In2O3-ZnIn2S4 nano heterogeneous composite material as well as preparation method and application thereof

Abstract

The invention relates to an In2O3-ZnIn2S4 nano heterogeneous composite material as well as a preparation method and application of the In2O3-ZnIn2S4 nano heterogeneous composite material. The preparation method of the composite material comprises the following steps: mixing an indium source and terephthalic acid in an organic solvent, heating in an oil bath, carrying out solid-liquid separation on a reaction mixture to take a solid phase, and heating and calcining the dried solid phase in an inert atmosphere to obtain an In2O3 sample; and dissolving the obtained In2O3 sample in water, adding a zinc source, an indium source and thioacetamide to obtain a mixed solution, heating in an oil bath, carrying out solid-liquid separation on the reaction mixture, and taking a solid phase to obtain the In2O3-ZnIn2S4 nano heterogeneous composite material. The unique heterogeneous interface construction accelerates the sodium ion transmission kinetics, and endows the material with the reversible specific capacity (1000mA / g) of 417.6 mAh / g. The three-dimensional nanosheet network structure effectively buffers the volume expansion effect in the charging and discharging process, and the capacity retention rate reaches 95% after 160 times of circulation. The electron conduction path is optimized through the synergistic effect of double metals, and the specific capacity of 320.6 mAh / g is still kept under the large current density of 8000 mA / g.

Description

Technical Field

[0001] This invention relates to the field of sodium-ion battery anode technology, and in particular to an In2O3-ZnIn2S4 nano-heterogeneous composite material, its preparation method, and its application. Background Technology

[0002] Against the backdrop of multiple challenges facing the world, including resource scarcity, climate change, and accelerated urbanization, the research and development of clean and renewable energy technologies has become a core issue in the global energy transition. With the rapid iteration of electric vehicle and smart grid technologies, traditional graphite anode lithium-ion batteries have gradually revealed their performance bottlenecks, driving innovative breakthroughs in new energy storage technologies.

[0003] Sodium-ion batteries are attracting attention from both academia and industry due to their unique physicochemical properties: as the fifth most abundant metallic element on Earth (2.64% of the Earth's crust), sodium has a significant advantage in resource abundance compared to lithium (0.0065%); its low self-discharge rate and cost-effectiveness give it a natural advantage for large-scale application. From a working principle perspective, sodium-ion batteries and lithium-ion batteries are homologous, and theoretically, a complete alternative technology system can be constructed. However, limited by the larger atomic radius of sodium ions (1.02 Å vs. lithium ions 0.76 Å), the intercalation-deintercalation process easily induces distortion of the graphite layered structure, leading to significant capacity decay (typically <35 mAh / g) in traditional graphite anodes. Furthermore, the higher ionic mass (Na... + 22.99 g / mol vsLi + The concentration of 6.94 g / mol leads to sluggish diffusion kinetics, causing key problems such as volume expansion of electrode materials (>300%) and decreased interface stability, which seriously restricts their practical application.

[0004] Current anode material systems mainly encompass carbon-based materials, alloys, and multi-component systems such as transition metal oxides / sulfides / selenides / phosphides. Among these, metal sulfur / oxides have attracted considerable attention due to their outstanding theoretical specific capacity (e.g., FeS2 894 mAh / g) and tunable electronic structure. However, these materials still face two major technological barriers: on the one hand, drastic volume deformation (sulfides > 400%) easily leads to electrode pulverization and failure; on the other hand, their intrinsic conductivity is too low (generally < 10). -6 The charge transport impedance caused by S / cm leads to a significant deterioration in cycle stability (typically <200 cycles) and rate performance (capacity retention <50% at 1C). Summary of the Invention

[0005] To address the above technical problems, this invention provides an In2O3-ZnIn2S4 nano-heteropolymer composite material, its preparation method, and its applications. The composite material obtained by this invention effectively solves the kinetic hysteresis and structural instability problems inherent in traditional metal oxide-sulfide anodes through interface engineering. The unique heterogeneous interface construction accelerates sodium ion transport kinetics, endowing the material with a reversible specific capacity of up to 417.6 mAh / g (1000 mA / g). The three-dimensional nanosheet network structure effectively buffers the volume expansion effect during charge and discharge processes, achieving a capacity retention of 95% after 160 cycles. The bimetallic synergistic effect optimizes the electron conduction path, maintaining a specific capacity of 320.6 mAh / g even at a high current density of 8000 mA / g.

[0006] The first objective of this invention is to provide a method for preparing In2O3-ZnIn2S4 nanocomposite materials, comprising the following steps: S1. Indium source and terephthalic acid are mixed in an organic solvent and heated in an oil bath. The reaction mixture is separated into solid and liquid phases. The dried solid phase is then calcined under an inert atmosphere to obtain an In2O3 sample. S2. Dissolve the obtained In2O3 sample in water, and add zinc source, indium source and sulfur source to obtain a mixed solution. Then heat in an oil bath to separate the solid and liquid phases of the reaction mixture and obtain the In2O3-ZnIn2S4 nano-heterogeneous composite material.

[0007] In some embodiments of the present invention, in step S1, the molar ratio of indium source to terephthalic acid is (1~2):(1~2). The indium source is selected from one or more of In(NO3)3·4H2O, InCl3 and In2(SO4)3.

[0008] In some embodiments of the present invention, in step S1, the organic solvent is selected from N,N-dimethylformamide; The oil bath heating temperature is 100~150℃, and the time is 1~4 hours; The inert atmosphere contains inactive gases including nitrogen and / or argon. The heating and calcination temperature is 400~600℃, and the calcination time is 1~4h.

[0009] In some embodiments of the present invention, in step S2, the zinc source is selected from one or more of ZnCl2, ZnSO4 and ZnNO3; The indium source is selected from one or more of InCl3, In2(SO4)3 and In(NO3)3; The sulfur source is selected from one or more of thioacetamide, thiourea, and sulfur powder.

[0010] In some embodiments of the present invention, in step S2, the oil bath heating temperature is 60~100℃ and the time is 1~4h.

[0011] In some embodiments of the present invention, in step S2, the mass ratio of the In2O3 sample, zinc source, indium source and sulfur source is (5~10):(20~27):(40~48):(20~30).

[0012] The second objective of this invention is to provide an In2O3-ZnIn2S4 nanoheteromaterial, which is prepared by the aforementioned preparation method; the In2O3-ZnIn2S4 nanoheteromaterial consists of three-dimensional ZnIn2S4 nanosheets embedded on the surface of In2O3 with a hollow nanorod structure.

[0013] A third objective of this invention is to provide a negative electrode material, including the In2O3-ZnIn2S4 nanoheteropolymer composite material.

[0014] A fourth objective of the present invention is to provide a negative electrode sheet comprising the aforementioned negative electrode material.

[0015] A fifth object of the present invention is to provide a sodium-ion battery, including the negative electrode.

[0016] The technical solution of the present invention has the following advantages compared with the prior art: This invention provides a sodium-ion battery anode material and its preparation method. This heterogeneous material features tunable structure and morphology and excellent electrochemical performance. The ZnIn2S4-In2O3 heterocomposite material prepared in this invention has a three-dimensional layered nanostructure, in which hollow In2O3 nanotubes serve as the internal support structure while the outer surface is composed of interconnected ZnIn2S4 nanosheets. These ZnIn2S4 nanosheets are formed by mesh-like edge stacking and self-assembly. When the In2O3-ZnIn2S4 heterocomposite material is used as a sodium-ion battery anode material, the hollow structure of the In2O3 nanotubes effectively alleviates volume expansion during cycling and provides channels for electron and sodium ion transport. The abundant ZnIn2S4 nanosheets on the surface have rich pores, providing effective transport channels for electrons and sodium ions and allowing for effective electrolyte wetting. Therefore, the synergistic effect of the In2O3 hollow nanotubes and ZnIn2S4 nanosheets gives it high discharge specific capacity, long cycle performance, and excellent rate performance when used as a sodium-ion battery anode material.

[0017] The In2O3-ZnIn2S4 heteromaterial provided by this invention can significantly improve the theoretical capacity of sodium-ion battery anode materials, which is beneficial to improving the actual capacity of the battery.

[0018] The In2O3-ZnIn2S4 heteromaterial prepared by this invention has a three-dimensional nanosheet embedded hollow nanorod structure, which can well adapt to the volume change problem generated during charging and discharging, thereby improving the cycle life of the battery. At the same time, it exposes more active sites of active materials, thereby improving the battery capacity.

[0019] The negative electrode material prepared by this invention has the advantages of long lifespan, high specific capacity, and high rate performance. Attached Figure Description

[0020] To make the content of this invention easier to understand, the invention will be further described in detail below with reference to specific embodiments and accompanying drawings, wherein... Figure 1 These are XRD images of the In2O3-ZnIn2S4 composite obtained in Example 1 of this invention, specifically pure phase ZnIn2S4 and In2O3. Figure 2 This is a SEM image of In2O3-ZnIn2S4 obtained in Embodiment 1 of the present invention; Figure 3 This is a TEM image of In2O3-ZnIn2S4 obtained in Example 1 of the present invention; Figure 4 This is the EDS image of In2O3-ZnIn2S4 obtained in Embodiment 1 of the present invention; Figure 5 This is a comparison of the cycling performance of the In2O3-ZnIn2S4 obtained in Example 1 of the present invention with that of the In2O3 obtained in Comparative Example 2 and the ZnIn2S4 obtained in Comparative Example 1 at 1000 mA / g. Figure 6 This is a comparison of the rate performance of the In2O3-ZnIn2S4 obtained in Example 1 of the present invention with the In2O3 obtained in Comparative Example 2 and the ZnIn2S4 anode materials obtained in Comparative Example 1. Figure 7 This is a SEM image of ZnIn2S4 obtained in Comparative Example 1 of this invention; Figure 8 This is a SEM image of In2O3 obtained in Comparative Example 2 of this invention. Detailed Implementation

[0021] The present invention will be further described below with reference to the accompanying drawings and specific embodiments, so that those skilled in the art can better understand and implement the present invention. However, the embodiments described are not intended to limit the present invention.

[0022] Example 1 This embodiment provides an In2O3-ZnIn2S4 nanoheteromeric composite material, its preparation method, and its application, as detailed below: I. Preparation method of In2O3-ZnIn2S4 nano-heteropolymer composite material, the specific steps are as follows: At room temperature, a certain amount of In(NO3)3·4H2O and terephthalic acid (molar ratio of In(NO3)3·4H2O to terephthalic acid 1:1) were added to 80 ml of N,N-dimethylformamide (DMF) and dissolved by sonication for 20 min. The mixed solution was then added to a 200 ml single-necked flask and heated in an oil bath at 120 °C for 2 h. Subsequently, the mixture was washed three times by centrifugation with water and ethanol, and dried in a forced-air drying oven at 60 °C for 12 h. The dried sample was then placed in a tube furnace and calcined at 120 °C for 2 h and 500 °C for 2 h under an Ar atmosphere with a program of 5 °C / min, finally yielding a pure phase In2O3 sample.

[0023] Subsequently, 100 mg of In₂O₃ was added to 100 ml of water, along with 270 mg of ZnCl₂, 420 mg of InCl₃, and 300 mg of thioacetamide. The mixture was magnetically stirred for 30 min to obtain a mixed solution. This solution was then added to a 200 ml single-necked flask and heated in an oil bath at 80 °C for 2 h. The mixture was then washed three times by centrifugation with water and ethanol, and dried in a forced-air drying oven at 60 °C for 12 h to obtain the In₂O₃-ZnIn₂S₄ nanoheteromeric composite material. The structure of the obtained composite material was characterized, and the results are shown below. Figures 1-4 ,Depend on Figure 1 The XRD patterns of the synthesized heterocomposite show the presence of the In2O3 phase, with peak positions corresponding to JCPDS card no. 06–0416, and the presence of the ZnIn2S4 phase, with peak positions corresponding to JCPDS card no. 65–2023. This demonstrates the successful preparation of the In2O3-ZnIn2S4 nanocomposite material. Furthermore, pure-phase In2O3 and ZnIn2S4 materials were successfully synthesized. Figure 2 It can be seen that the morphology of the In2O3-ZnIn2S4 nanoheteropolymer is mainly composed of three-dimensional nanosheets embedded on the surface of nanorods. Figure 3 It can be seen that three-dimensional nanosheets grow uniformly on the surface of hollow nanorods. Figure 4 It can be seen that In, O, S, and Zn elements are uniformly distributed in the heterocomposite, with In and O elements mainly distributed in the hollow nanorods, while S and Zn elements are mainly distributed in the nanosheet structure.

[0024] Comparative Example 1 This comparative example provides a synthesis of pure ZnIn2S4, as detailed below: At room temperature, a certain amount of ZnCl2, InCl3·4H2O, and thioacetamide (molar ratio 1:2:5) were added to a mixture of 15 ml deionized water and 15 ml anhydrous ethanol, and dissolved by sonication for 20 min. The mixture was then added to a 100 ml reactor and hydrothermally reacted at 180 °C for 4 h. Subsequently, the mixture was washed three times by centrifugation with water and ethanol, and dried in a forced-air drying oven at 60 °C for 12 h to obtain a pure-phase ZnIn2S4 sample.

[0025] The obtained ZnIn2S4 sample was structurally characterized, and the results are shown in the figure. Figure 8 As shown in the figure, the ZnIn2S4 sample mainly exhibits a nanosphere structure with a diameter of about 4µm, and the nanospheres are mainly self-assembled from interconnected nanosheets.

[0026] Comparative Example 2 This comparative example provides a synthesis of pure In2O3, as detailed below: At room temperature, a certain amount of In(NO3)3·4H2O and terephthalic acid (molar ratio of In(NO3)3·4H2O to terephthalic acid 1:1) were added to 80 ml of N,N-dimethylformamide (DMF) and sonicated for 20 min. The mixed solution was then added to a 200 ml single-necked flask and heated in an oil bath at 160 °C for 4 h. Subsequently, the mixture was washed three times by centrifugation with water and ethanol, and dried in a forced-air drying oven at 60 °C for 12 h. The dried sample was placed in a tube furnace and calcined at 120 °C for 2 h and then at 500 °C for 2 h under an Ar atmosphere with a program of 5 °C / min, finally obtaining a pure phase In2O3 sample. The structure of the obtained In2O3 sample was characterized, and the results are shown in [Figure 1]. Figure 8 As shown in the figure, In2O3 mainly exhibits a nanorod-like structure with a diameter of approximately 700 nm.

[0027] Performance testing The In2O3-ZnIn2S4 nanoheteropolymer obtained in Example 1, the ZnIn2S4 sample obtained in Comparative Example 1, and the In2O3 sample obtained in Comparative Example 2 were subjected to electrochemical performance tests, including cycle performance tests and rate performance tests. These tests are conventional testing methods in the field.

[0028] The In2O3-ZnIn2S4 nanocomposite material obtained in Example 1, the ZnIn2S4 sample obtained in Comparative Example 1, and the In2O3 sample obtained in Comparative Example 2 were mixed and ground with conductive carbon black (Super P) and binder (PVDF) at a weight ratio of 7:2:1, respectively, and uniformly coated on the surface of copper foil. After vacuum drying at 60°C, the mixtures were sliced ​​and used as the working electrode of the sodium-ion battery. Glass fiber GF / D was used as the separator, sodium metal sheet as the counter electrode, and 1M NaPF6 dissolved in dimethyl ethylene glycol (DME) was used as the electrolyte. The button cell 2032 was assembled in the following order: negative electrode shell, counter electrode, separator, electrolyte, working electrode, gasket, spring sheet, and positive electrode shell. The battery was then left to stand at room temperature for several hours before testing. All electrochemical performance tests were conducted using the NEWARE battery testing system. The experimental results are shown below. Figure 5 and Figure 6 .

[0029] Depend on Figure 5 It can be seen that, at a current density of 1000 mA / g, the sodium storage discharge specific capacity of the In2O3-ZnIn2S4 nanocomposite material after 160 cycles is 417.6 mAh / g. In comparison, the sodium storage discharge specific capacities of In2O3 and ZnIn2S4 after 100 cycles at a current density of 1000 mA / g are 122.3 and 191.6 mAh / g, respectively. Therefore, it can be seen that the In2O3-ZnIn2S4 nanocomposite material exhibits superior discharge specific capacity and cycle stability compared to the other two materials.

[0030] Depend on Figure 6 It can be seen that, at current densities of 200, 500, 1000, 2000, 3000, 5000 and 8000 mA / g, the In2O3-ZnIn2S4 nano-heteropolymer obtained in Example 1 has better rate performance than the other two comparative examples, and still exhibits a high sodium storage reversible specific capacity (320.6 mAh / g) even at a high current density of 8000 mA / g.

[0031] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A method for preparing an In2O3-ZnIn2S4 nano-heteropolymer composite material, characterized in that, Includes the following steps: S1. Indium source and terephthalic acid are mixed in an organic solvent and heated in an oil bath. The reaction mixture is separated into solid and liquid phases. The dried solid phase is then calcined under an inert atmosphere to obtain an In2O3 sample. S2. Dissolve the obtained In2O3 sample in water, and add zinc source, indium source and sulfur source to obtain a mixed solution. Then heat in an oil bath to separate the solid and liquid phases of the reaction mixture and obtain the In2O3-ZnIn2S4 nano-heterogeneous composite material.

2. The preparation method according to claim 1, characterized in that, In step S1, the molar ratio of indium source to terephthalic acid is (1~2):(1~2); The indium source is selected from one or more of In(NO3)3·4H2O, InCl3 and In2(SO4)3.

3. The preparation method according to claim 1, characterized in that, In step S1, the oil bath heating temperature is 100~150℃, and the time is 1~4h; The inert atmosphere contains inactive gases including nitrogen and / or argon. The heating and calcination temperature is 400~600℃, and the calcination time is 1~4h.

4. The preparation method according to claim 1, characterized in that, In step S2, the zinc source is selected from one or more of ZnCl2, ZnSO4, and ZnNO3; The indium source is selected from one or more of InCl3, In2(SO4)3 and In(NO3)3; The sulfur source is selected from one or more of thioacetamide, thiourea, and sulfur powder.

5. The preparation method according to claim 1, characterized in that, In step S2, the oil bath heating temperature is 60~100℃, and the time is 1~4h.

6. The preparation method according to claim 1, characterized in that, In step S2, the mass ratio of In2O3 sample, zinc source, indium source and sulfur source is (5~10):(20~27):(40~48):(20~30).

7. An In2O3-ZnIn2S4 nanoheteropolymer composite material, characterized in that, The In2O3-ZnIn2S4 nanoheteromaterial is prepared by the preparation method described in any one of claims 1 to 6, wherein the In2O3-ZnIn2S4 nanoheteromaterial is formed by embedding three-dimensional ZnIn2S4 nanosheets into the surface of In2O3 with a hollow nanorod structure.

8. A negative electrode material, characterized in that, Including the In2O3-ZnIn2S4 nanoheteropolymer composite material as described in claim 7.

9. A negative electrode sheet, characterized in that, Includes the negative electrode material as described in claim 8.

10. A sodium-ion battery, characterized in that, Includes the negative electrode sheet as described in claim 9.

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