Preparation method of graphene / boronene composite interface film modified zinc metal negative electrode and zinc ion battery

Abstract

The application relates to a preparation method of a graphene / boronene composite interface film modified zinc metal negative electrode and a zinc ion battery, and belongs to the technical field of zinc ion battery negative electrodes. The method selects graphene and boronene as modification materials, and under the action of a surfactant, a graphene and boronene composite interface film is formed on the surface of a zinc negative electrode through a constant current method. A Zn||Zn symmetrical battery assembled with the zinc metal negative electrode can be reversibly cycled for 1900h under a deposition capacity of 5mAcm ‑2 Current density, 1mAhcm ‑2 The zinc ion battery prepared by matching a commercial lithium manganate positive electrode has a reversible discharge specific capacity of 105.95mAhg ‑1 Under a current density of 1C, and excellent rate performance is exhibited.

Description

Technical Field

[0001] This invention relates to a method for preparing a graphene / borene composite interface film modified zinc metal anode and a zinc-ion battery, belonging to the field of zinc-ion battery anode technology. Background Technology

[0002] Against the backdrop of today's "dual-carbon" policy, green energy development has become a major investment focus for governments worldwide. Rechargeable batteries, as a crucial component of clean energy, are widely used in power batteries, renewable energy, and defense industries. Among various rechargeable batteries, zinc-ion batteries offer high safety due to their use of aqueous electrolytes. Furthermore, zinc-ion batteries boast higher energy density, longer lifespan, and competitive manufacturing costs, making them an ideal green battery system.

[0003] Although zinc-ion batteries have broad application prospects, there are still some problems with using zinc metal directly as the negative electrode: (1) During repeated charging and discharging of the battery, zinc ions and metallic zinc are repeatedly deposited and dissolved on the surface of the negative electrode, forming dendritic precipitates. As the precipitates grow, they eventually become zinc dendrites. These zinc dendrites are very likely to puncture the separator and cause a short circuit in the battery. At the same time, they will cause uneven thickness distribution of the zinc electrode and cause electrode deformation, resulting in a decrease in the capacity of the zinc-ion battery; (2) Hydrogen evolution reaction is an unavoidable side reaction in zinc metal batteries. It will consume some charge and reduce the coulombic efficiency of the battery. In addition, the evolved hydrogen gas will increase the pressure in the closed battery system, causing the battery to expand; (3) Zinc metal in the electrolyte will undergo chemical corrosion and electrochemical corrosion. The above problems interact and affect each other, resulting in a further reduction in the electrochemical performance of zinc-ion batteries.

[0004] To address these issues, the growth of zinc dendrites and interfacial side reactions are typically suppressed through interface modification between the electrode and electrolyte. To date, numerous methods for modifying the negative electrode of zinc-ion batteries have been developed, such as the sol-gel method, drop coating, wetting method, doctor blade method, and chemical vapor deposition. The sol-gel method is generally time-consuming, often requiring several days or weeks, and the gel releases gases and organic matter during drying. The drop coating method achieves performance modification by reacting the solution with the zinc negative electrode to form a film on its surface; however, the uneven distribution of droplets on the zinc negative electrode surface due to physical droplet fall makes large-scale preparation challenging. The wetting method immerses the zinc negative electrode in a solution for reaction, but residual solution on the surface is difficult to remove completely, affecting the final battery performance. The doctor blade method has certain requirements regarding the viscosity and other physical properties of the modified material, while chemical vapor deposition requires complex steps. Compared to other methods, electrodeposition can achieve mass production, has lower costs, simpler processes, and less pollution. Furthermore, by adjusting various parameters of the electrodeposition solution and electrochemical parameters, the thickness of the modified layer can be effectively and precisely controlled.

[0005] Graphene exhibits exceptional properties in carrier mobility, flexibility, thermal conductivity, and chemiluminescence. Boronene possesses a similar two-dimensional structure to graphene, characterized by strong in-plane covalent bonds and weak interlayer van der Waals forces. Furthermore, as a typical two-dimensional Dirac material composed of the lightest solid elements, boronene exhibits diverse surface configurations and complex multi-center bielectron bonds. Applying a heterojunction structure of graphene and boronene as a coating to modify the interface of a zinc-ion anode can effectively mitigate safety issues caused by zinc dendrite growth, thereby improving the electrochemical performance of the battery.

[0006] Therefore, the use of electrodeposition to controllably prepare an interfacial film of graphene and boronene as a surface modification coating for zinc ion anodes has certain innovation and practicality. Summary of the Invention

[0007] To overcome the shortcomings of existing technologies, one of the objectives of this invention is to provide a method for preparing a zinc metal anode modified with a graphene / borene composite interface film.

[0008] The second objective of this invention is to provide a zinc-ion battery.

[0009] To achieve the objectives of this invention, the following technical solutions are provided.

[0010] A method for preparing a zinc metal anode modified with a graphene / boronene composite interface film, the method comprising the following steps:

[0011] (1) The graphene aqueous dispersion, the boronene aqueous dispersion and the surfactant aqueous solution were mixed in a certain volume ratio, magnetically stirred and the pH was adjusted with citric acid / sodium citrate to obtain a suspension.

[0012] The surfactant is one of sodium dodecylbenzene sulfonate, sodium dodecyl sulfonate, hexadecyltrimethylammonium bromide or dioctadecyldimethylammonium bromide;

[0013] Preferably, the graphene sheet diameter is 50–200 nm;

[0014] Preferably, the concentration of the graphene aqueous dispersion is 0.5 mg / mL to 2 mg / mL;

[0015] Preferably, the boroene particle size is 1–10 nm;

[0016] Preferably, the concentration of the boronene aqueous dispersion is 0.5 mg / mL to 2 mg / mL;

[0017] Preferably, the concentration of the surfactant aqueous solution is 0.0001 mg / mL to 0.2 mg / mL;

[0018] Preferably, the volume ratio of the graphene aqueous dispersion, the boronene aqueous dispersion, and the surfactant aqueous solution is (0.5-2):(0.5-2):(1-5).

[0019] Preferably, the pH value of the suspension is 3 to 6.

[0020] (2) Using untreated zinc foil as the working electrode and carbon rod as the electrode to form a two-electrode system, and using the suspension obtained in the previous step as the deposition liquid, graphene and boronene are simultaneously deposited on the zinc foil surface by constant current method.

[0021] Preferably, the zinc foil has a thickness of 100–500 μm;

[0022] Preferably, the constant current is 0.0001A to 0.5A.

[0023] (3) Rinse the zinc foil surface with deionized water to remove any residual solution;

[0024] (4) The treated zinc foil was transferred to a constant temperature oven and dried at a constant temperature to obtain a graphene / borene composite interface film modified zinc metal anode.

[0025] A zinc-ion battery, wherein the zinc-ion battery negative electrode is prepared by the method for preparing a graphene / borene composite interface film modified zinc metal negative electrode according to the present invention.

[0026] Beneficial effects

[0027] 1. This invention provides a method for preparing a zinc metal anode modified with a graphene / borene composite interface film. The method forms a uniformly dispersed graphene / borene interface film with high mechanical strength on the surface of the zinc anode. This interface film, by utilizing the synergistic effect between graphene and borene, endows the zinc anode with high stability and corrosion resistance in aqueous solutions. Furthermore, as an interface passivation layer, it prevents direct contact between the zinc anode and the electrolyte, significantly inhibiting corrosion of the zinc anode and suppressing hydrogen evolution reaction and the formation of byproducts.

[0028] 2. This invention provides a method for preparing a zinc metal anode modified with a graphene / borene composite interface film. The method uses a surfactant to charge the uncharged graphene and borene in a suspension. Then, under the influence of an electric field in a constant current electrodeposition method, the graphene and borene adsorb onto the zinc anode and form a uniform film on its surface. The constant current electrodeposition method can optimize the deposition rate and thickness by adjusting the current density and time. It has advantages such as simple equipment, ease of operation, mild reaction conditions, fast deposition rate, and easy control of the deposition process. Furthermore, this method can be applied to large-scale processing and production, with lower costs, simpler processes, and less pollution.

[0029] 3. This invention provides a zinc-ion battery, wherein the zinc-ion battery negative electrode is prepared by the graphene / boronene composite interface film modified zinc metal negative electrode preparation method described in this invention, and the assembled Zn||Zn symmetric cell can achieve a current of 5 mA cm⁻¹. -2 Current density, 1 mAh cm⁻¹ -2 It can be reversibly circulated for 1900 hours at the deposition capacity.

[0030] 4. This invention provides a zinc-ion battery, wherein the negative electrode of the zinc-ion battery is prepared by the graphene / boronene composite interface film modified zinc metal negative electrode preparation method of this invention, and the positive electrode of the zinc-ion battery is commercially available lithium manganese oxide. It exhibits a yield of 105.95 mAh g⁻¹ after 50 charge-discharge cycles at a current density of 1C. -1 The reversible discharge specific capacity. Attached Figure Description

[0031] Figure 1 The image shows a scanning electron microscope (SEM) image of the zinc metal anode modified with the graphene / borene composite interface film prepared in Example 1.

[0032] Figure 2 The X-ray photoelectron spectroscopy (XPS) spectra of the zinc metal anode modified with the graphene / borene composite interface film prepared in Example 1 are shown in Figure (a), which is the XPS spectrum of C1s; Figure (b) is the XPS spectrum of S 2p; and Figure (c) is the XPS spectrum of B1S.

[0033] Figure 3The graphene / boronene composite interface film modified zinc metal anode prepared in Example 1 was assembled into a Zn||Zn symmetric cell at 5 mA cm⁻¹ -2 Current density, 1 mAh cm⁻¹ -2 Voltage-time curves under deposition capacity.

[0034] Figure 4 The constant current charge-discharge cycle curves of the graphene / boronene composite interface film modified zinc metal anode and matched lithium manganese oxide cathode prepared in Example 1 at a current density of 1C.

[0035] Figure 5 The rate performance of the graphene / borene composite interface film modified zinc metal anode and matched lithium manganese oxide cathode prepared in Example 1 at current densities of 0.5C, 1C, 2C, and 4C is shown. Detailed Implementation

[0036] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments, but this is not intended to limit the scope of the present invention.

[0037] Unless otherwise specified, all reagents and other instruments used are commercially available products.

[0038] Graphene aqueous dispersion: purchased from Jiangsu Xianfeng Nanotechnology.

[0039] Boronene aqueous dispersion: purchased from Beike New Materials Technology Co., Ltd.

[0040] The following tests were performed on a zinc metal anode modified with a graphene / boronene composite interface film prepared in the following examples:

[0041] (1) X-ray photoelectron spectroscopy (XPS) test: The instrument model is Thermo Scientific.

[0042] (2) Scanning electron microscope (SEM) test: The instrument is a field emission scanning electron microscope, model S4800, Hitachi, Japan.

[0043] (3) Button battery charge and discharge test: The instrument is a Xinwei button battery charge and discharge tester, model CT-4008T-5V10Ma-164, purchased from Shenzhen Xinwei Electronics Co., Ltd.

[0044] Example 1

[0045] A method for preparing a zinc metal anode modified with a graphene / boronene composite interface film, the method comprising the following steps:

[0046] (1) The graphene aqueous dispersion, boronene aqueous dispersion and sodium dodecyl sulfonate aqueous solution were mixed in a volume ratio of 4ml:4ml:12ml, magnetically stirred and the pH was adjusted to 5 with citric acid / sodium citrate to obtain a suspension.

[0047] The graphene sheet diameter is 50–200 nm;

[0048] The concentration of the graphene aqueous dispersion is 1 mg / mL;

[0049] The boronene particle size is 1–10 nm;

[0050] The concentration of the boronene aqueous dispersion is 1 mg / mL;

[0051] The concentration of the surfactant aqueous solution is 0.0005 mg / mL;

[0052] The volume ratio of the graphene aqueous dispersion, the boronene aqueous dispersion, and the surfactant aqueous solution is 1:1:3.

[0053] (2) Using untreated zinc foil as the working electrode and carbon rod as the electrode to form a two-electrode system, and using the suspension obtained in the previous step as the deposition liquid, graphene and boronene are simultaneously deposited on the zinc foil surface by constant current method.

[0054] The zinc foil has a thickness of 100 μm;

[0055] The constant current is 0.0005A.

[0056] (3) Rinse the zinc foil surface with deionized water to remove any residual solution;

[0057] (4) The treated zinc foil was transferred to a constant temperature oven and dried at a constant temperature to obtain a graphene / borene composite interface film modified zinc metal anode.

[0058] The zinc metal anode modified with a graphene / boronene composite interface film prepared in Example 1 was characterized by SEM, and the results are as follows: Figure 1 As shown, layered deposits with relatively uniform morphology were obtained on the zinc foil surface.

[0059] The graphene / borene composite interface film modified zinc metal anode prepared in Example 1 was characterized by XPS, and the results are as follows: Figure 2 As shown: Figure (a) is the XPS spectrum of C1s, where peaks of CO and C=O bonds can be observed, indicating that graphene was successfully adsorbed on the zinc anode surface; Figure (b) is the XPS spectrum of S 2p, indicating that there are residual sulfonate ions on the zinc anode surface; Figure (c) is the XPS spectrum of B1S, indicating that borene was successfully adsorbed on the zinc anode surface.

[0060] The graphene / boronene composite interface film modified zinc metal anode prepared in Example 1 was assembled into a Zn||Zn zinc metal symmetric battery at 5 mA cm⁻¹. -2 Current density, 1 mAh cm⁻¹ -2 The voltage-time curves under the deposition capacity are as follows: Figure 3 As shown, its cycle life exceeds 1900 hours.

[0061] The graphene / boronene composite interface film modified zinc metal anode prepared in Example 1 was matched with a commercial lithium manganese oxide cathode and assembled into a 2032 coin cell. The charge-discharge cycle curve at 1C current density is shown below. Figure 4 As shown: 105.95 mAh g⁻¹ after 50 charge-discharge cycles at a current density of 1C. -1 The reversible discharge specific capacity.

[0062] The graphene / boronene composite interface film modified zinc metal anode prepared in Example 1 was matched with a commercial lithium manganese oxide cathode and assembled into a 2032 coin cell. The rate performance at 0.5C, 1C, 2C, and 4C current densities is as follows: Figure 5 As shown: the average capacities at the corresponding rate of increase are 137.36, 111.17, 98.16, and 81.01 mAh g, respectively. -1 When the cycle rate gradually returns to the initial state (0.5C), the capacity loss is almost negligible.

[0063] Example 2

[0064] A method for preparing a zinc metal anode modified with a graphene / boronene composite interface film, the method comprising the following steps:

[0065] (1) The graphene aqueous dispersion, boronene aqueous dispersion and sodium dodecylbenzene sulfonate aqueous solution were mixed in a volume ratio of 1ml:4ml:10ml, magnetically stirred and the pH was adjusted to 3 with citric acid / sodium citrate to obtain a suspension.

[0066] The graphene sheet diameter is 50–200 nm;

[0067] The concentration of the graphene aqueous dispersion is 2 mg / mL;

[0068] The boronene particle size is 1–10 nm;

[0069] The concentration of the boronene aqueous dispersion is 0.5 mg / mL;

[0070] The concentration of the surfactant aqueous solution is 0.0001 mg / mL;

[0071] The volume ratio of the graphene aqueous dispersion, the boronene aqueous dispersion, and the surfactant aqueous solution is 0.5:2:5.

[0072] (2) Using untreated zinc foil as the working electrode and carbon rod as the electrode to form a two-electrode system, and using the suspension obtained in the previous step as the deposition liquid, graphene and boronene are simultaneously deposited on the zinc foil surface by constant current method.

[0073] The zinc foil has a thickness of 300 μm;

[0074] The constant current is 0.0001A.

[0075] (3) Rinse the zinc foil surface with deionized water to remove any residual solution;

[0076] (4) The treated zinc foil was transferred to a constant temperature oven and dried at a constant temperature to obtain a graphene / borene composite interface film modified zinc metal anode.

[0077] Example 3

[0078] A method for preparing a zinc metal anode modified with a graphene / boronene composite interface film, the method comprising the following steps:

[0079] (1) The graphene aqueous dispersion, boronene aqueous dispersion and hexadecyltrimethylammonium bromide aqueous solution were mixed in a volume ratio of 4ml:1ml:2ml, magnetically stirred and the pH was adjusted to 4 with citric acid / sodium citrate to obtain a suspension.

[0080] The graphene sheet diameter is 50–200 nm;

[0081] The concentration of the graphene aqueous dispersion is 0.5 mg / mL;

[0082] The boronene particle size is 1–10 nm;

[0083] The concentration of the boronene aqueous dispersion was 2 mg / mL;

[0084] The concentration of the surfactant aqueous solution is 0.2 mg / mL;

[0085] The volume ratio of the graphene aqueous dispersion, the boronene aqueous dispersion, and the surfactant aqueous solution is 2:0.5:1.

[0086] (2) Using untreated zinc foil as the working electrode and carbon rod as the electrode to form a two-electrode system, and using the suspension obtained in the previous step as the deposition liquid, graphene and boronene are simultaneously deposited on the zinc foil surface by constant current method.

[0087] The zinc foil has a thickness of 500 μm;

[0088] The constant current is 0.02A.

[0089] (3) Rinse the zinc foil surface with deionized water to remove any residual solution;

[0090] (4) The treated zinc foil was transferred to a constant temperature oven and dried at a constant temperature to obtain a graphene / borene composite interface film modified zinc metal anode.

[0091] Example 4

[0092] A method for preparing a zinc metal anode modified with a graphene / boronene composite interface film, the method comprising the following steps:

[0093] (1) The graphene aqueous dispersion, boronene aqueous dispersion and dioctadecyl dimethyl ammonium bromide aqueous solution were mixed in a volume ratio of 4 ml: 1 ml: 10 ml, magnetically stirred and the pH was adjusted to 6 with citric acid / sodium citrate to obtain a suspension.

[0094] The graphene sheet diameter is 50–200 nm;

[0095] The concentration of the graphene aqueous dispersion is 1 mg / mL;

[0096] The boronene particle size is 1–10 nm;

[0097] The concentration of the boronene aqueous dispersion was 2 mg / mL;

[0098] The concentration of the surfactant aqueous solution is 0.1 mg / mL;

[0099] The volume ratio of the graphene aqueous dispersion, the boronene aqueous dispersion, and the surfactant aqueous solution is 2:0.5:5.

[0100] (2) Using untreated zinc foil as the working electrode and carbon rod as the electrode to form a two-electrode system, and using the suspension obtained in the previous step as the deposition liquid, graphene and boronene are simultaneously deposited on the zinc foil surface by constant current method.

[0101] The zinc foil has a thickness of 200 μm;

[0102] The constant current is 0.5A.

[0103] (3) Rinse the zinc foil surface with deionized water to remove any residual solution;

[0104] (4) The treated zinc foil was transferred to a constant temperature oven and dried at a constant temperature to obtain a graphene / borene composite interface film modified zinc metal anode.

Claims

1. A method for preparing a zinc metal anode modified with a graphene / borene composite interface film, characterized in that: The method steps are as follows: ① A suspension is obtained by mixing graphene aqueous dispersion, boronene aqueous dispersion and surfactant aqueous solution in a certain volume ratio, stirring magnetically and adjusting the pH with citric acid / sodium citrate. The surfactant is one of sodium dodecylbenzene sulfonate, sodium dodecyl sulfonate, hexadecyltrimethylammonium bromide or dioctadecyldimethylammonium bromide; ② Using untreated zinc foil as the working electrode and carbon rod as the electrode to form a two-electrode system, and using the suspension obtained in the previous step as the deposition liquid, graphene and boronene were simultaneously deposited onto the zinc foil surface using a constant current method. ③ Rinse the zinc foil surface with deionized water to remove any residual solution; ④ The treated zinc foil is transferred to a constant temperature oven and dried at a constant temperature to obtain a graphene / borene composite interface film modified zinc metal anode.

2. The method for preparing a graphene / borene composite interface film modified zinc metal anode according to claim 1, characterized in that: The graphene sheet diameter is 50–200 nm; the concentration of the graphene aqueous dispersion is 0.5 mg / mL–2 mg / mL; the boronene particle size is 1–10 nm; the concentration of the boronene aqueous dispersion is 0.5 mg / mL–2 mg / mL; the concentration of the surfactant aqueous solution is 0.0001 mg / mL–0.2 mg / mL; the volume ratio of the graphene aqueous dispersion, boronene aqueous dispersion, and surfactant aqueous solution is (0.5–2):(0.5–2):(1–5); and the pH value of the suspension is 3–6.

3. The method for preparing a graphene / borene composite interface film modified zinc metal anode according to claim 1, characterized in that: The zinc foil has a thickness of 100–500 μm.

4. The method for preparing a graphene / borene composite interface film modified zinc metal anode according to claim 1, characterized in that: The constant current ranges from 0.0001A to 0.5A.

5. A zinc-ion battery, characterized in that: The zinc-ion battery negative electrode is prepared by the method described in any one of claims 1 to 4.

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