TABQ (at) MXene compound for positive electrode material of lithium ion battery and synthesis method of TABQ (at) MXene compound
Patent Information
- Application Number
- CN202510611112.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-05-13
- Publication Date
- 2025-09-19
AI Technical Summary
The organic electrode materials of existing lithium-ion batteries have high solubility in the electrolyte, which causes the battery capacity to decay rapidly, and their conductivity is insufficient, making it difficult to meet high-rate working requirements.
TABQ is compounded with MXene using covalent bonds, and TABQ is anchored on the MXene surface through strong interaction forces to form a TABQ@MXene complex, which improves the electrical conductivity and structural stability of the material.
The solubility of TABQ in the electrolyte is significantly reduced, the battery cycle stability is improved, and the high conductivity of MXene provides a fast channel for electron transfer, thereby improving the overall performance of the electrode.
Smart Images
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Abstract
Description
Technical Field
[0001] The present invention relates to a composite material containing TABQ@MXene and its application in lithium-ion batteries, belonging to the field of metal ion battery electrode materials. Background Art
[0002] Since the Industrial Revolution, the pace of industrialization and urbanization has accelerated, driving a continuous increase in global energy demand. With the widespread adoption of digitalization and electrification, electricity demand has further increased, exacerbating dependence on traditional fossil fuels. However, the over-exploitation and use of coal, oil, and natural gas have led to serious environmental problems, particularly global climate change. Against this backdrop, renewable energy sources such as wind and solar energy have developed rapidly, and how to efficiently store and utilize these energies has become a focus of current attention. Traditional ion energy storage batteries typically use metal oxides such as iron, cobalt, and nickel as electrode materials and are highly dependent on the mining of mineral resources. This not only exacerbates resource supply pressures but also brings serious environmental problems. In addition, these batteries are difficult to recycle, and their energy density is close to the theoretical limit, making it difficult to meet the future demand for higher performance in the energy storage field (Z. Luo, et al., ACS Appl. Mater. Interfaces 2022, 14, 11474-11482). Therefore, developing an efficient, clean, and safe battery material has become an urgent task to break the current dilemma in the energy storage field.
[0003] The core feature of organic lithium-ion batteries is the use of organic matter as electrode materials, which has the advantages of high energy density, environmental protection and potential low cost. Organic electrode materials are mainly composed of elements such as carbon, oxygen, nitrogen and sulfur, and contain rich active centers that can bind to lithium ions (J.Chen, et al.Angew.Chem.Int.Ed.2018,57,9443-9446). However, due to the high solubility of organic materials in the electrolyte, the battery capacity decays rapidly in a short period of time and cannot meet the needs of long-term use. In addition, organic materials have the disadvantage of insufficient conductivity, which makes it difficult to meet the requirements of batteries working at high rates. In subsequent studies, it was found that the combination of small molecule organic materials and porous materials can not only solve the solubility problem, but also give play to the advantages of their high theoretical capacity. In addition, the introduction of porous materials provides a fast channel for ion transport, which solves the disadvantage of insufficient conductivity of organic materials. Summary of the Invention
[0004] To address the aforementioned issues with organic electrode materials, the present invention provides a novel material that utilizes covalent bonds to combine TABQ and MXene, which has been successfully applied in lithium-ion batteries. This design anchors TABQ to the MXene surface through strong interactions, effectively inhibiting its dissolution in the electrolyte while significantly improving the material's electrical conductivity and structural stability.
[0005] In order to achieve the above object, the technical solution adopted in the present invention is:
[0006] The first aspect of the present invention provides a TABQ@MXene composite for lithium-ion battery positive electrode materials and a preparation method thereof, comprising the following steps:
[0007] Step 1: Weigh LiF and add it to a round-bottom flask, add concentrated hydrochloric acid and stir under N2 atmosphere for 20 minutes, then add Ti3AlC2 in small amounts to the round-bottom flask several times, heat to 65°C and stir for 12 hours, stop the reaction and cool to room temperature, pour the reaction product into a centrifuge tube, wash with deionized water several times until the solution pH = 7, pour out the upper liquid, add deionized water to the centrifuge tube again, centrifuge at 3500 rpm for 30 minutes, collect the suspension and freeze-dry to obtain black solid MXene;
[0008] Step 2: The black solid obtained in step 1 was dissolved in an organic solvent, ultrasonicated in an ice-water bath for 2 hours, TABQ in different proportions was added and stirred for 2 hours, the evenly stirred mixed solution was poured into a polytetrafluoroethylene hydrothermal reactor, heated at 150°C for 12 hours, the reaction was stopped, and the temperature of the hydrothermal reactor was lowered to room temperature. The product was poured into a centrifuge tube and the same organic solvent as in this step was added and centrifuged and washed several times until the solvent was colorless and transparent. The solid after centrifugation was taken and washed twice with ethanol, and then rinsed with deionized water to remove the ethanol. The obtained solid was freeze-dried for 12 hours to obtain the final product TABQ@MXene.
[0009] In some embodiments of the present invention, the organic solvent in step 2 is one of N,N-dimethylformamide (DMF) and toluene (TOL), preferably DMF.
[0010] In some embodiments of the present invention, the mass ratio of TABQ to MXene in step 2 is 2:1-1:2, and the concentration of the reaction solution is 5 g / L. Furthermore, the mass ratio of TABQ to MXene can be selected to be 1:1, 1:2, or 2:1, preferably 1:1.
[0011] The second aspect of the present invention is to provide a TABQ@MXene composite for lithium-ion battery positive electrode materials obtained by the above method.
[0012] The third aspect of the present invention provides an application of the above-mentioned TABQ@MXene composite for lithium-ion battery positive electrode materials. The composite containing the TABQ@MXene structure is used as a positive electrode material for a metal lithium-ion battery. The active material is a TABQ@MXene composite, which is mixed with a binder and a conductive agent in an organic solvent, coated on aluminum foil, and vacuum-dried at 80°C for more than 12 hours. The positive electrode sheet is cut to prepare a positive electrode sheet, and a lithium-ion battery is assembled using metallic lithium as the negative electrode, a separator, and an electrolyte.
[0013] The beneficial effects of the present invention are embodied in:
[0014] The electrode material synthesis method of the present invention is simple and efficient. TABQ and MXene are tightly bound together through the strong coordination between nitrogen and titanium atoms. This coordination has a stronger anchoring effect than traditional hydrogen bonding or physical adsorption, significantly reducing the solubility of TABQ in the electrolyte, thereby significantly improving the battery's cycling stability. Furthermore, MXene itself has excellent electrical conductivity, effectively improving the inherent poor conductivity of organic electrode materials, providing an efficient channel for electron transport, and further enhancing the overall performance of the electrode. BRIEF DESCRIPTION OF THE DRAWINGS
[0015] Figure 1 When the TABQ@MXene composite described in Example 1, Example 2, Example 3, and Example 4 is used as a positive electrode material for lithium-ion batteries, the -1 Cycling performance diagram at different current densities.
[0016] Figure 2 This is a scanned photo of the TABQ@MXene composite described in Example 1.
[0017] Figure 3 These are the thermogravimetric curves of the TABQ raw material and the TABQ@MXene composite described in Example 1.
[0018] Figure 4 This is the infrared spectrum of the TABQ@MXene composite and raw materials described in Example 1.
[0019] Figure 5 When the TABQ@MXene composite described in Example 1 is used as the positive electrode material for lithium-ion batteries, the -1 CV curve diagram under scanning rate.
[0020] Figure 6 When the TABQ@MXene composite described in Example 1 is used as a positive electrode material for lithium-ion batteries, the -1 Charge and discharge curves at different current densities.
[0021] Figure 7 When the TABQ@MXene composite described in Example 1 is used as a positive electrode material for lithium-ion batteries, the -1 Cycling performance diagram at different current densities.
[0022] Figure 8 This is a rate performance diagram at different current densities when the TABQ@MXene composite described in Example 1 is used as a positive electrode material for lithium-ion batteries. DETAILED DESCRIPTION
[0023] The following is a detailed description of an embodiment of the present invention. This embodiment is implemented based on the technical solution of the present invention, and a detailed implementation scheme and operation process are provided. Based on the embodiment of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.
[0024] Unless otherwise specified, the experimental methods used in the following examples are conventional methods.
[0025] Unless otherwise specified, the reagents and materials used in the following examples can be obtained from commercial sources.
[0026] The battery performance tests in the following examples were all conducted using a Xinwei battery test system. The positive electrode material obtained in the following examples, Ketjen black, and a binder (PVDF) were mixed uniformly in a solvent NMP at a mass ratio of 6:3:1 to form a slurry, which was then evenly coated on an aluminum foil current collector to form a working electrode. The lithium battery separator was polypropylene, and the lithium battery electrolyte was a 2M LiTFSI solution (commercially available) in a DME / DOL (volume ratio 1:1) solution. 2032 button cells were assembled in an argon-filled glove box, and the test voltage range was 1.2V-3.5V (vs Li + / Li).
[0027] Example 1: (TABQ@MXene prepared when the solvent is DMF and the mass ratio is 1:1)
[0028] LiF was weighed and added to a round-bottom flask. Concentrated hydrochloric acid was added and stirred under a nitrogen atmosphere for 20 minutes. TiAlC was then added to the flask in small portions. The temperature was raised to 65°C and stirred for 12 hours. The reaction was stopped and cooled to room temperature. The reaction product was poured into a centrifuge tube and washed several times with deionized water until the solution had a pH of 7. The supernatant was poured off, and deionized water was added to the centrifuge tube again. The tube was centrifuged at 3500 rpm for 30 minutes. The suspension was collected and freeze-dried to obtain a black solid MXene.
[0029] The resulting black solid was dissolved in DMF and sonicated in an ice-water bath for 2 hours. TABQ (1:1 by mass) was added and stirred for 2 hours. The homogenized mixture was poured into a polytetrafluoroethylene hydrothermal reactor and heated at 150°C for 12 hours. The reaction was stopped, and after the hydrothermal reactor temperature cooled to room temperature, the product was poured into a centrifuge tube and washed several times by centrifugation with DMF until the solvent became colorless and transparent. The solid was washed twice with ethanol and then rinsed with deionized water to remove the ethanol. The resulting solid was freeze-dried for 12 hours to obtain the final product, TABQ@MXene.
[0030] Example 2: (TABQ@MXene prepared when the solvent is TOL and the mass ratio is 1:1)
[0031] LiF was weighed and added to a round-bottom flask. Concentrated hydrochloric acid was added and stirred under a nitrogen atmosphere for 20 minutes. TiAlC was then added to the flask in small portions. The temperature was raised to 65°C and stirred for 12 hours. The reaction was stopped and cooled to room temperature. The reaction product was poured into a centrifuge tube and washed several times with deionized water until the solution had a pH of 7. The supernatant was poured off, and deionized water was added to the centrifuge tube again. The tube was centrifuged at 3500 rpm for 30 minutes. The suspension was collected and freeze-dried to obtain a black solid MXene.
[0032] The resulting black solid was dissolved in TOL and sonicated in an ice-water bath for 2 hours. TABQ (1:1 by mass) was added and stirred for 2 hours. The homogenized mixture was poured into a polytetrafluoroethylene hydrothermal reactor and heated at 150°C for 12 hours. The reaction was stopped, and after the hydrothermal reactor temperature cooled to room temperature, the product was poured into a centrifuge tube and washed several times by centrifugation with DMF until the solvent became colorless and transparent. The solid was washed twice with ethanol and then rinsed with deionized water to remove the ethanol. The resulting solid was freeze-dried for 12 hours to obtain the final product, TABQ@MXene.
[0033] Example 3: (TABQ@MXene prepared when the solvent is TOL and the mass ratio is 1:2)
[0034] LiF was weighed and added to a round-bottom flask. Concentrated hydrochloric acid was added and stirred under a nitrogen atmosphere for 20 minutes. TiAlC was then added to the flask in small portions. The temperature was raised to 65°C and stirred for 12 hours. The reaction was stopped and cooled to room temperature. The reaction product was poured into a centrifuge tube and washed several times with deionized water until the solution had a pH of 7. The supernatant was poured off, and deionized water was added to the centrifuge tube again. The tube was centrifuged at 3500 rpm for 30 minutes. The suspension was collected and freeze-dried to obtain a black solid MXene.
[0035] The resulting black solid was dissolved in DMF and sonicated in an ice-water bath for 2 hours. TABQ (1:2 by mass) was added and stirred for 2 hours. The homogenized mixture was poured into a polytetrafluoroethylene hydrothermal reactor and heated at 150°C for 12 hours. The reaction was stopped, and after the hydrothermal reactor temperature cooled to room temperature, the product was poured into a centrifuge tube and washed several times by centrifugation with DMF until the solvent became colorless and transparent. The solid was washed twice with ethanol and then rinsed with deionized water to remove the ethanol. The resulting solid was freeze-dried for 12 hours to obtain the final product, TABQ@MXene.
[0036] Example 4 (TABQ@MXene prepared when the solvent is TOL and the mass ratio is 2:1):
[0037] LiF was weighed and added to a round-bottom flask. Concentrated hydrochloric acid was added and stirred under a nitrogen atmosphere for 20 minutes. TiAlC was then added to the flask in small portions. The temperature was raised to 65°C and stirred for 12 hours. The reaction was stopped and cooled to room temperature. The reaction product was poured into a centrifuge tube and washed several times with deionized water until the solution had a pH of 7. The supernatant was poured off, and deionized water was added to the centrifuge tube again. The tube was centrifuged at 3500 rpm for 30 minutes. The suspension was collected and freeze-dried to obtain a black solid MXene.
[0038] The resulting black solid was dissolved in DMF and sonicated in an ice-water bath for 2 hours. TABQ (2:1 by mass) was added and stirred for 2 hours. The homogenized mixture was poured into a polytetrafluoroethylene hydrothermal reactor and heated at 150°C for 12 hours. The reaction was stopped, and after the hydrothermal reactor temperature cooled to room temperature, the product was poured into a centrifuge tube and centrifuged and washed several times with DMF until the solvent became colorless and transparent. The solid was washed twice with ethanol and then rinsed with deionized water to remove the ethanol. The resulting solid was freeze-dried for 12 hours to obtain the final product, TABQ@MXene.
[0039] Figure 1 When the TABQ@MXene composite described in Example 1, Example 2, Example 3, and Example 4 is used as a positive electrode material for lithium-ion batteries, the -1 Comparison of cycling performance under different current densities. It can be seen that when TABQ and MXene react in a DMF solvent with a mass ratio of 1:1, the optimal performance is achieved, with a specific capacity of 284 mAh g -1 , and has the best stability.
[0040] Figure 2 This is a scanning photo of TABQ@MXene described in Example 1, showing a tightly packed block structure, indicating that TABQ is accumulated in large quantities on MXene.
[0041] Figure 3This is the thermogravimetric analysis curve of the TABQ raw material and its composite with MXene described in Example 1. In order to study the changes in the thermal stability of the materials before and after composite, the experiment was carried out in a nitrogen atmosphere. It can be seen from the curve that the TABQ monomer begins to decompose at 118°C, while the decomposition temperature of the TABQ@MXene composite is significantly increased to 252°C. This result shows that the introduction of MXene greatly enhances the thermal stability of TABQ. This significant improvement in thermal stability is of great significance to the safety performance of the battery, and can effectively reduce the risk of thermal runaway of the battery in a high-temperature environment, thereby improving the reliability of the battery.
[0042] Figure 4 This is the infrared spectrum of the TABQ@MXene composite and the raw material described in Example 1. The peak corresponding to CN in the raw material is located at 1367 cm -1 , composite material at 1242cm -1 A new peak is added at 1629cm -1 A new peak at 1667cm corresponds to the generated coordination bond CN=. -1 The C=O bond did not change significantly, proving that the active site was not destroyed by high temperature and high pressure conditions.
[0043] Figure 5 When the TABQ@MXene composite described in Example 1 is used as the positive electrode material of lithium-ion batteries, the -1 CV curves at a low scan rate. Two broad peaks at 2.06-2.3V and 2.6-3.07V are observed in the CV curves, indicating multiple redox reactions. This result indicates that the C=O in the benzoquinone unit combines with the lithium ion in a two-step reaction. In subsequent cycles, the CV curves show a high degree of overlap, demonstrating that TABQ@MXene has a stable structure and can effectively sustain reversible redox reactions.
[0044] Figure 6 When the TABQ@MXene composite described in Example 1 is used as a positive electrode material for lithium-ion batteries, the -1 The charge and discharge curves under current density are as follows. The charge and discharge curves overlap to form a platform at 2.48V. After multiple cycles of activation, there is 250mAhg -1 High capacity above.
[0045] Figure 7 When the TABQ@MXene composite described in Example 1 is used as a positive electrode material for lithium-ion batteries, the -1 Cycling performance diagram under current density. TABQ@MXene has a high reversible capacity of 280 mAh g -1, and after 3000 cycles, there is still a capacity retention rate of 70% and a coulombic efficiency close to 100%, indicating that its cycle stability is high.
[0046] Figure 8 The rate performance diagram of the TABQ-MXene composite as the positive electrode material of lithium ion battery at different current densities is shown in Figure 1. The positive electrode of the TABQ-MXene composite is 0.05, 0.1, 0.2, 0.5, 1.0, Ag -1 At current densities of 316, 284, 225, 188, and 145 mAh g -1 The high discharge capacity, when the current density returns to the initial 0.05Ag -1 When the discharge capacity is still able to return to 306mAh g -1 , proving that the material not only has excellent rate performance, but also maintains excellent reversibility.
[0047] Through the embodiments of the present invention, a method for synthesizing a TABQ@MXene complex for lithium-ion battery positive electrode materials is provided, resulting in a complex containing a TABQ@MXene structure. The TABQ in this material is anchored on the MXene surface through coordination, exhibiting stronger adsorption, reducing its solubility in the electrolyte, and exhibiting better electrochemical performance than TABQ. Furthermore, the unique three-dimensional pore structure of MXene can provide a rapid transport pathway for lithium ions, increasing the material's conductivity, compensating for the insufficient conductivity of organic electrode materials, and improving their rate performance to a certain extent. When used as a cathode material for lithium-ion batteries, the TABQ@MXene material exhibits excellent cycle life, high reversible cycle capacity, and good rate performance.
Claims
1. A method for synthesizing a TABQ@MXene composite for lithium-ion battery cathode materials, characterized in that The steps include: Step 1: Weigh LiF and add it to a round-bottom flask, and add concentrated hydrochloric acid with a syringe and stir for 20 minutes under a N2 atmosphere. Then, add Ti3AlC2 in small amounts to the round-bottom flask several times, heat to 65°C, and heat with stirring for 12 hours. Stop the reaction and cool to room temperature. Pour the reaction product into a centrifuge tube and wash it with deionized water several times until the solution pH = 7. Pour out the upper liquid, add deionized water to the centrifuge tube again, centrifuge at 3500 rpm for 30 minutes, collect the suspension and freeze-dry to obtain black solid MXene; Step 2: The black solid obtained in step 1 was dissolved in an organic solvent and ultrasonicated in an ice-water bath for 2 hours. TABQ in different proportions was added and stirred for 2 hours. The evenly stirred mixed solution was poured into a polytetrafluoroethylene hydrothermal reactor and heated at 150°C for 12 hours to stop the reaction. After the temperature of the hydrothermal reactor dropped to room temperature, the product was poured into a centrifuge tube and the same organic solvent as in this step was added and centrifuged and washed several times until the solvent was colorless and transparent. The solid after centrifugation was washed twice with ethanol, and then rinsed with deionized water to remove the ethanol. The obtained solid was freeze-dried for 12 hours to obtain the final product TABQ@MXene.
2. The synthesis method according to claim 1, wherein: In step 2, the organic solvent is one of N,N-dimethylformamide (DMF) or toluene (TOL).
3. The synthesis method according to claim 1 or 2, characterized in that: The organic solvent in step 2 is DMF.
4. The synthesis method according to claim 1, wherein: In step 2, the mass ratio of TABQ to MXene is 2:1-1:2, and the concentration of the reaction solution is 5 g / L.
5. The synthesis method according to claim 1 or 4, characterized in that: In step 2, the mass ratio of TABQ to MXene is 1-1, 1:2 or 2:
1.
6. A TABQ@MXene composite for lithium-ion battery cathode material, characterized by: The method is obtained by the synthesis method according to any one of claims 1 to 5.
7. An application of a TABQ@MXene composite for lithium-ion battery cathode materials, characterized in that: The TABQ@MXene composite according to claim 6 is used as the active material, mixed with a binder and a conductive agent in an organic solvent, coated on an aluminum foil, and vacuum dried at 80°C for more than 12 hours. The positive electrode sheet is cut to prepare a positive electrode sheet, and metallic lithium is used as the negative electrode, a separator, and an electrolyte is added to assemble a lithium-ion battery.
8. The use according to claim 7, characterized in that: The binder is PVDF, the conductive agent is Ketjen black, and the usage ratio of TABQ@MXene composite, conductive agent, and binder is 6:3:1.