A cu with copper vacancies 2-x Te nanotubes, methods of making the same, and use in negative electrode materials for aqueous zinc ion batteries

Abstract

This invention discloses a Cu with copper vacancies 2‑x Te nanotubes, their preparation methods, and their application in aqueous zinc-ion battery anode materials; the Cu nanotubes with copper vacancies 2‑x The preparation method of Te nanotubes includes the following steps: (1) dissolving hexadecyltrimethylammonium bromide in water by heating and stirring; (2) adding NaOH, NaBH4 and Te powder to the solution obtained in step (1); (3) adding copper foil to the mixed solution obtained in step (2) and reacting at 25-85℃ for 0.25-6h to obtain Cu nanotubes with copper vacancies. 2‑x Te nanotubes, where 0 ≤ x ≤ 1. This invention utilizes the regulating effect of hexadecyltrimethylammonium bromide (CTAB) to prepare Cu... 2‑x Te nanotubes, and make the Cu 2‑x Te nanotubes possess copper vacancies and large interlayer spacing, exhibiting low intercalation potential and high specific capacity.

Description

Technical Field

[0001] This invention relates to the field of electrode materials technology, specifically to a Cu electrode with copper vacancies. 2-x Te nanotubes, their preparation methods, and their application in aqueous zinc-ion battery anode materials. Background Technology

[0002] Lithium-ion batteries are a crucial pillar of rechargeable batteries, but the scarcity and insecurity of lithium resources will inevitably become bottlenecks to their future development. Zinc, however, is relatively inexpensive and safe, and aqueous zinc-ion batteries have shown significantly improved electrochemical performance, making them a promising candidate for future high-performance batteries. Unfortunately, zinc can lead to uncontrolled dendrite growth during electrochemical reactions, which greatly reduces the battery's cycle life and coulombic efficiency. When dendrite growth severely punctures the separator, the battery may experience short circuits or even explosions, seriously hindering the practical application of zinc metal batteries.

[0003] To address the various problems associated with zinc, various strategies have been reported. For example, Cao et al. used electrodeposition to coat ZnP onto zinc foil, increasing the rate of zinc ion release during stripping / electroplating and thus improving cycle stability. Besides studies on surface-deposited alloy materials, constructing porous channels on the surface is also an effective method to mitigate zinc dendrite formation. For instance, Deng et al. proposed using kaolin to coat the zinc surface, which suppressed side reactions and achieved long-term cycle stability. Furthermore, assembled full cells can provide high specific capacity and good capacity retention. While current research has made some progress, most studies suffer from low depth of discharge, meaning low Zn utilization and resulting in low total energy density. Moreover, at high depths of discharge, zinc dendrite formation remains unavoidable, leading to poor cycle life. It is well known that replacing lithium metal anodes with graphite to avoid lithium metal formation is key to the commercialization of lithium-ion batteries (LIBs). Therefore, to solve the problems associated with zinc anodes more quickly and effectively, it is necessary to develop high-performance zinc-free metal anodes.

[0004] Currently, several intercalated anode materials have been reported. For example, Li et al. reported a novel aqueous solution zinc-ion battery anode material, Na. 0.14 TiS2 has a discharge potential of 0.3V and exhibits good cycle life (0.5A g). -1 (After 5000 cycles, the cycle retention rate was 77%). Furthermore, Wen et al. investigated the electrochemical performance of a TiSe2 intercalated anode in an aqueous zinc-ion battery system, which exhibited high specific capacity and long cycle stability. In addition, some intercalated anodes, such as NHVO@Ti3C2T... x Cu 2-xSe and Mo6S8 have been reported to have long discharge plateaus and long cycling stability. Although these intercalation anodes avoid the formation of zinc dendrites, their low capacity and high intercalation potential result in low energy density, hindering the development of commercialization. Therefore, it is still an urgent task to develop intercalation anodes with low intercalation potential, high electrochemical performance and long-term stability. SUMMARY

[0005] The object of the present application is to provide a Cu 2-x Te nanotube having copper vacancies and a large interlayer spacing, which exhibits a low intercalation potential and a high specific capacity. 2-x Te nanotube having copper vacancies and a large interlayer spacing, which exhibits a low intercalation potential and a high specific capacity.

[0006] To achieve the above object, the technical scheme adopted by the present application is as follows:

[0007] The present application discloses a Cu 2-x Te nanotube having copper vacancies and a large interlayer spacing, which exhibits a low intercalation potential and a high specific capacity.

[0008] (1) Dissolve cetyltrimethylammonium bromide in water by heating and stirring;

[0009] (2) Add NaOH, NaBH4 and Te powder to the solution obtained in step (1);

[0010] (3) Put copper foil into the mixed solution obtained in step (2) and react at 25-85℃ for 0.25-6h to obtain Cu 2-x Te nanotube having copper vacancies, wherein 0≤x≤1.

[0011] As a preferred technical scheme, in step (1), the concentration of cetyltrimethylammonium bromide is 0.025-0.25mmol / L.

[0012] As a preferred technical scheme, in step (2), the molar ratio of NaOH, NaBH4 and Te powder is 20-200:1-10:0.1-1.

[0013] The present application also discloses a Cu 2-x Te nanotube having copper vacancies, which is prepared by the above-mentioned method for preparing Cu 2-x Te nanotube having copper vacancies.

[0014] The present application also discloses the application of the above-mentioned Cu 2-x Te nanotube having copper vacancies in water-based zinc ion battery negative electrode materials.

[0015] The present application also discloses the application of the above-mentioned Cu 2-xApplication of Te nanotubes in energy storage electrode materials.

[0016] The beneficial effects of this invention are:

[0017] This invention utilizes the regulatory effect of hexadecyltrimethylammonium bromide (CTAB) to prepare Cu 2-x Te nanotubes, and make the Cu 2-x Te nanotubes possess copper vacancies and large interlayer spacing, exhibiting low intercalation potential and high specific capacity (at 0.1 Ag). -1 After the next 100 cycles, the capacity is 188.5 mAh g. -1 It effectively inhibits the formation of zinc dendrites and the decomposition of electrolyte, making this material promising for applications in aqueous zinc-ion batteries and other energy storage fields. Attached Figure Description

[0018] Figure 1 Cu with copper vacancies prepared in Example 1 2-x Scanning electron microscope image of Te nanotubes;

[0019] Figure 2 Cu prepared for Comparative Example 1 2-x Scanning electron microscope image of Te material;

[0020] Figure 3 Cu with copper vacancies prepared in Example 1 2-x XRD pattern of Te nanotubes;

[0021] Figure 4 Cu prepared for Comparative Example 1 2-x XRD patterns of Te materials;

[0022] Figure 5 Cu with copper vacancies prepared in Example 1 2-x Te nanotubes at a current of 0.1 A g -1 The following is a graph showing the cyclic performance.

[0023] Figure 6 Cu prepared for Comparative Example 1 2-x Te material at a current of 0.1A g -1 The following is a graph showing the cyclic performance.

[0024] Figure 7 Cu with copper vacancies prepared in Example 1 2-x A rocking chair-style zinc-ion full cell assembled from Te nanotubes and zinc-intercalated manganese dioxide showed a current of 0.1 A g. -1 The following is a graph showing the cyclic performance. Detailed Implementation

[0025] In order to make the objects, technical solutions and advantages of the present application clearer, the present application will be further described below with reference to the drawings.

[0026] Example 1

[0027] (1) 0.25 mmol of CTAB was dissolved in 50 mL of distilled water by heating and stirring.

[0028] (2) 0.2 mol of NaOH, 0.01 mol of NaBH4 and 1 mmol of Te powder were added into the solution prepared in step (1) respectively.

[0029] (3) The solution prepared in step (2) was put into a cut copper foil, and reacted at 65°C for 2 h, and then washed with deionized water and ethanol for three times respectively, and naturally dried to obtain Cu 2-x Te nanotubes with copper vacancies, wherein 0≤x≤1.

[0030] Comparative Example 1

[0031] (1) 0.2 mol of NaOH, 0.01 mol of NaBH4 and 1 mmol of Te powder were dissolved in 50 mL of distilled water by heating and stirring.

[0032] (2) The solution prepared in step (1) was put into a cut copper foil, and reacted at 65°C for 2 h, and then washed with deionized water and ethanol for three times respectively, and naturally dried to obtain Cu 2-x Te material, wherein 0≤x≤1.

[0033] Figure 1 The scanning electron microscope (SEM) image of the Cu 2-x Te nanotubes with copper vacancies obtained in Example 1, and the morphology of the material is nanotube.

[0034] Figure 2 The scanning electron microscope (SEM) image of the Cu 2-x Te material obtained in Comparative Example 1, and the morphology of the material is nanosheet. Figure 2

[0035] Figure 3 The XRD spectrum of the Cu 2-x Te nanotubes with copper vacancies obtained in Example 1, and the results show that the XRD characteristic peaks completely correspond to the standard card.

[0036] Figure 4 The XRD spectrum of the Cu 2-x Te material obtained in Comparative Example 1, and the results show that the XRD characteristic peaks correspond to the XRD spectrum of the Cu 2-x Te nanotubes with copper vacancies. Figure 1 ​​

[0037] Cu prepared in Example 1 and Comparative Example 1 2-x Te material was used to assemble button cells, and the cycling performance of the material was tested.

[0038] Cu prepared in Example 1 and Comparative Example 1 respectively 2-x A battery was assembled using Te material as the negative electrode, zinc foil as the counter electrode, glass fiber as the separator, and 2M ZnSO4·7H2O as the electrolyte. The assembled battery was then subjected to electrochemical performance testing on a LAND battery testing system.

[0039] Figure 5 Cu with copper vacancies prepared in Example 1 2-x Te nanotubes at a current of 0.1 A g -1 The cycling performance graph below shows that Cu with copper vacancies 2-x Te nanotubes at 0.1A g -1 After 100 cycles, the specific capacity reaches 188.5 mAh g. -1 It exhibits high specific capacity and excellent cycle stability.

[0040] Figure 6 Cu prepared for Comparative Example 1 2-x Te material at a current of 0.1A g -1 The following cycle performance graph shows that Cu 2-x Te electrode material at 0.1A g -1 After 100 cycles, the specific capacity is only 73.8 mAh g. -1 It was found that Cu in Comparative Example 1 2- x The specific capacity of the Te material is much lower than that of the Cu material with copper vacancies in Example 1. 2-x Te nanotubes.

[0041] Figure 7 Cu with copper vacancies prepared in Example 1 2-x A rocking chair-style zinc-ion full cell assembled from Te nanotubes and zinc-intercalated manganese dioxide showed a current of 0.1 A g. -1 The following is a cycle performance graph for the full cell at 0.1 A g. -1 After the next 100 cycles, it has 90.4 mAh g. -1 With its high specific capacity and near 100% coulombic efficiency, it exhibits excellent performance.

[0042] The above shows and describes the basic principles, main features and advantages of the present application. Those skilled in the art should understand that the present application is not limited to the above-mentioned embodiments, and the above-mentioned embodiments and descriptions in the specification are only to illustrate the principles of the present application. Without departing from the spirit and scope of the present application, various changes and improvements can be made to the present application, and these changes and improvements all fall within the scope of the claimed present application. The scope of protection of the present application is defined by the appended claims and their equivalents.

Claims

1. A Cu with copper vacancies 2-x The application of Te nanotubes in the anode material of aqueous zinc-ion batteries is characterized by: The Cu with copper vacancies 2-x The preparation method of Te nanotubes includes the following steps: (1) Hexadecyltrimethylammonium bromide is dissolved in water by heating and stirring; in step (1), the concentration of hexadecyltrimethylammonium bromide is 0.025-0.25 mmol / L; (2) Add NaOH, NaBH4 and Te powder to the solution obtained in step (1); in step (2), the molar ratio of NaOH, NaBH4 and Te powder is 20-200 : 1-10 : 0.1-1; (3) Add copper foil to the mixed solution obtained in step (2) and react at 25-85℃ for 0.25-6h to obtain Cu with copper vacancies. 2-x Te nanotubes, where 0 ≤ x ≤ 1.

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