Conductive carrier loaded 1, 10-phenanthroline-5, 6-diketone magnesium ion positive electrode material and preparation method and application thereof
By loading 1,10-phenanthroline-5,6-dione material onto a conductive carrier, and utilizing its dual active sites and optimized composite process, the problems of insufficient capacity and dissolution in magnesium-ion battery cathode materials were solved, resulting in a magnesium-ion battery cathode material with high energy density and long cycle life.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-12-09
- Publication Date
- 2026-03-13
AI Technical Summary
The single active site of existing organic cathode materials results in insufficient theoretical capacity of magnesium-ion batteries, making it difficult to break through the high energy density ceiling, and they are easily dissolved in electrolytes.
High-performance cathode materials were prepared by loading 1,10-phenanthroline-5,6-dione (PDO) onto a conductive carrier and growing it on the surface and inside the carrier in situ. Utilizing the dual active sites of C=O and C=N, and combining ultrasonication, stirring, rotary evaporation, and drying processes, a high-performance cathode material was prepared.
The theoretical capacity was increased to 510 mAh·g⁻¹, material dissolution was suppressed, electron conductivity was improved, electrode preparation steps were simplified, and the production threshold was lowered.
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Figure CN121662786A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of magnesium-ion battery technology, specifically relating to a conductive carrier-loaded 1,10-phenanthroline-5,6-dione magnesium ion cathode material, its preparation method, and its application. Background Technology
[0002] With the continued growth of global energy storage demand, magnesium-ion batteries (RMBs) have become the core development direction for next-generation electrochemical energy storage due to their advantages such as high magnesium abundance in the Earth's crust (approximately 2.0%, more than 300 times that of lithium), absence of dendrites in the anode, and high volumetric energy density. However, their industrialization process is facing a severe bottleneck in cathode materials: existing organic cathode materials, such as quinones (dependent on C=O sites) or traditional nitrogen-containing heterocyclic compounds (dependent on C=N sites), are limited by their single active center, resulting in inherently insufficient theoretical capacity and difficulty in breaking through the ceiling of high energy density. To address this, this invention aims to provide a solution from the molecular structure source, with the core being the introduction of 1,10-phenanthroline-5,6-dione as a new generation of organic magnesium storage cathode material. The unique rigid planar structure of this molecule, along with the synergistic C=O and C=N dual active sites, theoretically gives it higher specific capacity and better electronic conductivity. Simultaneously, its combination with a suitable conductive carrier can effectively suppress dissolution in the electrolyte. This invention provides a novel design paradigm and key material selection for achieving high-capacity, long-cycle-life magnesium-ion battery cathode materials. Summary of the Invention
[0003] To achieve the above-mentioned technical objectives, the present invention provides the following technical solution:
[0004] A conductive carrier-loaded 1,10-phenanthroline-5,6-dione (PDO) is characterized in that the core of the material is PDO loaded on the conductive carrier; the PDO molecule contains C=O and C=N dual magnesium storage active sites, and is loaded onto the surface and interior of the conductive carrier by in-situ growth.
[0005] Furthermore, the conductive carrier includes carbon-based materials, conductive polymers, and other materials; the carbon-based materials include, but are not limited to, expanded graphite (EG), graphene (G), acetylene black (ACET), carbon nanotubes (CNT), Ketjen black (KB), carbon paper, carbon cloth, etc.; the conductive polymers include, but are not limited to, polyaniline (PANI), polypyrrole (PPy), etc.; other conductive materials include, for example, MXene.
[0006] On the other hand, the present invention also provides a method for preparing the above-mentioned conductive carrier-supported magnesium phenanthroline dione ion cathode material, characterized by comprising the following steps:
[0007] S1. Raw material preparation: Add 60 mg PDO and 30 mg conductive carrier to 30 mL of solvent and mix to form a suspension; the solvent is selected from one or more combinations of ethanol, acetone, tetrahydrofuran, n-hexane, and dichloromethane, and the purity of each solvent is ≥95%;
[0008] S2. Ultrasonic stirring and synergistic dispersion: Place the suspension obtained in step S1 in an ultrasonic instrument and ultrasonically vibrate at a power of 800-1000W for 30 minutes; after ultrasonication, transfer the suspension to a magnetic stirrer and stir at a speed of 300-500rpm for 30 minutes to obtain a uniform dispersion.
[0009] S3. Rotary evaporation in situ composite: Transfer the uniformly dispersed liquid obtained in step S2 to a rotary evaporator, adjust the rotary evaporation temperature according to the type of solvent, and rotary evaporate for 10 minutes to half an hour until the solvent is completely removed to form a PDO / conductive carrier composite material.
[0010] S4. Drying and shaping: Place the product obtained in step S3 in a drying oven and dry it at 60-80℃ for 4-6 hours; after drying, cool the product to room temperature (25℃) and store it in a sealed container.
[0011] Furthermore, in step S1, the mass ratio of PDO to conductive carrier is 0.5 to 2:1.
[0012] Furthermore, in step S2, the ultrasonic time is 5 to 40 minutes; the stirring speed is 50 to 1000 rpm.
[0013] Furthermore, in step S3, the rotary evaporation temperature is 10–20° below the solvent's atmospheric boiling point.
[0014] Furthermore, in step S4, the drying temperature is 40-70°C, and the drying time is 2 to 24 hours.
[0015] On the other hand, the present invention also provides a method for preparing a magnesium-ion battery positive electrode sheet based on the above-mentioned positive electrode material, characterized by comprising the following steps:
[0016] (1) The conductive carrier loaded with 1,10-phenanthroline-5,6-dione (PDO) composite material prepared by the above method is mixed with polyvinylidene fluoride (PVDF) at a mass ratio of (8-11):1 and dispersed in N-methylpyrrolidone (NMP), wherein each gram of PD corresponds to 10-15 mL of NMP, and a uniform slurry is obtained by stirring.
[0017] (2) The slurry is coated onto the surface of double-sided carbon-coated aluminum foil, and the height of the scraper is controlled to be 200-300 μm and the coating rate is 5-10 cm / s;
[0018] (3) Place the coated aluminum foil in a vacuum drying environment and dry it for 8 to 12 hours at 60 to 80°C and a vacuum degree ≤ 0.09 MPa;
[0019] (4) After drying, the aluminum foil is cut into circular pieces with a diameter of 10-14 mm to obtain the positive electrode sheet, wherein the active material loading of the positive electrode sheet is 0.8-2 mg / cm³. 2 .
[0020] Furthermore, the width of the double-sided carbon-coated aluminum foil is ≥280mm, and the thickness of the carbon layer on the aluminum foil surface is 5~10μm; the purity of the PVDF is ≥95%, and the purity of the NMP is ≥95%.
[0021] On the other hand, the present invention also provides an application of the above-mentioned positive electrode material in the preparation of magnesium-ion batteries, characterized in that, in an anhydrous and oxygen-free glove box, the positive electrode sheet prepared according to the above method is assembled with magnesium sheet, glass fiber, stainless steel button battery assembly and magnesium hexafluoroisopropoxyborate dissolved in diethylene glycol dimethyl ether electrolyte to obtain a magnesium-ion battery.
[0022] Compared with the prior art, the beneficial effects of the present invention are:
[0023] The first development of 1,10-phenanthroline-5,6-dione (PDO), whose unique dual active sites (C=O, C=N) effectively increase the theoretical capacity to 510 mAh·g. -1 The actual discharge specific capacity far exceeds that of most existing organic materials containing only a single active site; the composite material process is optimized: the four-step process of "ultrasound, stirring, rotary evaporation and drying" is adopted to realize the in-situ growth of PD on the surface of conductive carrier, which can effectively inhibit agglomeration, improve conductivity and suppress dissolution problems; it is suitable for large-scale production: while ensuring high performance, the electrode preparation steps are simplified, conventional equipment and low-cost raw materials are used to lower the production threshold. Attached Figure Description
[0024] To more clearly illustrate the technical solution of the present invention, the accompanying drawings used in the description of the specific embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0025] Figure 1 This is a SEM image of the 1,10-phenanthroline-5,6-dione composite cathode material in this invention example;
[0026] Figure 2 The 1,10-phenanthroline-5,6-dione composite cathode material in this invention is used at 300 mA g -1Charge-discharge curves at current density;
[0027] Figure 3 The rate curve of the 1,10-phenanthroline-5,6-dione composite cathode material in this invention example;
[0028] Figure 4 The cycling curves of the 1,10-phenanthroline-5,6-dione composite cathode material in this invention are shown in the example. Detailed Implementation
[0029] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.
[0030] The invention will now be further described with reference to the accompanying drawings.
[0031] Example 1: Preparation of PDO-EG composite material and electrode fabrication
[0032] This embodiment is an exemplary implementation, demonstrating the composite process of PDO and expanded graphite (EG). The relevant parameters can be adjusted within the range according to actual needs.
[0033] S1. Raw material preparation: In a 50mL round-bottom flask, add 60mg of 1,10-phenanthroline-5,6-dione (PDO, purity 97%, containing C=O and C=N dual active sites, Shanghai Macklin), 30mg of EG (interlayer spacing 5-10μm, laboratory-made), and then add 30mL of mixed solvent (ethanol:tetrahydrofuran = 1:1, ethanol purity 95%, tetrahydrofuran purity 95%) to form a suspension. In this embodiment, the mass ratio of PDO to conductive carrier can be selected between 0.5 and 2:1; this embodiment uses 2:1.
[0034] S2. Ultrasonic stirring and synergistic dispersion: The suspension was placed in a KQ-500DE ultrasonic instrument and ultrasonicated at 900W power for 30 minutes, with a selectable range of 5 to 40 minutes (SEM observation showed that the particle size of PDO rod-shaped aggregates decreased from 10 μm to below 1 μm, and the active sites were initially exposed); then it was transferred to an 85-2 magnetic stirrer and stirred at 400 rpm for 30 minutes (speed range of 50 to 1000 rpm) to obtain a yellow-black uniform dispersion (Zeta potential test showed that the stability of the dispersion was improved by 60%).
[0035] S3. Rotary evaporation in situ composite: The dispersion was transferred to a RE-52AA rotary evaporator, the temperature was set to 60℃ and the vacuum degree to 0.095MPa, and the solvent was completely removed by rotary evaporation for half an hour (selectable range 10 minutes to half an hour) to obtain a black loose PDO-EG composite material (SEM observation showed that PDO grew in situ on the EG surface, and there were no free PDO particles).
[0036] S4. Drying and shaping: Place the composite material in a DHG-9070A drying oven and dry at 70℃ (optional range 40~70℃) for 5 hours (optional range 2~24 hours). After cooling to room temperature, seal and store. The composite material yield is 95.2%.
[0037] Preparation of the positive electrode sheet: The above PDO-EG composite material and PVDF (95% purity) were mixed at a mass ratio of 9:1 (the ratio can be selected from 8 to 11:1). 720 μL of NMP (95% purity) was added, and the mixture was stirred at 300 rpm for 60 minutes to obtain a uniform slurry. The slurry was coated onto double-sided carbon-coated aluminum foil (carbon layer thickness 8 μm (adjustable range 5–10 μm)), with a scraper height of 250 μm (adjustable range 200–300 μm) and a coating speed of 8 cm / s (adjustable range 5–10 cm / s). The foil was then vacuum-dried at 70℃ and 0.095 MPa for 10 hours, and cut into 12 mm round sheets with an active material loading of 0.9 mg / cm³. 2 (Adjustable range 0.8~2mg / cm) 2 ).
[0038] Battery assembly and performance testing: In an argon glove box (water and oxygen ≤ 0.1 ppm), CR2032 button batteries were assembled using the above-mentioned electrode as the positive electrode, magnesium sheet (purity ≥ 99%) as the negative electrode, glass fiber as the separator, and 0.5 mol / L magnesium hexafluoroisopropoxyborate / diethylene glycol dimethyl ether as the electrolyte.
[0039] Performance verification: The microstructure of the obtained PDO-EG composite material is as follows Figure 1 As shown, PDO is loaded onto the EG surface without agglomeration.
[0040] like Figure 2 As shown, electrochemical tests revealed that the material exhibited stable charge-discharge curves at a current of 300 mA / g, demonstrating excellent capacity performance; Figure 3 and 4 As shown, rate and cycle tests further demonstrate its high capacity and long lifespan characteristics.
[0041] Example 2: Preparation of PDO-CNT composite material and electrode fabrication
[0042] This embodiment is an exemplary implementation, demonstrating the composite process of PDO and carbon nanotubes (CNTs). The relevant parameters can be adjusted within the range according to actual needs.
[0043] S1. Raw material preparation: In a 50mL round-bottom flask, add 60mg of 1,10-phenanthroline-5,6-dione (PDO, purity 97%, containing C=O and C=N dual active sites, Shanghai Maclean's), 30mg of CNTs (diameter 10-20nm, commercially available analytical grade), and then add 30mL of ethanol solvent to form a suspension. In this embodiment, the mass ratio of PDO to conductive carrier can be selected from 0.5 to 2:1; this embodiment uses 2:1.
[0044] S2. Ultrasonic stirring and synergistic dispersion: The suspension was placed in a KQ-500DE ultrasonic instrument and ultrasonicated at 900W power for 30 minutes, with a selectable range of 5 to 40 minutes (SEM observation showed that the PDO aggregate particle size decreased to below 1μm); then transferred to an 85-2 magnetic stirrer and stirred at 400rpm for 30 minutes (speed range of 50 to 1000rpm) to obtain a uniform dispersion.
[0045] S3. Rotary evaporation in situ composite: The dispersion was transferred to a RE-52AA rotary evaporator and rotary evaporated at 60℃ and 0.095MPa for 20 minutes (selectable range: 10 minutes to half an hour). After the solvent was completely removed, a black and loose PDO-CNT composite material was obtained (SEM observation of PDO in situ growth on the CNT surface and between tubes).
[0046] S4. Drying and shaping: Place the composite material in a DHG-9070A drying oven at 70℃ (optional range 40~70℃) for 6 hours (optional range 2~24 hours), cool to room temperature and then seal for storage, yield 94.5%.
[0047] Preparation of the positive electrode: 90 mg of PDO-CNT composite material and 10 mg of PVDF were added to 720 μL of NMP and stirred at 300 rpm for 60 minutes to form a slurry. This slurry was then coated onto double-sided carbon-coated aluminum foil (carbon layer thickness 8 μm (adjustable range 5–10 μm)), with a doctor blade height of 250 μm (adjustable range 200–300 μm) and a coating speed of 8 cm / s (adjustable range 5–10 cm / s). The foil was then vacuum-dried at 70℃ and 0.095 MPa for 10 hours, and cut into 12 mm round discs with an active material loading of 0.9 mg / cm³. 2 (Adjustable range 0.8~2mg / cm) 2 ).
[0048] In the description of this specification, references to terms such as "an embodiment," "example," "specific example," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.
[0049] The preferred embodiments of the present invention disclosed above are merely illustrative of the invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the invention to the specific implementations described. Clearly, many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to better understand and utilize the invention. The invention is limited only by the claims and their full scope and equivalents.
Claims
1. A conductive carrier-supported 1,10-phenanthroline-5,6-dione (PDO), characterized in that, The core of the material is PDO loaded on a conductive carrier; the PDO molecule contains two magnesium storage active sites, C=O and C=N, and is loaded onto the surface and interior of the conductive carrier through in-situ growth.
2. The 1,10-phenanthroline-5,6-dione (PDO) magnesium ion cathode material supported on the conductive carrier according to claim 1, characterized in that, The conductive carrier includes carbon-based materials, conductive polymers, and other materials; the carbon-based materials include, but are not limited to, expanded graphite (EG), graphene (G), acetylene black (ACET), carbon nanotubes (CNT), Ketjen black (KB), carbon paper, carbon cloth, etc.; the conductive polymers include, but are not limited to, polyaniline (PANI), polypyrrole (PPy), etc.; other conductive materials include MXene, etc.
3. A method for preparing a magnesium phenanthroline dione cathode material supported on a conductive carrier as described in claim 1 or 2, characterized in that, Includes the following steps: S1. Raw material preparation: Add 60 mg PDO and 30 mg conductive carrier to 30 mL of solvent and mix to form a suspension; the solvent is selected from one or more combinations of ethanol, acetone, tetrahydrofuran, n-hexane, and dichloromethane, and the purity of each solvent is ≥95%; S2. Ultrasonic stirring and synergistic dispersion: Place the suspension obtained in step S1 in an ultrasonic instrument and ultrasonically vibrate at a power of 800-1000W for 30 minutes; after ultrasonication, transfer the suspension to a magnetic stirrer and stir at a speed of 300-500rpm for 30 minutes to obtain a uniform dispersion. S3. Rotary evaporation in situ composite: Transfer the uniformly dispersed liquid obtained in step S2 to a rotary evaporator, adjust the rotary evaporation temperature according to the type of solvent, and rotary evaporate for 10 minutes to half an hour until the solvent is completely removed to form a PDO / conductive carrier composite material. S4. Drying and shaping: Place the product obtained in step S3 in a drying oven and dry it at 60-80℃ for 4-6 hours; After drying, cool the product to room temperature (25°C) and store it in a sealed container.
4. The preparation method according to claim 3, characterized in that, In step S1, the mass ratio of PDO to conductive carrier is 0.5 to 2:
1.
5. The preparation method according to claim 3, characterized in that, In step S2, the ultrasonic time is 5 to 40 minutes; the stirring speed is 50 to 1000 rpm.
6. The preparation method according to claim 3, characterized in that, In step S3, the rotary evaporation temperature is 10-20° below the atmospheric boiling point of the solvent.
7. The preparation method according to claim 3, characterized in that, In step S4, the drying temperature is 40-70°C and the drying time is 2 to 24 hours.
8. A method for preparing a magnesium-ion battery positive electrode sheet based on the positive electrode material described in claim 1 or 2, characterized in that, Includes the following steps: (1) The conductive carrier loaded with 1,10-phenanthroline-5,6-dione (PDO) composite material prepared by any of the methods described in claims 3 to 7 is mixed with polyvinylidene fluoride (PVDF) at a mass ratio of (8 to 11):1 and dispersed in N-methylpyrrolidone (NMP), wherein each gram of PD corresponds to 10 to 15 mL of NMP, and stirred to obtain a uniform slurry; (2) The slurry is coated onto the surface of double-sided carbon-coated aluminum foil, and the height of the scraper is controlled to be 200-300 μm and the coating rate is 5-10 cm / s; (3) Place the coated aluminum foil in a vacuum drying environment and dry it for 8 to 12 hours at 60 to 80°C and a vacuum degree ≤ 0.09 MPa; (4) After drying, the aluminum foil is cut into circular pieces with a diameter of 10-14 mm to obtain the positive electrode sheet, wherein the active material loading of the positive electrode sheet is 0.8-2 mg / cm³. 2 .
9. The method for preparing a positive electrode sheet according to claim 8, characterized in that, The width of the double-sided carbon-coated aluminum foil is ≥280mm, and the thickness of the carbon layer on the aluminum foil surface is 5~10μm; the purity of the PVDF is ≥95%, and the purity of the NMP is ≥95%.
10. An application of the cathode material according to claim 1 in the preparation of magnesium-ion batteries, characterized in that, In an anhydrous and oxygen-free glove box, the positive electrode sheet prepared according to claim 8 or 9 is assembled with magnesium sheet, glass fiber, stainless steel button battery assembly and magnesium hexafluoroisopropoxyborate dissolved in diethylene glycol dimethyl ether electrolyte to obtain a magnesium-ion battery.