Nanometer flower-shaped layered hydroxide material as well as preparation method and application thereof
By preparing nano-flower-like NiMnFe-LDH materials, the problem of structural instability of layered hydroxides in aqueous zinc-ion batteries was solved, achieving high stability and excellent electrochemical performance, and improving the cycle life and capacity retention of the battery.
Patent Information
- Application Number
- CN202511796618.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-12-02
- Publication Date
- 2026-02-10
AI Technical Summary
Existing layered hydroxide cathode materials are structurally unstable in aqueous zinc-ion batteries, resulting in poor cycle performance. They also suffer from problems such as easy collapse of the layered structure, limited ion transport, and loss of metal ions.
By controlling the metal ratio and reaction conditions, nano-flower-like NiMnFe-LDH was prepared using a urea-assisted hydrothermal method, forming a stable layered structure, enhancing ion transport channels and electronic conductivity, and mitigating structural collapse caused by volume changes.
It significantly improves the cycle stability and electrochemical performance of the material, thereby enhancing the long-term energy storage performance and lifespan of aqueous zinc-ion batteries.
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Figure CN121494099A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of battery materials technology, specifically to a nano-flower-like layered hydroxide material, its preparation method, and its application. Background Technology
[0002] In recent years, with the rapid development of renewable energy and the continuous growth of grid energy storage demand, safe, low-cost, and environmentally friendly secondary battery systems have become a research hotspot in the field of energy storage. Among them, aqueous zinc-ion batteries (ZIBs), which are highly safe, low-cost, and environmentally friendly, have attracted widespread attention. Due to the high theoretical capacity (820 mAh•g⁻¹) and low redox potential (-0.76 V vs. SHE) of the zinc metal anode, it has broad application prospects in the field of electrochemical energy storage. However, the overall performance of the battery largely depends on the structural stability and electrochemical reversibility of the cathode material.
[0003] Among numerous cathode materials, layered double hydroxides (LDHs) have become a research hotspot due to their layered structure, tunable chemical composition, and reversible ion exchange performance. LDHs consist of a lamellar structure formed by divalent and trivalent metal cations bridged by hydroxyl groups, with anions and water molecules that can be inserted between the layers, providing a feasible channel for the insertion and extraction of Zn²⁺. By controlling the metal composition (such as Ni, Mn, Fe, Co, Zn, Al, etc.) and the interlayer anions, LDH materials exhibit high electrochemical activity and designability in aqueous batteries.
[0004] However, insufficient cycle stability is a key problem currently facing LDH-type cathode materials. Although various LDH preparation methods (such as co-precipitation, hydrothermal, and electrochemical deposition) have been used to construct LDH materials with different morphologies and compositions, the layered structure is still prone to collapse or delamination during long-term cycling. This is because during repeated Zn²⁺ intercalation and deintercalation, the LDH interlayer structure is easily affected by volume expansion and ionic stress, causing changes in interlayer spacing, structural collapse, or phase transformation, resulting in rapid capacity decay. It can be seen that the morphology and structure have a significant impact on stability.
[0005] In summary, existing layered hydroxide cathode materials exhibit unstable layered structures during the charge-discharge process of aqueous zinc-ion batteries, resulting in poor cycle performance. Therefore, constructing LDH materials with stable layered structures and excellent ion transport channels through reasonable composition control and morphology design is crucial for improving their cycle stability and achieving high-performance energy storage applications.
[0006] Therefore, there is an urgent need to develop a layered hydroxide material with high structural stability and excellent cycling performance to significantly improve the structural retention and electrochemical stability of aqueous zinc-ion battery cathodes during long-term cycling. Summary of the Invention
[0007] The purpose of this invention is to provide a nano-flower-like layered hydroxide material, its preparation method, and its application, in order to solve the problems mentioned in the background art.
[0008] To achieve the above objectives, the embodiments of the present invention provide the following technical solutions: A method for preparing a nano-flower-like layered hydroxide material includes the following steps: 1) Weigh Ni(NO3)2•6H2O, MnSO4•H2O and Fe(NO3)3•9H2O, add them to deionized water respectively, stir to dissolve, and obtain the first mixed solution; 2) Add the precipitant to the first mixed solution and stir until completely dissolved to obtain the second mixed solution; 3) Transfer the second mixed solution to the reaction vessel, and place the reaction vessel in a drying oven for heating to carry out the hydrothermal reaction; 4) After the hydrothermal reaction is completed, the product is naturally cooled to room temperature. The reaction product is then centrifuged to obtain the precipitate. The precipitate is washed with deionized water and anhydrous ethanol. 5) The washed precipitate was dried to obtain nano-flower-like NiMnFe-LDH.
[0009] As a preferred embodiment, the total metal ion concentration in the first mixed solution is 0.1-0.2 mol•L. -1 .
[0010] As a more preferred embodiment, the molar ratio of Ni, Mn and Fe ions in the first mixed solution is 6:X:Y, where 0 < X ≤ 3 and 0 < Y ≤ 3.
[0011] As a more preferred embodiment, in step 1), the amount of deionized water used is 40-70 mL; in step 2), the precipitant is urea, and the amount of urea used is 0.4-1.2 g.
[0012] As a more preferred embodiment, in step 3), the heating is performed at a temperature of 130-180°C for 6-12 hours.
[0013] As a more preferred embodiment, in step 5), the drying process is to dry at a temperature of 60-80°C for 8-12 hours.
[0014] As a more preferred option, in step 4), the precipitate is washed alternately with deionized water and anhydrous ethanol for a total of 4 washes.
[0015] As a more preferred embodiment, in step 3), the reactor is a stainless steel reactor lined with polytetrafluoroethylene, and the drying box is a forced-air drying box; in step 5), a vacuum drying box is used for drying.
[0016] This invention also provides a nano-flower-like layered hydroxide material, prepared by the above-described method for preparing nano-flower-like layered hydroxide materials. This invention also provides the application of the above-mentioned nano-flower-like layered hydroxide material as a positive electrode material for aqueous zinc-ion batteries.
[0017] The beneficial effects of the embodiments of the present invention are: The nano-flower-like layered hydroxide material prepared by this invention has the following significant advantages and technical effects: 1. Significantly improved structural stability; 2. Synergistic effect of multiple metal ions, enhancing valence state stability; 3. Flower-like nanostructure promotes ion and electron transport; 4. Excellent electrochemical performance; 5. The preparation method of this nano-flower-like layered hydroxide material is simple, mild, and easy to scale up. Attached Figure Description
[0018] Figure 1 This is a SEM image of the nanoflower-like layered hydroxide material according to an embodiment of the present invention.
[0019] Figure 2 The image shows the XRD pattern of the nanoflower-like layered hydroxide material according to an embodiment of the present invention.
[0020] Figure 3 This is a rate performance diagram of a battery assembled using the nanoflower-like layered hydroxide material according to an embodiment of the present invention.
[0021] Figure 4 The diagram shows the charge-discharge cycle performance of a battery assembled using the nanoflower-like layered hydroxide material according to an embodiment of the present invention. Detailed Implementation
[0022] Although layered bimetallic hydroxides (LDHs) have been widely studied as cathode materials for aqueous zinc-ion batteries due to their tunable structure and good reversible zinc storage, existing technologies still suffer from the following major drawbacks: 1. Poor structural stability and short cycle life: During repeated Zn²⁺ intercalation and deintercalation, the interlayer structure of LDHs is easily affected by volume expansion and ionic stress, leading to unstable interlayer spacing, structural collapse, or peeling, resulting in rapid capacity decay. 2. Unstable valence states of transition metal ions: During long-term charge-discharge cycles, some Mn or Fe ions are prone to dissolution or disproportionation reactions, resulting in the loss of active centers and reducing the electrochemical reversibility of the material. 3. Insufficient conductivity and uneven reaction: As LDHs are ionic insulating structures, electron transport is limited, and the electrode reaction areas are unevenly distributed, further exacerbating local structural degradation and reducing cycle stability. 4. Unreasonable morphology and structure: Traditional LDHs are mostly plate-like or block-like structures with low specific surface area and insufficient porosity, which is not conducive to electrolyte wetting and ion diffusion, and makes it difficult to buffer stress changes generated during charge-discharge processes.
[0023] Therefore, the existing layered hydroxides still have insufficient cycle stability in aqueous zinc-ion batteries, which limits their application in high-performance energy storage devices.
[0024] To address the problems of poor structural stability, easy loss of metal ions, and short cycle life of existing layered hydroxides, the present invention aims to: 1. Provide a method for preparing nanoflower-like layered hydroxides, achieving the formation of a nanoflower-like self-assembled structure by controlling the metal ratio, reaction temperature, and precipitation kinetics; this structure can effectively alleviate the structural collapse problem caused by volume changes during cycling. 2. Stabilize the metal valence state and enhance interlayer bonding through multi-metal synergistic effects (Ni–Mn–Fe) and anion regulation, thereby improving the structural retention and electrochemical reversibility of the material during long-cycle charge-discharge. 3. Improve the conductivity and ion diffusion rate of the material; by constructing a high specific surface area flower-like nanostructure, promote full electrolyte wetting and rapid electron transport, fundamentally improving the reaction uniformity and stability of the electrode.
[0025] Through the above measures, the nano-flower-like NiMnFe-LDH prepared by this invention exhibits excellent cycle stability and high capacity retention in aqueous zinc-ion batteries, which can significantly improve the long-term energy storage performance and service life of the battery.
[0026] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.
[0027] All reagents used in the following examples are commercially available.
[0028] The present invention provides a method for preparing a nano-flower-like layered hydroxide material, comprising the following steps: 1) Weigh out Ni(NO3)2•6H2O, MnSO4•H2O, and Fe(NO3)3•9H2O, and add them separately to 40-70 mL of deionized water. Stir to dissolve and obtain the first mixed solution. The total metal ion concentration in the first mixed solution is 0.1-0.2 mol•L. -1 The molar ratio of Ni, Mn and Fe ions in the first mixed solution is 6:X:Y, where 0 < X ≤ 3 and 0 < Y ≤ 3. 2) Add a precipitant to the first mixed solution and stir until completely dissolved to obtain a second mixed solution. Preferably, the precipitant is urea, and the amount of urea used is 0.4-1.2g. 3) Transfer the second mixed solution to a reaction vessel and place the reaction vessel in a drying oven. Heat at 130-180℃ for 6-12 hours to carry out a hydrothermal reaction. During the reaction, urea slowly decomposes to produce hydroxide ions (OH-). - In a mild alkaline environment, the synergistic deposition of Ni, Mn and Fe elements is achieved, which promotes the self-assembly growth of nanoflower-like layered hydroxides. Preferably, the reactor is a stainless steel reactor with a polytetrafluoroethylene liner, and the drying oven is a forced-air drying oven. 4) After the hydrothermal reaction is completed, the product is naturally cooled to room temperature. The reaction product is then centrifuged to obtain a precipitate. The precipitate is washed with deionized water and anhydrous ethanol to remove residual impurities. Preferably, the precipitate is washed alternately with deionized water and anhydrous ethanol for a total of 4 washes. 5) Place the washed precipitate in a vacuum drying oven and dry it at 60-80℃ for 8-12 hours to obtain the final product, nano-flower-like NiMnFe-LDH.
[0029] This invention also provides nanoflower-like layered hydroxide materials prepared using the above-described preparation method.
[0030] This invention also provides the use of the above-mentioned nano-flower-like layered hydroxide material as a cathode material for aqueous zinc-ion batteries. This nano-flower-like NiMnFe-LDH exhibits excellent cycle stability and high capacity retention in aqueous zinc-ion batteries, significantly improving the long-term energy storage performance and lifespan of the battery. Example
[0031] Weigh out Ni(NO3)2•6H2O, MnSO4•H2O, and Fe(NO3)3•9H2O, and add them separately to 40 mL of deionized water. Stir to dissolve and obtain a first mixed solution. The total metal ion concentration in the first mixed solution is 0.1 mol•L. -1 The first mixed solution has a Ni, Mn, and Fe ion molar ratio of 6:1:3. Urea is added to the first mixed solution as a precipitant, with an amount of 0.4 g of urea. The mixture is stirred until completely dissolved to obtain a second mixed solution. The second mixed solution is transferred to a stainless steel reactor lined with polytetrafluoroethylene, and the reactor is placed in a forced-air drying oven and heated at 130°C for 12 hours to carry out a hydrothermal reaction. After the hydrothermal reaction is completed, the mixture is naturally cooled to room temperature. The reaction product is centrifuged to obtain a precipitate, which is then washed alternately with deionized water and anhydrous ethanol four times to remove residual impurities. The washed precipitate is placed in a vacuum drying oven and dried at 60°C for 12 hours to obtain the final product, nano-flower-like NiMnFe-LDH. Example
[0032] Weigh out Ni(NO3)2•6H2O, MnSO4•H2O, and Fe(NO3)3•9H2O, and add them separately to 50 mL of deionized water. Stir to dissolve and obtain a first mixed solution. The total metal ion concentration in the first mixed solution is 0.12 mol•L. -1 The first mixed solution has a Ni, Mn, and Fe ion molar ratio of 6:2:1. Urea is added to the first mixed solution as a precipitant, with an amount of 0.6 g of urea. The mixture is stirred until completely dissolved to obtain a second mixed solution. The second mixed solution is transferred to a stainless steel reactor lined with polytetrafluoroethylene (PTFE), and the reactor is placed in a forced-air drying oven and heated at 140°C for 10 hours for a hydrothermal reaction. After the hydrothermal reaction, the mixture is allowed to cool naturally to room temperature. The reaction product is centrifuged to obtain a precipitate, which is then washed alternately with deionized water and anhydrous ethanol four times to remove residual impurities. The washed precipitate is placed in a vacuum drying oven and dried at 65°C for 10 hours to obtain the final product, nano-flower-like NiMnFe-LDH. Example
[0033] Weigh out Ni(NO3)2•6H2O, MnSO4•H2O and Fe(NO3)3•9H2O, and add them separately to 55 mL of deionized water. Stir to dissolve and obtain the first mixed solution. The total metal ion concentration in the first mixed solution is 0.15 mol•L. -1The first mixed solution has a Ni, Mn, and Fe ion molar ratio of 6:1.5:1.5. Urea is added to the first mixed solution as a precipitant at a concentration of 0.8 g, and stirred until completely dissolved to obtain a second mixed solution. The second mixed solution is transferred to a stainless steel reactor lined with polytetrafluoroethylene, and the reactor is placed in a forced-air drying oven and heated at 155°C for 9 hours for hydrothermal reaction. After the hydrothermal reaction, the mixture is naturally cooled to room temperature, and the reaction product is centrifuged to obtain a precipitate. The precipitate is then washed alternately with deionized water and anhydrous ethanol for a total of 4 washes to remove residual impurities. The washed precipitate is placed in a vacuum drying oven and dried at 70°C for 10 hours to obtain the final product, nano-flower-like NiMnFe-LDH. Example
[0034] Weigh out Ni(NO3)2•6H2O, MnSO4•H2O, and Fe(NO3)3•9H2O, and add them separately to 60 mL of deionized water. Stir to dissolve and obtain a first mixed solution. The total metal ion concentration in the first mixed solution is 0.18 mol•L. -1 The first mixed solution has a Ni, Mn, and Fe ion molar ratio of 6:2:3. Urea is added to the first mixed solution as a precipitant, with an amount of 1g of urea. The mixture is stirred until completely dissolved to obtain a second mixed solution. The second mixed solution is transferred to a stainless steel reactor lined with polytetrafluoroethylene, and the reactor is placed in a forced-air drying oven and heated at 170°C for 7 hours to carry out a hydrothermal reaction. After the hydrothermal reaction is completed, the mixture is naturally cooled to room temperature. The reaction product is centrifuged to obtain a precipitate, which is then washed alternately with deionized water and anhydrous ethanol for a total of 4 washes to remove residual impurities. The washed precipitate is placed in a vacuum drying oven and dried at 70°C for 9 hours to obtain the final product, nano-flower-like NiMnFe-LDH. Example
[0035] Weigh out Ni(NO3)2•6H2O, MnSO4•H2O, and Fe(NO3)3•9H2O, and add them separately to 70 mL of deionized water. Stir to dissolve and obtain a first mixed solution. The total metal ion concentration in the first mixed solution is 0.2 mol•L. -1The first mixed solution has a Ni, Mn, and Fe ion molar ratio of 6:3:1. Urea is added to the first mixed solution as a precipitant, with an amount of 1.2 g of urea. The mixture is stirred until completely dissolved to obtain a second mixed solution. The second mixed solution is transferred to a stainless steel reactor lined with polytetrafluoroethylene, and the reactor is placed in a forced-air drying oven and heated at 180°C for 6 hours to carry out a hydrothermal reaction. After the hydrothermal reaction is completed, the mixture is naturally cooled to room temperature. The reaction product is centrifuged to obtain a precipitate, which is then washed alternately with deionized water and anhydrous ethanol for a total of 4 washes to remove residual impurities. The washed precipitate is placed in a vacuum drying oven and dried at 80°C for 8 hours to obtain the final product, nano-flower-like NiMnFe-LDH.
[0036] Experimental Example 1 The nanoflower-like NiMnFe-LDH prepared in Example 3 was analyzed using SEM, and the obtained SEM images are shown below. Figure 1 As shown, this NiMnFe-LDH is a three-dimensional flower-like structure assembled from ultrathin nanosheets, which significantly increases the specific surface area and porosity of the material. After being assembled into a battery, it is beneficial for electrolyte penetration and Zn 2+ The spread of.
[0037] Experiment Example 2 X-ray diffraction (XRD) was performed on the nanoflower-like NiMnFe-LDH prepared in Example 3, and the obtained XRD pattern is shown below. Figure 2 As shown, a comparison with the standard PDF card (PDF#40-0215) reveals that the synthesized NiMnFe-LDH material possesses a hydrotalcite-like crystal structure similar to NiFe-LDH, exhibiting a typical layered structure.
[0038] Experimental Example 3 The specific steps for assembling a battery using the nanoflower-like NiMnFe-LDH prepared in Example 3 are as follows: 1) Slurry preparation First, weigh 200 mg of Nafion membrane solution and put it into a small bottle for later use. Weigh 80 mg of nano-flower-shaped NiMnFe-LDH and 10 mg of acetylene black as a conductive agent. After mixing them thoroughly, add them to the small bottle, add an appropriate amount of anhydrous ethanol, and stir overnight for later use.
[0039] 2) Electrode preparation The pre-prepared slurry is evenly applied to the pre-treated carbon cloth, dried in a vacuum drying oven, and weighed to ensure that the amount of active material is about 1 mg.
[0040] 3) Battery assembly The battery is assembled in the following order: positive electrode shell, electrode sheet, separator, electrolyte (1M ZnSO4 + 0.1M MnSO4), negative electrode sheet (commercial zinc sheet), gasket, spring sheet, and negative electrode shell. After assembly on the battery assembly machine, it can be used for testing.
[0041] Experiment Example 4 The performance of the battery assembled in Experiment Example 3 was tested, and the results are as follows: Figure 3 and Figure 4 As shown, when the nano-flower-like NiMnFe-LDH is used as the positive electrode material in an aqueous zinc-ion battery, NiMnFe-LDH exhibits excellent cycle stability and high capacity performance. At 0.1 A•g -1 Achieving a current density of 300 mAh•g -1 Specific capacity ( Figure 3 ), while at 1A•g -1 After 10,000 cycles at a current density, the capacity retention rate can reach over 85%. Figure 4 ).
[0042] This nanoflower-like NiMnFe-LDH exhibits multi-metal synergistic effects, with Ni, Mn, and Fe metal ions synergistically distributed within the layers. 3+ The presence of Mn inhibits the Jahn-teller effect, alleviates metal dissolution, enhances the stability of the layered structure, and suppresses the structural collapse problem of the material during charging and discharging, thereby improving the overall structural stability and cycle life.
[0043] The nano-flower-like layered hydroxide material prepared by this invention has the following significant advantages and technical effects: 1. Structural stability is significantly improved By controlling the precipitation rate through a urea slow-release method, Ni, Mn, and Fe metal ions are synergistically co-deposited to form an ordered layered structure, which ultimately self-assembles into a flower-like nanostructure. This structure can effectively buffer Zn during charge and discharge processes. 2+ The volume change caused by insertion and extraction prevents interlayer collapse and crystal phase transformation, thereby significantly improving cycle stability.
[0044] 2. Synergistic effect of multiple metal ions enhances valence stability. In traditional Mn-based layered hydroxides, Mn 3+ The presence of significant Jahn-Teller distortion in Mn ions easily leads to lattice distortion and Mn dissolution, resulting in capacity decay. This invention introduces Ni and Fe elements to modulate the electronic structure of the layers, making the valence state changes of Mn during charging and discharging more gradual and significantly reducing the lattice distortion caused by the Jahn-Teller effect. Simultaneously, Fe... 3+Its stable valence state can act as an "electronic buffer" during charging and discharging, improving the overall structural stability and cycle life.
[0045] 3. Flower-like nanostructures promote ion and electron transport. The flower-like structure is composed of numerous ultrathin nanosheets, forming a hierarchical porous network that significantly increases the electrode's specific surface area and improves electrolyte wettability and Zn. 2+ Increase diffusion rate, reduce ion transport impedance, and improve rate performance.
[0046] 4. Excellent electrochemical performance When this material is used as the positive electrode in aqueous zinc-ion batteries, at 1 A•g -1 The capacity retention rate exceeds 85% after 10,000 cycles at current density, and it can still maintain good charge and discharge stability and high specific capacity at multiple rates.
[0047] 5. The process is simple, the conditions are mild, and it is easy to scale up. This invention employs a urea-assisted hydrothermal method, which requires no expensive equipment or complex templates, has mild reaction conditions (130-180℃), and uses inexpensive and readily available raw materials, making it suitable for large-scale preparation and industrialization.
[0048] Based on the above-described preferred embodiments of the present invention, and through the foregoing description, those skilled in the art can make various changes and modifications without departing from the inventive concept. The technical scope of this invention is not limited to the contents of the specification.
Claims
1. A method for preparing a nano-flower-like layered hydroxide material, characterized in that, Includes the following steps: 1) Weigh Ni(NO3)2•6H2O, MnSO4•H2O and Fe(NO3)3•9H2O, add them to deionized water respectively, stir to dissolve, and obtain the first mixed solution; 2) Add the precipitant to the first mixed solution and stir until completely dissolved to obtain the second mixed solution; 3) Transfer the second mixed solution to the reaction vessel, and place the reaction vessel in a drying oven for heating to carry out the hydrothermal reaction; 4) After the hydrothermal reaction is completed, the product is naturally cooled to room temperature. The reaction product is then centrifuged to obtain the precipitate. The precipitate is washed with deionized water and anhydrous ethanol. 5) The washed precipitate was dried to obtain nano-flower-like NiMnFe-LDH.
2. The method for preparing the nano-flower-like layered hydroxide material according to claim 1, characterized in that, The total metal ion concentration in the first mixed solution is 0.1-0.2 mol•L. -1 .
3. The method for preparing the nano-flower-like layered hydroxide material according to claim 2, characterized in that, The molar ratio of Ni, Mn and Fe ions in the first mixed solution is 6:X:Y, where 0 < X ≤ 3 and 0 < Y ≤ 3.
4. The method for preparing the nano-flower-like layered hydroxide material according to claim 1, characterized in that, In step 1), the amount of deionized water used is 40-70 mL; in step 2), the precipitant is urea, and the amount of urea used is 0.4-1.2 g.
5. The method for preparing the nano-flower-like layered hydroxide material according to claim 1, characterized in that, In step 3), the heating is performed at a temperature of 130-180°C for 6-12 hours.
6. The method for preparing the nano-flower-like layered hydroxide material according to claim 1, characterized in that, In step 5), the drying process is to dry at a temperature of 60-80°C for 8-12 hours.
7. The method for preparing the nano-flower-like layered hydroxide material according to claim 1, characterized in that, In step 4), the precipitate is washed alternately with deionized water and anhydrous ethanol for a total of 4 washes.
8. The method for preparing the nano-flower-like layered hydroxide material according to claim 1, characterized in that, In step 3), the reactor is a stainless steel reactor with a polytetrafluoroethylene liner, and the drying box is a forced-air drying box; in step 5), a vacuum drying box is used for drying.
9. A nano-flower-like layered hydroxide material, characterized in that, It is prepared by the preparation method of the nanoflower-like layered hydroxide material according to any one of claims 1-8.
10. The application of the nano-flower-like layered hydroxide material as described in claim 9 as a cathode material for aqueous zinc-ion batteries.