Metal nanoparticle anchored and nitrogen atom doped carbon sphere negative electrode carrier as well as preparation method and application thereof

Abstract

The invention relates to a metal nanoparticle anchored and nitrogen atom doped carbon sphere negative electrode carrier and a preparation method and application thereof.The preparation method comprises the steps that polyvinylpyrrolidone, metal salt, glucose and organic acid are dissolved in deionized water, a precursor is obtained through a hydrothermal reaction, then the precursor is calcined in the mixed atmosphere of hydrogen and argon, and the metal nanoparticle anchored and nitrogen atom doped carbon sphere negative electrode carrier is obtained. And finally, the metal nanoparticle anchored and nitrogen atom doped carbon sphere negative electrode carrier with uniform morphology and particle size of 200-250nm is prepared. The carrier material has high zinc affinity, low hydrogen evolution activity and an optimized three-dimensional structure, and the electrochemical performance of a zinc negative electrode can be remarkably improved. The dendrite-free zinc-deficient negative electrode prepared on the basis of the negative electrode carrier is applied to an aqueous zinc ion battery, the battery shows excellent cycling stability and rate capability, and growth of zinc dendrites and hydrogen evolution reaction are effectively inhibited. The preparation process is simple and controllable, large-scale production is easy to realize, and the preparation method has important research significance and application prospect.

Description

Technical Field

[0001] The present invention belongs to the technical field of electrochemical energy storage materials, and particularly relates to a metal nanoparticle-anchored and nitrogen atom-doped carbon sphere negative electrode carrier, a preparation method thereof and an application thereof. Background Art

[0002] With the increasingly severe problems of global energy shortage and environmental pollution, the development of new energy storage devices with high energy density, high safety and long cycle life has become a research hotspot in electrochemical energy. Among many new energy storage devices, aqueous rechargeable batteries (such as aqueous magnesium ion, aluminum ion and zinc ion batteries, etc.) are regarded as important candidates for the next-generation large-scale energy storage technology due to their intrinsic safety, low cost and high ionic conductivity. Among them, aqueous zinc ion batteries show great application potential in the field of large-scale energy storage due to the good stability and compatibility of the metal zinc negative electrode in aqueous electrolytes, as well as advantages such as a low redox potential (-0.76 V vs. standard hydrogen electrode) and a high theoretical capacity (820 mAh / g). However, in practical applications, there are problems of uneven local current density and irregular zinc ion deposition in the deposition and dissolution process of the zinc negative electrode in aqueous electrolytes, which easily lead to the growth of zinc dendrites, hydrogen evolution reaction and corrosion phenomenon. These problems not only cause the gradual accumulation of "dead zinc" in the negative electrode during the cycle, reducing the overall activity of the battery, but also seriously affect the cycle stability and rate performance of the battery, thus restricting the further application of aqueous zinc ion batteries in the field of large-scale energy storage.

[0003] To solve these problems, researchers have proposed various modification strategies, including surface coating modification, electrolyte regulation, carrier material design, etc. For example, Chinese Patent CN 117174839 A discloses a Te-modified zinc negative electrode material, which realizes the regulation of the zinc ion deposition process by loading Te material on the zinc layer surface, and improves the zinc negative electrode at 1 mAh / cm 2Cycling stability at the areal capacity. However, the interfacial bonding between the Te layer and the zinc substrate and the long cycling performance at high areal capacity still need to be further verified; Patent CN 118712318 A discloses a zinc phosphide anode material, which effectively reduces the corrosion and hydrogen evolution of the zinc anode in the aqueous electrolyte by in-situ generating a zinc phosphate protective layer on the zinc foil surface. However, the in-situ generated zinc phosphate layer has high requirements for reaction conditions (such as pH value, temperature) and is difficult to control process parameters; In addition, Chinese Patent CN 118645601 A forms a heterogeneous metal interface on the zinc anode surface through electrochemical deposition and displacement reaction, further improving the cycling stability and electrochemical performance of the zinc anode. This technology uses a multi-component metal interface to reduce the overpotential of zinc deposition, which helps to achieve uniform deposition and inhibit dendrite growth. However, the disadvantage of this scheme is that its preparation process is relatively complex, and the multi-step reaction process has high requirements for the reaction conditions at each stage. Generally speaking, although the surface coating modification strategy shows significant advantages in improving the cycling stability and electrochemical performance of the zinc anode, it may still face key problems such as uneven interfacial reactions and insufficient long-term adhesion in practical applications, and in the large-scale production process, the complexity and cost problems of its preparation process also need to be further solved.

[0004] In view of the limitations of the surface coating modification strategy, researchers have optimized the zinc ion deposition behavior fundamentally by designing carrier materials, such as constructing porous structures, introducing functional materials or regulating interfacial properties, so as to effectively solve problems such as dendrite growth and interface instability. In recent years, carbon-based materials have been widely used as the anode carriers of zinc-ion batteries due to their high conductivity, zincophilicity, good chemical stability and adjustable pore structures. For example, Chinese Patent CN 118039814A proposes a metal-doped zinc anode material, in which nano-zinc and doped metals (such as Mg, Ca, Al, etc.) are deposited in porous carbon microspheres by arc plasma method. With the guiding effect of the pores, the interfacial properties of the zinc anode are improved, enabling uniform deposition, and thus significantly improving the cycling stability and electrochemical performance of the zinc anode. In addition, Chinese Patent CN118448558 A uses electrospinning technology to prepare a three-dimensional porous dry zinc anode. By introducing polystyrene or polymethyl methacrylate spheres as the thermal decomposition template, a continuous three-dimensional porous structure is formed inside the zinc anode. This structure can not only provide more channels for the diffusion of zinc ions, but also effectively relieve the volume expansion problem during the zinc deposition process, thereby inhibiting the growth of zinc dendrites. The three-dimensional porous zinc anode can stably cycle for more than 1500 hours at a current density of 1mA / cm 2 , showing excellent cycling stability. However, the inherent hydrogen evolution activity of the carbon-based carrier leads to the aggravation of side reactions during the long-term cycling under high-rate conditions, resulting in hydrogen evolution and interface instability, and shortening the anode life.

[0005] Although these modification strategies have alleviated the problems existing in zinc anodes to a certain extent, the existing technologies still face challenges such as poor dissolution / deposition reversibility, insufficient interfacial stability, poor high-rate performance, and poor long-term cycling stability. In addition, the preparation processes of some composite materials are complex and the production costs are high, making it difficult to meet the requirements of large-scale production and commercial applications, which has become an important factor restricting their practical applications. Summary of the Invention

[0006] Based on the above problems, the present invention proposes a carbon sphere negative electrode carrier based on metal nanoparticle anchoring and nitrogen atom doping, its preparation method and application. This technology uses a carbon sphere carrier as a cavity to stably anchor metal nanoparticles inside it. At the same time, the electronic structure and surface activity of the carbon material are regulated by nitrogen atom doping, thereby macroscopically constructing a carrier structure with uniform nucleation sites and microscopically realizing uniform and dense zinc deposition. This solution not only significantly improves the cycling stability and rate performance of aqueous zinc-ion batteries, but also provides a new technical path for realizing low-cost and large-scale production, having important research significance and application prospects.

[0007] Aiming at the deficiencies of existing negative electrode materials for aqueous zinc-ion batteries in terms of cycling stability, rate performance, and preparation processes, the present invention proposes a metal nanoparticle anchoring and nitrogen atom doping carbon sphere negative electrode carrier, its preparation method and application. This technology uniformly anchors metal nanoparticles inside a nitrogen-doped carbon sphere carrier, combines the doping of nitrogen atoms to regulate the electronic structure and surface activity of the carbon material, constructs a multifunctional negative electrode carrier with high zinc affinity, low hydrogen evolution activity, and optimized three-dimensional structure, and significantly improves the electrochemical performance of the zinc negative electrode. Applying it to aqueous zinc-ion batteries significantly improves the cycling stability and rate performance of the batteries.

[0008] The technical solution adopted by the present invention is as follows:

[0009] First, the present invention provides a preparation method of a metal nanoparticle anchoring and nitrogen atom doping carbon sphere negative electrode carrier. By using hydrothermal reaction and heat treatment processes, metal nanoparticle anchoring and nitrogen atom doping carbon spheres are synthesized. The specific steps are as follows:

[0010] S1. Dissolve a certain amount of polyvinylpyrrolidone (PVP) and metal salts in deionized water. Subsequently, add an appropriate amount of glucose. After complete dissolution, inject a certain volume of organic acid. After stirring, transfer the homogeneous solution to a hydrothermal reaction kettle for hydrothermal reaction. After the reaction is completed, cool to room temperature, centrifuge, wash, and dry to obtain a precursor.

[0011] S2. Calcinate the precursor obtained in step S1 in a reducing atmosphere to obtain the metal nanoparticle anchoring and nitrogen atom doping carbon sphere negative electrode carrier.

[0012] Furthermore, the present invention strictly controls by adjusting the preparation process parameters, such as the types and dosages of PVP, metal salts, organic acids, the dosage of glucose, the hydrothermal reaction temperature and time, the calcination temperature and time, etc., and finally prepares metal nanoparticle-anchored and nitrogen atom-doped carbon sphere carriers with uniform morphology, a particle size of about 200-250 nm, and no aggregation of metal particles on the surface.

[0013] Furthermore, the PVP is K15, K20, K30, K60, or K90.

[0014] Furthermore, the metal salt is bismuth nitrate pentahydrate, stannous chloride dihydrate, zinc nitrate hexahydrate, copper nitrate trihydrate, indium chloride tetrahydrate, or a combination thereof.

[0015] Furthermore, the organic acid is formic acid, glacial acetic acid, propionic acid, methanesulfonic acid, or trifluoroacetic acid.

[0016] Furthermore, the molar ratio of the metal salt to glucose is (0.2-1):(2-10).

[0017] Furthermore, the mass-volume ratio of PVP to the organic acid is (0.1-0.5):(1-5) g / mL.

[0018] Furthermore, the stirring time is 30-60 min.

[0019] Furthermore, the temperature of the hydrothermal reaction is 100-200 °C, and the reaction time is 0.5-5 h.

[0020] Furthermore, the reducing atmosphere is a mixed atmosphere of hydrogen and argon, wherein the volume fraction of hydrogen is 5%.

[0021] Furthermore, the calcination temperature is 400-800 °C, and the calcination time is 0.5-5 h; the heating rate of the calcination is 1-5 °C / min.

[0022] Second, the present invention provides a metal nanoparticle-anchored and nitrogen atom-doped carbon sphere negative electrode carrier, which is prepared by the above method.

[0023] Third, the present invention provides a highly reversible dendrite-free zinc-deficient negative electrode based on a metal nanoparticle-anchored and nitrogen atom-doped carbon sphere negative electrode carrier. The metal nanoparticle-anchored and nitrogen atom-doped carbon sphere negative electrode carrier is used as the negative electrode active material, and is uniformly mixed with zinc powder, carbon nanotubes, and polytetrafluoroethylene (PTFE) emulsion in proportion, ground, and then coated on a copper mesh current collector and dried to obtain a zinc-deficient negative electrode sheet based on the metal nanoparticle-anchored and nitrogen atom-doped carbon sphere negative electrode carrier. By means of electrodeposition, a certain amount of zinc is deposited on the negative electrode sheet and then assembled into a symmetric battery.

[0024] Furthermore, the mass ratio of the metal nanoparticle-anchored nitrogen-doped carbon sphere anode carrier, zinc powder, carbon nanotubes, and polytetrafluoroethylene (PTFE) emulsion is 80:5:5:10.

[0025] Furthermore, the loading amount of the zinc-deficient anode sheet is 4 - 5 mg / cm 2 .

[0026] Furthermore, the electroplating method consists of the above-mentioned zinc-deficient anode sheet based on the metal nanoparticle-anchored nitrogen-doped carbon sphere anode carrier and a reusable zinc foil. By assembling them into a battery, a specific current density is set for the electroplating process, and the deposition amount of zinc is precisely controlled by setting the electroplating time.

[0027] Furthermore, the current density during the electroplating process is 5 - 80 mA / cm 2 , and the zinc deposition amount is 1 - 50 mAh / cm 2 .

[0028] Fourthly, the present invention provides an application of a highly reversible dendrite-free zinc-deficient anode based on a metal nanoparticle-anchored nitrogen-doped carbon sphere anode carrier in an aqueous zinc-ion battery.

[0029] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0030] (1) The present invention provides a simple preparation method for a metal nanoparticle-anchored nitrogen-doped carbon sphere anode carrier. Using PVP, metal source, organic acid, and glucose as raw materials, a precursor is obtained through a simple hydrothermal reaction. After drying, heat treatment is carried out to obtain the metal nanoparticle-anchored nitrogen-doped carbon sphere anode carrier. The prepared anode carrier reduces the voltage polarization of the zinc anode, improves the reversibility of zinc deposition / dissolution, and enables it to maintain stable electrochemical performance at high current densities.

[0031] (2) The present invention provides an application of a highly reversible dendrite-free zinc-deficient anode based on a metal nanoparticle-anchored nitrogen-doped carbon sphere anode carrier in an aqueous zinc-ion battery. By virtue of the synergistic effect of metal nanoparticle anchoring and nitrogen doping, the cycle stability of the zinc anode is significantly improved, and the growth of zinc dendrites and the occurrence of hydrogen evolution reaction are effectively inhibited.

[0032] (3) The present invention provides a simple preparation method for a highly reversible dendrite-free zinc-deficient anode based on a metal nanoparticle-anchored nitrogen-doped carbon sphere anode carrier. Its preparation process is simple, controllable, and easy to achieve large-scale production. Description of the Drawings

[0033] Figure 1It is the X-ray diffraction pattern of the negative electrode carrier of bismuth nanoparticles anchored on nitrogen atom-doped carbon spheres prepared in Example 1 of the present invention.

[0034] Figure 2 It is the field emission scanning electron microscope image of the negative electrode carrier of bismuth nanoparticles anchored on nitrogen atom-doped carbon spheres prepared in Example 1 of the present invention.

[0035] Figure 3 It is the X-ray photoelectron spectroscopy pattern of the negative electrode carrier of bismuth nanoparticles anchored on nitrogen atom-doped carbon spheres prepared in Example 1 of the present invention.

[0036] Figure 4 It is the comparative diagram of linear sweep voltammetry curves of the zinc-deficient negative electrodes based on the negative electrode carrier of bismuth nanoparticles anchored on nitrogen atom-doped carbon spheres and the nitrogen atom-doped carbon sphere carrier prepared in Example 1 and Comparative Example 1 of the present invention.

[0037] Figure 5 It is the rate performance comparative diagram of the symmetric battery assembled with the zinc-deficient negative electrodes based on the negative electrode carrier of bismuth nanoparticles anchored on nitrogen atom-doped carbon spheres and the nitrogen atom-doped carbon sphere carrier prepared in Example 1 and Comparative Example 1 of the present invention at 80 mA / cm 2 、1 mAh / cm 2 under the conditions.

[0038] Figure 6 It is the cycle performance comparative diagram of the symmetric battery assembled with the zinc-deficient negative electrodes based on the negative electrode carrier of bismuth nanoparticles anchored on nitrogen atom-doped carbon spheres and the nitrogen atom-doped carbon sphere carrier prepared in Example 1 and Comparative Example 1 of the present invention at 10 mA / cm 2 、50 mAh / cm 2 under the conditions.

[0039] Figure 7 It is the field emission scanning electron microscope images of the highly reversible dendrite-free zinc-deficient negative electrode based on the negative electrode carrier of bismuth nanoparticles anchored on nitrogen atom-doped carbon spheres prepared in Example 1 of the present invention before and after deposition at 10 mA / cm 2 under the conditions. Detailed implementation manners

[0040] Although many researchers have adopted modification strategies such as surface coating, electrolyte regulation, or carrier material design to improve the electrochemical performance of zinc anodes in aqueous zinc-ion batteries, their high-rate performance still needs to be further improved. It is worth noting that the highly reversible dendrite-free zinc-deficient negative electrode based on the carbon sphere negative electrode carrier anchored with metal nanoparticles and doped with nitrogen atoms prepared in the present invention not only has a high hydrogen evolution overpotential and effectively inhibits the formation of zinc dendrites, but also exhibits excellent cycle stability and rate performance, ultimately achieving a significant improvement in the performance of aqueous zinc-ion batteries.

[0041] Next, in combination with the embodiments of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described. Obviously, the described embodiments are only some representative embodiments of the present invention, rather than all embodiments. All other embodiments obtained by those skilled in the art without creative efforts fall within the protection scope of the present invention.

[0042] Example 1

[0043] A carbon sphere negative electrode carrier based on the anchoring of metal nanoparticles and nitrogen atom doping is prepared as follows:

[0044] (1) Measure 10 mL of deionized water into a beaker, add 0.3 g of PVP (K30) and 0.6 mmol of bismuth nitrate pentahydrate; subsequently, add 6 mmol of glucose, and after complete dissolution, inject 2 mL of glacial acetic acid. After stirring for 30 min, transfer the homogeneous solution to the inner lining of a 35 mL hydrothermal reaction kettle and react at 180 °C for 4 h. After the reaction is completed, cool to room temperature, centrifuge, wash, and dry to obtain a precursor powder;

[0045] (2) Place the precursor obtained in step (1) in a 5% H2 / Ar atmosphere, heat it to 600 °C at a heating rate of 2 °C / min, and hold for 4 h for heat treatment to obtain the bismuth nanoparticle-anchored and nitrogen atom-doped carbon sphere negative electrode carrier of this example (denoted as Bi@NC).

[0046] Figure 1 is the X-ray diffraction pattern of the bismuth nanoparticle-anchored and nitrogen atom-doped carbon sphere negative electrode carrier prepared in Example 1. From Figure 1 It can be seen that the main diffraction peaks of the phases in this spectrum can all be indexed as metallic bismuth (JSPDS card number 085-1329). At the same time, these sharp, narrow, and symmetric diffraction peaks have a flat and stable baseline, indicating that the sample has good crystallinity. In addition, no characteristic peaks of other impurity phases were observed, indicating that the preparation method of this example can obtain a pure-phase bismuth nanoparticle-anchored and nitrogen atom-doped carbon sphere negative electrode carrier.

[0047] Figure 2 is the field emission scanning electron microscope image of the bismuth nanoparticle-anchored and nitrogen atom-doped carbon sphere negative electrode carrier prepared in Example 1. From Figure 2It can be seen that the bismuth nanoparticles prepared in Example 1 are anchored to the nitrogen atom-doped carbon sphere negative electrode carrier, presenting a uniform spherical morphology with a particle size of about 200 - 250 nm, and there is no obvious aggregation of metal particles on the surface, indicating that the metal particles are uniformly anchored inside the carbon sphere cavity. The uniform distribution of bismuth nanoparticles in the carbon sphere cavity helps to avoid particle aggregation and exposure, thereby enhancing the structural stability of the carrier material. The encapsulation effect of the carbon sphere not only helps to buffer volume expansion to maintain the integrity of the electrode structure, but also provides a continuous conductive network, optimizing charge transfer and ion diffusion characteristics, and further improving the electrochemical activity of the carrier.

[0048] As Figure 3 shown, the X-ray photoelectron spectroscopy diagram of the bismuth nanoparticles anchored to the nitrogen atom-doped carbon sphere negative electrode carrier obtained in Example 1. The high-resolution spectrum of Bi 4f shows that the characteristic peaks of Bi 4f 7 / 2 and Bi 4f 5 / 2 are located at 156.4 eV and 161.9 eV respectively, indicating that bismuth mainly exists in the metallic state. In addition, the spectrum of N 1s can be fitted to the characteristic peaks of pyridine-N (398.7 eV), pyrrole-N (400.1 eV), graphite-N (401.1 eV) and quaternary ammonium-N (404.4 eV), confirming that nitrogen atoms have been successfully doped into the carbon skeleton, which helps to improve the conductivity and electrochemical activity of the bismuth nanoparticles anchored to the nitrogen atom-doped carbon sphere negative electrode carrier.

[0049] Comparative Example 1

[0050] A nitrogen atom-doped carbon sphere negative electrode carrier has the following preparation method:

[0051] (1) Measure 10 mL of deionized water into a beaker, add 0.3 g of PVP (K30) and 6 mmol of glucose; after complete dissolution, inject 2 mL of glacial acetic acid, stir for 30 min, then transfer the homogeneous solution to the inner lining of a 35 mL hydrothermal reaction kettle and react at 180 °C for 4 h. After the reaction, cool to room temperature, centrifuge, wash and dry to obtain the precursor powder;

[0052] (2) Place the precursor obtained in step (1) in a 5% H2 / Ar atmosphere, heat it to 600 °C at a heating rate of 2 °C / min, and hold for 4 h for heat treatment to obtain the nitrogen atom-doped carbon sphere negative electrode carrier of this comparative example (denoted as NC).

[0053] A preparation method for a zinc-deficient negative electrode based on a bismuth nanoparticle-anchored and nitrogen atom-doped carbon sphere negative electrode carrier or a nitrogen atom-doped carbon sphere carrier for an aqueous zinc-ion battery is as follows:

[0054] The negative electrode carriers prepared in Example 1 and Comparative Example 1 were used as the negative electrode active materials, and were uniformly mixed with zinc powder, carbon nanotubes, and PTFE in a mass ratio of 80:5:5:10. After carefully grinding with a mortar, they were uniformly pressed on a brass mesh and then dried at 80 °C to obtain a zinc-deficient negative electrode sheet based on bismuth nanoparticle-anchored and nitrogen-doped carbon sphere negative electrode carriers (denoted as Bi@NC@Zn) and a zinc-deficient negative electrode sheet based on nitrogen-doped carbon sphere carriers (denoted as NC@Zn), with a loading amount of 5 mg / cm 2 . By means of electrodeposition, a certain amount of zinc was deposited on the negative electrode sheet and then assembled into a symmetric battery to test the electrochemical performance of the negative electrode material by charge and discharge.

[0055] Figure 4 Figure 6 is a comparative diagram of linear sweep voltammetry curves of symmetric batteries assembled with zinc-deficient negative electrodes prepared in Example 1 and Comparative Example 1. It can be seen from the figure that at the same hydrogen evolution current (-10 mA / cm 2 ), the hydrogen evolution potential of the zinc-deficient negative electrode based on nitrogen-doped carbon sphere carriers is relatively low (-1.61 V vs. mercury / mercuric oxide electrode), indicating that it has a relatively high hydrogen evolution activity. After introducing the bismuth metal component, the hydrogen evolution potential of the zinc-deficient negative electrode based on bismuth nanoparticle-anchored and nitrogen-doped carbon sphere negative electrode carriers was increased (-1.67 V vs. mercury / mercuric oxide electrode), indicating that bismuth nanoparticle-anchored and nitrogen-doped carbon sphere carriers can effectively inhibit the occurrence of the hydrogen evolution reaction of the zinc negative electrode, which is beneficial to improving the interfacial stability and cycling performance of the electrode; Figure 5 It can be seen that at 80 mA / cm 2 and 1 mAh / cm 2 , the symmetric battery assembled with the zinc-deficient negative electrode based on bismuth nanoparticle-anchored and nitrogen-doped carbon sphere negative electrode carriers obtained in Example 1 showed lower voltage polarization (1.09 V vs. 1.51 V of the NC@Zn negative electrode) in the rate performance test; Figure 6 Combined with 2 , at 10 mA / cm 2 and 50 mAh / cm Figure 7 2 , the symmetric battery assembled with the zinc-deficient negative electrode based on bismuth nanoparticle-anchored and nitrogen-doped carbon sphere negative electrode carriers obtained in Example 1 showed more excellent cycling stability, with a cycling life of up to 700 hours; in addition, as

[0056] shown, the surface of the zinc-deficient negative electrode based on metal nanoparticle-anchored and nitrogen-doped carbon sphere negative electrode carriers obtained in Example 1 was flat after deposition at 10 mA / cmExample 2

[0057] (1) Measure 10 mL of deionized water into a beaker, add 0.1 g of PVP (K15) and 0.2 mmol of stannous chloride dihydrate; subsequently, add 10 mmol of glucose. After complete dissolution, inject 4 mL of formic acid. After stirring for 30 min, transfer the homogeneous solution to the inner lining of a 35 mL hydrothermal reactor and react at 100 °C for 0.5 h. After the reaction is completed, cool to room temperature, centrifuge, wash, and dry to obtain the precursor powder;

[0058] (2) Place the precursor obtained in step (1) in a 5% H2 / Ar atmosphere and heat it to 400 °C at a heating rate of 1 °C / min, and hold for 0.5 h for heat treatment to obtain the tin nanoparticle-anchored and nitrogen atom-doped carbon sphere anode support of this example.

[0059] Example 3

[0060] (1) Measure 10 mL of deionized water into a beaker, add 0.2 g of PVP (K20) and 0.4 mmol of zinc nitrate hexahydrate; subsequently, add 8 mmol of glucose. After complete dissolution, inject 1 mL of methanesulfonic acid. After stirring for 30 min, transfer the homogeneous solution to the inner lining of a 35 mL hydrothermal reactor and react at 150 °C for 1 h. After the reaction is completed, cool to room temperature, centrifuge, wash, and dry to obtain the precursor powder;

[0061] (2) Place the precursor obtained in step (1) in a 5% H2 / Ar atmosphere and heat it to 400 °C at a heating rate of 4 °C / min, and hold for 1 h for heat treatment to obtain the zinc nanoparticle-anchored and nitrogen atom-doped carbon sphere anode support of this example.

[0062] Example 4

[0063] (1) Measure 10 mL of deionized water into a beaker, add 0.4 g of PVP (K60) and 0.8 mmol of copper nitrate trihydrate; subsequently, add 4 mmol of glucose. After complete dissolution, inject 3 mL of propionic acid. After stirring for 60 min, transfer the homogeneous solution to the inner lining of a 35 mL hydrothermal reactor and react at 180 °C for 2 h. After the reaction is completed, cool to room temperature, centrifuge, wash, and dry to obtain the precursor powder;

[0064] (2) Place the precursor obtained in step (1) in a 5% H2 / Ar atmosphere and heat it to 600 °C at a heating rate of 4 °C / min, and hold for 2 h for heat treatment to obtain the copper nanoparticle-anchored and nitrogen atom-doped carbon sphere anode support of this example.

[0065] Example 5

[0066] (1) Measure 10 mL of deionized water into a beaker, add 0.5 g of PVP (K90) and 1 mmol of indium chloride tetrahydrate; subsequently, add 2 mmol of glucose. After complete dissolution, inject 5 mL of trifluoroacetic acid. After stirring for 60 min, transfer the homogeneous solution to the inner lining of a 35 mL hydrothermal reactor and react at 200 °C for 5 h. After the reaction is completed, cool to room temperature, centrifuge, wash and dry to obtain the precursor powder;

[0067] (2) Place the precursor obtained in step (1) in a 5% H2 / Ar atmosphere and heat it to 800 °C at a heating rate of 5 °C / min, and hold for 5 h for heat treatment to obtain the negative electrode carrier of indium nanoparticles anchored and nitrogen atom-doped carbon spheres in this example.

[0068] Example 6

[0069] (1) Measure 10 mL of deionized water into a beaker, add 0.2 g of PVP (K30), 0.2 mmol of bismuth nitrate pentahydrate and 0.2 mmol of copper nitrate trihydrate; subsequently, add 8 mmol of glucose. After complete dissolution, inject 4 mL of glacial acetic acid. After stirring for 45 min, transfer the homogeneous solution to the inner lining of a 35 mL hydrothermal reactor and react at 200 °C for 2 h. After the reaction is completed, cool to room temperature, centrifuge, wash and dry to obtain the precursor powder;

[0070] (2) Place the precursor obtained in step (1) in a 5% H2 / Ar atmosphere and heat it to 600 °C at a heating rate of 2 °C / min, and hold for 2 h for heat treatment to obtain the negative electrode carrier of bismuth and copper nanoparticles anchored and nitrogen atom-doped carbon spheres in this example.

Claims

1. A preparation method of a negative electrode carrier of metal nanoparticles anchored to nitrogen atom-doped carbon spheres, characterized in that, By using a hydrothermal reaction and a heat treatment process, metal nanoparticles are anchored to nitrogen atom-doped carbon spheres. The specific steps are as follows: S1. Dissolve polyvinylpyrrolidone and metal salts in deionized water, add glucose and organic acid, stir, and then transfer to a hydrothermal reaction kettle for hydrothermal reaction. After the reaction is completed, cool, centrifuge, wash, and dry to obtain a precursor. S2. Calcinate the precursor obtained in step S1 in a reducing atmosphere to obtain a negative electrode carrier of metal nanoparticles anchored to nitrogen atom-doped carbon spheres.

2. The preparation method according to claim 1, wherein The polyvinylpyrrolidone is K15, K20, K30, K60 or K90; the metal salt is bismuth nitrate pentahydrate, stannous chloride dihydrate, zinc nitrate hexahydrate, copper nitrate trihydrate, indium chloride tetrahydrate or a combination thereof; the organic acid is formic acid, glacial acetic acid, propionic acid, methanesulfonic acid or trifluoroacetic acid.

3. The preparation method according to claim 1, characterized in that, The molar ratio of the metal salt to glucose is (0.2-1):(2-10); the mass-volume ratio of the polyvinylpyrrolidone to the organic acid is (0.1-0.5):(1-5) g / mL; the stirring time is 30-60 min.

4. The preparation method according to claim 1, wherein The temperature of the hydrothermal reaction is 100-200 °C, and the reaction time is 0.5-5 h.

5. The preparation method according to claim 1, characterized in that, The reducing atmosphere is a mixed atmosphere of hydrogen and argon, where the volume fraction of hydrogen is 5%.

6. The preparation method according to claim 1, wherein, The calcination temperature is 400-800 °C, the calcination time is 0.5-5 h, and the heating rate is 1-5 °C / min.

7. A negative electrode carrier of metal nanoparticles anchored to nitrogen atom-doped carbon spheres prepared by the preparation method according to any one of claims 1-6.

8. Application of the negative electrode carrier of metal nanoparticles anchored to nitrogen atom-doped carbon spheres according to claim 7 in an aqueous zinc-ion battery for preparing a dendrite-free and zinc-deficient negative electrode sheet.

9. The application according to claim 8, characterized in that, The specific method of the application is as follows: Use the negative electrode carrier of metal nanoparticles anchored to nitrogen atom-doped carbon spheres as the negative electrode active material, mix it evenly with zinc powder, carbon nanotubes, and polytetrafluoroethylene emulsion in proportion, grind, coat it on a copper mesh current collector, and dry to obtain a zinc-deficient negative electrode sheet based on the negative electrode carrier of metal nanoparticles anchored to nitrogen atom-doped carbon spheres. Deposit zinc on the negative electrode sheet by electrodeposition and then assemble it into a symmetric battery.

10. The application according to claim 9, wherein The mass ratio of the metal nanoparticle anchored on the nitrogen atom-doped carbon sphere negative electrode carrier, zinc powder, carbon nanotubes, and polytetrafluoroethylene emulsion is 80:5:5:10; the loading amount of the zinc-deficient negative electrode sheet is 4-5 mg / cm 2 ; the current density in the electrodeposition process is 5-80 mA / cm 2 , and the zinc deposition amount is 1-50 mAh / cm 2 .

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