Thin film negative electrode material, preparation method and application thereof

Abstract

This invention discloses a thin-film anode material, its preparation method, and its application. The invention employs magnetron sputtering to deposit a target containing indium oxide, yttrium oxide, and zinc oxide onto the surface of a zinc foil substrate, forming a wide-bandgap polycrystalline semiconductor protective layer. The zinc foil with this protective layer serves as a thin-film anode material and can be used as the anode in zinc-ion batteries. This thin-film anode material's protective layer can induce the deposition of Zn. 2+ Improving coulombic efficiency and suppressing the HER (electrocatalytic hydrogen evolution reaction) process effectively increases the cycle stability of the battery. This invention provides a new selection of protective layer materials and a new preparation method for improving the performance of zinc-ion battery anodes. It features process controllability, good film uniformity, and strong stability, and has broad application prospects.

Description

Technical Field

[0001] This invention relates to the field of battery materials technology, and to a thin-film anode material, its preparation method, and its application, particularly to a thin-film protective layer material for anodes, its preparation method, and its application. Background Technology

[0002] Rechargeable aqueous zinc-ion batteries (AZIBs) are attracting widespread attention. Compared to lithium resources, zinc resources are abundant and less expensive. Furthermore, aqueous electrolytes are non-flammable, non-explosive, non-toxic, and pollution-free, and multivalent ion storage can lead to greater theoretical capacity and capacity density. Therefore, AZIBs stand out among many ion batteries, demonstrating broad application prospects. However, zinc anodes in aqueous electrolytes face interconnected challenges such as hydrogen evolution reaction (HER), byproduct formation, and dendrite growth. HER causes gas expansion in the battery, and insoluble byproducts precipitate on the anode surface (Zhao Y. et al. Nat. Comm. 2023, 14). These byproducts reduce the coulombic efficiency of zinc ion insertion / extraction and induce uneven zinc deposition. Subsequently, zinc dendrite growth leads to battery failure and accelerates the HER process. To overcome these defects, a protective layer covering the anode has been proposed; however, existing metal and insulating protective layers are not ideal. Semiconductor materials have kinetic advantages in suppressing HER, while also avoiding the film rupture problem caused by repeated zinc deposition under the insulating protective layer.

[0003] For example, the HER activity of Sn / TiO2-filled carbon spheres is reduced compared to that of Sn-filled carbon spheres. This is because the TiO2 (101) and TiO2 (103) surfaces provide a higher |∆G| than Sn (101) and Sn (200) surfaces. H* | Value contrast (Sun PX et al. Adv. Energy Mater. 2024, 14). Semiconductor Te, as an artificial protective layer for Zn, exhibits different work functions leading to the formation of ohmic contacts. Furthermore, Te, due to its ΔG... H* Sn has a more negative value than Zn, exhibiting excellent HER suppression capability (Chen J. et al. Adv. Funct. Mater. 2025, 35). The introduction of Sn causes a shift in the distance between the p-band center and the Fermi level of In₂O₃, thereby altering the ΔG of In₂O₃. H* These studies indicate that HER activity is fundamentally related to semiconductor bandgap width and composition, but the exact relationship and detailed mechanisms have not yet been fully investigated. Summary of the Invention

[0004] In view of this, the present invention provides an amorphous semiconductor protective layer, a preparation method thereof, and its application. The main purpose is to provide a wide-bandgap semiconductor protective layer that can effectively protect the negative electrode while reducing hydrogen evolution reaction and enhancing battery stability.

[0005] To achieve the above objectives, the present invention mainly provides the following technical solutions: This invention provides a thin-film anode material comprising a zinc foil substrate and a wide-bandgap polycrystalline semiconductor protective layer covering the surface; the wide-bandgap polycrystalline semiconductor protective layer is prepared by magnetron sputtering of a target material onto the surface of the zinc foil substrate, the target material being composed of indium oxide, yttrium oxide, and zinc oxide; wherein the molar ratio of indium oxide, yttrium oxide, and zinc oxide is in the range of 1:(0.001-3):1; The parameters for magnetron sputtering are: RF power of 30-50W, background pressure of 1-2Pa, argon flow rate of 10-30sccm, sputtering temperature of 20-30℃, and sputtering time of 20-40min.

[0006] Preferably, the molar ratio of indium oxide, yttrium oxide and zinc oxide is in the range of 1:(1-2):1.

[0007] Preferably, the molar ratio of indium oxide, yttrium oxide and zinc oxide is in the range of 1:1:1, 1:1.5:1 or 1:2:1.

[0008] Preferably, the thickness of the wide-bandgap polycrystalline semiconductor protective layer is 0.070-25 μm.

[0009] Preferably, the surface roughness of the wide-bandgap polycrystalline semiconductor protective layer is less than 0.5 μm.

[0010] In another aspect, the present invention provides a method for preparing the above-mentioned thin film anode material, comprising the following steps: magnetron sputtering a target material onto a zinc foil substrate, and covering the surface of the zinc foil substrate to obtain the thin film anode material; The target material is composed of indium oxide, yttrium oxide, and zinc oxide with a purity of 99.9%.

[0011] Preferably, the steps further include: ultrasonically cleaning the thin-film anode material in deionized water at 100W for 1-2 times, 15 minutes each time; and then ultrasonically cleaning the thin-film anode material in anhydrous ethanol at 100W for 1-2 times, 15 minutes each time.

[0012] Preferably, the step further includes: drying the cleaned thin-film anode material at 50-70°C.

[0013] In another aspect, the present invention also provides an application of any of the above-mentioned thin-film anode materials, wherein the thin-film anode material is used as the anode material of a zinc-ion battery and disposed at the anode of the zinc-ion battery.

[0014] In another aspect, the present invention provides a wide bandgap polycrystalline semiconductor protective layer composed of indium oxide, yttrium oxide, and zinc oxide, with a film thickness of 0.070-25 μm and a surface roughness of less than 0.5 μm; the wide bandgap polycrystalline semiconductor protective layer is prepared by magnetron sputtering, and the target material is composed of indium oxide, yttrium oxide, and zinc oxide; wherein the molar ratio of indium oxide, yttrium oxide, and zinc oxide is in the range of 1:(0.001-3):1.

[0015] Compared with existing technologies, the thin-film anode material prepared by magnetron sputtering in this invention has the following significant technical advantages: 1. Yttrium can effectively adjust the bandgap of semiconductor materials, thereby affecting the conductivity and dynamic properties of artificial protective film.

[0016] 2. Wide-bandgap polycrystalline semiconductor protective layer InYZnO material can balance the H in the protective layer film. + Adsorption with Zn 2+ Competitive affinity relationships inhibit HER and induce Zn deposition. 2+ .

[0017] 3. Zinc foil protected by InYZnO material, a wide-bandgap polycrystalline semiconductor protective layer, serves as the negative electrode of a zinc-ion battery. By suppressing the Helovsky reaction in the HER, the symmetric battery exhibits a longer cycle life.

[0018] 4. The material has the characteristics of process controllability, good film uniformity and strong stability during preparation.

[0019] Therefore, this invention provides an efficient and sustainable method for preparing anode thin film anode materials, which significantly enhances the cycle performance of zinc-ion batteries. Attached Figure Description

[0020] Figure 1 An X-ray diffraction pattern of an IYZ-1 material provided in an embodiment of the present invention; Figure 2 A scanning electron microscope image and energy-dispersive spectrum of IYZ-1 material provided in an embodiment of the present invention; Figure 3 A coulombic efficiency curve of IYZ-1@Zn as a zinc-ion battery negative electrode provided in an embodiment of the present invention; Figure 4 Cyclic performance diagram of a zinc-ion symmetric battery prepared according to Example 1 of the present invention; Figure 5 Cyclic performance diagram of a zinc-ion symmetric battery prepared in Comparative Example 1 provided for this invention; Figure 6 The cycling performance diagram of a zinc-ion symmetric battery prepared in Comparative Example 2 is provided for the present invention. Detailed Implementation

[0021] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments.

[0022] On one hand, embodiments of the present invention provide a thin-film anode material, comprising a zinc foil substrate and a wide-bandgap polycrystalline semiconductor protective layer covering the surface; the wide-bandgap polycrystalline semiconductor protective layer is prepared by magnetron sputtering of a target material onto the surface of the zinc foil substrate, the target material being composed of indium oxide, yttrium oxide, and zinc oxide; wherein the molar ratio of indium oxide, yttrium oxide, and zinc oxide is in the range of 1:(0.001-3):1; The parameters for magnetron sputtering are: RF power of 30-50W, background pressure of 1-2Pa, argon flow rate of 10-30sccm, sputtering temperature of 20-30℃, and sputtering time of 20-40min.

[0023] The wide-bandgap polycrystalline semiconductor protective layer is composed of indium oxide, yttrium oxide, and zinc oxide, with the molar ratio of indium oxide, yttrium oxide, and zinc oxide ranging from 1:(0.001-3):1, a film thickness of 0.070-25 μm, and a surface roughness of less than 0.5 μm.

[0024] Based on its composition, the wide bandgap polycrystalline semiconductor protective layer of this invention can be referred to as InYZnO material. In the InYZnO material of this invention, the Y element in InYZnO can effectively adjust the bandgap of the semiconductor material; while the InYZnO material can balance the H in the protective layer. + Adsorption with Zn 2+ Competitive affinity relationships inhibit HER and induce Zn deposition. 2+ This effectively increases the cycle stability of the battery.

[0025] On the other hand, embodiments of the present invention also provide a method for preparing a thin-film anode material, comprising the following steps: The target material is magnetron sputtered onto a zinc foil substrate, and the zinc foil substrate surface is covered to obtain the thin film anode material; The target material is composed of indium oxide, yttrium oxide, and zinc oxide with a purity of 99.9%.

[0026] The zinc foil with InYZnO material on its surface prepared by the above method can be used as the negative electrode of zinc-ion batteries.

[0027] The targets used in this invention were all purchased from Hezhong New Materials Co., Ltd. The targets were prepared using conventional methods in the art. The purity of indium oxide, yttrium oxide and zinc oxide in the targets was 99.9%, and the molar ratio was consistent with that in the examples.

[0028] Example 1 This invention provides a method for preparing a thin-film anode material, comprising the following steps: A target material is magnetron sputtered onto a zinc foil substrate, covering the surface of the zinc foil substrate to obtain a zinc foil covered with a 7.1 μm thick IYZ-1 protective layer film with a surface roughness of 0.125 μm. The molar ratio of indium oxide, yttrium oxide, and zinc oxide in the target material is 1:1:1. The target material is composed of indium oxide, yttrium oxide, and zinc oxide with a purity of 99.9%.

[0029] The parameters for magnetron sputtering are: RF power of 30W, background pressure of 1Pa, argon flow rate of 10sccm, temperature of 20℃, and sputtering time of 30min.

[0030] like Figure 1 As shown, the wide-bandgap polycrystalline semiconductor protective layer material obtained in Example 1 is designated IYZ-1. The diffraction peaks at 36.3°, 39.0°, and 43.2° correspond to the characteristic peaks of Zn (PDF#04-0831) with hexagonal crystal system and space group P63 / mmc. No other diffraction peaks were observed outside the zinc substrate, which is attributed to the amorphous properties of the film.

[0031] like Figure 2 As shown, by Figure 2 a (cross-sectional SEM image) and Figure 2 b (EDS pattern) shows that the IYZ-1 protective layer is rich in In, and its thickness is approximately 7.1 μm. The cross-sectional EDS distribution also detected In in the zinc substrate, which is attributed to the high-energy bombardment of the target material during magnetron sputtering. The zinc foil material with the obtained IYZ-1 protective layer film is designated IYZ-1@Zn. Surface SEM image of IYZ-1@Zn ( Figure 2 c) This shows that the zinc anode surface is uniformly covered with an IYZ thin film layer.

[0032] Using IYZ-1@Zn as the negative electrode material, this invention employs a CR2032 coin cell to test the electrochemical performance of the IYZ-1@Zn negative electrode. In assembling the zinc-ion half-cell, glass fiber was used as the separator, 2M ZnSO4 as the electrolyte, and IYZ-1@Zn as the counter electrode. All components were assembled in air to form CR2032 type ZIBs. To evaluate the Zn half-cell performance... 2+The coulombic efficiency (CE) of the embedding / stripping was measured with a fixed discharge time of 30 minutes, a cutoff voltage of 0.5 V, and a current density of 5 mA cm⁻¹. -2 In the CE curves, Zn / / Ti half-cells were assembled using titanium foils with different anode materials. At 5 mA cm⁻¹... -2 / 5 mAh cm -2 At the specified current density, the IYZ-1@Zn / / Ti half-cell maintained an average CE of 99.41% after 1500 cycles, demonstrating good cycle stability. Figure 3 As shown. At 2 mA cm -2 1 mAh cm -2 Under these conditions, IYZ-1@Zn exhibits an ultra-long cycle life of 3000 hours, such as Figure 4 As shown in the figure. These data demonstrate that the battery exhibits excellent cycle stability and electrochemical performance.

[0033] In this embodiment, a target material composed of indium oxide, yttrium oxide, and zinc oxide in a specific molar ratio is deposited on the surface of zinc foil using magnetron sputtering to form an IYZ-1 protective layer. The zinc foil with this protective layer is then used as the negative electrode of a zinc-ion battery. In this embodiment, the Y element in InYZnO can effectively adjust the bandgap of the semiconductor material; while the wide bandgap InYZnO thin film can balance the H... + Adsorption with Zn 2+ Competitive affinity relationships inhibit HER and induce Zn deposition. 2+ This effectively increases the cycle stability of the battery.

[0034] Example 2 This invention provides a method for preparing a thin-film anode material, comprising the following steps: A target material is magnetron sputtered onto a zinc foil substrate, covering the surface of the zinc foil substrate to obtain a zinc foil covered with a 300 nm thick IYZ-2 protective layer film with a surface roughness of 0.125 μm. The molar ratio of indium oxide, yttrium oxide, and zinc oxide in the target material is 1:1.5:1. The target material is composed of indium oxide, yttrium oxide, and zinc oxide with a purity of 99.9%.

[0035] The parameters for magnetron sputtering are: RF power of 40W, background pressure of 1.5Pa, argon flow rate of 15sccm, temperature of 25℃, and sputtering time of 20min.

[0036] The diffraction peaks of IYZ-2 are very similar to those of IYZ-1. Referring to the method in Example 1, IYZ-2@Zn was used as the negative electrode to assemble a zinc-ion battery, at 5 mA cm⁻¹ -2 / 5 mAh cm -2At current density, the IYZ-1@Zn / / Ti half-cell short-circuited after 1300 cycles; the IYZ-2@Zn half-cell has a cycle life of 1000 hours.

[0037] Example 3 This invention provides a method for preparing a thin-film anode material, comprising the following steps: A target material is magnetron sputtered onto a zinc foil substrate, covering the surface of the zinc foil substrate to obtain a zinc foil covered with an IYZ-3 protective layer film with a thickness of 5 μm and a surface roughness of 0.125 μm. The molar ratio of indium oxide, yttrium oxide, and zinc oxide in the target material is 1:2:1. The target material is composed of indium oxide, yttrium oxide, and zinc oxide with a purity of 99.9%.

[0038] The parameters for magnetron sputtering are: RF power of 50W, background pressure of 2Pa, argon flow rate of 25sccm, temperature of 30℃, and sputtering time of 40min.

[0039] The diffraction peaks of IYZ-3 are very similar to those of IYZ-1. Following the method in Example 1, IYZ-3@Zn was used as the negative electrode to assemble a zinc-ion battery, at 5 mA cm⁻¹ -2 / 5 mAh cm -2 At current density, the IYZ-3@Zn / / Ti half-cell short-circuited after 1100 cycles; the cycle life of IYZ-3@Zn is 800 hours.

[0040] Comparative Example 1 The only difference between Comparative Example 1 and Example 1 is that the molar ratio of indium oxide, yttrium oxide, and zinc oxide is 1:3:1, and the resulting material is designated as IYZ-4.

[0041] Following the method of Example 1, IYZ-4 was used as the positive electrode protective layer material, and detailed X-ray diffraction (XRD) tests and zinc-ion battery performance evaluations were performed. Compared with IYZ-1, no diffraction peaks other than those on the zinc substrate were observed, attributed to the amorphous properties of the film. A zinc-ion battery was assembled using IYZ-4@Zn as the negative electrode, and performance was evaluated at 5 mA cm⁻¹. -2 / 5 mAh cm -2 At current density, the IYZ-4@Zn / / Ti half-cell short-circuited after 300 cycles; for example... Figure 5 As shown, at 2 mA cm -2 1mAh cm -2 Under these conditions, the cycle life of IYZ-4@Zn is 986 hours. Its coulombic efficiency and cycle life are significantly lower than those of Example 1.

[0042] This significant difference indicates that the electrochemical performance of the IYZ-1 material is superior to that of the IYZ-4 material. The higher Y content leads to a significant decrease in its coulombic efficiency and cycle stability. Therefore, introducing an appropriate amount of Y into the InYZnO material can effectively improve the electrochemical performance of the negative electrode, increase coulombic efficiency, and improve cycle life. This comparative result demonstrates the superiority of the IYZ-1 protective layer material of this invention in zinc-ion battery applications.

[0043] Comparative Example 2 The only difference between Comparative Example 2 and Example 1 is that the molar ratio of indium oxide, yttrium oxide, and zinc oxide is 1:0.001:1, and the resulting material is represented by the code IZ.

[0044] Referring to the method in Example 1, a zinc-ion symmetric cell was assembled using IZ@Zn as the negative electrode at 5 mA cm⁻¹. -2 / 5 mAhcm -2 At current density, the IZ@Zn / / Ti half-cell short-circuited after 100 cycles; at 2 mA cm⁻¹ -2 1 mAh cm -2 Under these conditions, the cycle life of IZ@Zn is 866 hours, such as Figure 6 As shown, its specific capacity and capacity retention are much lower than those of Example 1.

[0045] As can be seen from Examples 1 to 3 and Comparative Examples 1 and 2 above, when the thin-film anode material prepared by the present invention is used as the anode of a zinc-ion battery, the Y element in the protective layer InYZnO material can effectively adjust the bandgap of the semiconductor material; and the InYZnO wide bandgap thin film can balance H + Adsorption with Zn 2+ Affinity competition induces Zn deposition. 2+ Improve coulombic efficiency. At 5 mA cm⁻¹ -2 / 5 mAh cm -2 At the specified current density, the IYZ-1@Zn / / Ti half-cell maintained an average CE of 99.41% after 1500 cycles. The protective film effectively increased the cycle stability of the cell by suppressing the HER process at 2 mAcm. -2 1 mAh cm -2 Under these conditions, IYZ-1@Zn exhibits an ultra-long cycle life of 3000 hours. Therefore, compared with other embodiments and comparative examples, Example 1 demonstrates higher coulombic efficiency and superior cycle performance, verifying the significant advantages of this technical approach in improving battery performance.

[0046] On the other hand, embodiments of the present invention also provide an application of a thin-film negative electrode material, which is used as a negative electrode material in a zinc-ion battery and is disposed at the negative electrode of the zinc-ion battery.

[0047] The IYZ-1@Zn thin film anode material prepared by this invention can have high coulombic efficiency and long cycle life as an anode material for zinc-ion batteries.

[0048] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A thin film negative electrode material, characterized by, It consists of a zinc foil substrate and a wide-bandgap polycrystalline semiconductor protective layer covering the surface; the wide-bandgap polycrystalline semiconductor protective layer is prepared by magnetron sputtering of a target material onto the surface of the zinc foil substrate, the target material being composed of indium oxide, yttrium oxide, and zinc oxide; wherein the molar ratio of indium oxide, yttrium oxide, and zinc oxide is in the range of 1:(0.001-3):1; The parameters for magnetron sputtering are: RF power of 30-50W, background pressure of 1-2Pa, argon flow rate of 10-30sccm, sputtering temperature of 20-30℃, and sputtering time of 20-40min.

2. The thin film negative material of claim 1, wherein, The molar ratio of the indium oxide, the yttrium oxide, and the zinc oxide is in the range of 1:(1-2):

1.

3. The thin film negative material of claim 1, wherein, The molar ratio of the indium oxide, the yttrium oxide, and the zinc oxide is in the range of 1:1:1, 1:1.5:1, or 1:2:

1.

4. The thin-film negative material according to any one of claims 1 to 3, characterized in that, The thickness of the wide-bandgap polycrystalline semiconductor protective layer is 0.070-25 μm.

5. The thin film negative material according to any one of claims 1-3, characterized in that, The surface roughness of the wide-bandgap polycrystalline semiconductor protective layer is less than 0.5 μm.

6. A method of producing the thin-film negative electrode material according to any one of claims 1 to 3, characterized by, The process includes the following steps: magnetron sputtering a target material onto a zinc foil substrate, thereby covering the surface of the zinc foil substrate to obtain the thin-film anode material; The target material is composed of indium oxide, yttrium oxide, and zinc oxide with a purity of 99.9%.

7. The production method according to claim 6, wherein The steps also include: placing the thin-film anode material in deionized water and ultrasonically cleaning it 1-2 times at 100W, 15 minutes each time; then placing the thin-film anode material in anhydrous ethanol and ultrasonically cleaning it 1-2 times at 100W, 15 minutes each time.

8. The production method according to claim 7, characterized by, The steps also include: drying the cleaned thin-film anode material at 50-70°C.

9. Use of the thin film negative electrode material according to any one of claims 1 to 3, characterized in that The thin-film negative electrode material is used as the negative electrode material of the zinc-ion battery and is disposed at the negative electrode of the zinc-ion battery.

10. A wide-bandgap polycrystalline semiconductor protective layer, characterized in that, The film is composed of indium oxide, yttrium oxide, and zinc oxide, with a thickness of 0.070-25 μm and a surface roughness of less than 0.5 μm. The wide bandgap polycrystalline semiconductor protective layer is prepared by magnetron sputtering, and the target material is composed of indium oxide, yttrium oxide, and zinc oxide. The molar ratio of indium oxide, yttrium oxide, and zinc oxide is in the range of 1:(0.001-3):1.

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