A multi-component gradient three-dimensional zinc negative electrode induced by stack deposition, and a preparation method and application thereof

Abstract

The application discloses a multi-component gradient three-dimensional zinc negative electrode induced by stack deposition and a preparation method and application thereof, relates to the field of electrochemical energy storage, and in-situ constructs a general strategy of multi-component gradient 3D host skeleton induced stack zinc deposition / detachment by combining a solution immersion method and a thermal evaporation technology: an amino-functionalized polysiloxane passivation layer distributed along a concentration gradient effectively inhibits zinc anode corrosion, and conductive zincophilic Ag nanoparticles distributed along a reverse concentration gradient guide zinc to uniformly nucleate and deposit at the bottom; the electric field distribution, zinc ion flux and deposition path of the electrode are optimized, dendrite-free, dense and high-load zinc deposition is realized; a symmetrical battery based on the gradient electrode can be stably cycled for more than 5000 hours under high current density / capacity, exhibits high coulombic efficiency and excellent long cycle stability; and a full battery prepared in cooperation with a manganese dioxide positive electrode has a capacity retention rate of 82.2% after 800 cycles.

Description

Technical Field

[0001] This application relates to the field of electrochemical energy storage technology, specifically to an induced stack deposition multi-component gradient three-dimensional zinc anode and its preparation method and application. Background Technology

[0002] The design optimization of the zinc metal anode aims to solve its cycle stability issues in practical applications, while also extending its application to other metal batteries. Rechargeable aqueous zinc-ion batteries have a high theoretical capacity (820 mAh·g). -1 With its advantages of high safety, low cost, abundant zinc raw material reserves, and environmental friendliness, zinc has become an important candidate for next-generation large-scale energy storage and power supply for portable electronic devices. However, as the market demand for batteries with "high current density, high areal capacity load, and long cycle life" increases, the stability of zinc metal anodes has become a key bottleneck restricting their commercialization.

[0003] Zinc metal anodes face three core problems during charge and discharge: first, dendrite growth, caused by uneven electric field and Zn... 2+ Flux disturbances cause zinc to grow disorderly in a dendritic form, easily piercing the diaphragm and causing short circuits; secondly, corrosion and side reactions occur, and in aqueous environments, hydrogen evolution easily occurs, generating inert products such as Zn(OH)2, which depletes active materials and hinders Zn production. 2+ Transmission; thirdly, high current / high capacity (≥5 mA·cm) -2 ≥10 mAh·cm -2 Under operating conditions, its cyclic stability is poor, and its lifespan is only a few hundred hours or a few hundred cycles, which cannot meet the requirements for long-term operation.

[0004] While existing research has proposed optimization strategies such as "three-dimensional confined framework design" to regulate zinc deposition and suppress dendrite formation through porous structures, some shortcomings remain: most of these strategies are single-function guiding, lacking the ability to suppress hydrogen evolution, corrosion, and guide Zn deposition. 2+ The synergistic effect of multiple objectives, such as uniform deposition, is difficult to adapt to the differentiated requirements of "surface suppression of side reactions and internal promotion of nucleation"; it also has poor adaptability under high current / high capacity and short cycle life. Developing zinc anode design strategies that can simultaneously suppress corrosion and dendrite formation and adapt to high current / high capacity is crucial.

[0005] This invention proposes a multi-component gradient three-dimensional zinc anode technology for induced stack deposition. By integrating solution immersion and thermal evaporation processes, it relies on the synergistic mechanism of amino-functionalized polysiloxane passivation layers with a concentration gradient to inhibit corrosion and zinc-loving Ag nanoparticles with a concentration gradient to guide uniform deposition, to achieve a dendrite-free, corrosion-resistant, and durable zinc metal anode. This provides an innovative solution for the practical application of rechargeable aqueous zinc-ion batteries and the design of other metal batteries. Summary of the Invention

[0006] Technical problems solved: This application provides a multi-component gradient three-dimensional zinc anode with induced stack deposition, its preparation method and application, which can solve the problems of low coulombic efficiency and short cycle life under high current / high capacity conditions caused by dendrite growth, corrosion and side reactions of zinc metal anode during charging and discharging in the prior art; at the same time, it solves the technical problems of "dendrite suppression + corrosion side reaction resistance + guided uniform nucleation" that are difficult to adapt to the existing three-dimensional confined framework, and provides core support for the practical application of rechargeable zinc-ion batteries.

[0007] The specific technical solution of this invention is as follows: A multi-component gradient three-dimensional zinc anode with induced stack deposition is constructed using a three-dimensional host framework as the working electrode, zinc foil as the counter electrode, and 2.0 M ZnSO4 solution as the electrolyte, forming a beaker cell. The anode is then subjected to an application of 5 mA·cm⁻¹. -2 Deposition was performed using a constant current for 2 or 4 hours, corresponding to 10 mAh·cm⁻¹, respectively. -2 Or 20 mAh·cm -2 Based on the area capacity, a set of multi-component gradient three-dimensional zinc anodes with induced stack deposition were prepared.

[0008] Furthermore, the three-dimensional host skeleton is: CP, g -PSiO x -NH2 / CP, g' -Ag / CP、 g' -Ag / g -PSiO x One or more of -NH2 / CP; corresponding to the multi-component gradient three-dimensional zinc anode prepared by induced stacking deposition, Zn / CP, Zn / g -PSiO x -NH2 / CP, Zn- g' -Ag / CP、Zn / g' -Ag / g -PSiO x One or more of -NH2 / CP.

[0009] This application also discloses a method for preparing any of the above-mentioned induced stack deposition multi-component gradient three-dimensional zinc anodes, including the following steps: The first step is to pretreat the carbon paper CP: cover the bottom of the CP with tape to protect it from subsequent reactions, and then self-assemble amino-functionalized polysiloxanes on the CP surface in a concentration gradient. g -PSiO x -NH2 passivation layer; The second step is preparation. g -PSiO x-NH2 / CP host: The pretreated CP was immersed in 1.0 vol.% anhydrous ethanol solution of 3-aminopropyltriethoxysilane (APTES) and reacted at 60°C for 30 minutes, followed by drying in a vacuum drying oven at 60°C for 2 hours to obtain... g -PSiO x -NH2 / CP host; The third step is preparation. g' -Ag / g -PSiO x -NH2 / CP host: Peel off the tape covering the bottom of the CP, and place the bottom-up side up. g -PSiO x -NH2 / CP is placed in a thermal evaporation vacuum chamber at 1 Å·s -1 The evaporation rate self-assembles at the bottom into an inverse concentration gradient. g' -Ag nanolayers, with an average thickness of 20nm, ultimately yielded g' -Ag / g -PSiO x -NH2 / CP host; The fourth step is to use CP, g -PSiO x -NH2 / CP, g' -Ag / CP or g' -Ag / g -PSiO x A beaker cell was assembled using -NH2 / CP as the working electrode, zinc foil as the counter electrode, and 2.0 M ZnSO4 solution as the electrolyte; by applying 5 mA·cm⁻¹… -2 Deposition was performed using a constant current for 2 or 4 hours, corresponding to 10 mAh·cm⁻¹, respectively. -2 Or 20 mAh·cm -2 The areal capacity was used to prepare Zn / CP and Zn / g -PSiO x -NH2 / CP, Zn- g' -Ag / CP or Zn / g' -Ag / g -PSiO x -NH2 / CP.

[0010] This application discloses the application of the induced stack deposition of a multi-component gradient three-dimensional zinc anode as described above in battery assembly, wherein the battery is a CR2032 type half-cell, a CR2032 type symmetric cell, a CR2032 type Zn||MnO2 full cell, and a 6×7 cm cell. 2 One or more types of large-size pouch batteries.

[0011] Furthermore, the assembly of the CR2032 type half-cell includes the following steps: S11. Battery materials: The three-dimensional host skeleton is used as the working electrode, zinc foil as the counter electrode, glass fiber membrane as the separator, and 2.0 M ZnSO4 solution as the electrolyte. S12. Battery Assembly: Assemble CR2032 coin cells in the order of “working electrode-separator-counter electrode”, inject electrolyte, and seal to obtain a half cell, which is used to evaluate the reversibility of long-term zinc plating / stripping process and coulombic efficiency (CE).

[0012] Furthermore, the assembly of the CR2032 type symmetrical battery includes the following steps: S21. Preparation of pre-deposited zinc electrodes: Zinc is pre-deposited on a three-dimensional host framework to obtain Zn / CP and Zn / g -PSiO x -NH2 / CP, Zn / g' -Ag / CP or Zn / g' -Ag / g -PSiO x -NH2 / CP, i.e., a multi-component gradient electrode with pre-deposited zinc, serves as the positive and negative electrodes of a symmetrical cell; S22. Battery materials: A multi-component gradient electrode with pre-deposited zinc is used as the positive and negative electrodes, a glass fiber membrane is used as the separator, and a 2.0 M ZnSO4 solution is used as the electrolyte. S23. Assemble the battery: Assemble the CR2032 coin cell in the order of "positive electrode-separator-negative electrode", inject the electrolyte, and seal to obtain a symmetrical battery, which is used to evaluate the long-cycle stability and rate performance under different current densities and different areal capacities.

[0013] Furthermore, the assembly of the CR2032 type Zn||MnO2 full cell includes the following steps: S31. Battery materials: The negative electrode is a multi-component gradient three-dimensional zinc anode deposited by induced stacking, the positive electrode is MnO2 / CP, the separator is a glass fiber membrane, and the electrolyte is a 2.0 M ZnSO4 + 0.2 M MnSO4 aqueous solution. The electrolyte volume is 70 μL. S32. Assemble the battery: Assemble the CR2032 coin cell in the order of "positive electrode-separator-negative electrode", inject the electrolyte, and seal to obtain a Zn||MnO2 full cell.

[0014] Furthermore, the 6×7 cm 2 The assembly of large-size pouch cells includes the following steps: S41, Battery materials: Zn / g' -Ag / g -PSiOx-NH2 / CP is the anode, and the Zn / g' -Ag / g -PSiOx-NH2 / CP pre-deposited zinc has an areal capacity of 12~15 mAh‧cm. -2 MnO2 / CF is used as the cathode, the negative / positive capacity ratio N / P is controlled at 2.6~3.0, glass fiber membrane is used as the diaphragm, and 2.0 M ZnSO4 + 0.2 M MnSO4 solution is used as the electrolyte, with a volume of 0.7 mL. S42. Assemble the battery: Stack the positive electrode, separator, and negative electrode in the aluminum-plastic film in the order of "positive electrode - separator - negative electrode", inject the electrolyte, and seal by heat pressing to obtain a 6×7 cm battery. 2 Large-size pouch cells were used to verify scalability.

[0015] Furthermore, the preparation method of the MnO2 / CP is as follows: S1. Preparation of hydrothermal reaction solution: Dissolve 67mg KMnO4 and 0.5mL 6M HCl solution in 60mL deionized water, stir until a homogeneous solution is formed, and transfer the solution to a 100mL stainless steel reactor with a polytetrafluoroethylene liner. S2. In-situ hydrothermal growth preparation of MnO2 / CP cathode: CP is immersed in the above hydrothermal reaction solution and sealed, kept at 85℃ for 20 minutes, then removed and cooled to obtain MnO2 / CP cathode; the MnO2 active material loading on the surface of the MnO2 / CP cathode is 1.2~1.5 mg·cm³. -2 .

[0016] Furthermore, the preparation method of the MnO2 / CF is as follows: S1. Preparation of MnO2 active material powder: 0.658 g KMnO4 and 2.4 mL 6 M HCl were added to 76 mL deionized water and magnetically stirred for 10 minutes to form a homogeneous mixture; then the mixture was transferred to a 100 mL hydrothermal autoclave and reacted at 140 °C for 10 hours; after cooling to room temperature, it was centrifuged and washed, and the brown solid powder was collected and dried in a vacuum environment at 60 °C for 12 hours to obtain MnO2 active material powder; S2. Preparation of positive electrode slurry: Mix the above MnO2 active material powder, Ketjen Black KB, and polyvinylidene fluoride PVDF in a weight ratio of 8:1:1, add N-methylpyrrolidone NMP solvent, and stir to form positive electrode slurry; S3. Coating: Coating the positive electrode slurry onto a surface with a size of 6×7 cm. 2 The carbon felt (CF) surface is coated with the CF, and then the coated CF is dried overnight in a vacuum oven at 60°C to obtain the MnO2 / CF cathode; the MnO2 active material loading of the MnO2 / CF cathode is 15~16 mg·cm³. -2 .

[0017] Furthermore, the electrochemical performance of the above battery system meets the following parameters: Half-cell performance: 1 mA·cm -2 / 1 mAh·cm -2 The coulombic efficiency (CE) after 500 cycles is 99.67%, 5 mA·cm⁻¹. -2 The core eccentricity (CE) was 98.92% after 300 cycles. Symmetrical cell performance: 1 mA‧cm -2 / 1 mAh·cm -2 After more than 6000 hours of cycling (voltage hysteresis of approximately 13mV), 10mA·cm -2 The cycle lasts up to 5000 hours; Zn||MnO2 full cell performance: 0.2 A·g -1 Lower reversible specific capacity 300.1 mAh·g -1 10 A‧g -1 Approximately 97mAh·g -1 2 A·g -1 After 800 cycles, the capacity retention rate was 82.2% (first cycle capacity 243.53 mAh·g). -1 After cycling, the concentration was 200.11 mAh·g. -1 ); Performance of large-size pouch batteries: Open circuit voltage 1.52 V, specific capacity still 98.9 mAh·g after 350 cycles. -1 Two sections connected in series can light up an LED light.

[0018] The principle of this patented multi-component gradient three-dimensional zinc anode achieves its function through the following mechanism: Dendrite suppression strategy: Multi-component gradient electrodes suppress dendrite formation through the synergistic effect of "surface passivation protection + zinc-loving site guidance", with a top amino-functionalized polysiloxane passivation layer ( g -PSiO x The -NH2) passivation layer can resist corrosion, inhibit hydrogen evolution side reactions, and promote the desolvation of zinc ions, effectively preventing Zn 2+ On the surface, Ag nanoparticles at the bottom act as zinc-loving seed crystals, providing abundant nucleation sites and reducing the nucleation barrier, inducing preferential deposition at the bottom, and ultimately achieving stacked deposition / stripping behavior; Deposition pathway regulation mechanism: Multi-component concentration gradient optimization of Zn 2+ Transport and deposition pathways, with the top passivation layer guiding Zn. 2+ Diffusion towards the highly conductive region at the bottom, with Ag nanoparticles at the bottom guiding Zn. 2+First, nuclei are formed uniformly at the bottom of the 3D skeleton, and then the entire 3D space is filled from bottom to top in a "first-in / last-out" pattern to further improve space utilization. Mechanism for improved cycle stability and coulombic efficiency: The multi-component gradient three-dimensional zinc anode undergoes stacked deposition / stripping during electrochemical cycling. Deposition results in no dendrite formation, and stripping almost completely removes Zn from the electrode surface, significantly improving coulombic efficiency, which is achieved at 10 mA·cm⁻¹. -2 It can cycle for more than 5,000 hours at high current density, which improves cycle stability and durability.

[0019] The beneficial effects of this invention are: 1. This invention designs a multi-component gradient three-dimensional zinc anode with induced stacking deposition, which can achieve dendrite-free, uniform, and dense deposition: g -PSiO x -NH2 layer inhibits corrosion and side reactions. g' - The Ag layer guides preferential nucleation at the bottom, significantly improving 3D space utilization, effectively reducing the short-circuit risk of dendrites piercing the diaphragm, and achieving stable cycling under high current density / large capacity conditions; 2. The electrochemical performance of the multi-component gradient three-dimensional zinc anode and its matching battery system designed in this invention is as follows: Half-cell (zinc foil as the counter electrode) at 1 mA·cm⁻¹ -2 / 1 mAh·cm -2 The coulombic efficiency (CE) after 500 cycles is 99.67%, 5 mA·cm⁻¹ -2 The CE (electrochemical conductivity) remained at 98.92% after 300 cycles at high current density; the symmetric cell maintained this at 10 mA·cm⁻¹. -2 / 10 mAh·cm -2 After stable cycling for over 5000 hours, the voltage hysteresis is only about 13mV; the Zn||MnO2 full cell at 2 A‧g -1 After 800 cycles, the capacity retention was 82.2%, 10 A·g -1 It still provides approximately 97 mAh·g at high rates. -1 Specific capacity; 6×7 cm 2 The specific capacity of the large-size pouch battery remains at 98.9 mAh·g after 350 cycles. -1 ; 3. Through an innovative strategy of multi-component gradient design, deposition behavior regulation, and process integration, a three-dimensional composite zinc anode was successfully developed that achieves multiple objectives, including corrosion resistance, dendrite formation suppression, and optimized ion / electron transport. This overcomes the limitations of existing three-dimensional framework multifunctional guided fabrication methods and simultaneously enables the development of large-size pouch cells (6×7 cm). 2 The efficient preparation of ) has strong technical scalability; 4. This technology has significant advantages in the fields of large-scale energy storage and portable electronic devices. Its multi-component gradient design concept and preparation process can be extended to other metal-based battery systems such as lithium metal batteries, sodium metal batteries, and magnesium metal batteries, providing key technical support for the next generation of high-stability, high-energy-density rechargeable metal batteries and promoting performance upgrades and application expansion in the field of electrochemical energy storage. Attached Figure Description

[0020] Figure 1 In Embodiment 1 of the present invention g' -Ag / g -PSiO x Schematic diagrams of the preparation process of -NH2 / CP and stacked deposition / exfoliation, where a is a schematic diagram of the preparation process and b is a schematic diagram of stacked deposition / exfoliation; Figure 2 In Embodiment 1 of the present invention g' -Ag / g -PSiO x SEM images of -NH2 / CP and corresponding elemental distribution maps, showing PSiO2 x Concentration gradient distribution of -NH2 and Ag nanoparticles, where a is... g' -Ag / g -PSiO x SEM images of -NH2 / CP: b is the carbon element distribution, c is the nitrogen element distribution, d is the oxygen element distribution, e is the silicon element distribution, and f is the silver element distribution. Figure 3 These are in-situ optical observations of the evolution of zinc deposition morphology in Embodiment 1 and Comparative Examples 1, 2, and 3 of the present invention, showing... g' -Ag / g -PSiOx-NH2 / CP inhibits surface deposition and dendrite formation, where a is the evolution of zinc deposition morphology observed in in-situ by optical observation in Comparative Example 1 (CP), and b is the evolution of zinc deposition morphology in Comparative Example 2 (CP). g -PSiO x The evolution of zinc deposition morphology observed in situ by in-situ optical observations of -NH2 / CP, where c is comparative example 3 ( g' The evolution of zinc deposition morphology observed in situ by optical observation of -Ag / CP, where d is from Example 1 ( g' -Ag / g -PSiO x Evolution of zinc deposition morphology observed in situ by optical observations of -NH2 / CP; Figure 4 These are the in-situ SEM images and corresponding elemental distribution maps of Embodiment 1 and Comparative Example 1 of the present invention, showing... g' -Ag / g -PSiO x-NH2 / CP induces a "stacked" zinc deposition / stripping mechanism with significantly higher space utilization than CP, where a1 is the comparative example 1 (CP) deposition of 5 mAh·cm⁻¹. -2 EDS plots at time a2, a2 ​​represents Comparative Example 1 (CP) deposition of 10 mAh·cm⁻¹ -2 EDS plot at time, a3 is the comparative example 1 (CP) deposition of 20 mAh·cm -2 EDS plots at different times, a4 is the EDS plot of Comparative Example 1 (CP) after complete stripping, b1 is the EDS plot of Example 1 ( g' -Ag / g -PSiO x -NH2 / CP) deposition 5 mAh·cm -2 EDS plot at time b2 is Example 1 ( g' -Ag / g -PSiO x -NH2 / CP) deposition 10 mAh·cm -2 EDS plot at time b3, b3 is Example 1 ( g' -Ag / g -PSiO x -NH2 / CP) deposition 20 mAh·cm -2 EDS plot at time, b4 is Example 1 ( g' -Ag / g -PSiO x -NH2 / CP) stripping 15 mAh·cm -2 EDS plot at time, b5 is Example 1 ( g' -Ag / g -PSiO x EDS plot after complete stripping of -NH2 / CP; Figure 5 This refers to the half-cell performance tests of Embodiment 1 and Comparative Examples 1, 2, and 3 of the present invention, at current densities of 1 mA·cm⁻¹. -2 5 mA·cm -2 10 mA·cm -2 Coulomb efficiency at that time, showing g' -Ag / g -PSiO x -NH2 / CP has a significantly higher coulombic efficiency than CP. g -PSiO x -NH2 / CP and g' -Ag / CP; Figure 6 This refers to the symmetrical battery tests of Embodiment 1 of the present invention and Comparative Examples 1, 2, and 3, at current densities of 1 mA·cm⁻¹. -2 5 mA·cm-2 10 mA·cm -2 The zinc deposition / stripping voltage curves at that time show g' -Ag / g -PSiO x -NH2 / CP exhibits low polarization voltage and long cycle life, with the figure above showing 1 mA·cm. -2 The zinc deposition / stripping voltage curves at 5 mA·cm⁻¹ are shown in the middle figure. -2 The zinc deposition / stripping voltage curves at 10 mA·cm are shown in the figure below. -2 Zinc deposition / stripping voltage curve at the time; Figure 7 The Zn||MnO2 full cells of Example 1 and Comparative Examples 1, 2, and 3 of this invention are at 0.5 A·g -1 ~10 A·g -1 Rate performance at 2 A·g -1 Long-cycle performance of Zn / g' -Ag / g -PSiO x -NH2 / CP exhibits excellent rate performance, long cycle life (800 cycles), and high capacity retention (82.2%), where a represents the Zn||MnO2 full cells of Example 1 and Comparative Examples 1, 2, and 3 at 0.5 A·g -1 ~10 A·g -1 The following graph shows the rate performance of Zn||MnO2 full cells from Example 1 and Comparative Examples 1, 2, and 3 at 2 A·g⁻¹. -1 Long-cycle performance graph below; Figure 8 The large-sized (6×7 cm) assembly is from Embodiment 1 of the present invention. 2 Long-cycle performance test of pouch battery, demonstrating Zn / g' -Ag / g -PSiO x - Scalability of NH2 / CP; Figure 9 The large-sized (6×7 cm) assembly is from Embodiment 1 of the present invention. 2 Optical photograph of a soft-pack battery illuminating an LED light panel. Detailed Implementation

[0021] To make the objectives and advantages of this invention clearer, the invention will be specifically described below with reference to embodiments. It should be understood that the following text is merely used to describe one or more specific embodiments of the invention and does not strictly limit the scope of protection specifically claimed by the invention.

[0022] Example 1: Preparation of a multi-component gradient three-dimensional zinc anode and a Zn||MnO2 full cell by induced stack deposition, comprising the following steps: Step 1, Pretreatment of carbon paper CP: The bottom of the commercial CP is covered with polyimide tape to protect it from subsequent reactions, followed by the self-assembly of an amino-functionalized polysiloxane passivation layer on the CP surface in the order of concentration gradient. g -PSiO x -NH2 passivation layer; The second step is preparation. g -PSiO x -NH2 / CP host: The pretreated CP was immersed in a 1.0 vol.% solution of 3-aminopropyltriethoxysilane (APTES) in anhydrous ethanol and reacted in a 60°C water bath for 30 minutes to create a concentration gradient on the CP surface. g -PSiO x -NH2 self-assembled layer, the CP after reaction was removed, the surface residual solution was rinsed with anhydrous ethanol, and then dried in a vacuum drying oven at 60℃ for 2 hours to obtain g -PSiO x -NH2 / CP host; The third step is preparation. g' -Ag / g -PSiO x -NH2 / CP host: Peel off the polyimide tape covering the bottom of the CP, and place the bottom side up. g -PSiO x -NH2 / CP is placed in a thermal evaporation vacuum chamber at 1 Å·s -1 The evaporation rate self-assembles at the bottom into an inverse concentration gradient. g' -Ag nanolayers were evaporated until the average thickness of the Ag nanoparticle layer reached 20 nm, and then naturally cooled to obtain a 3D multi-component gradient host. g' -Ag / g -PSiO x -NH2 / CP host; The fourth step is to use CP, g -PSiO x -NH2 / CP, g' -Ag / CP or g' -Ag / g -PSiO x A beaker-type three-electrode cell was assembled using -NH2 / CP as the working electrode, zinc foil as the counter electrode, and 2.0 M ZnSO4 solution as the electrolyte. The cell was tested using the Xinwei battery testing system by applying 5 mA·cm⁻¹. -2 Zinc deposition was performed using a constant current for 2 hours, yielding an areal capacity of 10 mAh·cm³. -2Multi-component gradient confined zinc anode, denoted as Zn / g' -Ag / g -PSiO x -NH2 / CP.

[0023] The preparation of the MnO2 / CP cathode includes: S1. Preparation of hydrothermal reaction solution: Dissolve 67mg KMnO4 and 0.5mL 6M HCl solution in 60mL deionized water, stir magnetically for 10 minutes until a homogeneous solution is formed, and transfer the solution to a 100mL stainless steel hydrothermal high-pressure reactor with Teflon lining. S2. In-situ hydrothermal growth preparation of MnO2 / CP cathode: CP is immersed in the above hydrothermal reaction solution and sealed, kept at 85℃ for 20 minutes, then removed and cooled to obtain MnO2 / CP cathode; the MnO2 active material loading on the surface of the MnO2 / CP cathode is 1.2~1.5 mg·cm³. -2 .

[0024] Battery packaging: with Zn / g' -Ag / g -PSiO x -NH2 / CP is the negative electrode, MnO2 / CP is the positive electrode, glass fiber membrane is the separator, and 2.0 M ZnSO4 + 0.2 M MnSO4 aqueous solution is the electrolyte, with an electrolyte volume of 70 μL. A CR2032 coin cell is assembled in the order of "positive electrode-separator-negative electrode", the electrolyte is injected, and after sealing, a Zn||MnO2 full cell is obtained.

[0025] Example 2, 6×7 cm 2 The assembly of large-size pouch cells includes the following steps: The preparation method of MnO2 / CF is as follows: S1. Preparation of MnO2 active material powder: 0.658 g KMnO4 and 2.4 mL 6 M HCl were added to 76 mL deionized water and magnetically stirred for 10 minutes to form a homogeneous mixture; then the mixture was transferred to a 100 mL hydrothermal autoclave and reacted at 140 °C for 10 hours; after cooling to room temperature, it was centrifuged and washed, and the brown solid powder was collected and dried in a vacuum environment at 60 °C for 12 hours to obtain MnO2 active material powder; S2. Preparation of positive electrode slurry: Mix the above MnO2 active material powder, Ketjen Black KB, and polyvinylidene fluoride PVDF in a weight ratio of 8:1:1, add N-methylpyrrolidone NMP solvent, and magnetically stir for 4 hours until a uniform positive electrode slurry is formed. S3. Coating: Coating the positive electrode slurry onto a surface with a size of 6×7 cm. 2The carbon felt (CF) surface is coated with the CF, and then the coated CF is dried overnight in a vacuum oven at 60°C to obtain the MnO2 / CF cathode; the MnO2 active material loading of the MnO2 / CF cathode is 15~16 mg·cm³. -2 .

[0026] Fabrication of large-size zinc anodes: using 6×7 cm 2 of g' -Ag / g -PSiO x -NH2 / CP is the working electrode, zinc foil is the counter electrode, and an application of 5 mA·cm⁻¹ is used. -2 A constant current deposition process for 2.4 hours yielded an areal capacity of 12.5 mAh‧cm². -2 Large-size zinc anode Zn / g' -Ag / g -PSiOx-NH2 / CP.

[0027] Soft-pack battery assembly: Aluminum-plastic film is used as the encapsulation material, following the principle of "zinc anode (pre-deposited zinc capacity 12 mAh·cm³)". -2 A "glass fiber diaphragm-MnO2 / CF cathode" stack was constructed, with the negative / positive capacity ratio (N / P) controlled at 2.6. 2.0 M ZnSO4 + 0.2 M MnSO4 electrolyte (0.7 mL) was injected, and the mixture was sealed using a heat-sealing machine (120℃, 0.5 MPa) to obtain a 6×7 cm... 2 Large-size pouch battery.

[0028] Example 3, Battery electrochemical performance test: Half-cell performance test: g' -Ag / g -PSiO x A CR2032 coin cell was assembled using NH2 / CP as the working electrode and zinc foil as the counter electrode; the Xinwei testing system was used to measure the results at 1 mA·cm⁻¹. -2 / 1 mAh·cm -2 5 mA·cm -2 / 5mAh·cm -2 Under constant current charge-discharge cycle conditions, the coulombic efficiency (CE) and cycle stability were recorded.

[0029] Symmetrical battery performance testing: with Zn / g' -Ag / g -PSiO x -NH2 / CP are the positive and negative electrodes, respectively, to assemble a CR2032 coin cell; at 1 mA·cm -2 / 1 mAh·cm -2 10 mA·cm-2 / 10 mAh·cm -2 Cycle life and voltage hysteresis were tested under certain conditions.

[0030] Full cell performance testing: using MnO2 / CP cathode and Zn / g' -Ag / g -PSiO x -NH2 / CP is the negative electrode, at 0.2 A·g -1 2 A·g -1 10 A·g -1 Specific capacity, cycle stability, and capacity retention were tested at current density.

[0031] Comparative Example 1: Preparation of pure CP-based zinc anode and full cell: Except for replacing the 3D substrate with unmodified pure CP, the other steps (zinc anode preparation, MnO2 / CP cathode preparation, and full cell assembly) are the same as in Example 1, resulting in a pure CP-based zinc anode (Zn / CP) and the corresponding Zn||MnO2 full cell.

[0032] Comparative Example 2, Two-component gradient ( g -PSiO x Preparation of ( / CP)-based zinc anode and full cell: except for 3D substrate replacement with only modification g -PSiO x Except for the CP of -NH2, the remaining steps are the same as in Example 1, yielding a two-component gradient-based zinc anode (Zn / g -PSiO x / CP) and full battery.

[0033] Comparative Example 3, Two-component gradient ( g Preparation of (-Ag / CP)-based zinc anode and full cell: Except for replacing the 3D substrate with CP that only evaporates the Ag nanoparticle layer, the remaining steps are the same as in Example 1, yielding a two-component gradient-based zinc anode (Zn / g -Ag / CP) and full battery.

[0034] Performance test results: Key performance tests were conducted on the batteries of Example 1 and Comparative Examples 1-3, and the results are shown in Table 1 below: Table 1 .

[0035] As shown in the table above, the multi-component gradient zinc anode and its matching battery of the present invention are significantly superior to pure CP and dual-component gradient batteries in terms of key performance such as coulombic efficiency, cycle life, and specific capacity, thus verifying the superiority of the multi-component gradient design.

[0036] The above description is merely a preferred embodiment of the present invention. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention. Structures and preparation methods not specifically described or explained in this invention, unless otherwise specified or limited, shall be implemented using conventional methods in the art.

Claims

1. A multi-component gradient three-dimensional zinc anode with induced stack deposition, characterized in that, A beaker cell was assembled using a three-dimensional host skeleton as the working electrode, zinc foil as the counter electrode, and 2.0 M ZnSO4 solution as the electrolyte; a 5 mA·cm² electrolyte was applied. -2 Deposition was performed using a constant current for 2 hours or 4 hours, corresponding to 10 mAh‧cm⁻¹, respectively. -2 Or 20 mAh‧cm -2 Based on the area capacity, a set of multi-component gradient three-dimensional zinc anodes with induced stack deposition were prepared.

2. The induced stacked deposition multi-component gradient three-dimensional zinc anode according to claim 1, characterized in that, The three-dimensional host skeleton is: CP, g -PSiO x -NH2 / CP, g' -Ag / CP、 g' -Ag / g -PSiO x One or more of -NH2 / CP; corresponding to the multi-component gradient three-dimensional zinc anode prepared by induced stacking deposition, Zn / CP, Zn / g -PSiO x -NH2 / CP, Zn- g' -Ag / CP、Zn / g' -Ag / g -PSiO x One or more of -NH2 / CP.

3. A method for preparing a multi-component gradient three-dimensional zinc anode by induced stacking deposition as described in claim 1 or 2, characterized in that, Includes the following steps: The first step is to pretreat the carbon paper CP: cover the bottom of the CP with tape to protect it from subsequent reactions, and then self-assemble amino-functionalized polysiloxanes on the CP surface in a concentration gradient. g -PSiO x -NH2 passivation layer; The second step is preparation. g -PSiO x -NH2 / CP host: The pretreated CP was immersed in 1.0 vol.% anhydrous ethanol solution of 3-aminopropyltriethoxysilane (APTES) and reacted at 60°C for 30 minutes, followed by drying in a vacuum drying oven at 60°C for 2 hours to obtain... g -PSiO x -NH2 / CP host; The third step is preparation. g' -Ag / g -PSiO x -NH2 / CP host: Peel off the tape covering the bottom of the CP, and place the bottom-up side up. g -PSiO x -NH2 / CP is placed in a thermal evaporation vacuum chamber at 1 Å·s -1 The evaporation rate self-assembles at the bottom into an inverse concentration gradient. g' -Ag nanolayers, with an average thickness of 20nm, ultimately yielded g' -Ag / g -PSiO x -NH2 / CP host; The fourth step is to use CP, g -PSiO x -NH2 / CP, g' -Ag / CP or g' -Ag / g -PSiO x A beaker cell was assembled using -NH2 / CP as the working electrode, zinc foil as the counter electrode, and 2.0 M ZnSO4 solution as the electrolyte; by applying 5 mA‧cm -2 Deposition was performed using a constant current for 2 hours or 4 hours, corresponding to 10 mAh‧cm⁻¹, respectively. -2 Or 20 mAh‧cm -2 The areal capacity was used to prepare Zn / CP and Zn / g -PSiO x -NH2 / CP, Zn- g' -Ag / CP or Zn / g' -Ag / g -PSiO x -NH2 / CP.

4. The application of the induced stacking deposition of a multi-component gradient three-dimensional zinc anode as described in claim 1 or 2 in battery assembly, characterized in that, The battery is a CR2032 type half-cell, a CR2032 type symmetrical cell, a CR2032 type Zn||MnO2 full cell, and measures 6×7 cm. 2 One or more types of large-size pouch batteries.

5. The application according to claim 4, characterized in that, The assembly of the CR2032 type half-cell includes the following steps: S11. Battery materials: The three-dimensional host skeleton is used as the working electrode, zinc foil as the counter electrode, glass fiber membrane as the separator, and 2.0 MZnSO4 solution as the electrolyte. S12. Battery Assembly: Assemble CR2032 coin cells in the order of "working electrode - separator - counter electrode", inject electrolyte, seal to obtain half cells, and use them to evaluate the reversibility of long-term zinc plating / stripping process and coulombic efficiency (CE).

6. The application according to claim 4, characterized in that, The assembly of the CR2032 symmetrical battery includes the following steps: S21. Preparation of pre-deposited zinc electrodes: Zinc is pre-deposited on a three-dimensional host framework to obtain Zn / CP and Zn / g -PSiO x -NH2 / CP, Zn / g' -Ag / CP or Zn / g' -Ag / g -PSiO x -NH2 / CP, i.e., a multi-component gradient electrode with pre-deposited zinc, serves as the positive and negative electrodes of a symmetrical cell; S22. Battery materials: a multi-component gradient electrode with pre-deposited zinc is used as the positive and negative electrodes, a glass fiber membrane is used as the separator, and a 2.0M ZnSO4 solution is used as the electrolyte; S23. Assemble the battery: Assemble the CR2032 coin cell in the order of "positive electrode-separator-negative electrode", inject the electrolyte, and seal to obtain a symmetrical battery, which is used to evaluate the long-cycle stability and rate performance under different current densities and different areal capacities.

7. The application according to claim 4, characterized in that, The assembly of the CR2032 type Zn||MnO2 full cell includes the following steps: S31. Battery materials: The negative electrode is a multi-component gradient three-dimensional zinc anode deposited by induced stacking, the positive electrode is MnO2 / CP, the separator is a glass fiber membrane, and the electrolyte is a 2.0 M ZnSO4 + 0.2 M MnSO4 aqueous solution. The electrolyte volume is 70 μL. S32. Assemble the battery: Assemble the CR2032 coin cell in the order of "positive electrode-separator-negative electrode", inject the electrolyte, and seal to obtain a Zn||MnO2 full cell.

8. The application according to claim 4, characterized in that, The 6×7 cm 2 The assembly of large-size pouch cells includes the following steps: S41, Battery materials: Zn / g' -Ag / g -PSiOx-NH2 / CP is the anode, and the Zn / g' -Ag / g -PSiOx-NH2 / CP pre-deposited zinc has an areal capacity of 12~15 mAh‧cm. -2 MnO2 / CF is used as the cathode, the negative / positive capacity ratio N / P is controlled at 2.6~3.0, glass fiber membrane is used as the diaphragm, and 2.0 M ZnSO4 + 0.2 M MnSO4 solution is used as the electrolyte, with a volume of 0.7 mL. S42. Assemble the battery: Stack the positive electrode, separator, and negative electrode in the aluminum-plastic film in the order of "positive electrode - separator - negative electrode", inject the electrolyte, and seal by heat pressing to obtain a 6×7 cm battery. 2 Large-size pouch cells were used to verify scalability.

9. The application according to claim 7, characterized in that, The preparation method of the MnO2 / CP is as follows: S1. Preparation of hydrothermal reaction solution: Dissolve 67mg KMnO4 and 0.5mL 6M HCl solution in 60mL deionized water, stir until a homogeneous solution is formed, and transfer the solution to a 100mL stainless steel reactor with a polytetrafluoroethylene liner. S2. In-situ hydrothermal growth preparation of MnO2 / CP cathode: CP is immersed in the above hydrothermal reaction solution and sealed. The solution is kept at 85°C for 20 minutes, then removed and cooled to obtain the MnO2 / CP cathode. The MnO2 active material loading on the surface of the MnO2 / CP cathode is 1.2~1.5 mg·cm³. -2 .

10. The application according to claim 8, characterized in that, The preparation method of the MnO2 / CF is as follows: S1. Preparation of MnO2 active material powder: 0.658 g KMnO4 and 2.4 mL 6 M HCl were added to 76 mL deionized water and magnetically stirred for 10 minutes to form a homogeneous mixture; then the mixture was transferred to a 100 mL hydrothermal autoclave and reacted at 140 °C for 10 hours; after cooling to room temperature, it was centrifuged and washed, and the brown solid powder was collected and dried in a vacuum environment at 60 °C for 12 hours to obtain MnO2 active material powder; S2. Preparation of positive electrode slurry: Mix the above MnO2 active material powder, Ketjen Black KB, and polyvinylidene fluoride PVDF in a weight ratio of 8:1:1, add N-methylpyrrolidone NMP solvent, and stir to form positive electrode slurry; S3. Coating: Coating the positive electrode slurry onto a surface with a size of 6×7 cm. 2 The carbon felt (CF) surface is coated with the CF, and then the coated CF is dried overnight in a vacuum oven at 60°C to obtain the MnO2 / CF cathode; the MnO2 active material loading of the MnO2 / CF cathode is 15~16 mg·cm³. -2 .

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