Application of superfine copper nanoparticle anchored 3D CNT-rGO composite material rapidly prepared through laser induction in zinc-iodine battery

Abstract

The invention provides application of a superfine copper nanoparticle anchored 3DCNT-rGO composite material rapidly prepared through laser induction in preparation of a zinc-iodine battery, and belongs to the technical field of energy storage materials. The prepared composite material is composed of one-dimensional carbon nanotubes, reduced graphene oxide two-dimensional nanosheets and superfine copper nanoparticles, and the superfine copper nanoparticles are evenly distributed on a CNT-rGO three-dimensional conductive network. The 3D Cu-coated CNT-rGO material prepared by the method can provide rich adsorption sites for iodine species, so that the synergistic effect of physical constraint and chemical adsorption of the iodine species in a three-dimensional skeleton structure is realized. Moreover, the super-system nanoparticles provide abundant catalytic sites for the 3D Cu-coated CNT-rGO composite material, the redox kinetics in the iodine / polyiodide conversion process is accelerated, and the electrochemical performance of the micro zinc-iodine battery is remarkably improved. The research provides a new method for synthesizing the three-dimensional carbon material loaded with the superfine metal material, and meanwhile, an innovative way is provided for customizing an electrocatalyst for a high-performance micro zinc-iodine battery.

Description

Technical Field

[0001] The present invention belongs to the technical field of electrochemical energy storage batteries, and particularly relates to the application of a 3D CNT-rGO composite material anchored with ultrafine copper nanoparticles prepared by laser-induced rapid preparation in a zinc-iodine battery. Background Art

[0002] In zinc-iodine batteries, three-dimensional carbon materials are often used as carriers for anchoring iodine. However, due to the physical accumulation of carbon materials during the electrode assembly process, the weak physical interaction between non-polar carbon materials and iodine species, and the scarcity of catalytic sites for iodine conversion, the catalytic activity of the iodine redox reaction is reduced, and the shuttle of iodine substances cannot be completely inhibited. In addition, three-dimensional micro-nano structured carbon materials face problems such as interlayer re-stacking, large contact resistance, complex processes, high energy consumption, and long processing time, making it difficult to effectively maintain the excellent intrinsic properties of three-dimensional carbon materials.

[0003] In recent years, strategies such as heteroatom doping, metal cluster modification, and transition metal compound modification have significantly improved the binding of iodine on the surface of carbon materials and accelerated the conversion of iodine and polyiodides. In particular, ultrafine metal nanoparticles (MNPs), due to the high density of unsaturated metal atoms on their surface, provide more catalytic active sites, thus improving atomic efficiency and catalytic activity. However, the inherent aggregation tendency of MNPs poses a huge challenge to achieving uniform dispersion.

[0004] Therefore, designing a new method for rapidly preparing three-dimensional carbon materials loaded with ultrafine metal materials is of great significance for the further development of zinc-iodine batteries. Summary of the Invention

[0005] To solve the above problems, we provide the application of a 3D CNT-rGO composite material anchored with ultrafine copper nanoparticles prepared by laser-induced rapid preparation in a zinc-iodine battery. The preparation method is to add graphene oxide to a certain volume of carbon nanotube solution, use Cu(CH3COO)2 as a metal precursor, and prepare a Cu(CH3COO)2-CNT-GO film through vacuum filtration and freeze-drying. In an argon-hydrogen mixed gas atmosphere, the graphene oxide in the mixed film is reduced by laser marking technology to form a stable three-dimensional network structure, and at the same time, the successful preparation of ultrafine copper nanoparticles is achieved. Then, the prepared 3D Cu@CNT-rGO composite material is loaded with iodine as the positive electrode material of the zinc-iodine battery to improve the electrochemical performance of zinc-iodine.

[0006] The object of the present invention is achieved through the following technical solutions.

[0007] An application of a 3D CNT-rGO composite material anchored with ultrafine copper nanoparticles prepared by laser-induced rapid preparation in a zinc-iodine battery, the method comprising the following steps:

[0008] Step 1. Synthesize graphene oxide (GO) using graphite powder as raw material using the improved Hummer method. Pre-treat carbon nanotube powder by carboxylation reaction: Slowly add carbon nanotube powder to a mixed solution of concentrated HNO3 and concentrated H2SO4. Ultrasonic disperse the mixture for 20-40 minutes, transfer to an 80°C oil bath and stir for 2-4 hours. After cooling to room temperature, dilute with deionized water, centrifuge and collect the precipitate. Subsequently, the sediment is redispersed and placed in a dialysis bag for dialysis to neutralize.

[0009] Step 2. Add the GO dispersion to the CNT solution, stir and maintain ultrasound. Then add Cu(CH3COO)2 and mix thoroughly, and then vacuum filter the resulting mixture with a cellulose acetate filter membrane. Subsequently, freeze-dry the Cu(CH3COO)2-CNT-GO film.

[0010] Step 3. In an argon-hydrogen mixed atmosphere, the Cu(CH3COO)2-CNT-GO film obtained in step 2 is processed and shaped into a forked-finger 3DCu@CNT-rGO electrode using laser marking technology.

[0011] Step 4. Mix the 3D Cu@CNT-rGO electrode obtained in step 3 with iodine and place it in a closed glass bottle, heat it at 100°C for 2-15h, and then place it in a 45°C forced air oven to remove the iodine attached to the surface of the electrode material, and finally obtain a cross-finger 3D Cu@CNT-rGO-I2 electrode.

[0012] Step 5. Add Zn(CF3SO3)2 and PVA to 20 mL of deionized water, stir continuously at 85°C until the solution becomes transparent, and cool to room temperature. Finally, the PVA / Zn(CF3SO3)2 semi-solid gel electrolyte is prepared by vacuum degassing.

[0013] Step 6. Assemble the interdigitated 3D Cu@CNT-rGO-I2 electrode obtained in step 3 and the interdigitated zinc foil, drop the PVA / Zn(CF3SO3)2 semi-solid gel electrolyte described in step 5 into the interdigitated microelectrode, and encapsulate the interdigitated microelectrode with a thermoplastic film.

[0014] Preferably, the mass of the carbon nanotubes in step 1 is 1g-9g.

[0015] Preferably, the volume of the deionized water in step 1 is 1L-3L.

[0016] Preferably, in step 2, the concentration of graphene oxide is 4 mg / mL-9 mg / mL, the concentration of carbon nanotubes is 2 mg / mL-5 mg / mL, and the volume ratio of CNT to GO is 1:(1-4).

[0017] Preferably, in step 2, the mass of Cu(CH3COO)2 is 2 mg / mL - 8 mg / mL.

[0018] Preferably, in step 3, a power of 5 W - 20 W and a speed of 10 mm s -1 -100 mm s -1 .

[0019] Preferably, in step 3, the length of the interdigital electrode is about 3 mm - 15 mm, the width is 50 μm - 800 μm, and the spacing between two adjacent microelectrodes is 50 μm - 500 μm.

[0020] Preferably, in step 4, the mass ratio of the Cu@CNT-rGO composite material to iodine is 1:(1 - 6).

[0021] Preferably, in step 5, the molar concentration of Zn(CF3SO3)2 is 1 mol / L - 3 mol / L, and the mass of PVA is 1 g - 8 g.

[0022] The beneficial effects of the above technical solutions of the present invention are as follows:

[0023] (1) The 3D Cu@CNT-rGO composite material prepared by the present invention evolves from a two-dimensional dense structure to a three-dimensional network, and at the same time, ultrafine copper nanoparticles are uniformly distributed on the three-dimensional framework of CNT-rGO.

[0024] (2) The 3D Cu@CNT-rGO composite material prepared by the present invention can provide rich catalytic active sites for iodine species, realize the synergistic effect of physical confinement and chemical adsorption, accelerate the redox kinetics, effectively catalyze the iodine / polyiodide conversion, and can significantly improve the electrochemical performance of zinc-iodine batteries.

[0025] (3) The 3D Cu@CNT-rGO composite material prepared by the present invention has excellent performance in a micro zinc-iodine battery. At a current of 2.6 mAh cm -2 the capacity is 1.29 mAh cm -2 , and at the same time, it has a high areal energy density of 1.55 mWh cm -2 and a high areal power density of 33.58 mW cm -2 , as well as an ultra-long life of 4000 cycles. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 Schematic diagram of the preparation process of the 3D Cu@CNT-rGO composite material prepared by the present invention

[0027] Figure 2The plasticity and stretchability demonstration diagram of the 3D Cu@CNT-rGO composite material prepared for this invention

[0028] Figure 3 SEM images of cross-sections of 3D Cu@CNT-rGO composite materials with different ratios prepared for this invention

[0029] Figure 4 SEM image of the cross-section of the 3D Cu@CNT-rGO composite material prepared for this invention

[0030] Figure 5 XRD and XPS of the 3D Cu@CNT-rGO composite material prepared for this invention

[0031] Figure 6 LSV curves of the redox processes of 3D CNT-rGO and 3D Cu@CNT-rGO for this invention, and the slope curves of Tafel calculated from the LSV curves

[0032] Figure 7 CV curves of 3D CNT-rGO and 3D Cu@CNT-rGO with different ratios, and rate performance at different current densities

[0033] Figure 8 Cycling performance of 3D CNT-rGO and 3D Cu@CNT-rGO with different ratios, and long cycling performance of 3D Cu@CNT-rGO(1:3) at high current density

[0034] Figure 9 SEM images of the zinc negative electrode after 100 cycles of 3D CNT-rGO / I2 and 3D Cu@CNT-rGO / I2 Specific implementation manners

[0035] The present invention will be further elaborated through specific embodiments below. Unless otherwise specified, the technical means used in the present invention are all methods well known to those skilled in the art. In addition, the present invention includes but is not limited to the following embodiments. Any equivalent replacement or partial improvement carried out under the spirit and principle of the present invention will be regarded as within the protection scope of the present invention. In the following embodiments:

[0036] Scanning electron microscope (SEM): JEOL JSM-7001F, Japan;

[0037] D8 Advanced X-ray diffractometer (XRD): Bruker AXS, Germany;

[0038] X-ray photoelectron spectrometer (XPS): Thermo Fisher ESCALAB XI;

[0039] Transmission electron microscope (TEM): JEOL JEM-2100;

[0040] Example 1

[0041] (1) Synthesis of GO and CNT: Using the improved Hummer's method, graphene oxide (GO) was synthesized with graphite powder as the raw material. The carbon nanotube powder was pretreated by carboxylation reaction: 1 g of carbon nanotube powder was slowly added to a mixed solution of 130 mL of concentrated HNO3 and concentrated H2SO4 (volume ratio 1:3). After ultrasonic dispersion of the mixture for 20 minutes, it was transferred to an 80 °C oil bath and stirred for 2 h. After cooling to room temperature, 1 L of deionized water was added for dilution, and the precipitate was collected by centrifugation at 10000 rpm for 30 min. Subsequently, the sediment was redispersed and placed in a dialysis bag for dialysis to neutralize.

[0042] (2) Preparation of Cu(CH3COO)2-CNT-GO film: GO (4 mg / mL) was added to a predetermined volume of CNT (2 mg / mL) solution (CNT:GO = 1:1), and stirring and ultrasonic treatment were carried out for 2 h. Then 2 mg of Cu(CH3COO)2 was added and mixed thoroughly, and the resulting mixture was vacuum filtered through a cellulose acetate filter membrane. The Cu(CH3COO)2-CNT-GO film was freeze-dried.

[0043] (3) Preparation of 3D Cu@CNT-rGO composite: Under an argon-hydrogen mixed atmosphere, using a fiber laser with a power of 5 W and a speed of 10 mms -1 , the Cu(CH3COO)2-CNT-GO film was marked and processed to prepare a 3D Cu@CNT-rGO composite. The length between each finger of the 3D Cu@CNT-rGO was about 3 mm, the width was 50 μm, and the distance between two finger-like microelectrodes was 50 μm.

[0044] (4) Preparation of 3D Cu@CNT-rGO / I2 composite: The 3D Cu@CNT-rGO and iodine were mixed at a mass ratio of 1:1 and placed in a closed glass bottle. It was heated at 100 °C for 10 h, and then placed in a 45 °C forced-air oven to remove the iodine attached to the surface of the electrode material, and finally the positive electrode material was obtained.

[0045] (5) 1 mol / L Zn(CF3SO3)2 and 1 g of PVA were added to 20 mL of deionized water, and continuously stirred at 85 °C until the solution became transparent. It was cooled and allowed to stand at room temperature. Finally, a PVA / Zn(CF3SO3)2 semi-solid gel electrolyte was prepared by vacuum degassing.

[0046] (6) Assemble the interdigital 3D Cu@CNT-rGO-I2 electrode obtained in step (4) and the interdigital zinc foil, and drop the PVA / Zn(CF3SO3)2 semi-solid gel electrolyte described in step (5) into the interdigital microelectrode, and encapsulate the interdigital microelectrode with a thermoplastic film.

[0047] Example 2

[0048] (1) Synthesis of GO and CNT: Using the improved Hummer method, graphene oxide (GO) was synthesized with graphite powder as the raw material. The carbon nanotube powder was pretreated by carboxylation reaction: 3 g of carbon nanotube powder was slowly added to a mixed solution of 130 mL of concentrated HNO3 and concentrated H2SO4 (volume ratio 1:3). After ultrasonic dispersion of the mixture for 20 minutes, it was transferred to an 80 °C oil bath and stirred for 2 h. After cooling to room temperature, 1 L of deionized water was added for dilution, and the precipitate was collected by centrifugation at 10000 rpm for 30 min. Subsequently, the sediment was redispersed and loaded into a dialysis bag for dialysis to neutralize.

[0049] (2) Preparation of Cu(CH3COO)2-CNT-GO film: GO (8 mg / mL) was added to a predetermined volume of CNT (4 mg / mL) solution (CNT:GO = 1:3), and stirring and ultrasonic treatment were carried out for 2 h. Then 8 mg of Cu(CH3COO)2 was added and mixed evenly, and the resulting mixture was vacuum filtered through a cellulose acetate filter membrane. The Cu(CH3COO)2-CNT-GO film was freeze-dried.

[0050] (3) Preparation of 3D Cu@CNT-rGO composite: Under an argon-hydrogen mixed atmosphere, a fiber laser with a power of 20 W and a speed of 48 mms -1 was used to engrave the Cu(CH3COO)2-CNT-GO film to prepare a 3D Cu@CNT-rGO composite. The length of each finger of the 3D Cu@CNT-rGO was about 7 mm, the width was 500 μm, and the distance between the two interdigital microelectrodes was 200 μm.

[0051] (4) Preparation of 3D Cu@CNT-rGO / I2 composite: 3D Cu@CNT-rGO and iodine were mixed at a mass ratio of 1:3 and placed in a sealed glass bottle, heated at 100 °C for 10 h, and then placed in a 45 °C blast oven to remove the iodine attached to the surface of the electrode material, and finally the positive electrode material was obtained.

[0052] (5) 2 mol / L Zn(CF3SO3)2 and 4 g PVA were added to 20 mL of deionized water, and the mixture was continuously stirred at 85 °C until the solution became transparent. Then it was cooled and allowed to stand at room temperature. Finally, a PVA / Zn(CF3SO3)2 semi-solid gel electrolyte was prepared by vacuum degassing.

[0053] (6) The interdigital 3D Cu@CNT-rGO-I2 electrode obtained in step (4) and an interdigital zinc foil were assembled. The PVA / Zn(CF3SO3)2 semi-solid gel electrolyte described in step (5) was dropped into the interdigital microelectrodes, and the interdigital microelectrodes were encapsulated with a thermoplastic film.

[0054] Example 3

[0055] (1) Synthesis of GO and CNT: Using the improved Hummer method, graphite powder was used as the raw material to synthesize graphene oxide (GO). The carbon nanotube powder was pretreated by carboxylation reaction: 3 g of carbon nanotube powder was slowly added to a mixed solution of 130 mL of concentrated HNO3 and concentrated H2SO4 (volume ratio 1:3). After the mixture was ultrasonically dispersed for 20 minutes, it was transferred to an 80 °C oil bath and stirred for 2 h. After cooling to room temperature, 1 L of deionized water was added for dilution, and the precipitate was collected by centrifugation at 10,000 rpm for 30 min. Subsequently, the sediment was redispersed and loaded into a dialysis bag for dialysis to neutralize.

[0056] (2) Preparation of Cu(CH3COO)2-CNT-GO film: GO (8 mg / mL) was added to a predetermined volume of CNT (4 mg / mL) solution (CNT:GO = 1:3), and stirring and ultrasonic treatment were carried out for 2 h. Then 8 mg of Cu(CH3COO)2 was added and mixed thoroughly. Then the resulting mixture was vacuum filtered through a cellulose acetate filter membrane. The Cu(CH3COO)2-CNT-GO film was freeze-dried.

[0057] (3) Preparation of 3D Cu@CNT-rGO composite: In an argon-hydrogen mixed atmosphere, a fiber laser with a power of 15 W and a speed of 100 mms -1 was used to engrave the Cu(CH3COO)2-CNT-GO film to prepare a 3D Cu@CNT-rGO composite. The length between each finger of the 3D Cu@CNT-rGO was about 17 mm, the width was 800 μm, and the distance between the two interdigital microelectrodes was 500 μm.

[0058] (4) Preparation of 3D Cu@CNT-rGO / I2 composite material: 3D Cu@CNT-rGO and iodine were mixed at a mass ratio of 1:3 and placed in a sealed glass bottle. It was heated at 100 °C for 10 h, and then placed in a forced-air oven at 45 °C to remove the iodine adhering to the surface of the electrode material, and finally the positive electrode material was obtained.

[0059] (5) 2 mol / L Zn(CF3SO3)2 and 4 g of PVA were added to 20 mL of deionized water, and continuously stirred at 85 °C until the solution became transparent, then cooled and allowed to stand at room temperature. Finally, a PVA / Zn(CF3SO3)2 semi-solid gel electrolyte was prepared by vacuum degassing.

[0060] (6) The interdigital 3D Cu@CNT-rGO-I2 electrode obtained in step (4) and the interdigital zinc foil were assembled, and the PVA / Zn(CF3SO3)2 semi-solid gel electrolyte described in step (5) was dropped into the interdigital microelectrode, and the interdigital microelectrode was encapsulated with a thermoplastic film.

[0061] The flow chart of preparing and assembling the micro zinc-iodine battery with the positive electrode composite material prepared in this example is as Figure 1 shown.

[0062] Experimental results:

[0063] Morphology and structure characterization:

[0064] As Figure 2 shown, the Cu(CH3COO)2-CNT-GO film can be processed into three-dimensional microelectrodes of arbitrary shapes, such as butterfly and donut ( Figure 2 a, b), by laser direct writing technology. In addition, the film also has excellent ductility, and 3D Cu@CNT-rGO microelectrodes with a tensile structure can be prepared ( Figure 2 c).

[0065] As Figure 3 shown, through SEM, a significant increase in the interlayer spacing of the 3D Cu@CNT-rGO composite materials with ratios of 1:1, 1:2, 1:3, and 1:4 can be seen, and the thicknesses are approximately 186.5 μm, 198 μm, 251 μm, and 310 μm respectively ( Figure 3 a-d). The ratio of CNT to GO has a significant effect on the pore structure of the 3D CNT-rGO composite material. The increase in the GO content is beneficial to the formation of a more obvious three-dimensional network structure, thus providing a wider surface area and ensuring the optimal exposure of active sites ( Figure 3 e-l).

[0066] As Figure 4As shown, a large number of ultrafine copper nanoparticles with a diameter of about 2 - 6 nm are uniformly dispersed on the CNT-rGO cross-linking interface as seen by TEM( Figure 4 a). At the same time, the lattice spacing in the HRTEM image is 0.212 nm( Figure 4 b, c), corresponding to the copper (111) crystal plane, which confirms the successful preparation of the ultrafine copper nanoparticles.

[0067] As Figure 5 shown, XRD analysis confirms that the diffraction peaks of 3D Cu@CNT-rGO are consistent with the Cu diffraction peaks indexed in PDF#70 - 3080( Figure 5 a), thus verifying the successful formation of the ultrafine copper nanoparticles under laser induction. In addition, it is further confirmed by the XPS results( Figure 5 b).

[0068] Electrocatalytic activity characterization:

[0069] To deeply explore the profound influence of the electrocatalytic sites of the 3D CNT-rGO composite anchored with ultrafine copper nanoparticles on the redox reaction kinetics, a comparative analysis of the Tafel slopes of the reduction and oxidation reactions was carried out. According to the linear sweep voltammetry (LSV) test of the Zn-I2 battery( Figure 6 a, b) shown, during the iodine redox process, 3D Cu@CNT-rGO / I2 exhibits a smaller overpotential. Figure 6 c shows that the Tafel slopes of the oxidation peaks of 3D Cu@CNT-rGO / I2 and 3D CNT-rGO / I2 cathodes are 222 mV dec -1 and 292 mV dec -1 . For the reduction process, the Tafel slopes of 3D Cu@CNT-rGO / I2 and 3D CNT-rGO / I2 cathodes are 238 mV dec -1 and 290 mV dec -1 ( Figure 6 d). These results indicate that 3D Cu@CNT-rGO / I2 has higher electrocatalytic activity for the I2 / I - conversion.

[0070] Electrochemical performance characterization:

[0071] Using 3D Cu@CNT-rGO / I2 and 3D CNT-rGO / I2 composites as cathodes respectively, 2MPVA / Zn(CF3SO3)2 as the electrolyte, and Zn as the anode, a micro zinc-iodine battery was assembled and its electrochemical performance was explored.

[0072] As Figure 7As shown in a), the CV curves of the 3D Cu@CNT-rGO / I2 composite electrode at sweep rates of 0.2, 0.4, 0.6, 0.8, and 1.0 mV s -1 The reduction and oxidation peaks corresponding to the I2 / I - redox process appear at 1.12 V and 1.35 V (vs. Zn 2 + / Zn), respectively. As Figure 7 shown in b), the rate performance of the 3D CNT-rGO / I2 cathode and 3D Cu@CNT-rGO / I2 cathodes with different ratios was evaluated at current densities from 2.6 to 26.3 mA cm -2 . The reversible specific capacities of 3D Cu@CNT-rGO / I2(1:3) at 2.6, 5.3, 7.9, 10.5, 13.2, 15.8, and 26.3 mA cm -2 are 1.29, 1.07, 0.95, 0.85, 0.76, 0.68, and 0.65 mAh cm -2 , respectively. Even at a high current density of 26.3 mA cm -2 , the discharge specific capacity of 3D Cu@CNT-rGO / I2(1:3) remains stable.

[0073] As Figure 8 shown, the cycling performance of 3D CNT-rGO and 3D Cu@CNT-rGO with different ratios, as well as the long cycling performance of 3D Cu@CNT-rGO(1:3) at high current densities. 3D Cu@CNT-rGO(1:3) exhibits the best performance. After 2000 cycles at a current of 2.6 mA cm -2 , its capacity can still remain at 0.9 mAh cm -2 , and the capacity retention rate is as high as 91.2% ( Figure 8 a). Subsequently, its cycle life was tested at a higher current density of 26.3 mA cm -2 ( Figure 8 b). After 4000 cycles, the capacity retention rate of the ZIMBs remains at 80%.

[0074] As Figure 9As shown in the figure, SEM tests were carried out on the surface of the zinc anode after the microelectrochemical cycling of Zn||3D CNT-rGO / I2 and Zn||3D Cu@CNT-rGO / I2. After 100 cycles of the battery using the 3D CNT-rGO cathode, zinc was mainly deposited in the vertical direction, forming a large number of dendritic zinc dendrites. In contrast, the surface of zinc after cycling with the 3D Cu@CNT-rGO cathode was smoother and flatter. The results show that the 3D Cu@CNT-rGO cathode can effectively inhibit the shuttling effect and play a certain protective role for the zinc anode.

Claims

1. Application of a laser-induced rapid preparation of ultrafine copper nanoparticles-anchored 3D CNT-rGO composite material in the preparation of zinc-iodine batteries, the method comprising the following steps: Step 1. Using the improved Hummer method, graphene oxide (GO) is synthesized with graphite powder as the raw material. The carbon nanotube powder is pretreated by carboxylation reaction: the carbon nanotube powder is slowly added to a mixed solution of concentrated HNO3 and concentrated H2SO4. After ultrasonic dispersion of the mixture for 20 - 40 min, it is transferred to an 80 °C oil bath and stirred for 2 - 4 h. After cooling to room temperature, deionized water is added for dilution, and the precipitate is centrifuged and collected. Subsequently, the sediment is redispersed and loaded into a dialysis bag for dialysis to neutralize. Step 2. The GO dispersion is added to the CNT solution, and stirring and ultrasonic maintenance are carried out. Cu(CH3COO)2 is added and mixed evenly, and then the obtained mixture is vacuum filtered through a cellulose acetate filter membrane. Subsequently, the Cu(CH3COO)2-CNT-GO film is freeze-dried. Step 3. Under an argon-hydrogen mixed atmosphere, the Cu(CH3COO)2-CNT-GO film obtained in Step 2 is processed and shaped by laser marking technology to prepare an interdigital 3D Cu@CNT-rGO electrode. Step 4. The 3D Cu@CNT-rGO electrode obtained in Step 3 is mixed with iodine and placed in a sealed glass bottle, heated at 100 °C for 2 - 15 h, and then placed in a 45 °C forced-air oven to remove the iodine attached to the surface of the electrode material, finally obtaining an interdigital 3D Cu@CNT-rGO-I2 electrode. Step 5. Zn(CF3SO3)2 and PVA are added to 20 mL of deionized water, and continuously stirred at 85 °C until the solution becomes transparent, cooled and left standing at room temperature. Finally, a PVA / Zn(CF3SO3)2 semi-solid gel electrolyte is prepared by vacuum degassing. Step 6. The interdigital 3D Cu@CNT-rGO-I2 electrode obtained in Step 3 and an interdigital zinc foil are assembled, and the PVA / Zn(CF3SO3)2 semi-solid gel electrolyte described in Step 5 is dropped into the interdigital microelectrode, and the interdigital microelectrode is encapsulated using a thermoplastic film.

2. The preparation method according to claim 1, wherein: In Step 1, the mass of the carbon nanotubes is 1 g - 9 g, the volume ratio of the concentrated HNO3 and concentrated H2SO4 is 1:3, and the volume of the deionized water is 1 L - 3 L.

3. The preparation method according to claim 1, characterized in that: In Step 2, the concentration of the GO dispersion is 4 mg / mL - 9 mg / mL, the concentration of the CNT solution is 2 mg / mL - 8 mg / mL, the mass ratio of graphene oxide to carbon nanotubes is 1:(1 - 4), and the mass of the Cu(CH3COO)2 is 4 mg - 16 mg.

4. The preparation method according to claim 1, wherein: In step 3, a fiber laser with a power of 5W - 20W and a speed of 10mm s -1 -100mm s -1 is used for marking.

5. The preparation method according to claim 1, characterized in that: In Step 3, the length of each finger of the Cu@CNT-rGO is about 3 mm - 15 mm, the width is 50 μm - 800 μm, and the distance between the two interdigital microelectrodes is 50 μm - 500 μm.

6. The preparation method according to claim 1, characterized in that: In Step 4, the mass ratio of the Cu@CNT-rGO composite material to iodine is 1:(1 - 6).

7. The preparation method according to claim 1, wherein: In the step 5, the molar concentration of Zn(CF3SO3)2 is 1 mol / L - 3 mol / L, and the mass of PVA is 1 g - 8 g.

8. A printable and recyclable photo-assisted enhanced zinc-iodine battery obtained by the preparation method according to any one of claims 1-7.

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