Preparation method and application of flexible zinc ion battery electrode

Abstract

The invention discloses a method for constructing a flexible zinc ion battery electrode through plasma-assisted multi-step light irradiation sintering and application of the flexible zinc ion battery electrode. According to the method, NiSe-coated MXene positive electrode slurry and zinc powder negative electrode slurry are prepared, and low-temperature plasma surface modification is combined, so that the wettability and interface bonding force of the flexible substrate are improved; and then, constructing an interdigital unsintered electrode by adopting direct-writing ink-jet printing, and introducing a multi-step light irradiation sintering process with gradually increased energy density to realize controllable sintering of the electrode material from glue discharging and necking to deep densification. The photothermal conversion characteristic of NiSe-coated MXene is fully utilized in multi-step light irradiation sintering, rapid interconnection is achieved under the low heat load condition, and solvent burst and substrate heat damage are effectively avoided. The prepared flexible zinc ion battery has low resistance, high specific capacity, good cycling stability and excellent mechanical flexibility, and is suitable for the field of flexible energy storage devices.

Description

Technical Field

[0001] This invention belongs to the field of flexible energy storage device manufacturing technology, specifically relating to a method for constructing NiSe@MXene flexible zinc-ion battery electrodes using plasma surface modification combined with a multi-step photo-irradiation sintering process and its application. Background Technology

[0002] With the rapid development of wearable electronic devices, electronic skin, and medical health monitoring technologies, higher demands are being placed on flexible and miniaturized energy storage systems to match these technologies. Aqueous zinc-ion batteries, due to their high theoretical specific capacity (820mAh / g), low cost, environmental friendliness, and high safety, are considered one of the most promising power systems in the field of flexible energy storage.

[0003] Traditional coating processes struggle to meet the demands of microscale, patterned, and customized manufacturing. 3D printing technologies such as direct-write inkjet printing and electrohydraulic inkjet printing, however, enable high-precision structural designs and are suitable for the integrated manufacturing of flexible devices. Nevertheless, existing flexible printed electrodes still face challenges such as poor substrate interface wettability and limitations in sintering processes. Commonly used flexible substrate materials are chemically inert and hydrophobic, making them prone to shrinkage and line breakage when directly printing aqueous or polar solvent slurries. This results in low electrode resolution, poor adhesion, and affects the stability of devices under bending conditions. Furthermore, residual solvents and insulating binders in the printed electrodes require sintering to form a conductive network. Traditional thermal sintering is time-consuming and prone to damaging the flexible substrate. Existing one-step high-energy light irradiation sintering methods, under thick-film conditions, easily trigger severe solvent vaporization, causing blistering, cracking, or detachment of the film.

[0004] In the field of electrode materials, two-dimensional transition metal carbides / nitrides (MXenes) have attracted widespread attention in flexible energy storage due to their high conductivity, good flexibility, and excellent dispersibility. Their surfaces are rich in polar functional groups, making them suitable for preparing high-concentration printable inks. Simultaneously, MXenes exhibit excellent light absorption in the visible to near-infrared bands, enabling efficient photothermal conversion during photo-irradiation sintering, thus promoting electrode densification and conductive network formation without damaging the flexible substrate. However, single MXene electrodes are prone to interlayer stacking, limiting ion transport channels and resulting in relatively low specific capacity. To improve electrode capacity, MXenes are often combined with transition metal chalcogenides. Among them, nickel selenide possesses strong metallicity and abundant electrochemical active sites, resulting in a theoretically high capacity. However, current technologies for combining nickel selenide with MXene and applying it to fully printed flexible zinc-ion batteries still face technical challenges such as ink rheological property control, interfacial bonding stability, and low-temperature rapid sintering, requiring new material design and preparation methods to address these challenges. Summary of the Invention

[0005] In summary, the purpose of this invention is to overcome the shortcomings of the prior art and provide a method for preparing a flexible zinc-ion battery electrode and its application, aiming to fully leverage the high electrochemical performance of NiSe and the photothermal synergistic advantages of MXene, and solve the problems of flexible interface bonding and non-destructive densification.

[0006] The first aspect of this invention provides a method for preparing a flexible zinc-ion battery electrode, comprising the following steps: S1: Configure NiSe@MXene positive electrode paste and zinc metal negative electrode paste; Specifically, the following steps are included: S11: The NiSe@MXene composite material is thoroughly mixed with conductive agent, binder and solvent to prepare a paste-like printable NiSe@MXene cathode slurry; S12: Zinc powder is thoroughly mixed with conductive agent, binder and solvent to prepare a paste-like printable zinc powder negative electrode slurry.

[0007] S2: Flexible substrate modified by low-temperature plasma technology; A hydrophilic flexible substrate was obtained by surface treatment of a flexible substrate using low-temperature plasma technology.

[0008] S3: Direct-write inkjet printing of unsintered interdigitated electrodes; Specifically, the following steps are included: S31: On the hydrophilic flexible substrate described in step S2, silver paste is printed using direct-write inkjet printing technology to form interdigitated electrode current collectors; S32: Select one end of the interdigitated electrode current collector in step S31, and use direct writing inkjet printing technology to print the NiSe@MXene cathode slurry prepared in step S11 on its surface to construct an unsintered NiSe@MXene cathode; S33: Select the other end of the interdigital electrode current collector in step S31, and use direct-write inkjet printing technology to print the zinc powder negative electrode slurry prepared in step S12 on its surface to construct an unsintered zinc negative electrode and obtain an unsintered interdigital electrode.

[0009] S4: Multi-step light irradiation sintering preparation of flexible zinc-ion battery electrodes; The unsintered interdigitated electrode described in step S3 is placed in a pulsed intense light sintering device, and a flexible zinc-ion battery electrode is obtained by sintering it using a multi-step light irradiation sintering method with progressively increasing energy density.

[0010] Furthermore, the NiSe@MXene composite material described in step S11 comprises MXene sheets and NiSe particles uniformly loaded on their surface. The MXene sheets have a layered structure, with an average thickness of 1–3 nm for each MXene layer. The NiSe particles exhibit a hexagonal crystal structure, with a particle size distribution of 50–200 nm and a loading of 0.8–2.5 mg / cm³. 2 .

[0011] Furthermore, the conductive agent in step S11 is one or more of activated carbon, carbon black, graphene, or carbon nanotubes; the binder is polyvinylidene fluoride or carboxymethyl cellulose; and the solvent is N-methylpyrrolidone.

[0012] Furthermore, in step S11, the mass ratio of the NiSe@MXene composite material to the conductive agent and the binder is 7-8:1-2:1.

[0013] Furthermore, the NiSe@MXene cathode slurry described in step S11 has a viscosity of 15–50 mPa·s and a solid content of 15–25% to ensure smoothness and uniformity of deposition during the printing process.

[0014] Furthermore, the zinc powder mentioned in step S12 is spherical micron-sized zinc powder with an average particle size of 20–100 μm.

[0015] Furthermore, the conductive agent in step S12 is one or more of activated carbon, carbon black, graphene, or carbon nanotubes; the binder is polyvinylidene fluoride or carboxymethyl cellulose; and the solvent is N-methylpyrrolidone.

[0016] Furthermore, in step S12, the mass ratio of zinc powder to conductive agent and binder is 8-9:0.5-1:0.5-1.

[0017] Furthermore, the flexible substrate material mentioned in step S2 is PET, PI, or PDMS.

[0018] Furthermore, the specific process of the low-temperature plasma technology described in step S2 is as follows: the processing power is 100-300 W, the gas flow rate is 20-80 sccm, the cavity pressure is 10-40 Pa, the processing time is 30-120 s, and the working gas is one or more of argon and oxygen.

[0019] Furthermore, the specific parameters for direct-write inkjet printing in step S3 are as follows: nozzle inner diameter is 200–400 μm, printing speed is 2–10 mm / s, direct-write air pressure is 1–5 MPa, and substrate temperature is 30–50°C.

[0020] Furthermore, the finger spacing of the interdigitated electrode current collector in step S31 is 350-500 μm, and the linewidth is 400-600 μm.

[0021] Furthermore, the multi-step photo-irradiation sintering described in step S4 includes three stages with progressively increasing energy: the first stage has a photo-irradiation energy density of 5–10 J / cm². 2 The irradiation voltage is 500-550V, the pulse width is 1-3 ms, and the number of irradiations is 1-3 times; the irradiation energy density in the second stage is 12-18 J / cm³. 2 The irradiation voltage is 650-700V, the pulse width is 3-6 ms, and the number of irradiations is 2-4 times; the energy density of the third stage irradiation is 20-32 J / cm³. 2 The irradiation voltage is 800-850V, the pulse width is 5-10 ms, and the number of irradiations is 3-5 times, so as to achieve the stepwise sintering and densification of the electrode material.

[0022] A second aspect of this invention provides a flexible zinc-ion battery, characterized in that it is assembled using electrodes prepared by the method described in the first aspect. The battery has a fully printed, integrated interdigitated structure, exhibiting excellent mechanical flexibility and electrochemical performance.

[0023] The beneficial effects of this invention are as follows: This invention selects NiSe@MXene as the positive electrode active material for flexible zinc-ion batteries. NiSe has a hexagonal crystal structure and metal-like conductivity, with low electron transport impedance. When combined with MXene, which has high conductivity, to form a composite structure, a continuous and efficient electron transport network can be created, enabling the electrode to maintain rapid charge transfer capability under high-rate charge-discharge conditions. Simultaneously, the reversible multivalent state reaction of Ni2+ / Ni3+ in NiSe endows it with a high theoretical specific capacity, which is beneficial for improving the energy density of the battery.

[0024] This invention utilizes low-temperature plasma to modify the surface of a flexible substrate, effectively breaking C-H bonds on the substrate surface and introducing hydrophilic functional groups such as -OH, -COOH, and -C=O. This increases the surface energy from < 40 mN / m to > 70 mN / m, effectively suppressing shrinkage and dewetting of the conductive paste during printing, resulting in more continuous, smooth, and clearly defined printed lines. Simultaneously, the introduced active functional groups can form hydrogen bonds or chemical bonds with binder molecules in the electrode paste, significantly enhancing the interfacial bonding between the electrode film and the flexible substrate, and improving the structural stability and reliability of the flexible electrode under bending, stretching, and other deformation conditions.

[0025] This invention employs direct-write inkjet printing technology to directly construct unsinterlocked interdigitated electrode structures, achieving integrated forming of positive and negative electrode patterns. This method eliminates the need for complex processes such as photolithography, masking, or wet etching, offering advantages such as simplified workflow, high material utilization, and strong pattern design flexibility, making it particularly suitable for the rapid fabrication of flexible electronic devices. The unsinterlocked interdigitated electrodes formed through direct-write printing allow for precise control of electrode spacing and linewidth, providing a uniform, continuous, and repeatable microstructure foundation for subsequent photo-irradiation sintering.

[0026] MXene exhibits strong light absorption across a broad spectral range, while NiSe particles, being dark in color, also possess excellent light absorption properties. Combining these two materials allows for rapid generation of localized heat under light irradiation, forming an "internal photothermal source." This enables the electrode materials to achieve sintering interconnection within millisecond timescales, with heat primarily concentrated in the functional electrode layers, significantly reducing the risk of thermal damage to the flexible substrate. This compatibility not only improves sintering efficiency but also effectively broadens the application scope of photoirradiation sintering in flexible energy storage material systems.

[0027] This invention designs and employs a multi-step photo-irradiation sintering strategy of "resin removal—necking—densification," achieving precise control over the electrode sintering process through progressively increasing energy input. The low-energy stage gently removes solvents and organic components, avoiding pores and microcracks caused by rapid vaporization; the medium-energy stage induces surface softening of nanoparticles and forms preliminary necking connections; the high-energy stage further promotes deep particle interconnection and overall densification based on structural stability. Compared to traditional single-step high-energy sintering methods, this multi-step photo-irradiation sintering process effectively reduces thermal stress concentration, avoids electrode surface cracking and structural damage, resulting in flexible electrodes with lower porosity, a more continuous conductive network, and lower resistivity, with resistivity decreasing by more than 40%.

[0028] This invention achieves the fabrication of flexible zinc-ion battery electrodes under low-temperature, rapid, and high-reliability conditions through synergistic optimization of material design, substrate modification, printing method, and sintering process. It significantly improves the electrical performance, mechanical flexibility, and electrochemical stability of the electrodes, and has good prospects for engineering applications. Attached Figure Description

[0029] Figure 1 Here is a SEM image of the NiSe@MXene composite material in Example 1; Figure 2 The image shows a comparison of the contact angles of NiSe@MXene slurry on a flexible PET substrate in Example 1 (plasma pretreatment) and Comparative Example 3 (without plasma pretreatment). Figure 3 Macroscopic morphology of the unsintered interdigitated electrodes in Example 1 (plasma pretreatment) and Comparative Example 3 (no plasma pretreatment); Figure 4 SEM images of the NiSe@MXene cathode surface in Example 1 (multi-step photo-radiation sintering) and Comparative Example 2 (conventional thermal sintering); Figure 5 Electrode optical microscopy images of Example 1 (multi-step light irradiation sintering) and Comparative Example 2 (conventional hot sintering) (black represents NiSe@MXene positive electrode, silver represents zinc negative electrode); Figure 6 Here is a SEM image of the NiSe@MXene cathode surface in Comparative Example 1 (conventional single-step photo-irradiation sintering); Figure 7 This is a morphology image of the PET flexible substrate after sintering in Comparative Example 2 (conventional hot sintering); Detailed Implementation

[0030] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the specific embodiments of the present invention will be described in detail below with reference to the examples in the specification.

[0031] Many specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways different from those described herein, and those skilled in the art can make similar extensions without departing from the spirit of the invention. Therefore, the invention is not limited to the specific embodiments disclosed below.

[0032] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The phrase "in one embodiment" appearing in different places in this specification does not necessarily refer to the same embodiment, nor is it a single or selective embodiment that excludes other embodiments. Unless otherwise specified, the experimental methods used in the following embodiments are conventional methods. Unless otherwise specified, the materials, reagents, methods, and instruments used are all conventional materials, reagents, methods, and instruments in the art, and can be obtained commercially by those skilled in the art.

[0033] Example 1: A method for preparing a flexible zinc-ion battery electrode includes the following steps: S1: Configure NiSe@MXene positive electrode paste and zinc metal negative electrode paste; Specifically, the following steps are included: S11: Weigh the NiSe@MXene composite material, Super P, and PVDF according to a mass ratio of 7:2:1, add them to the solvent NMP, and stir until homogeneous to obtain a paste-like printable NiSe@MXene cathode slurry with a solid content of 20 wt% and a viscosity of approximately 30 mPa·s. The morphology of the NiSe@MXene composite material is as follows: Figure 1As shown, the NiSe particles have a diameter of approximately 50-100 nm and are uniformly loaded onto MXene sheets.

[0034] S12: Weigh zinc powder, acetylene black, and PVDF according to a mass ratio of 8:1:1, add them to the solvent NMP, and stir evenly to obtain a paste-like printable zinc powder negative electrode slurry.

[0035] S2: Flexible substrate modified by low-temperature plasma technology; A 120 μm thick PET film was selected as a flexible substrate and placed in the processing chamber of a vacuum plasma cleaner. Surface modification was performed under argon gas conditions, with an argon flow rate of 50 sccm, an RF power supply of 150 W, a chamber pressure of 20 Pa, and a processing time of 60 s. After plasma treatment, as shown... Figure 2 As shown, tests using a contact angle meter revealed that the contact angle of the slurry on the PET surface significantly decreased from 135.2° before treatment to 16.41°. This indicates that the substrate surface changed from a hydrophobic state to a highly hydrophilic state, and the surface wettability was significantly improved.

[0036] S3: Direct-write inkjet printing of unsintered interdigitated electrodes; Interdigital electrodes were constructed using a three-axis direct-write inkjet printer with a nozzle diameter of 300 μm and a printing speed of 5 mm / s. The specific steps included: S31: On the hydrophilic flexible substrate described in step S2, silver paste is printed using direct-write inkjet printing technology at a printing pressure of 5 MPa to form an interdigitated electrode current collector with a finger spacing of 400 μm. S32: Select one end of the interdigitated electrode current collector in step S31, and use direct writing inkjet printing technology to print the NiSe@MXene cathode slurry prepared in step S11 on its surface. The printing pressure is 2 MPa to construct an unsintered NiSe@MXene cathode. S33: Select the other end of the interdigitated electrode current collector in step S31, and use direct-write inkjet printing technology to print the zinc powder negative electrode slurry prepared in step S12 onto its surface. The printing pressure is 2 MPa to construct an unsintered zinc negative electrode, thus obtaining an unsintered interdigitated electrode. Figure 3 As shown, thanks to the plasma surface modification treatment described in step S2, the printing paste has good spreading and wetting properties on the flexible substrate surface, the printing lines have straight and clear edges, and there are no obvious shrinkage, broken lines or open circuits. The unsintered interdigitated electrodes with complete structure were successfully constructed.

[0037] S4: Multi-step light irradiation sintering preparation of flexible zinc-ion battery electrodes; The unsintered interdigitated electrode described in step S3 is placed in a pulsed high-intensity light sintering device and sintered using a multi-step light irradiation method with progressively increasing energy density, including the following steps: The first stage of light irradiation voltage is 500 V, and the energy density is 8 J / cm³. 2 The pulse width was 2 ms and the number of irradiations was 2. This stage gently removed the solvent, and the disappearance of the wet gloss on the ink layer surface was observed.

[0038] The second stage of light irradiation voltage is 700 V, and the energy density is 15 J / cm³. 2 The pulse width was 4 ms and the number of irradiations was 3. This stage induced the surface softening of nanoparticles and established a preliminary conductive pathway.

[0039] The third stage of light irradiation voltage is 850 V, and the energy density is 24 J / cm³. 2 The pulse width is 6 ms and the number of irradiations is 4. In this stage, the excellent photothermal conversion effect of MXene and NiSe is utilized to absorb light and generate heat, so as to achieve deep interconnection and densification of active materials and current collectors.

[0040] Testing revealed that the sintered electrode surface was smooth and dense, with its line resistance reduced to 0.7 Ω / cm, indicating a significant improvement in electrode conductivity. Figure 4 As shown, scanning electron microscopy revealed that the NiSe@MXene particles achieved close packing and effective interconnection. No obvious pores caused by solvent evaporation were found inside the electrode, nor were any cracks caused by thermal shock, demonstrating good sintering quality and structural integrity.

[0041] Example 2: This embodiment provides a method for preparing a flexible zinc-ion battery electrode, the steps of which are basically the same as those in Embodiment 1, except that: in step S4, the energy density of the third stage in the multi-step sintering is adjusted to 32 J / cm². 2 Test results show that with further increases in energy density, the density of the electrode material continues to increase, the conductivity of the electrode slightly improves after sintering, and its line resistance further decreases to 0.6 Ω / cm. However, slight thermal deformation and curling of the flexible PET substrate were observed, indicating that the light irradiation energy under these conditions is close to or slightly exceeds the thermal tolerance limit of the substrate, which has a certain impact on the structural stability of the flexible substrate.

[0042] Comparative Example 1 (Conventional single-step photo-irradiation sintering): This comparative example provides a method for preparing a flexible zinc-ion battery electrode, the steps of which are basically the same as those in Example 1, except that in step S4, the multi-step sintering is replaced with a traditional single-step sintering, that is, directly using an energy density of 30 J / cm². 2The electrode was continuously irradiated five times under the light irradiation conditions. Figure 6 As shown, under these sintering conditions, the residual solvent in the electrode rapidly vaporizes and splashes within a short time, resulting in a large number of micron-sized pores and cracks forming on the electrode surface. This damages the structural integrity of the electrode film, and consequently, the conductivity of the electrode decreases significantly after sintering, with a line resistance as high as 5.2 Ω / cm, which is insufficient to meet the application requirements of flexible electrodes.

[0043] Comparative Example 2 (Traditional Hot Sintering): This comparative example provides a method for preparing a flexible zinc-ion battery electrode, the steps of which are basically the same as those in Example 1, except that in step S4, photo-irradiation sintering is replaced with traditional thermal sintering, that is, the unsintered interdigitated electrode is placed in a vacuum oven at 80°C and heated for 12 hours. Figure 4 , 5 As shown, although a certain degree of physical contact and connection is formed on the electrode surface after hot sintering, effective fusion interconnection does not occur between the particles, resulting in a low overall densification degree. Simultaneously, due to prolonged overall heating, the flexible PET substrate exhibits significant warping, such as... Figure 7 As shown, this leads to increased internal stress in the electrode structure, decreased adhesion stability between the electrode film and the substrate, and a risk of peeling.

[0044] Comparative Example 3 (without plasma pretreatment): This comparative example provides a method for preparing a flexible zinc-ion battery electrode, the steps of which are basically the same as those in Example 1, except that step S2 is omitted, i.e., the PET flexible substrate is not subjected to plasma surface modification treatment. Figure 2 As shown, the substrate surface energy is low. During the subsequent printing process, the NiSe@MXene paste exhibits significant shrinkage and dewetting on the PET surface. This makes it difficult for the NiSe@MXene paste to form a continuous and uniform line structure during printing, resulting in a significantly increased short-circuit rate of the interdigitated electrodes. Figure 3 As shown, even when a film layer is formed in a local area, the adhesion between the electrode film layer and the substrate is still weak after the 3M tape adhesion test, and large-area peeling occurs. This indicates that the substrate that has not undergone plasma treatment cannot meet the requirements for high-quality flexible electrode preparation.

[0045] Comparative Example 4: This comparative example provides a method for preparing a flexible zinc-ion battery electrode, the steps of which are basically the same as in Example 1, except that pure NiSe particles are used instead of the NiSe@MXene composite material used in step S11. Experimental results show that although the obtained electrode maintains a complete macroscopic morphology, its intrinsic conductivity is relatively low due to the lack of a highly conductive framework provided by MXene, with an electrode resistance of 145.6 kΩ / cm before sintering. Furthermore, during the photo-irradiation sintering process, the lack of efficient photothermal conversion by MXene leads to insufficient sintering in some areas of the electrode, resulting in microcracks or localized fractures in some locations, affecting the overall structural continuity and electrical performance of the electrode.

[0046] The resistance of the flexible zinc-ion battery electrodes prepared by any one of the methods in Examples 1-2 and Comparative Examples 1-4 was tested before and after sintering. Subsequently, the flexible electrodes prepared above were assembled into flexible zinc-ion batteries (using hydrogel electrolyte), and constant current charge-discharge tests and 100 cycle stability tests were conducted at a rate of 0.2 C. The specific performance data obtained are shown in Table 1.

[0047] Table 1 Comparison of electrode resistance and battery capacity performance between Examples 1-2 and Comparative Examples 1-4 As shown in Table 1, in Example 1, the electrode's line resistance significantly decreased from 125.4 kΩ / cm before sintering to 0.7 Ω / cm after using a process combining plasma surface modification and multi-step photo-irradiation sintering, achieving an effective transition from a high-resistance state to a high-conductivity state. The flexible zinc-ion battery assembled based on this electrode can release a high specific capacity of 282.5 mAh / g at a 0.2 C rate and retains 88.0% of its capacity after 100 cycles, demonstrating excellent electrochemical performance and structural stability. In Example 2, by further increasing the energy density of the third-stage photo-irradiation, the electrode resistance was further reduced to 0.6 Ω / cm. However, the excessively high energy input caused thermal damage to the flexible substrate, affecting the mechanical integrity of the electrode and consequently reducing the battery's cycle stability, with its capacity retention decreasing to 81.5%.

[0048] In contrast, Comparative Example 1, employing a single-step high-energy photo-irradiation sintering process, suffered from internal film cracking due to rapid solvent vaporization, resulting in damaged electrode structure, high resistance, and low specific capacity. Comparative Example 2, using a traditional thermal sintering method, failed to achieve effective molten interconnection between particles, limiting the sintering effect and resulting in the worst electrochemical performance. Furthermore, the results of Comparative Example 3 indicate that plasma surface modification plays a crucial role in the formation of fully printed flexible electrodes; untreated substrates struggle to achieve continuous and stable electrode structures. Comparative Example 4 further validates the dual role of MXene in the composite cathode, not only constructing an efficient electron transport network but also significantly improving photo-irradiation sintering efficiency as a photothermal enhancement component, which is of great significance for improving electrode sintering quality and increasing battery specific capacity.

[0049] Finally, it should be noted that although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A method for preparing a flexible zinc-ion battery electrode, characterized in that, Includes the following steps: S1: Configure NiSe@MXene positive electrode paste and zinc metal negative electrode paste; Specifically, the following steps are included: S11: The NiSe@MXene composite material is thoroughly mixed with conductive agent, binder and solvent to prepare a paste-like printable NiSe@MXene cathode slurry; S12: Zinc powder is thoroughly mixed with conductive agent, binder and solvent to prepare a paste-like printable zinc powder negative electrode slurry; S2: Flexible substrate modified by low-temperature plasma technology; A hydrophilic flexible substrate was obtained by surface treatment of a flexible substrate using low-temperature plasma technology. S3: Direct-write inkjet printing of unsintered interdigitated electrodes; Specifically, the following steps are included: S31: On the hydrophilic flexible substrate described in step S2, silver paste is printed using direct-write inkjet printing technology to form interdigitated electrode current collectors; S32: Select one end of the interdigitated electrode current collector in step S31, and use direct-write inkjet printing technology to print the NiSe@MXene cathode slurry described in step S11 on its surface to construct an unsintered NiSe@MXene cathode; S33: Select the other end of the interdigital electrode current collector in step S31, and use direct writing inkjet printing technology to print the zinc powder negative electrode paste described in step S12 on its surface to construct an unsintered zinc negative electrode and obtain an unsintered interdigital electrode. S4: Multi-step light irradiation sintering preparation of flexible zinc-ion battery electrodes; The unsintered interdigitated electrode described in step S3 is placed in a pulsed intense light sintering device, and a flexible zinc-ion battery electrode is obtained by sintering it using a multi-step light irradiation sintering method with progressively increasing energy density.

2. The method for preparing the flexible zinc-ion battery electrode according to claim 1, characterized in that, The multi-step photo-irradiation sintering described in step S4 includes three stages with progressively increasing energy: the first stage has a photo-irradiation energy density of 5–10 J / cm³. 2 The irradiation voltage is 500-550V, the pulse width is 1-3 ms, and the number of irradiations is 1-3 times; the irradiation energy density in the second stage is 12-18 J / cm³. 2 The irradiation voltage is 650-700V, the pulse width is 3-6 ms, and the number of irradiations is 2-4 times; the energy density of the third stage irradiation is 20-32 J / cm³. 2 The irradiation voltage is 800-850V, the pulse width is 5-10 ms, and the number of irradiations is 3-5 times.

3. The method for preparing the flexible zinc-ion battery electrode according to claim 1, characterized in that, The NiSe@MXene composite material described in step S11 comprises MXene sheets and NiSe particles uniformly loaded on their surface; the MXene sheets have a layered structure with an average thickness of 1–3 nm for each MXene layer, and the NiSe particles exhibit a hexagonal crystal structure with a particle size distribution of 50–200 nm and a loading of 0.8–2.5 mg / cm³. 2 .

4. The method for preparing the flexible zinc-ion battery electrode according to claim 3, characterized in that, The viscosity of the NiSe@MXene cathode slurry described in step S11 is 15–50 mPa·s, and the solid content is 15–25%.

5. The method for preparing the flexible zinc-ion battery electrode according to claim 1, characterized in that, The zinc powder mentioned in step S12 is spherical micron-sized zinc powder with an average particle size of 20-100 μm.

6. The method for preparing the flexible zinc-ion battery electrode according to claim 1, characterized in that, The flexible substrate material is PET, PI, or PDMS.

7. The method for preparing the flexible zinc-ion battery electrode according to claim 6, characterized in that, The specific process of the low-temperature plasma technology described in step S2 is as follows: the processing power is 100-300 W, the gas flow rate is 20-80 sccm, the cavity pressure is 10-40 Pa, the processing time is 30-120 s, and the working gas is one or more of argon and oxygen.

8. The method for preparing the flexible zinc-ion battery electrode according to claim 1, characterized in that, The specific parameters for direct-write inkjet printing in step S3 are: nozzle inner diameter of 200-400 μm, printing speed of 2-10 mm / s, direct-write air pressure of 1-5 MPa, and substrate temperature of 30-50℃.

9. The method for preparing the flexible zinc-ion battery electrode according to claim 1, characterized in that, The finger spacing of the interdigitated electrode current collector in step S31 is 350-500μm, and the line width is 400-600μm.

10. A flexible zinc-ion battery, characterized in that, The electrodes prepared by any one of claims 1-9 are assembled.

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