A zinc ion battery manganese selenide-based positive electrode material and a preparation method and application thereof

Abstract

The application relates to the technical field of zinc ion battery positive electrode materials, in particular to a zinc ion battery manganese selenide-based positive electrode material and a preparation method and application thereof, wherein the zinc ion battery manganese selenide-based positive electrode material comprises flaky graphene and composite particles loaded on the surface of the flaky graphene; the composite particles comprise manganese selenide particles and a graphene coating layer for coating the manganese selenide particles. The manganese selenide particles are coated by the graphene coating layer to form a coating structure, so that the dissolution of manganese elements can be effectively prevented, and thus the reduction of active substances is avoided; meanwhile, the graphene has good conductivity and can provide good zinc ion kinetics. When the zinc ion battery manganese selenide-based positive electrode material is used for preparing a water-based zinc ion battery, the zinc ion battery manganese selenide-based positive electrode material has excellent electrochemical performance, and the cycle number can reach 1000 cycles, and the zinc ion battery manganese selenide-based positive electrode material has excellent cycle performance.

Description

Technical Field

[0001] This invention relates to the field of zinc-ion battery cathode material technology, and in particular to a manganese selenide-based cathode material for zinc-ion batteries, its preparation method, and its application. Background Technology

[0002] The rapid development of devices for the Internet of Things (IoT) and healthcare has fueled a surge in demand for wearable smart electronics. Energy storage devices, an integral part of electronic products, have seen significant progress over the years, but system performance remains unsatisfactory. Commonly used lithium-ion batteries employ toxic organic electrolytes, which may greatly hinder their application in wearables and pose a significant environmental threat. Furthermore, flammable organic liquids increase the risk of safety accidents, and the raw materials for lithium-ion batteries are expensive.

[0003] Aqueous lithium-ion batteries can effectively solve the aforementioned problems of lithium-ion batteries; zinc is abundant in the earth's crust (70ppm) and inexpensive; Zn metal can exist stably in the air, so zinc-ion batteries can be assembled and produced in the air, greatly reducing production costs; at the same time, the aqueous electrolyte used is non-toxic to the human body, will not cause pollution to the environment, and will not cause safety issues such as combustion.

[0004] However, research on cathode materials for aqueous zinc-ion batteries is still in its early stages. Among the many proposed cathode materials, manganese-based compounds, especially MnO2, have attracted particular attention due to their advantages of high energy density, non-toxicity, and low cost. Furthermore, manganese-based materials currently make Zn... 2+ Slow storage kinetics and the easy dissolution of manganese in the electrolyte lead to a decline in battery performance.

[0005] Therefore, existing technologies still need to be improved and developed. Summary of the Invention

[0006] In view of the shortcomings of the prior art, the purpose of this invention is to provide a manganese selenide-based cathode material for zinc-ion batteries, its preparation method and application, aiming to solve the problem of manganese-based materials in existing zinc-ion batteries making Zn... 2+ The problem lies in the slow storage kinetics and the fact that manganese is readily soluble in electrolytes.

[0007] The technical solution of the present invention is as follows:

[0008] A manganese selenide-based cathode material for zinc-ion batteries includes sheet-like graphene and composite particles loaded on the surface of the sheet-like graphene; the composite particles include manganese selenide particles and a graphene coating layer that coats the manganese selenide particles.

[0009] The zinc-ion battery manganese selenide-based cathode material, wherein the thickness of the graphene coating layer is 1 nm to 20 nm.

[0010] The zinc-ion battery manganese selenide-based cathode material wherein the manganese selenide particles have a particle size of 2 nm to 100 nm.

[0011] A method for preparing a manganese selenide-based cathode material for zinc-ion batteries includes the following steps:

[0012] The manganese source and the selenium source are mixed to obtain the first mixed solution;

[0013] The first mixed solution is mixed with the graphene oxide solution to obtain a second mixed solution;

[0014] The second mixed solution is mixed with a reducing agent to obtain a third mixed solution;

[0015] The third mixed solution was subjected to a hydrothermal reaction in a reactor to obtain the manganese selenide-based cathode material for zinc-ion batteries.

[0016] The method for preparing the zinc-ion battery manganese selenide-based cathode material, wherein the manganese source is selected from one or more of manganese chloride, manganese sulfate, manganese acetate, and manganese nitrate; and the selenium source is selected from one or more of selenium oxide, selenium powder, sodium selenate, selenium chloride, and selenium sulfate.

[0017] The method for preparing the zinc-ion battery manganese selenide-based cathode material, wherein the molar ratio of the manganese source to the selenium source is (1-2):(1-2).

[0018] The method for preparing the zinc-ion battery manganese selenide-based cathode material, wherein the concentration of the graphene oxide is 1-100 mg / mL; and the reducing agent is selected from one or more of N2H4 and hydrogen peroxide.

[0019] The method for preparing the zinc-ion battery manganese selenide-based cathode material, wherein the volume ratio of the graphene oxide to the reducing agent is (1-100):(1-100).

[0020] The method for preparing the zinc-ion battery manganese selenide-based cathode material, wherein the hydrothermal reaction temperature is 100-300℃ and the hydrothermal reaction time is 3-60 hours.

[0021] Application of a zinc-ion battery manganese selenide-based cathode material in new energy electric vehicles, electronic product energy storage batteries, and integrated circuit energy storage batteries.

[0022] Beneficial effects: This invention provides a manganese selenide-based cathode material for zinc-ion batteries, its preparation method, and its application. The manganese selenide-based cathode material for zinc-ion batteries includes sheet-like graphene and composite particles loaded on the surface of the sheet-like graphene. The composite particles include manganese selenide particles and a graphene coating layer that coats the manganese selenide particles. Its main advantages are as follows: (1) Sheet graphene can serve as a three-dimensional conductive network for electrodes prepared from the material, providing a fast electron transport channel, promoting the full utilization of the material's capacity and improving capacity retention under high current; (2) The manganese selenide particles in the material are nanoparticles with a large specific surface area, which can provide more ion transport paths; (3) The functional groups on the surface of sheet graphene have a higher affinity for water, which can promote the full wetting of the electrolyte and the electrode; (4) The graphene coated on the outer layer of the particles can adapt to the morphological changes brought about by the first phase transition of the material, thereby ensuring the stability of the electrode structure; (5) The surface defects of the graphene coated on the outer layer of the particles can effectively adsorb ions and accelerate the electrochemical energy storage reaction of the active material; (6) The inhibitory effect of the coated graphene on manganese dissolution and loss can alleviate capacity decay, thereby improving the battery's service life. Furthermore, by using a graphene coating layer to coat manganese selenide particles to form a coating structure, this invention can effectively prevent the dissolution of manganese elements, thus preventing the reduction of active materials; at the same time, graphene has good conductivity and can provide good zinc ion dynamics. Furthermore, the preparation method of manganese selenide-based cathode material for zinc-ion batteries is simple, low-cost, green and pollution-free, with high safety performance and good zinc ion kinetics. When this manganese selenide-based cathode material is used to prepare aqueous zinc-ion batteries, it exhibits excellent electrochemical performance and can cycle up to 1000 times, demonstrating excellent cycle performance. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the process flow for preparing a manganese selenide-based cathode material for zinc-ion batteries according to the present invention.

[0024] Figure 2 The image shows the XRD pattern of the MnSe@RGO composite cathode material prepared in Example 1 of this invention.

[0025] Figure 3 This is a SEM image of the MnSe@RGO composite cathode material prepared in Example 1 of the present invention;

[0026] Figure 4 This is a TEM image of the MnSe@RGO composite cathode material prepared in Example 1 of this invention;

[0027] Figure 5 The image shows the HRTEM image of the MnSe@RGO composite cathode material prepared in Example 1 of this invention.

[0028] Figure 6This is a SEM image of the MnSe@RGO composite cathode material prepared in Example 2 of the present invention;

[0029] Figure 7 Cycling performance of MnO2, MnSe, and MnSe@RGO cathode materials prepared in Examples 1-3 in aqueous zinc-ion batteries. Detailed Implementation

[0030] This invention provides a manganese selenide-based cathode material for zinc-ion batteries, its preparation method, and its application. To make the objectives, technical solutions, and effects of this invention clearer and more explicit, the invention is further described in detail below. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0031] It will be understood by those skilled in the art that, unless otherwise defined, all terms used herein (including technical and scientific terms) have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. It should also be understood that terms such as those defined in general dictionaries should be understood to have the same meaning as in the context of the prior art, and should not be interpreted in an idealized or overly formal sense unless specifically defined as herein.

[0032] This invention provides a manganese selenide-based cathode material for zinc-ion batteries, comprising sheet-like graphene and composite particles loaded on the surface of the sheet-like graphene; the composite particles comprise manganese selenide particles and a graphene coating layer that coats the manganese selenide particles.

[0033] In this embodiment, manganese selenide particles are coated with graphene (RGO) to form a graphene coating layer on the surface of the manganese selenide particles. This coating structure effectively prevents the dissolution of manganese, thus avoiding a reduction in active material. Furthermore, graphene has good conductivity, providing favorable zinc ion storage kinetics and improving battery performance. The manganese selenide coated with the graphene layer is loaded on the surface of sheet-like graphene, which acts as a three-dimensional conductive network, accelerating the electrochemical reaction rate. Simultaneously, the interaction between its surface functional groups and the aqueous solvent promotes sufficient wetting of the electrolyte and electrode. The loaded manganese selenide particles are nanoparticles with a large surface area, providing a large reaction surface and accelerating the material's reaction rate. In addition, the graphene coating on the outer layer of the particles can alleviate the instability of the electrode's mechanical structure caused by particle phase transitions. The surface defects of graphene have a higher adsorption capacity for ions, thereby accelerating the electrochemical energy storage reaction of the electrode material. Furthermore, graphene can effectively suppress manganese dissolution and loss, thus mitigating capacity decay and improving battery life. When this manganese selenide-based cathode material is used to prepare aqueous zinc-ion batteries, it exhibits excellent electrochemical performance and can cycle up to 1000 times, demonstrating superior cycle performance.

[0034] In some embodiments, the thickness of the graphene coating layer is 1 nm to 20 nm. The small mass fraction of graphene at this nanoscale thickness does not significantly dilute the high capacity advantage of manganese selenide. The nanoscale graphene thickness ensures a short ion transport path between the electrolyte and the manganese selenide particles, thereby enabling high-rate electrochemical reactions in the material. This not only improves the overall conductivity of the material but also prevents the loss of manganese.

[0035] In some embodiments, the manganese selenide particles have a particle size of 2 nm to 100 nm. On the one hand, nanoparticles in this particle size range have a larger specific surface area than micron-sized particles, thereby ensuring more electrochemical reaction interfaces between the electrode and the electrolyte and improving the rate performance of the battery. On the other hand, the morphological changes of nanoparticles in this particle size range during the phase transition process do not cause excessive stress and strain accumulation, which can ensure the mechanical structure stability of the electrode and thus improve the cycle stability of the battery.

[0036] In addition, such as Figure 1 As shown, the present invention also provides a method for preparing a manganese selenide-based cathode material for zinc-ion batteries, comprising the following steps:

[0037] Step S10: Mix the manganese source and the selenium source to obtain the first mixed solution;

[0038] Step S20: Mix the first mixed solution with the graphene oxide solution to obtain a second mixed solution;

[0039] Step S30: Mix the second mixed solution with a reducing agent to obtain a third mixed solution;

[0040] Step S40: The third mixed solution is subjected to a hydrothermal reaction in a reactor to obtain the zinc-ion battery manganese selenide-based cathode material.

[0041] In this embodiment, a hydrothermal reaction is used to synthesize manganese selenide particles using manganese and selenium sources as raw materials. Combined with the reduction of graphene oxide by a reducing agent, graphene-coated manganese selenide composite particles are obtained. Furthermore, the composite particles are loaded onto the surface of sheet-like graphene. This coating not only prevents manganese dissolution by utilizing the graphene coating layer, thus avoiding a reduction in active material, but also leverages the excellent conductivity of graphene to provide good zinc-ion kinetics for aqueous zinc-ion batteries. Moreover, the preparation method of the manganese selenide-based cathode material for zinc-ion batteries is simple, low-cost, environmentally friendly, pollution-free, safe, and exhibits good zinc-ion kinetics.

[0042] In some embodiments, the manganese source is selected from, but is not limited to, one or more of manganese chloride, manganese sulfate, manganese acetate, and manganese nitrate; the selenium source is selected from, but is not limited to, one or more of selenium oxide, selenium powder, sodium selenate, selenium chloride, and selenium sulfate. Selecting the above materials as manganese and selenium sources allows for the production of nanoscale manganese selenide particles during the hydrothermal reaction. This enables graphene to effectively coat the manganese selenide particles, preventing manganese from dissolving in the electrolyte and thus improving battery performance.

[0043] In some embodiments, the molar ratio of the manganese source to the selenium source is (1-2):(1-2), which allows for better preparation of nano-manganese selenide particles.

[0044] In a preferred embodiment, the molar ratio of the manganese source to the selenium source is 1:1; the first mixed solution of the manganese source and the selenium source mixed in this molar ratio can save raw materials and allow both the manganese source and the selenium source to react more completely, so that the product contains only manganese selenide particles and does not contain selenium source or manganese source, thereby making the obtained composite particles all graphene-coated manganese selenide particles.

[0045] In some embodiments, the concentration of the graphene oxide is 1–100 mg / mL; the reducing agent is selected from one or more of N2H4 (hydrazine hydrate) and hydrogen peroxide.

[0046] In a preferred embodiment, the reducing agent is hydrazine hydrate. Using hydrazine hydrate as a reducing agent for graphene oxide can enable graphene to form a good three-dimensional structure, enhance the ion diffusion ability of graphene, and achieve a high degree of reduction.

[0047] In some embodiments, the volume ratio of graphene oxide to the reducing agent is (1-100):(1-100). At this volume ratio, adding the reducing agent to the second mixed solution containing graphene oxide can effectively reduce the graphene oxide to obtain graphene.

[0048] In some embodiments, the hydrothermal reaction temperature is 100–300°C, and the reaction time is 3–60 hours. Reacting the third mixed solution at 100–300°C for 3–60 hours yields a graphene-coated manganese selenide particle structure, which is then loaded onto the surface of sheet-like graphene. This achieves the goal of preventing manganese from dissolving in the electrolyte using the graphene coating, while simultaneously utilizing the excellent conductivity of graphene to provide good zinc-ion kinetics for the zinc-ion battery.

[0049] The present invention also provides an aqueous zinc-ion battery, comprising a zinc metal negative electrode, a glass fiber separator, an aqueous electrolyte, and a zinc-ion battery positive electrode; the zinc-ion battery positive electrode is made of the above-mentioned zinc-ion battery manganese selenide positive electrode material; the aqueous zinc-ion battery has excellent electrochemical performance, and the number of cycles can reach 1000 cycles, exhibiting excellent cycle performance.

[0050] In addition, this invention also provides an application of a zinc-ion battery manganese selenide-based cathode material in new energy electric vehicles, electronic product energy storage batteries, and integrated circuit energy storage batteries.

[0051] In this embodiment, using manganese selenide-based cathode material as the cathode of zinc-ion batteries is of great significance for promoting the application of zinc-ion batteries in flexible devices.

[0052] The following examples further illustrate the present invention in detail. It should also be understood that the following examples are only for further explanation of the present invention and should not be construed as limiting the scope of protection of the present invention. Any non-essential improvements and adjustments made by those skilled in the art based on the above description of the present invention are within the scope of protection of the present invention.

[0053] Example 1

[0054] This embodiment provides a method for preparing a manganese selenide-based cathode material for zinc-ion batteries, including the following steps:

[0055] Step S1: Dissolve manganese chloride and selenium oxide in deionized water at a molar ratio of 1:1 and stir for 12 hours to obtain the first mixed solution;

[0056] Step S2: Add 24 mL (10 mg / mL) of graphene oxide solution to the first mixed solution and stir for 10 h to obtain the second mixed solution;

[0057] Step S3: Add 28 mL of hydrazine hydrate reducing agent to the second mixed solution and stir for 3 h to obtain the third mixed solution;

[0058] Step S4: The third mixed solution is placed in a high-pressure reactor for high-temperature hydrothermal reaction at 180°C for 30 hours to obtain MnSe@RGO composite cathode material.

[0059] Example 2

[0060] This embodiment provides a method for preparing a manganese selenide-based cathode material for zinc-ion batteries, including the following steps:

[0061] Step S1: Dissolve manganese chloride and selenium oxide in deionized water at a molar ratio of 1:1 and stir for 12 hours to obtain the first mixed solution;

[0062] Step S2: Add 12 mL (5 mg / mL) of graphene oxide solution to the first mixed solution and stir for 8 hours to obtain the second mixed solution;

[0063] Step S3: Add 32 mL of hydrazine hydrate reducing agent to the second mixed solution and stir for 3 h to obtain the third mixed solution;

[0064] Step S4: The third mixed solution is placed in a high-pressure reactor for high-temperature hydrothermal reaction at 150°C for 24 hours to obtain MnSe@RGO composite cathode material.

[0065] Example 3

[0066] This embodiment provides a method for preparing a manganese selenide-based cathode material for zinc-ion batteries, including the following steps:

[0067] Step S1: Dissolve manganese chloride and selenium oxide in deionized water at a molar ratio of 1:1 and stir for 12 hours to obtain the first mixed solution;

[0068] Step S2: Add 36 mL (10 mg / mL) of graphene oxide solution to the first mixed solution and stir for 8 hours to obtain the second mixed solution;

[0069] Step S3: Add 24 mL of hydrazine hydrate reducing agent to the second mixed solution and stir for 3 h to obtain the third mixed solution;

[0070] Step S4: The third mixed solution is placed in a high-pressure reactor for high-temperature hydrothermal reaction at 150°C for 24 hours to obtain MnSe@RGO composite cathode material.

[0071] Example 4

[0072] This embodiment provides a method for preparing a manganese selenide-based cathode material for zinc-ion batteries, including the following steps:

[0073] Step S1: Dissolve manganese chloride and selenium oxide in deionized water at a molar ratio of 1:1 and stir for 12 hours to obtain the first mixed solution;

[0074] Step S2: Add 12 mL (5 mg / mL) of graphene oxide solution to the first mixed solution and stir for 8 hours to obtain the second mixed solution;

[0075] Step S3: Add 32 mL of hydrazine hydrate reducing agent to the second mixed solution and stir for 3 h to obtain the third mixed solution;

[0076] Step S4: The third mixed solution is placed in a high-pressure reactor for high-temperature hydrothermal reaction at 150°C for 24 hours to obtain MnSe@RGO composite cathode material.

[0077] Performance testing: The zinc-ion battery MnSe@RGO composite cathode material of Examples 1-4 was used to make button batteries (the negative electrode is zinc metal, the electrolyte is 2M ZnSO4 solution, and the separator is glass fiber), and the batteries were cycled at a current density of 5C at room temperature.

[0078] The MnSe@RGO composite cathode material prepared in Example 1 was subjected to XRD testing, and the results are as follows: Figure 2 As shown in the XRD in Example 1, pure MnSe@RGO material can be prepared using the preparation method of the present invention, and this preparation method can be applied to mass production.

[0079] Taking the MnSe@RGO composite cathode materials prepared in Examples 1 and 2 as examples, their microstructure was observed. Figure 3 , Figure 4 and Figure 5 These are SEM, TEM, and HRTEM images of the MnSe@RGO composite cathode material prepared in Example 1. Figure 6 Here is a SEM image of the MnSe@RGO composite cathode material prepared in Example 2; from Figure 3-6 It can be seen that the prepared MnSe material is well encapsulated in RGO. This encapsulation structure can effectively prevent the dissolution of manganese, thus avoiding the reduction of active material; in addition, RGO has good conductivity, which can provide good zinc ion kinetics.

[0080] Finally, taking MnO2, MnSe, and the MnSe@RGO cathode materials prepared in Examples 1-3 as examples, their cycle performance in zinc-ion batteries was tested. Figure 7As can be seen, after 1000 cycles, the battery's specific capacity hardly decreased, demonstrating excellent electrochemical performance and ultra-long cycle life.

[0081] In summary, this invention provides a manganese selenide-based cathode material for zinc-ion batteries, its preparation method, and its application. The manganese selenide-based cathode material comprises sheet-like graphene and composite particles loaded on the surface of the sheet-like graphene. The composite particles comprise manganese selenide particles and a graphene coating layer that coats the manganese selenide particles. This invention utilizes the graphene coating layer to coat the manganese selenide particles, forming a coating structure that effectively prevents the dissolution of manganese, thus avoiding a reduction in active material. Simultaneously, graphene possesses good conductivity, providing excellent zinc-ion kinetics. Furthermore, the preparation method of the manganese selenide-based cathode material for zinc-ion batteries is simple, low-cost, environmentally friendly, and pollution-free, offering high safety performance and good zinc-ion kinetics. When this manganese selenide-based cathode material is used to prepare aqueous zinc-ion batteries, it exhibits excellent electrochemical performance, with a cycle life of up to 1000 cycles, demonstrating excellent cycle performance.

[0082] It should be understood that the application of the present invention is not limited to the examples above. Those skilled in the art can make improvements or modifications based on the above description, and all such improvements and modifications should fall within the protection scope of the appended claims.

Claims

1. A manganese selenide-based cathode material for zinc-ion batteries, characterized in that, It includes sheet-like graphene and composite particles loaded on the surface of the sheet-like graphene; the composite particles include manganese selenide particles and a graphene coating layer that coats the manganese selenide particles. The thickness of the graphene coating is 1 nm to 20 nm; the particle size of the manganese selenide particles is 2 nm to 100 nm.

2. A method for preparing the manganese selenide-based cathode material for zinc-ion batteries as described in claim 1, characterized in that, Including the following steps: The manganese source and the selenium source are mixed to obtain the first mixed solution; The first mixed solution is mixed with the graphene oxide solution to obtain a second mixed solution; The second mixed solution is mixed with a reducing agent to obtain a third mixed solution; The third mixed solution was subjected to a hydrothermal reaction in a reactor to obtain the manganese selenide-based cathode material for zinc-ion batteries.

3. The method for preparing the manganese selenide-based cathode material for zinc-ion batteries according to claim 2, characterized in that, The manganese source is selected from one or more of manganese chloride, manganese sulfate, manganese acetate, and manganese nitrate; the selenium source is selected from one or more of selenium oxide, selenium powder, selenium chloride, and selenium sulfate.

4. The method for preparing the manganese selenide-based cathode material for zinc-ion batteries according to claim 2, characterized in that, The molar ratio of the manganese source to the selenium source is (1~2):(1~2).

5. The method for preparing the manganese selenide-based cathode material for zinc-ion batteries according to claim 2, characterized in that, The concentration of the graphene oxide is 1~10 mg / mL; the reducing agent is N2H4.

6. The method for preparing the manganese selenide-based cathode material for zinc-ion batteries according to claim 5, characterized in that, The volume ratio of the graphene oxide to the reducing agent is (1~100):(1~100).

7. The method for preparing the manganese selenide-based cathode material for zinc-ion batteries according to claim 2, characterized in that, The hydrothermal reaction temperature is 100~300℃, and the hydrothermal reaction time is 3~60 hours.

8. The application of the zinc-ion battery manganese selenide-based cathode material as described in claim 1 in new energy electric vehicles, electronic product energy storage batteries, and integrated circuit energy storage batteries.

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