Zinc negative electrode material and preparation method thereof

Abstract

The application discloses a zinc negative electrode material and a preparation method thereof, and particularly relates to the technical field of metallurgical solid waste resource utilization and energy storage material preparation. The selective dissolution ability of a eutectic solvent to zinc is utilized, zinc components in flue dust are directly leached by using a choline chloride-based eutectic solvent, and the dissolution of impurities is simultaneously inhibited, so that a non-purified electrolyte which can be directly used for electrodeposition is obtained. By adding a texture control additive in the system, the solvation structure of zinc ions and the adsorption behavior of a cathode interface are changed under non-epitaxial deposition conditions, a control mechanism for inducing the preferential growth of zinc along a (002) crystal surface is established, and one-step conversion from solid waste to electrodeposition raw materials is realized.

Description

Technical Field

[0001] This invention belongs to the field of metallurgical solid waste resource utilization and energy storage material preparation technology, specifically relating to a zinc anode material and its preparation method. Background Technology

[0002] Hydrometallurgical zinc smelting is currently the mainstream zinc smelting process. However, the zinc oxide dust generated during this process, produced by the volatilization of large amounts of leaching residue in rotary kilns, is complex in composition and low in value, making its efficient utilization a long-standing challenge for the industry. Currently, the utilization of zinc oxide dust mainly follows two traditional paths: as a supplementary raw material returned to the zinc smelting system; or as a raw material for hydrometallurgical purification to produce zinc sulfate and zinc chloride chemical products. While these methods achieve zinc recycling to some extent, the added value of the products is low, failing to address the core value of zinc as a functional material.

[0003] Aqueous zinc-ion batteries have become an ideal technology for meeting the requirements of large-scale energy storage due to their inherent safety, low cost, and environmental friendliness. However, the zinc anode in this system suffers from severe dendrite growth and hydrogen evolution corrosion. Studies have shown that inducing zinc to preferentially grow along the thermodynamically more stable (002) crystal plane (i.e., "texturing") can significantly suppress dendrite growth and improve cycle stability, becoming a key approach to overcome the bottleneck of the anode.

[0004] Currently, methods for obtaining zinc anodes with (002) crystal plane preferential growth are mainly based on aqueous electrolytes prepared with high-purity zinc salts. For example, patent application CN118431391A discloses a method for preparing a zinc anode, which uses an electroplating solution containing zinc salt, acid, and manganese salt for non-epitaxial electrodeposition to obtain a zinc anode with a (002) crystal plane texture coefficient greater than or equal to 99%. Patent application CN118480832A discloses a method for texturing the surface of metallic zinc by non-epitaxial electrodeposition in a mixed aqueous solution containing ZnSO4 and phytic acid. Patent application CN115679380B discloses a method for preparing (002) crystal plane oriented metallic zinc, which uses a two-electrode electrochemical deposition technique, with iron foil, titanium foil, or copper foil as the working electrode, commercial zinc foil as the counter electrode, and zinc salt aqueous solution as the electrolyte. Constant current density discharge deposition is used to deposit (002) crystal plane oriented metallic zinc on the working electrode.

[0005] However, the above methods all rely on electrolytes prepared with high-purity zinc salts. If the zinc source is replaced with industrial-grade zinc oxide fume leaching solutions with complex compositions, the coexisting impurity ions (such as iron, lead, and silicon) will severely interfere with the initial nucleation and subsequent growth processes of electrocrystallization, rendering existing precise texture control strategies ineffective. Furthermore, zinc oxide fume, as an important secondary zinc resource, requires multiple leaching, deep purification, and separation processes in its traditional treatment to selectively extract zinc from the complex system and obtain high-purity zinc salts before it can be used for subsequent electrodeposition to prepare functional materials. This process involves multiple purification, extraction, or displacement steps, resulting in a lengthy process flow, high reagent consumption, high production costs, and a large amount of waste liquid and residue generated. Summary of the Invention

[0006] To address the technical problems of complex processes and the inability to precisely control the zinc crystal texture in existing electrodeposition textured zinc anode technology for treating zinc oxide fume leachate, this invention provides a method for preparing zinc anode materials.

[0007] This invention utilizes the selective dissolution capability of eutectic solvents for zinc to achieve direct conversion from solid waste to electrolyte. Based on this, by introducing a specific amount of texture-regulating additives into the leaching system, precise induction of the crystal texture of the zinc deposition layer is achieved under a non-purified electrolyte environment, thereby obtaining a high-performance zinc anode with a specific orientation.

[0008] To achieve the above objectives, the technical solution of the present invention is as follows.

[0009] The first objective of this invention is to provide a method for preparing a zinc anode material, comprising the following steps: Zinc oxide dust was added to a choline-based eutectic solvent at 50℃~80℃, and a zinc ion-containing leachate was obtained through a leaching reaction. The zinc ion-containing leachate and an inorganic chloride salt were used as electrolytes to perform non-epitaxial electrodeposition on an inert substrate to obtain a zinc anode material with (002) crystal plane orientation.

[0010] Temperatures below 50℃ to 80℃ will result in high solvent viscosity and reduced deposition efficiency.

[0011] The inorganic chloride salt has a mass of 0.1% to 5% based on the mass of the choline eutectic solvent.

[0012] The choline-based eutectic solvent is prepared by mixing choline chloride with a hydrogen bond donor in a molar ratio of 1:1 to 3, wherein the hydrogen bond donor is urea or ethylene glycol.

[0013] In a preferred embodiment, the inorganic chloride salt is NaCl, KCl, or NH4Cl.

[0014] The role of introducing inorganic chloride salt additives is to increase the concentration of free chloride ions in the system, thereby enhancing the complex ion [ZnCl] x (Urea) y ] - / [ZnCl x (EG) y ] - The stability of the zinc nucleation overpotential is controlled by the reaction of Cl ions and Ch in inorganic chloride salts. + (Choline cations) form a complex ion ([ChCl2]). − [Ch2Cl3] − Selective adsorption on the cathode surface can alter the growth rate of different crystal planes, thereby precisely controlling the crystal texture of deposited zinc. When the additive content is below 0.1%, its guiding effect on crystal plane growth is not significant, making it difficult to form a specific texture; when the content exceeds 5%, it may lead to excessive electrolyte viscosity or salting out, which in turn damages the uniformity of the coating.

[0015] In a preferred embodiment, the zinc content in the zinc oxide fume is 75%–82%; the ratio of the zinc oxide fume to the choline eutectic solvent is 1g:10mL–50mL.

[0016] Insufficient choline-based eutectic solvent can lead to limited mass transfer, excessively high viscosity, and the formation of dendrites or loose deposits in the zinc anode, reducing its purity and adhesion. Excessive choline-based eutectic solvent results in slow deposition rate and low efficiency.

[0017] In a preferred embodiment, the non-epitaxial electrodeposition adopts a constant potential mode, and the electrodeposition parameters are: deposition potential of -1.5V to -0.8V, and deposition temperature of 50℃ to 80℃.

[0018] The deposition potential is -1.5V to -0.8V, and the deposition temperature is 50℃ to 80℃.

[0019] An excessively positive potential (>-0.8V) results in very slow deposition or even no deposition at all; an excessively negative potential (<-1.5V) leads to more side reactions and solvent decomposition (easily producing dendrites and sponge-like crystals).

[0020] Too low a temperature (<50℃) results in low efficiency, high energy consumption, and viscous solution; too high a temperature (>80℃) results in uneven zinc deposition.

[0021] In a preferred embodiment, when the non-epitaxy electrodeposition is performed in a constant current mode, the electrodeposition parameters are: a current density of 1 mA / cm². 2 ~20mA / cm 2 The deposition temperature is 50℃~80℃.

[0022] In a preferred embodiment, when the non-epitaxial electrodeposition is performed in pulsed current mode, the parameter conditions for the non-epitaxial electrodeposition are: pulsed current density of 2 mA / cm². 2 ~30mA / cm 2 The pulse width is 0.1ms to 10ms, the duty cycle is 10% to 50%, and the deposition temperature is 50℃ to 80℃.

[0023] Low current (<1mA / cm) 2 This results in slow nucleation and discontinuous zinc coating; excessively high current (>20mA / cm) leads to slow nucleation and discontinuous zinc coating. 2 This leads to severe hydrogen evolution and a loose zinc coating structure that is prone to peeling off.

[0024] In a preferred embodiment, the leaching reaction time is 0.5 hours to 4 hours, and the stirring speed is 200 rpm to 800 rpm.

[0025] In a preferred embodiment, the inert substrate is copper foil, titanium foil, stainless steel foil, or conductive glass.

[0026] A second objective of the present invention is to provide a zinc anode material with (002) crystal plane orientation prepared by the preparation method described above.

[0027] In a preferred embodiment, the crystal texture factor of the zinc anode material is greater than 70%.

[0028] The crystal texture factor measures the intensity of the preferred orientation of grains in a certain direction.

[0029] Compared with the prior art, the present invention has the following beneficial effects: This invention provides a method for preparing zinc anode materials. This invention utilizes the selective solubility of zinc in eutectic solvents to directly leach zinc components from flue dust using choline chloride-based eutectic solvents, while simultaneously inhibiting the dissolution of impurities, thereby obtaining a non-purified electrolyte that can be directly used for electrodeposition, achieving a one-step conversion from solid waste to electrodeposition raw materials.

[0030] This invention utilizes the unique coordination chemistry environment of eutectic solvents to construct a precise control mechanism from selective leaching to directional deposition in a choline chloride-urea / ethylene glycol system by actively introducing inorganic chloride salts as texture-regulating additives. During the leaching stage, the synergistic coordination between chloride ions and urea components / ethylene glycol, along with Zn... 2+ They combine to form [ZnCl2(Urea)2] / [ZnCl] x (EG)y] 2-x Or similar mixed coordination anions [ZnCl3(Urea)] - Mixed coordination anionic complexes, wherein the urea component / ethylene glycol and chloride ions co-construct Zn2+ The multi-level solvation shell structure has chloride ions embedded in the first coordination layer, while urea components / ethylene glycol occupy the coordination sites in the outer layers, forming a coordination environment similar to a "protective shell". This transforms the originally insoluble zinc-containing phase into electrochemically active soluble solvation ions, while effectively suppressing the electrochemical activity of impurity ions such as Fe and Pb through steric hindrance and charge shielding effects.

[0031] During the deposition stage, texture-regulating additives adjust the Cl content within the system. - The chemical potential was used to dynamically optimize the ratio of chloride coordination numbers in the solvated anion, thereby finely controlling the Zn content. 2+ The desolvation kinetics at the cathode interface significantly enhanced the nucleation overpotential. Simultaneously, the texture-controlled additive-induced formation of [Ch]... x Cl x+1 ] - Interfacial active complex ions selectively limit the growth rate of non-(002) crystal planes through specific adsorption on the cathode surface. This allows for the establishment of a regulatory mechanism that induces preferential deposition of zinc along the (002) crystal plane under non-epitaxial growth conditions. Ultimately, selective leaching of zinc and non-epitaxial electrodeposition of textured zinc anodes are completed in a choline chloride eutectic solvent medium, achieving a short-process coupling of "recycling-electrodeposition integration" and significantly improving process integration and resource utilization efficiency. Attached Figure Description

[0032] Figure 1 The images shown are scanning electron microscope (SEM) images and EDS images of the zinc anode material prepared in Example 1 of this invention. Specifically, image a is the SEM image of the zinc anode material prepared in Example 1 of this invention at a scale bar of 100 μm; image b is the SEM image of the zinc anode material prepared in Example 1 of this invention at a scale bar of 50 μm; image c is the distribution map of carbon (C); image d is the distribution map of copper (Cu); and image e is the distribution map of zinc (Zn).

[0033] Figure 2 The image shows the XRD pattern of the zinc anode prepared in Example 1 of this invention.

[0034] Figure 3 This is a SEM image of the zinc negative electrode prepared in Example 2 of the present invention.

[0035] Figure 4 The image shows the XRD pattern of the zinc anode prepared in Example 2 of this invention.

[0036] Figure 5 This is a SEM image of the zinc negative electrode prepared in Example 3 of the present invention.

[0037] Figure 6 The image shows the XRD pattern of the zinc anode prepared in Comparative Example 3 of this invention.

[0038] Figure 7 This is a SEM image of the zinc anode prepared in Comparative Example 1 of this invention. Detailed Implementation

[0039] To enable those skilled in the art to better understand and implement the technical solutions of this invention, the invention will be further described below with reference to specific embodiments and accompanying drawings. Unless otherwise specified, all reagents used in this invention are commercially available, and all methods used are conventional techniques in the art.

[0040] Currently, methods for obtaining zinc anodes with (002) crystal plane preferential growth are mainly based on aqueous electrolytes prepared with high-purity zinc salts. For example, patent application CN118431391A discloses a method for preparing a zinc anode, which uses an electroplating solution containing zinc salt, acid, and manganese salt for non-epitaxial electrodeposition to obtain a zinc anode with a (002) crystal plane texture coefficient greater than or equal to 99%. Patent application CN118480832A discloses a method for texturing the surface of metallic zinc by non-epitaxial electrodeposition in a mixed aqueous solution containing ZnSO4 and phytic acid. Patent application CN115679380B discloses a method for preparing (002) crystal plane oriented metallic zinc, which uses a two-electrode electrochemical deposition technique, with iron foil, titanium foil, or copper foil as the working electrode, commercial zinc foil as the counter electrode, and zinc salt aqueous solution as the electrolyte, and uses constant current density discharge deposition to deposit (002) crystal plane oriented metallic zinc on the working electrode.

[0041] However, the above methods all rely on electrolytes prepared with high-purity zinc salts. If the zinc source is replaced with industrial-grade zinc oxide fume leaching solution with a complex composition, the coexisting impurity ions (such as iron, lead, and silicon) will severely interfere with the initial nucleation and subsequent growth process of electrocrystallization, causing the existing precise texture control strategies to fail. Furthermore, zinc oxide fume, as an important secondary zinc resource, requires multiple leaching, deep purification, and separation processes in its traditional treatment to selectively extract zinc from the complex system and obtain high-purity zinc salts before it can be used for subsequent electrodeposition to prepare functional materials. This process involves multiple purification, extraction, or displacement steps, resulting in a lengthy process flow, high reagent consumption, high production costs, and a large amount of waste liquid and residue generated. Based on these problems, this invention provides a zinc anode material and its preparation method.

[0042] The technical solution of the present invention will be analyzed in detail below.

[0043] This invention provides a method for preparing a zinc anode material. Zinc oxide dust is added to a choline-based eutectic solvent at 50°C to 80°C, and a non-purified leachate containing zinc ions is obtained through a leaching reaction. The non-purified leachate containing zinc ions and an inorganic chloride salt are used as electrolytes to perform non-epitaxial electrodeposition on an inert substrate to obtain a zinc anode material with (002) crystal plane orientation.

[0044] The inorganic chloride salt has a mass of 0.1% to 5% based on the mass of the choline eutectic solvent.

[0045] The choline-based eutectic solvent is prepared by mixing choline chloride with a hydrogen bond donor in a molar ratio of 1:1 to 3, wherein the hydrogen bond donor is urea or ethylene glycol.

[0046] In the above technical solution, the present invention utilizes the selective dissolution capability of eutectic solvents for zinc to directly leach zinc components from flue dust using choline chloride eutectic solvent, while inhibiting the dissolution of impurities, thereby obtaining a non-purified electrolyte that can be directly used for electrodeposition, realizing a one-step conversion from solid waste to electrodeposition raw material, eliminating the cumbersome deep purification steps; on this basis, by utilizing the unique coordination chemical environment of eutectic solvents, the first solvation shell structure and interfacial charge distribution of zinc ions are further modulated by introducing texture-regulating additives (inorganic chloride salts), regulating the chloride ion chemical potential and the formed interfacial active complex ions in the system, significantly increasing the nucleation overpotential and generating crystal plane selective adsorption, thereby establishing a new non-epitaxial electrodeposition regulation mechanism in complex systems that can induce zinc to preferentially grow along the (002) crystal plane. The eutectic solvent in the preparation method of this invention has the unique property of having both clean extraction and electrochemical deposition functions. It completes the selective leaching of zinc and non-epitaxial electrodeposition of textured zinc anode in the same choline-based eutectic solvent medium, realizing a short process coupling of "recovery-electrodeposition integration", which significantly improves the process integration and resource utilization efficiency.

[0047] The technical solution of the present invention will be further illustrated below through the following embodiments and comparative examples.

[0048] Example 1 A method for preparing a zinc anode material includes the following steps: S1. Flux Preparation and Leaching: Choline chloride and urea were weighed at a molar ratio of 1:2, mixed, and stirred at 80°C until a homogeneous and transparent liquid was formed, yielding a choline chloride-urea eutectic solvent. 5g of zinc oxide dust (mainly ZnO, with trace amounts of PbS and Fe2O3) from a smelter in Jiangxi Province was added to 100mL of the preheated choline chloride-urea eutectic solvent at 60°C, and leached for 2 hours with stirring at 500rpm. After the reaction, the solution was filtered to obtain a zinc-rich leachate. ICP-OES analysis showed that the zinc leaching rate was over 95%, and the dissolution rates of iron and lead impurities were less than 5%.

[0049] S2, Electrodeposition Control: Using the zinc-rich leachate and 3% NaCl (based on the mass of the choline chloride-urea eutectic solvent, NaCl is 3% by mass) as the electrolyte, a three-electrode system (copper foil as the working electrode, platinum sheet as the counter electrode, and Ag / AgCl as the reference electrode) was used for constant potential electrodeposition at 60°C. The deposition potential was -1.2V, and the deposition time was 1 hour, resulting in a zinc layer.

[0050] S3, Post-processing: The deposited zinc layer is peeled off from the copper substrate, washed three times each with deionized water and anhydrous ethanol, and dried in a vacuum drying oven at 60°C for 6 hours to obtain the zinc anode material.

[0051] Example 2 A method for preparing a zinc anode material includes the following steps: S1. Flux Preparation and Leaching: Choline chloride and ethylene glycol were weighed at a molar ratio of 1:2, mixed, and stirred at 80°C until a homogeneous and transparent liquid was formed, yielding a choline chloride-ethylene glycol eutectic solvent. 5g of zinc oxide dust (mainly ZnO, with trace amounts of PbS and Fe2O3) from a smelter in Jiangxi Province was added to 100mL of the preheated choline chloride-ethylene glycol eutectic solvent at 70°C, and leached for 1.5 hours with stirring at 500rpm. After the reaction, the solution was filtered to obtain a zinc-rich leachate. Inductively coupled plasma atomic emission spectrometry (ICP-AES) analysis showed that the zinc leaching rate was over 95%, and the leaching rates of impurities such as iron and lead were less than 5%.

[0052] S2, Electrodeposition Control: The zinc-rich leachate and 1.5% NaCl (based on the mass of the choline chloride-urea eutectic solvent, NaCl is 1.5% by mass) were used as the electrolyte. A three-electrode system (copper foil as the working electrode, platinum sheet as the counter electrode, and Ag / AgCl as the reference electrode) was employed for pulsed electrodeposition at 70°C with a pulse current density of 10 mA / cm². 2 A zinc layer was obtained by setting a pulse width of 2ms, a duty cycle of 30%, and a deposition time of 1.5 hours.

[0053] S3, Post-processing: The deposited zinc layer is peeled off from the copper substrate, washed three times each with deionized water and anhydrous ethanol, and dried in a vacuum drying oven at 60°C for 6 hours to obtain the zinc anode material.

[0054] Example 3 A method for preparing a zinc anode material includes the following steps: S1. Flux Preparation and Leaching: Choline chloride and urea were weighed at a molar ratio of 1:2, mixed, and stirred at 80°C until a homogeneous and transparent liquid was formed, yielding a choline chloride-urea eutectic solvent. 5g of zinc oxide dust (mainly ZnO, with trace amounts of PbS and Fe2O3) from a smelter in Jiangxi Province was added to 100mL of the preheated choline chloride-urea eutectic solvent at 60°C, and leached for 2 hours with stirring at 500rpm. After the reaction, the solution was filtered to obtain a zinc-rich leachate. ICP-OES analysis showed that the zinc leaching rate was over 95%, and the dissolution rates of impurities such as iron and lead were less than 5%.

[0055] S2, Electrodeposition Control: The zinc-rich leachate and 0.8% NaCl (based on the mass of the choline chloride-urea eutectic solvent, the mass of NaCl is 0.8%) were used as the electrolyte. A three-electrode system (copper foil as the working electrode, platinum sheet as the counter electrode, and Ag / AgCl as the reference electrode) was employed, and constant current mode was performed at 80°C with a current density of 5 mA / cm². 2 A zinc layer was obtained after a deposition time of 2 hours.

[0056] S3, Post-processing: The deposited zinc layer is peeled off from the copper substrate, washed three times each with deionized water and anhydrous ethanol, and dried in a vacuum drying oven at 50°C for 8 hours to obtain the zinc anode material.

[0057] To further illustrate the technical effects of the present invention, a comparative example is also provided, as follows.

[0058] Comparative Example 1 A method for preparing a zinc anode material includes the following steps: When electrodepositing zinc on a copper substrate, the copper sheet is first polished, then ultrasonically cleaned at 40 kHz, and activated by acid washing with hydrochloric acid. A mixed aqueous solution of 0.5 M ZnSO4 and 1 wt% Na2SO4 is prepared, stirred to dissolve, and then filtered. A three-electrode system is used (copper foil as the working electrode, platinum sheet as the counter electrode, and Ag / AgCl as the reference electrode), at 20 mA / cm². 2 Deposition was performed at room temperature for 50 minutes under constant current mode. After deposition, the copper substrate was removed, rinsed with deionized water, and dried with nitrogen to obtain a copper sheet with a zinc coating.

[0059] Comparative Example 2 A method for preparing a zinc anode material includes the following steps: S1, Flux Preparation and Leaching: Weigh choline chloride and urea at a molar ratio of 1:2, mix, and stir at 80℃ until a homogeneous, transparent liquid is formed, yielding a choline chloride-urea eutectic solvent. Take 5g of zinc oxide dust (mainly ZnO, with small amounts of PbS and Fe2O3 associated with it) from a smelter in Jiangxi Province, add it to 100mL of the preheated choline chloride-urea eutectic solvent at 60℃, and leach for 2 hours with stirring at 500rpm. After the reaction is complete, filter to obtain a zinc ion-rich leachate.

[0060] S2, Electrodeposition Control: The zinc-rich leaching solution served as the electrolyte. A three-electrode system (copper foil as the working electrode, platinum sheet as the counter electrode, and Ag / AgCl as the reference electrode) was used for constant potential electrodeposition at 60°C. The deposition potential was -1.2V, and the deposition time was 1 hour. No NaCl was added to obtain a zinc layer.

[0061] S3, Post-processing: The deposited zinc layer is peeled off from the copper substrate, washed three times each with deionized water and anhydrous ethanol, and dried in a vacuum drying oven at 60°C for 6 hours to obtain the zinc anode material.

[0062] XRD analysis showed that the texture coefficient of the (002) crystal facet of the zinc anode prepared in Comparative Example 2 was 68.5%, which was significantly lower than that in Example 1 with added NaCl. This indicates that the added chloride ions will form chloride-choline complex anions with choline (reaction formulas 1 and 2). These complex anions preferentially and selectively adsorb on the highly active prismatic crystal faces (such as (101) and (100)) during zinc deposition, thereby differentially inhibiting the growth of these crystal faces and thus changing the preferred orientation of zinc deposition ((002) crystal facet). Since different chloride ion concentrations will cause changes in the adsorption equilibrium state, the relative proportions of different crystal faces in the deposition layer will eventually show a controllable difference.

[0063] Ch + +Cl − →[ChCl2] − (1) [ChCl2]+Cl − →[Ch2Cl3] − (2) Where Ch + It is a choline cation.

[0064] Symmetrical battery test: The electrodeposited zinc negative electrode was cut into 12mm round pieces and assembled into a coin cell with the same zinc sheet, glass fiber separator, and electrolyte. After standing for 2 hours to soak, the cell was connected to a battery testing system at 1mA / cm. 2Constant current charge-discharge cycles were performed at the specified current density, and the voltage-time curves were recorded. Failure was considered to have occurred when the polarization voltage exceeded a set threshold (e.g., ±0.1V) or a short circuit occurred. The zinc anode material prepared in Comparative Example 2 was tested at 1 mA / cm². 2 It can cycle stably for about 250 hours at current density.

[0065] Figure 1 The images show SEM and EDS images of the zinc anode material prepared in Example 1 of this invention. The SEM images show that a tightly bonded zinc deposition layer, approximately 10 μm thick, has been electroplated onto the copper foil surface. EDS analysis further confirms that the zinc deposition layer has high purity (further examination using inductively coupled plasma revealed a zinc metal purity of 99.89%) and that the coating is tightly bonded.

[0066] Figure 2 The image shows the XRD pattern of the zinc anode prepared in Example 2 of this invention. According to XRD analysis, the texture factor of the (002) crystal plane of the prepared zinc anode is 82.3%. Figure 3 This is a SEM image of the zinc anode prepared in Example 2 of the present invention. SEM observation shows that the surface of the deposited layer is relatively dense; in the symmetric cell test, at 1 mA / cm 2 It can cycle stably for more than 400 hours at current density.

[0067] Figure 4 The image shows the XRD pattern of the zinc anode prepared in Example 3 of this invention. According to XRD analysis, the texture factor of the (002) crystal plane of the prepared zinc anode is 75.6%. Figure 5 This is a SEM image of the zinc anode prepared in Example 3 of the present invention. SEM observation shows that a small number of dendrite sprouts exist on the surface of the deposited layer. In the symmetric cell test, at 1 mA / cm... 2 It can cycle stably for about 300 hours at current density.

[0068] Figure 6 The image shows the XRD pattern of the zinc anode prepared in Comparative Example 1 of this invention. According to XRD analysis, the texture coefficient of the (002) crystal plane of the prepared zinc anode is only 32.4%, which shows random orientation.

[0069] Figure 7 This is a SEM image of the zinc anode prepared in Comparative Example 1 of this invention. SEM observation shows obvious dendrites on the surface of the deposited layer. In the symmetric cell test, at 1 mA / cm²... 2 A short circuit occurs in less than 100 hours of cycling at the current density.

[0070] In summary, this invention not only achieves a short-process coupling of "recycling-electrodeposition integration", but also establishes a new non-epitaxial electrodeposition control mechanism for inducing preferential growth of zinc along the (002) crystal plane in the same eutectic solvent medium of choline chloride through the synergistic effect of selective leaching and texture-regulating additives (inorganic chloride salts). Experimental data show that Example 2 with added NaCl achieved the highest (002) texture coefficient of 82.3% and a dense deposition layer, with a symmetric cell cycle life of over 400 hours; while Comparative Example 2 without added NaCl had a texture coefficient of only 68.5% and a cycle life of about 250 hours; Comparative Example 1 with the traditional aqueous solution system had a texture coefficient of only 32.4% and short-circuited in less than 100 hours of cycling. This fully demonstrates the effectiveness of the technical path of texture regulation achieved by chloride ion-mediated crystal plane selective adsorption in this invention.

[0071] It should be noted that when numerical ranges are involved in this invention, it should be understood that the two endpoints of each numerical range, as well as any value between the two endpoints, can be selected. Since the steps and methods used are the same as in the embodiments, preferred embodiments are described in this invention to avoid redundancy. Although preferred embodiments of this invention have been described, those skilled in the art, once they understand the basic inventive concept, can make other changes and modifications to these embodiments, and all such changes and modifications fall within the scope of this invention.

[0072] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. If these modifications and variations fall within the scope of equivalents of this invention, then this invention also intends to include these modifications and variations.

Claims

1. A method for preparing a zinc anode material, characterized in that, Includes the following steps: Zinc oxide dust was added to a choline-based eutectic solvent at 50℃~80℃, and a zinc ion-containing leachate was obtained through a leaching reaction. The zinc ion-containing leachate and an inorganic chloride salt were used as electrolytes to perform non-epitaxial electrodeposition on an inert substrate to obtain a zinc anode material with (002) crystal plane orientation. The inorganic chloride salt has a mass percentage of 0.1% to 5% based on the mass of the choline eutectic solvent. The choline-based eutectic solvent is prepared by mixing choline chloride with a hydrogen bond donor in a molar ratio of 1:1 to 3, wherein the hydrogen bond donor is urea or ethylene glycol.

2. The method for preparing the zinc anode material according to claim 1, characterized in that, The inorganic chloride salt is NaCl, KCl, or NH4Cl.

3. The method for preparing the zinc anode material according to claim 1, characterized in that, The zinc oxide fume contains 75% to 82% zinc; the ratio of zinc oxide fume to choline eutectic solvent is 1g:10mL to 50mL.

4. The method for preparing the zinc anode material according to claim 1, characterized in that, The non-epitaxial electrodeposition adopts a constant potential mode, and the parameters for the non-epitaxial electrodeposition are: deposition potential of -1.5V to -0.8V and deposition temperature of 50℃ to 80℃.

5. The method for preparing the zinc anode material according to claim 1, characterized in that, When the non-epitaxial electrodeposition is performed in constant current mode, the parameter conditions for the non-epitaxial electrodeposition are: current density of 1 mA / cm². 2 ~20mA / cm 2 The deposition temperature is 30℃~80℃.

6. The method for preparing the zinc anode material according to claim 1, characterized in that, When the non-epitaxial electrodeposition is performed in pulsed current mode, the parameter conditions for the non-epitaxial electrodeposition are: pulsed current density of 2 mA / cm². 2 ~30mA / cm 2 The pulse width is 0.1ms to 10ms, the duty cycle is 10% to 50%, and the deposition temperature is 50℃ to 80℃.

7. The method for preparing the zinc anode material according to claim 1, characterized in that, The leaching reaction takes 0.5 to 4 hours.

8. A zinc anode material prepared by the method of any one of claims 1 to 7.

9. The zinc anode material according to claim 8, characterized in that, The crystal texture coefficient of the zinc anode material is greater than 70%.

Images