid addition rate of formaldehyde solution. The preparation method provided in Examples 7-8 did not perform ultrasonic and vacuum wetting after adding conductive carbon to the glacial acetic acid solution of 2,5-dihydroxy-1,4-benzoquinone (DHBQ). As a result, 2,5-dihydroxy-1,4-benzoquinone (DHBQ) did not fully penetrate into the porous structure of KB, and 2,5-dihydroxy-1,4-benzoquinone and conductive carbon were not fully mixed evenly, affecting the distribution of KB in the PDBM@KB anode material. The preparation method provided in Examples 9-10 affected the performance of the PDBM@KB anode material because the reaction was not carried out under a protective atmosphere or the reaction temperature was too low.
[0155] Table 1: Performance Test Results
[0156]
[0157] The above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.
Claims
1. An in-situ synthesized organic composite anode material for aqueous magnesium-ion batteries, characterized in that, The quinone-aldehyde polycondensation reaction was carried out in situ by reacting a uniformly mixed suspension of 2,5-dihydroxy-1,4-benzoquinone and conductive carbon with formaldehyde solution.
2. The in-situ synthesized organic composite anode material for aqueous magnesium-ion batteries according to claim 1, characterized in that, The conductive carbon doping amount in the in-situ synthesized organic composite anode material for aqueous magnesium-ion batteries is 10wt%~30wt%.
3. The in-situ synthesized aqueous magnesium-ion battery organic composite anode material according to claim 1, characterized in that, The conductive carbon is selected from at least one of Ketjen black, carbon nanotubes, carbon nanofibers, carbon black, and graphene.
4. A method for preparing an in-situ synthesized organic composite anode material for aqueous magnesium-ion batteries, characterized in that, The preparation of an in-situ synthesized organic composite anode material for an aqueous magnesium-ion battery according to any one of claims 1-3 comprises the following steps: adding conductive carbon to a glacial acetic acid solution containing dissolved 2,5-dihydroxy-1,4-benzoquinone, and sequentially performing ultrasonic dispersion and vacuum impregnation treatment to obtain a uniformly mixed suspension of 2,5-dihydroxy-1,4-benzoquinone and conductive carbon; slowly adding formaldehyde solution to the uniformly mixed suspension of 2,5-dihydroxy-1,4-benzoquinone and conductive carbon under vigorous stirring, and then carrying out a quinone-aldehyde condensation reaction at 35-40°C for 24-72 hours in a protective atmosphere to obtain the in-situ synthesized organic composite anode material for an aqueous magnesium-ion battery.
5. The method for preparing an in-situ synthesized organic composite anode material for aqueous magnesium-ion batteries according to claim 4, characterized in that, The ultrasonic dispersion time is 1~3 hours.
6. The method for preparing an in-situ synthesized organic composite anode material for aqueous magnesium-ion batteries according to claim 4, characterized in that, The vacuum impregnation treatment takes 1 to 3 hours and is performed 1 to 3 times.
7. The method for preparing an in-situ synthesized organic composite anode material for aqueous magnesium-ion batteries according to claim 4, characterized in that, The formaldehyde solution is added slowly at a rate of 5~50 μL / min.
8. The method for preparing an in-situ synthesized organic composite anode material for aqueous magnesium-ion batteries according to claim 4, characterized in that, In the formaldehyde solution and the uniformly mixed suspension of 2,5-dihydroxy-1,4-benzoquinone and conductive carbon, the mass ratio of 2,5-dihydroxy-1,4-benzoquinone, conductive carbon and formaldehyde is 1:0.11~0.43:1.2, and the volume ratio of the formaldehyde solution and the uniformly mixed suspension of 2,5-dihydroxy-1,4-benzoquinone and conductive carbon is 2~4:
50.
9. An organic composite negative electrode for an aqueous magnesium-ion battery, characterized in that, The current collector of the aqueous magnesium-ion battery organic composite anode is loaded with the in-situ synthesized aqueous magnesium-ion battery organic composite anode material as described in any one of claims 1-3.
10. An aqueous magnesium-ion battery, characterized in that, Including the organic composite negative electrode for an aqueous magnesium-ion battery as described in claim 9.