Double-interface layer for protecting zinc metal negative electrode and zinc metal battery
By constructing a double interface layer on the surface of the zinc metal anode and combining the properties of metallic tin and boron nitride, the problems of zinc dendrites and side reactions were solved, and the efficient and stable operation of zinc metal batteries was achieved.
Patent Information
- Application Number
- CN202511378016.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-09-25
- Publication Date
- 2026-01-09
AI Technical Summary
Existing zinc metal anodes suffer from problems such as zinc dendrite formation and frequent side reactions during use, especially uneven growth of zinc in the later stages of deposition and unstable contact with electrolyte, which leads to a decline in battery performance.
A dual-interface layer structure was constructed, consisting of a zinc-loving tin interface layer and a zinc-repellent boron nitride interface layer, which respectively regulate the initial nucleation and later growth of zinc ions, suppress dendrite formation, and reduce side reactions.
Effective control of the zinc ion deposition process was achieved, which improved the cycle life and coulombic efficiency of zinc metal batteries, suppressed dendrite formation and side reactions, and significantly improved battery performance.
Smart Images
Figure CN121306969A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to a dual-interface layer for protecting a zinc metal negative electrode and a zinc metal battery, belonging to the field of new energy battery technology. Background Technology
[0002] Aqueous rechargeable batteries have attracted considerable attention from researchers as a low-cost, safe, and environmentally friendly energy storage device. The advantages of aqueous zinc-ion batteries in terms of energy density and power density make them a promising alternative to current lithium-ion energy storage systems. On the negative electrode side of zinc-ion batteries, metallic zinc has a low redox potential (-0.762 V vs. standard hydrogen electrode) and a high theoretical capacity (5855 mAh cm⁻¹). -3 Zinc metal anodes, with their high reserves and low toxicity, are considered the most promising anode material for aqueous zinc secondary batteries. Although zinc metal anodes exhibit superior physicochemical properties and attractive application prospects, the current use of zinc metal electrodes still faces many formidable challenges, such as zinc dendrites and side reactions.
[0003] Artificial interface layers are considered a simple and efficient strategy. Introducing an artificial interface layer at the electrode-electrolyte interface can not only significantly reduce the contact between zinc metal and aqueous electrolyte, regulate the electric field distribution, reduce current density, and guide uniform deposition, but also alleviate volume expansion during deposition / stripping. In recent years, the inventors have conducted a series of studies at the electrode-electrolyte interface, designing a series of high-performance interface layers. One such work involves preparing an ultrathin metal interface layer (Cu / Ag@Zn) with strong metal affinity ("zinc affinity") on the surface of a zinc metal anode. This strong "zinc affinity" property can regulate the initial nucleation behavior of zinc ions, allowing zinc ions to preferentially deposit at adsorption sites to form a Zn-M alloy (M being a metal), preventing the two-dimensional diffusion process of zinc ions on the zinc metal surface. Ultimately, this results in a dendrite-free zinc metal electrode with high coulombic efficiency, significantly improving the overall performance of zinc metal batteries. However, this strategy also has inherent limitations. Since zinc deposition occurs on the surface of the metal interface layer, while the introduction of "zinc-loving" sites can address the kinetics issues to some extent, excessive zinc deposition leading to site coverage problems will undoubtedly result in the loss of "zinc-loving" function, leaving zinc in a disordered growth state during the later stages of deposition. Furthermore, the direct exposure of deposited zinc to the electrolyte can also cause instability, water decomposition, and Zn degradation. 2+ Problems such as the exacerbation of irreversible depletion. Summary of the Invention
[0004] To solve the above problems, the present invention provides, in a first aspect, a dual-interface layer for protecting zinc metal anodes.
[0005] The technical solution to the problem solved by this invention is as follows: A dual-interface layer for protecting a zinc metal anode comprises a zinc-loving tin metal interface layer covering the surface of the zinc metal anode and a zinc-repellent boron nitride interface layer covering the tin metal interface layer.
[0006] How to effectively regulate the later growth process while controlling the initial nucleation of zinc ions to achieve long-term suppression of zinc dendrites is one of the key issues in zinc metal battery research. Addressing the shortcomings of existing "zinc-loving" interface layers, many research teams have demonstrated that constructing a stable interface layer with low metal affinity ("zinc-repellent") on the zinc metal surface can effectively regulate the later zinc ion deposition process, suppress dendrite growth, and reduce side reactions by inhibiting the contact between zinc metal and aqueous electrolytes, thereby improving the cycle efficiency of the zinc metal anode. However, the effect of a single "zinc-repellent" interface layer in suppressing zinc dendrites and side reactions also has certain limitations. The lack of "zinc-loving" sites leads to localized non-uniformity in zinc ion deposition, which requires the interface layer to have strong mechanical properties to maintain its complete morphological characteristics.
[0007] This invention addresses the protection of the zinc metal anode in zinc metal batteries by proposing a method for constructing a dual-interface layer. This method aims to overcome the shortcomings of existing "zinc-loving" interface layer strategies, achieve effective control over the zinc ion deposition process, and improve the performance of zinc metal batteries. The following section provides a detailed analysis of the dual-interface layer structure, the advantages of each layer, the preparation method, battery applications, and optimal solution selection.
[0008] 1. The tin-metal interface layer utilizes the suitable affinity between zinc and tin to regulate the initial nucleation behavior of zinc ions, providing suitable initial deposition sites and guiding the orderly deposition of zinc ions. Tin and zinc metal anodes have a certain compatibility, forming a relatively stable interface on the zinc surface, providing a good foundation for the subsequent construction of the boron nitride interface layer.
[0009] 2. The boron nitride interface layer has low metal affinity, which can effectively regulate the late-stage zinc ion deposition process and inhibit dendrite growth. By preventing excessive aggregation and uncontrolled growth of zinc ions, zinc deposition becomes more uniform. It can also inhibit the contact between zinc metal and aqueous electrolytes, reducing the occurrence of side reactions, such as reducing the inherent instability of zinc metal, water decomposition, and Zn... 2+To address issues such as irreversible degradation and improve the cycling efficiency of zinc metal anodes, two-dimensional nanomaterials, due to their excellent mechanical strength and flexibility, can eliminate excessive local stress on the interface layer, maintaining its intact morphology. Therefore, introducing a zinc-repellent two-dimensional nanomaterial interface layer on top of a zinc-loving interface layer is expected to achieve effective control over the zinc growth process. Hexagonal boron nitride (h-BN) two-dimensional nanomaterials possess excellent mechanical strength and flexibility, capable of eliminating excessive local stress on the interface layer, maintaining its intact morphology, and ensuring the stable function of the interface layer during long-term cycling. Simultaneously, hexagonal boron nitride (h-BN) has a wide band gap (>5.9 eV), indicating that it is a good electronic insulator and an excellent material for an interface layer.
[0010] As a preferred embodiment of the above technical solution, the thickness of the tin interface layer is 1~2 μm, and the thickness of the boron nitride interface layer is 5~10 μm.
[0011] In the above technical solution of the present invention, the thicknesses of the tin interface layer and the boron nitride interface layer are optimized. The thickness of the tin interface layer is 1~2 μm, and the thickness of the boron nitride interface layer is 5~10 μm. Appropriate thicknesses ensure that each layer performs optimally. Too thin a layer may not effectively provide the corresponding regulation and protection, while too thick a layer may increase interface resistance or affect lithium-ion transport.
[0012] As a preferred embodiment of the above technical solution, the tin interface layer is prepared by an in-situ chemical reaction method.
[0013] As a preferred embodiment of the above technical solution, the boron nitride interface layer is prepared by coating.
[0014] As a preferred embodiment of the above technical solution, the in-situ chemical reaction involves a displacement reaction between the zinc metal anode and a soluble tin salt.
[0015] As a preferred embodiment of the above technical solution, the soluble tin salt is tin tetrachloride.
[0016] As a preferred embodiment of the above technical solution, the concentration of tin tetrachloride is 0.01~0.1 mol per liter.
[0017] Secondly, the present invention provides a zinc metal battery.
[0018] A zinc metal battery includes a zinc metal negative electrode, the zinc metal negative electrode comprising a zinc-loving tin metal interface layer covering the surface of the zinc metal negative electrode and a zinc-repellent boron nitride interface layer covering the tin metal interface layer.
[0019] Applying the aforementioned dual-interface layer to a zinc metal battery results in a zinc metal anode comprising a zinc-loving tin interface layer covering the surface of the zinc metal anode and a zinc-repellent boron nitride interface layer covering the tin interface layer. Through the synergistic effect of the dual-interface layers, the performance of the zinc metal anode is improved, thereby enhancing the overall performance of the zinc metal battery, such as cycle life and coulombic efficiency. Simultaneously, the preferred parameters, such as the preparation methods and thicknesses of the tin and boron nitride interface layers, are also applicable to ensure the stability and consistency of battery performance.
[0020] As a preferred embodiment of the above technical solution, the thickness of the tin interface layer is 1~2 μm, and the thickness of the boron nitride interface layer is 5~10 μm.
[0021] As a preferred embodiment of the above technical solution, the tin interface layer is prepared by an in-situ chemical reaction method.
[0022] As a preferred embodiment of the above technical solution, the boron nitride interface layer is prepared by coating.
[0023] In summary, the present invention has the following beneficial effects: 1. This invention combines the advantages of zinc-repellent and zinc-affinity materials to construct a dual-interface layer structure (NB@Sn@Zn) with tin as the zinc-affinity layer and boron nitride as the zinc-repellent layer. The resulting dual-interface layer structure can effectively regulate the initial nucleation behavior and subsequent growth behavior of zinc ions, achieving full control over the zinc ion deposition process and effectively suppressing the formation of zinc dendrites; 2. The low ion diffusion barrier and high hydrogen adsorption of the interface layer effectively promote the rapid diffusion of zinc ions in the interface layer to regulate uniform zinc deposition, while inhibiting the hydrogen evolution reaction. The zinc-loving / zinc-repellent interface layer exhibits good electrochemical performance, achieving a cycle life of up to 1050 hours (6 mA cm⁻¹). -2 / 6 mAh cm -2 The average coulombic efficiency reached 99.4% (1 mA cm⁻¹). -2 / 1 mAh cm -2 Furthermore, the NB@Sn@Zn ||MnO2 full cell still maintains a 75mAh g⁻¹ after 2000 cycles. -1 Reversible capacity. Attached Figure Description
[0024] Figure 1 The reaction time for preparing the zinc-loving metal interface layer was selected.
[0025] Figure 2 This is the XRD pattern of the dual-interface layer.
[0026] Figure 3 This is a cross-sectional SEM image of the zinc double interface layer.
[0027] Figure 4 The LSV curves of the double-interface zinc foil and the blank zinc foil in the electrolyte are shown.
[0028] Figure 5 The chronoamperographs are for the double-interface zinc foil and the blank zinc foil at an overpotential of -150 mV.
[0029] Figure 6 Coulombic efficiency plots for Zn / Cu half-cells using blank zinc foil and double-interface zinc foil. Test conditions: 1 mA / cm². 2 1mAh / cm 2 .
[0030] Figure 7 Cycle time-voltage plots for Zn / Zn symmetric cells using blank zinc foil and double-interface zinc foil. Test conditions: 1 mA / cm². 2 1mAh / cm 2 .
[0031] Figure 8 Cycle time-voltage plots for Zn / Zn symmetric cells using blank zinc foil and double-interface zinc foil. Test conditions: 6 mA / cm². 2 3mAh / cm 2 .
[0032] Figure 9 Cycle time-voltage plots for Zn / Zn symmetric cells using blank zinc foil and double-interface zinc foil. Test conditions: 6 mA / cm². 2 6mAh / cm 2 .
[0033] Figure 10 Surface morphology analysis of zinc metal electrodes after 10 cycles.
[0034] Figure 11 The diagram shows the cycling capacity of the Zn / MnO2 full cell in the preferred and blank electrolytes, with a cycling condition of 1 A / g. Detailed Implementation
[0035] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.
[0036] This specific embodiment is merely an explanation of the present invention and is not intended to limit the present invention. Any changes made by those skilled in the art after reading the specification of the present invention, as long as they are within the scope of the claims, will be protected by patent law. Example 1
[0037] Screening of the reaction time at the zinc-loving interface layer. A 0.05 mol / L solution was prepared by dissolving SnCl₄·5H₂O in N-methylpyrrolidone. Zinc foil was immersed in the solution and reacted for 1 minute (Sn-1@Zn), 2 minutes (Sn-2@Zn), and 3 minutes (Sn-3@Zn), respectively. After drying, it was cut into 10 mm diameter circular electrodes using a special mold. A 2032-type symmetrical battery was assembled using blank zinc, Sn-1@Zn, Sn-2@Zn, and Sn-3@Zn as electrodes and glass fiber as the separator. Charge-discharge cycle tests were performed using a Xinwei battery testing system at a charge-discharge current of 1 mA / cm² for 1 hour, and the test data were recorded. Figure 1 As shown.
[0038] Example Result Analysis according to Figure 1 The results showed that the symmetric cell had the longest cycle life when the reaction time was 2 minutes, indicating that the reaction time of 2 minutes was optimal. Example 2
[0039] Using the preferred electrode from Example 1, an NB@Sn-2@Zn electrode was prepared by manually coating boron nitride nanosheets onto the electrode surface. Boron nitride nanosheets were mixed with polyvinylpyrrolidone at a mass ratio of 9:1, and then, using N-methylpyrrolidone as a diluent, the mixture was ground into a homogeneous slurry. This slurry was then coated onto the surface of the Sn-2@Zn electrode using a doctor blade. The composition of the electrode surface was analyzed using X-ray diffraction (e.g., ...). Figure 2 As shown), the surface morphology and thickness of the Sn-2@Zn electrode on the NB@Sn-2@Zn electrode were measured using scanning electron microscopy (SEM). Figure 3 (As shown).
[0040] Example Result Analysis according to Figure 2 It can be observed that both the tin and boron nitride interface layers were successfully fabricated on the zinc electrode surface. Furthermore, the SEM images clearly show the presence of both the tin and boron nitride interface layers. The tin interface layer has a thickness of 1.6 micrometers, and the boron nitride interface layer has a thickness of 7 micrometers. Figure 3 The bilayer structure of the boron nitride and tin interface layer can be clearly seen. Example 3
[0041] Linear sweep voltammetry (LSV) experiments were conducted in a three-electrode system, with blank zinc foil and NB@Sn-2@Zn as working electrodes, a platinum sheet as the counter electrode, and a silver / silver chloride electrode as the reference electrode. Linear sweep voltammetry curves were obtained in the potential range of -1.5 to -0.9 V, as shown below. Figure 4 As shown.
[0042] Example Result Analysis We can see from the LSV curve that the zinc-loving-zinc-repellent dual-interface layer structure can effectively suppress the hydrogen production reaction. Example 4
[0043] Deposition model of zinc ions in a dual-interface layer was tested. The zinc deposition model was obtained through Zn / Zn symmetric cell testing, using blank zinc or NB@Sn-2@Zn as the working electrode, counter electrode, and reference electrode, respectively. A standard CR2032 coin cell was fabricated. The cell was tested using chronoamperometry, with a voltage set to -150 mV and a test time set to 400 s. The test results are as follows: Figure 5 As shown.
[0044] Example Result Analysis pass Figure 5 The test results showed that the current of the blank zinc foil was constantly decreasing, while the current of the double-interface zinc foil remained stable. This indicates that the two-dimensional diffusion of zinc ions on the zinc metal anode surface is suppressed in the preferred electrolyte, and zinc ions tend to deposit at the original adsorption site, effectively avoiding the dendrite growth problem caused by two-dimensional diffusion. Example 5
[0045] Zn / Cu half-cells were assembled using zinc foil or double-interface zinc foil as the counter and reference electrodes, copper foil as the working electrode, and glass fiber as the separator to fabricate standard CR2032 coin cells. The parameters during the testing process were recorded using a Xinwei battery testing system, with the current density set to 1 mA / cm². 2 The discharge cycle time was 1 hour, and the charging cycle cutoff voltage was 0.5V. The test results are as follows: Figure 6 .
[0046] Example Result Analysis By comparing the coulombic efficiency, we can see that the double-interface zinc foil has a longer cycle life and a higher coulombic efficiency, indicating that the side reactions are significantly suppressed, which is consistent with the results obtained in Example 1. Example 6
[0047] In this embodiment, zinc foil or double-interface zinc foil is used as the working electrode, counter electrode, and reference electrode. The parameters during the test are recorded using a Xinwei battery testing system, and the charge / discharge current density is set to 1 mA / cm² during the test. 2 The time was set to 1 hour, and the test results were as follows: Figure 7 The charge / discharge current density is set to 6 mA / cm². 2 The time was set to 0.5 hours, and the test results were as follows: Figure 8 The charge / discharge current density is set to 6 mA / cm².2 The time was set to 1 hour, and the test results were as follows: Figure 9 .
[0048] Example Result Analysis Depend on Figure 7-9 It can be seen that the dual-interface layer enables the zinc metal anode to maintain a long cycle life, and the dual-interface layer also exhibits excellent long cycle performance under large capacity. Example 7
[0049] Evolution of surface morphology of zinc metal anode with double interface layer. Symmetrical cells were assembled using blank zinc foil and zinc foil with double interface layer, and cyclic testing was performed according to the test method in Example 5. The surface morphology changes of the zinc metal anode were observed after 10 cycles. Experimental results are as follows: Figure 10 As shown.
[0050] Result Analysis of Example 7 According to the scanning electron microscope image of Example 10, the surface of the blank zinc metal is covered with dense zinc dendrites; however, the zinc foil with double interface layer shows a smooth morphology, indicating that no zinc dendrites are generated during the cycling process. Example 8
[0051] Using MnO2 as the positive electrode, MnO2, conductive carbon, and PVDF were mixed in a mass ratio of 8:1:1, with NMP as a diluent, and thoroughly ground to ensure uniform mixing. The uniformly mixed slurry was then evenly coated onto the surface of stainless steel foil and vacuum-dried at 80℃ for 12 hours. After drying, it was cut into 10mm diameter discs to serve as the working electrodes. Zinc foil was used as the negative electrode to assemble a standard CR2032 battery. The parameters during the testing process were recorded using a Xinwei battery testing system. The test results are as follows: Figure 10 As shown.
[0052] Example Result Analysis like Figure 11 As shown, it can be observed that the capacity of the zinc metal full cell is significantly higher than that of the blank zinc foil when the double interface layer is present. The main reason is that when the double interface layer is present, the corrosion reaction of the zinc metal anode and the hydrogen evolution reaction of the electrolyte are effectively suppressed, and the formation of zinc dendrites is also alleviated. Therefore, the zinc metal-based full cell containing the double interface layer has a higher capacity.
Claims
1. A dual-interface layer for protecting a zinc metal anode, characterized in that: It comprises a zinc-loving tin metal interface layer covering the surface of a zinc metal anode and a zinc-repellent boron nitride interface layer covering the tin metal interface layer.
2. The dual-interface layer for protecting a zinc metal anode according to claim 1, characterized in that: The thickness of the tin interface layer is 1~2 μm, and the thickness of the boron nitride interface layer is 5~10 μm.
3. The dual-interface layer for protecting a zinc metal anode according to claim 1, characterized in that: The tin interface layer is prepared by in-situ chemical reaction.
4. The dual-interface layer for protecting a zinc metal anode according to claim 1, characterized in that: The boron nitride interface layer is prepared by coating.
5. A dual-interface layer for protecting a zinc metal anode according to claim 3, characterized in that: The in-situ chemical reaction involves a displacement reaction between the zinc metal anode and a soluble tin salt.
6. A dual-interface layer for protecting a zinc metal anode according to claim 5, characterized in that: The soluble tin salt is tin tetrachloride.
7. A dual-interface layer for protecting a zinc metal anode according to claim 6, characterized in that: The concentration of tin tetrachloride is 0.01 to 0.1 mol per liter.
8. A zinc metal battery, comprising a zinc metal negative electrode, characterized in that: The zinc metal anode comprises a zinc-loving tin metal interface layer covering the surface of the zinc metal anode and a zinc-repellent boron nitride interface layer covering the tin metal interface layer.
9. A zinc metal battery according to claim 8, characterized in that: The thickness of the tin interface layer is 1~2 μm, and the thickness of the boron nitride interface layer is 5~10 μm.
10. A zinc metal battery according to claim 8, characterized in that: The tin interface layer is prepared by in-situ chemical reaction; the boron nitride interface layer is prepared by coating.