PTCDA / Ti3C2T x Application of MXene as an anode material for aqueous manganese-ion batteries

Abstract

This invention provides a composite material PTCDA / Ti3C2T x MXene anodes are used in aqueous manganese-ion batteries. MXene possesses a stable two-dimensional layered structure, while PTCDA can be used for manganese ion storage during charge and discharge. The intercalation of PTCDA into MXene leads to interaction between the two, significantly improving the electrode's electronic conductivity and ion diffusion coefficient. This achieves rapid ion diffusion kinetics and high cycle stability in the anode of rechargeable aqueous manganese-ion batteries, resulting in high reversible specific capacity and long cycle life, exhibiting excellent electrochemical performance. The PTCDA / Ti3C2T electrode of this invention... x When MXene anodes are used in aqueous manganese-ion batteries, at 0.5 A g... ‑1 At a current density, it provides 199mAh g ‑1 It has high reversible capacity and excellent cycling stability at 10 A g. ‑1 At the specified current density, the capacity retention rate reaches 82% after 1000 charge-discharge cycles.

Description

Technical Field

[0001] This invention belongs to the field of aqueous manganese-ion battery technology, specifically relating to a PTCDA / Ti3C2T battery composed of MXene and organic materials. x MXene materials and their application as anode materials in aqueous manganese-ion batteries. Background Technology

[0002] With the increasing prevalence of electric vehicles and the construction of smart grids, the importance of energy storage systems (ESSs) is becoming increasingly prominent. Among various energy storage systems, aqueous batteries, with their unique advantages such as high safety, low toxicity, ease of manufacturing, low cost, environmental friendliness, and high ionic conductivity, are considered the optimal solution for balancing cost-effectiveness, safety, and energy demand. However, aqueous batteries still face many technical challenges on the road to commercialization, especially the limitations of output voltage and power density, which have become bottlenecks restricting their further development. To overcome this predicament, the key lies in discovering and developing new electrode materials or new battery systems with excellent performance. This is not only the core of driving innovation in aqueous battery technology but also a key factor in realizing its large-scale commercial application. While the use of high-performance electrode materials is indeed crucial, exploring and applying new electrode systems is of even greater significance in the development of aqueous batteries. This is because it not only improves material performance but is also a crucial step in promoting the overall development of aqueous battery technology.

[0003] In various battery systems, manganese metal shows great potential in the field of aqueous battery due to its unique physical and chemical properties. Manganese is expected to achieve higher energy density during charge and discharge. Furthermore, its low cost and non-toxicity meet the requirements of sustainable development and environmental protection. Despite these advantages, manganese still faces challenges as an anode material. During charge and discharge, manganese anodes are prone to side reactions with the electrolyte, leading to problems such as manganese oxidation and spontaneous corrosion. These problems limit the coulombic efficiency (CE) and cycle stability of the battery. Coulombic efficiency is a key indicator for evaluating the energy conversion efficiency of a battery and directly affects its actual performance. Meanwhile, cycle stability is crucial for evaluating battery life and performance stability, and is key to ensuring long-term stable operation of the battery. Therefore, solving the side reaction problems of manganese anodes and improving their coulombic efficiency and cycle stability has become an urgent need for the application of manganese metal in aqueous battery fields. Summary of the Invention

[0004] The purpose of this invention is to provide a PTCDA / Ti3C2T xThis invention relates to the application of MXene as an anode material in aqueous manganese-ion batteries and the construction of a highly stable aqueous manganese-ion battery. The invention focuses on the research of a composite material composed of organic materials and MXene as an anode material for aqueous manganese-ion batteries. Due to the high HOMO energy level of manganese metal, it is prone to hydrogen evolution and oxygen evolution side reactions when used as an anode material, leading to severe corrosion problems and significantly affecting the overall performance of the battery. This invention aims to enhance the overall electrochemical performance of the battery by replacing the traditional manganese metal anode. Specifically, this invention employs the following technical solution:

[0005] On the one hand, the PTCDA / Ti3C2T of the present invention x The application of MXene as an anode material in aqueous manganese-ion batteries employs a method including the following steps: PTCDA / Ti3C2T x MXene is prepared into a slurry and coated onto an electrode, then dried to serve as the negative electrode of the battery; wherein, the PTCDA / Ti3C2T x MXene was synthesized via electrostatic self-assembly. For PTCDA / Ti3C2T... x MXene material, due to its stable two-dimensional layered structure, exhibits a more stable composite structure due to the interaction between PTCDA and MXene during PTCDA intercalation. The electrode can use graphite paper as a substrate, with an active material coating area of ​​1cm × 1cm and a drying temperature of 45-60℃. (PTCDA / Ti3C2T) x The optimal loading of MXene is 0.5-1 mg, and the optimal drying time is 1-2 hours.

[0006] Preferably, for the applications described above, PTCDA / Ti3C2T x MXene was obtained using the following preparation method:

[0007] Step (1): Mix the raw PTCDA powder with dimethylformamide (DMF) and sonicate for 10-40 minutes;

[0008] Step (2): Centrifuge at 6000-10000 rpm for 10-40 minutes to remove water from MXene / H2O, then mix DMF and MXene, centrifuge to remove DMF; then add DMF and MXene again, mix and centrifuge to remove DMF, repeat the DMF treatment to fully remove water to obtain MXene / DMF;

[0009] Step (3): The products obtained in steps (1) and (2) are ultrasonically dispersed to obtain a mixture. The mixture is then vacuum filtered, washed, and dried.

[0010] For the application described above, preferably, in step (1), the ratio of the mass of the original PTCDA powder to the volume of DMF is 18-22:4-6, mg / mL; more preferably 20:5, mg / mL.

[0011] For the application described above, preferably, in step (2), the ratio of the mass of MXene in the MXene / H2O liquid to the volume of DMF added each time is 15-20:4-6, mg / mL; more preferably 16:5, mg / mL.

[0012] For the applications described above, preferably, the mass ratio of the original PTCDA powder to MXene is 2-8:2-8, more preferably 5-7:3-5, and even more preferably 6:4.

[0013] For the above-described application, preferably, the filter membrane used for vacuum filtration in step (3) is a 0.22μm nylon membrane, and the membrane is washed 3-5 times with deionized water and anhydrous ethanol respectively. The drying temperature is 40-45℃ and the drying time is 1 hour.

[0014] For the applications described above, preferably, PTCDA / Ti3C2T x MXene is made into a slurry by combining PTCDA / Ti3C2T x MXene is mixed with acetylene black, polyvinylidene fluoride, and NMP, and then oscillated in a vortex oscillator. More preferably, PTCDA / Ti3C2T... x The mass ratio of MXene, acetylene black, and polyvinylidene fluoride is (4~8):(1~3):(1~3). When PTCDA / Ti3C2T x When the mass of MXene powder is 15-25 mg, the volume of NMP is 500 μL.

[0015] On the other hand, the present invention also provides an aqueous manganese-ion battery comprising PTCDA / Ti3C2T x MXene anode, CuFe-TBA cathode and Mn-containing 2+ The electrolyte for ions; the PTCDA / Ti3C2T x The MXene anode is made of PTCDA / Ti3C2T x MXene is prepared by forming a slurry, coating it onto an electrode, and drying it. The PTCDA / Ti3C2T... x MXene was synthesized via electrostatic self-assembly. This PTCDA / Ti3C2T... x The energy storage mechanism of MXene / Mn battery systems is as follows: Figure 5As shown, CuFe-TBA is used as the positive electrode, and PTCDA / Ti3C2T is used as the negative electrode. x A full cell was constructed using MXene as the anode and 1 M MnSO4 as the electrolyte. Its energy storage mechanism is based on the presence of Mn ions in PTCDA / Ti3C2T x Intercalation / deintercalation of MXene anode (breaking and recovery of C=O bonds).

[0016] The composite material PTCDA / Ti3C2T described in this invention x MXene anodes are used in aqueous manganese-ion batteries. MXene has a stable two-dimensional layered structure, and PTCDA can be used to store manganese ions during charge and discharge. When PTCDA is intercalated into MXene, the interaction between PTCDA and MXene significantly improves the electronic conductivity and ion diffusion coefficient of the electrode. This achieves rapid ion diffusion kinetics and high cycle stability in the anode of rechargeable aqueous manganese-ion batteries, resulting in high reversible specific capacity and long cycle life, exhibiting excellent electrochemical performance.

[0017] The beneficial effects of this invention are as follows:

[0018] (1) The PTCDA / Ti3C2T of the present invention x When MXene anodes are used in aqueous manganese-ion batteries, at 0.5 A g... -1 At a current density, it provides 199mAh g -1 It has high reversible capacity and excellent cycling stability at 10 A g. -1 At the specified current density, the capacity retention rate reaches 82% after 1000 charge-discharge cycles.

[0019] (2) The PTCDA / Ti3C2T of the present invention x The MXene anode, through the interaction between PTCDA and MXene, achieves rapid ion diffusion kinetics and high cycle stability in rechargeable aqueous manganese-ion batteries.

[0020] (3) The PTCDA / Ti3C2T of the present invention x Compared to traditional manganese metal anodes, MXene anodes do not undergo corrosion reactions, and hydrogen and oxygen evolution is less likely to occur, resulting in higher cycle stability, better storage of manganese ions, and higher coulombic efficiency.

[0021] (4) The negative electrode material of the present invention is PTCDA / Ti3C2T x MXene is used in aqueous manganese-ion batteries, which have advantages such as low cost, environmental friendliness and high safety compared to traditional lithium-ion batteries, and have great application potential in the field of electrochemical energy storage. Attached Figure Description

[0022] Figure 1 a is the PTCDA / Ti3C2T of the present invention. x SEM images of MXene Figure 1 b is the TEM image;

[0023] Figure 2 The PTCDA / Ti3C2T of the present invention x MXene with different ratios of PTCDA and MXene;

[0024] Figure 3 The PTCDA / Ti3C2T of the present invention x CV curves of MXene at different scan rates;

[0025] Figure 4 The PTCDA / Ti3C2T of the present invention x GCD curves of MXene at different current densities;

[0026] Figure 5 The PTCDA / Ti3C2T of the present invention x Schematic diagram of the energy storage mechanism of the MXene / manganese battery system;

[0027] Figure 6 The PTCDA / Ti3C2T of the present invention x MXene at 10A g -1 The charge-discharge cycle stability curves at the current density.

[0028] Figure 7 The PTCDA / Ti3C2T of the present invention x Comparison of coulombic efficiency between MXene and manganese metal. Detailed Implementation

[0029] The following embodiments are further illustrations of the present invention and serve as explanations of the technical content of the present invention. However, the essence of the present invention is not limited to the embodiments described below. Those skilled in the art can and should know that any simple changes or substitutions based on the spirit of the present invention should fall within the protection scope claimed by the present invention. Example 1

[0030] A composite material PTCDA / Ti3C2T x The preparation method of MXene as the negative electrode of aqueous manganese-ion batteries includes the following steps:

[0031] (1) Mix 20 mg of PTCDA raw powder with 5 mL of dimethylformamide (DMF) and sonicate for 30 minutes;

[0032] (2) Remove water from MXene / H2O with MXene content of 16mg by centrifuging at 8000 rpm for 30 minutes. Then mix 5mg DMF with MXene and shake well. Centrifuge for 5 minutes to remove DMF. Repeat three times to completely remove water molecules to obtain MXene / DMF.

[0033] (3) Mix the materials from steps (1) and (2) and disperse them by ultrasonication. Vacuum filter the resulting mixture using a 0.22 μm nylon filter membrane. After filtration, wash the mixture 3-5 times with deionized water and anhydrous ethanol respectively, and then place it in a vacuum drying oven and dry it at 40°C for 1 hour.

[0034] (4) The PTCDA / Ti3C2T obtained in step (3) x MXene powder was mixed with acetylene black and polyvinylidene fluoride in a mass ratio of 8:1:1, wherein PTCDA / Ti3C2T x 20 mg of MXene powder was added to 500 μL of NMP and then vortexed for 1 hour.

[0035] (5) Take 24 μL of the uniformly dispersed slurry obtained in step (4) and coat it onto a 1 cm × 1 cm graphite paper, so that the active material loading on each graphite paper is 0.8 mg. Then dry it in a vacuum drying oven at 40 °C for 1 hour to obtain PTCDA / Ti3C2T. x MXene negative electrode.

[0036] PTCDA / Ti3C2T in Example 1 x SEM images of MXene are as follows Figure 1 As shown in figure a, its obvious intercalation structure is illustrated in the TEM image. Figure 1 b, showing its very thin layered structure. The scaling factor curves of PTCDA and MXene at different ratios are shown below. Figure 2 As shown, the optimal ratio is 6:4. PTCDA / Ti3C2T x CV curves of MXene anode at different scan rates are as follows: Figure 3 As shown, each CV curve has a similar shape and two pairs of distinct redox peaks, indicating a multi-step reversible Mn oxidation process. 2+ Ion insertion / deintercalation process. PTCDA / Ti3C2T x The GCD curves of the MXene anode at different current densities are as follows: Figure 4As shown, the results indicate that both GCD curves exhibit two pairs of GCD plateaus, corresponding to a pair of redox peaks in the CV curves. PTCDA / Ti3C2T x The energy storage mechanism of MXene / Mn battery systems is as follows: Figure 5 As shown, CuFe-TBA is used as the positive electrode, and PTCDA / Ti3C2T is used as the negative electrode. x A full cell was constructed using MXene as the anode and 1 MnSO4 as the electrolyte. Its energy storage mechanism is based on the presence of Mn ions in PTCDA / Ti3C2T x Intercalation / deintercalation of MXene anode (C=O bond breaking and recovery). PTCDA / Ti3C2T x MXene anode at 10A g -1 The charge-discharge cycle stability curves at current densities are as follows: Figure 6 As shown, after 1000 cycles, its capacity can retain 81.7% of the initial capacity, and the coulombic efficiency is close to 100%. Compared with pure PTCDA, the prepared aqueous manganese ion battery anode material PTCDA / Ti3C2T... x MXene exhibits high reversible specific capacity and excellent cycling stability. Figure 7 It is PTCDA / Ti3C2T x The comparison graph of the coulombic efficiency of MXene and manganese metal (with manganese metal as the negative electrode, copper sheet as the positive electrode, and 1 M manganese sulfate as the electrolyte in a full cell) clearly shows that PTCDA / Ti3C2T x MXene has superior coulomb efficiency. Example 2

[0037] A PTCDA / Ti3C2T anode material for aqueous manganese-ion batteries x The preparation method of MXene is similar to that in Example 1, except that in step (4), PTCDA / Ti3C2T x The mass ratio of MXene powder, acetylene black, and polyvinylidene fluoride is 6:2:2. Example 3

[0038] A PTCDA / Ti3C2T anode material for aqueous manganese-ion batteries x The preparation method of MXene is similar to that in Example 1, except that in step (4), PTCDA / Ti3C2T x The mass ratio of MXene powder, acetylene black, and polyvinylidene fluoride is 7:2:1.

[0039] In the technical solution of this invention, although some numerical values ​​with better effects are given in the above embodiments, such as the ratio between PTCDA and MXene, this invention is not limited to the ratio between PTCDA and MXene given in the above embodiments. The specific ratio between PTCDA and MXene is determined according to actual needs. For example, the embodiments give the oscillation time of the slurry in the vortex oscillator with better effects, but this invention is not limited to the oscillation time in the vortex oscillator given in the above embodiments. However, the time should not be too short, and the specific oscillation time is determined according to actual needs. That is, the content protected by this invention is subject to the scope described and defined in the claims.

[0040] It should be noted that the above-described embodiments of the present invention are merely explanations and elaborations to enable those skilled in the art to understand the technical essence of the present invention, and therefore the described technical content is not intended to limit the scope of protection of the present invention. The scope of protection of the present invention should be determined by the claims. Those skilled in the art should understand that any modifications, equivalent substitutions, and improvements made based on the essential spirit of the present invention should be within the scope of protection of the present invention.

Claims

1. An aqueous manganese-ion battery, comprising PTCDA / Ti3C2T x MXene anode, CuFe-TBA cathode and Mn-containing 2+ The electrolyte for ions; the PTCDA / Ti3C2T x The MXene anode is made of PTCDA / Ti3C2T x MXene is made into a slurry and coated onto the electrode, then dried to serve as the negative electrode of the battery. The PTCDA / Ti3C2T x The MXene is synthesized by electrostatic self-assembly; specifically, the PTCDA / Ti3C2T x The MXene is prepared by the following method: Step (1): Mix the raw PTCDA powder with dimethylformamide (DMF) and sonicate for 10-40 minutes; Step (2): Centrifuge at 6000-10000 rpm for 10-40 minutes to remove water from MXene / H2O, then mix DMF and MXene, centrifuge to remove DMF; then add DMF and MXene again, mix and centrifuge to remove DMF, repeat the DMF treatment to fully remove water to obtain MXene / DMF; Step (3): The products obtained in steps (1) and (2) are ultrasonically dispersed to obtain a mixture. The mixture is then vacuum filtered, washed, and dried.

2. The aqueous manganese-ion battery as described in claim 1, characterized in that, In step (1), the ratio of the mass of the original PTCDA powder to the volume of DMF is 18-22:4-6, mg / mL.

3. The aqueous manganese-ion battery as described in claim 2, characterized in that, In step (1), the ratio of the mass of the original PTCDA powder to the volume of DMF is 20:5, mg / mL.

4. The aqueous manganese-ion battery as described in claim 1, characterized in that, In step (2), the ratio of the mass of MXene in the MXene / H2O liquid to the volume of DMF added each time is 15-20:4-6, mg / mL.

5. The aqueous manganese-ion battery as described in claim 4, characterized in that, In step (2), the ratio of the mass of MXene in the MXene / H2O liquid to the volume of DMF added each time is 16:5, mg / mL.

6. The aqueous manganese-ion battery as described in claim 1, characterized in that, The mass ratio of the original PTCDA powder to MXene is 2-8:2-8.

7. The aqueous manganese-ion battery as described in claim 6, characterized in that, The mass ratio of the original PTCDA powder to MXene is 5-7:3-5.

8. The aqueous manganese-ion battery as described in claim 7, characterized in that, The mass ratio of the original PTCDA powder to MXene is 6:

4.

9. The aqueous manganese-ion battery as described in claim 1, characterized in that, The filter membrane used in step (3) for vacuum filtration is a 0.22μm nylon membrane, which is washed 3-5 times with deionized water and anhydrous ethanol respectively, and the drying temperature is 40-45℃ and the drying time is 1 hour.

10. The aqueous manganese-ion battery as described in claim 1, characterized in that, PTCDA / Ti3C2T x The slurry of MXene was made by mixing PTCDA / Ti3C2T x MXene was mixed with acetylene black, polyvinylidene fluoride, and NMP and then shaken in a vortex shaker.

11. The aqueous manganese-ion battery as described in claim 10, characterized in that, PTCDA / Ti3C2T x The mass ratio of MXene, acetylene black and polyvinylidene fluoride is (4-8):(1-3):(1-3), when PTCDA / Ti3C2T x The volume of NMP is 500 μL when the mass of MXene powder is 15-25 mg.

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