阅读说明：本技术 一种纳米带状或棒状的FeOOH及其制备方法和应用 (Nano-ribbon or rod-shaped FeOOH and preparation method and application thereof ) 是由 邵涟漪 汪世鸽 吴方丹 关杰多 喻露 史晓艳 孙志鹏 于 2021-08-31 设计创作，主要内容包括：本发明属于钠离子电池负极材料技术领域,公开了一种纳米带状或棒状的FeOOH及其制备方法和应用。该方法是通过将三价铁盐溶解在去离子水中、再加入尿素,搅拌溶解后,然后加入十二烷基磺酸钠,搅拌溶解后,转移到水热釜中反应；将最终产物进行抽滤分离,用去离子水和无水乙醇洗涤,最终制备得到具有纳米带状的FeOOH。改变表面活性剂种类(聚丙烯酸、聚乙烯吡咯烷酮和十二烷基苯磺酸钠)可以获得纳米棒状FeOOH。本发明操作简单,制备的特殊结构纳米带状或棒状的FeOOH可以减少扩散距离和增大比表面积,在钠离子电池领域具有重要的应用前景。(The invention belongs to the technical field of negative electrode materials of sodium ion batteries, and discloses a nano strip-shaped or rod-shaped FeOOH, and a preparation method and application thereof. Dissolving trivalent ferric salt in deionized water, adding urea, stirring for dissolving, then adding sodium dodecyl sulfate, stirring for dissolving, and transferring to a hydrothermal kettle for reaction; and carrying out suction filtration and separation on the final product, washing with deionized water and absolute ethyl alcohol, and finally preparing the nano-belt FeOOH. The nano-rod FeOOH can be obtained by changing the surfactant types (polyacrylic acid, polyvinylpyrrolidone and sodium dodecyl benzene sulfonate). The method is simple to operate, and the prepared nano-belt-shaped or rod-shaped FeOOH with a special structure can reduce the diffusion distance and increase the specific surface area, and has important application prospect in the field of sodium ion batteries.)

1. A preparation method of nano strip-shaped or rod-shaped FeOOH is characterized by comprising the following operation steps:

(1) dissolving ferric trichloride hexahydrate in deionized water, adding urea solid into the deionized water, and stirring to dissolve the urea solid to prepare a mixed solution of ferric trichloride and urea;

(2) adding a surfactant into the mixed solution of ferric trichloride and urea obtained in the step (1), and stirring until the surfactant is completely dissolved to obtain a mixed solution; the surfactant is sodium dodecyl sulfate, polyacrylic acid, polyvinylpyrrolidone or sodium dodecyl benzene sulfonate; when the surfactant is sodium dodecyl sulfate, heating to 70-90 ℃ while stirring;

(3) transferring the mixed solution obtained in the step (2) to a reaction kettle for hydrothermal reaction;

(4) and (3) carrying out suction filtration on a final product obtained by the hydrothermal reaction, sequentially washing for 2-3 times by using deionized water and ethanol, and drying to obtain the nano band-shaped or rod-shaped FeOOH.

2. The method of claim 1, wherein: when the surfactant in the step (2) is sodium dodecyl sulfate, the nano strip FeOOH is obtained in the step (4); and (3) when the surfactant in the step (2) is polyacrylic acid, polyvinylpyrrolidone or sodium dodecyl benzene sulfonate, obtaining the nano-rod-shaped FeOOH in the step (4).

3. The method of claim 1, wherein: the mass ratio of the ferric trichloride hexahydrate in the step (1) to the surfactant in the step (2) is 1:0.22: 0.06.

4. The method of claim 1, wherein: in the step (1), the concentration of the ferric trichloride hexahydrate in the deionized water is 0.5 mol/L.

5. The method of claim 1, wherein: the heating in step (2) is heating to 90 ℃.

6. The method of claim 1, wherein: the temperature of the hydrothermal reaction in the step (3) is 80-100 ℃, and the reaction time is 5-30 h; the hydrothermal reaction was carried out under a closed condition and then cooled to room temperature.

7. The method of claim 1, wherein: in the step (3), the washing is respectively carried out for 3 times by using deionized water and ethanol, and the drying conditions are as follows: drying at 60 deg.C for 10-20 hr.

8. A nano ribbon-like or rod-like FeOOH prepared by the preparation method of any one of claims 1 to 7.

9. Use of nanobelt-like or rod-like FeOOH according to claim 8 for the preparation of negative electrode material for sodium ion battery.

Technical Field

The invention belongs to the technical field of negative electrode materials of sodium ion batteries, and particularly relates to a nano strip-shaped or rod-shaped FeOOH, and a preparation method and application thereof.

Background

With the rapid development of industrialization and the rapid increase of population, the problems of shortage of fossil fuel resources and environmental pollution become more and more serious, and the development and utilization of clean and renewable energy sources become more important and urgent. In recent years, lithium ion batteries have been widely used in the fields of mobile phones, notebook computers, digital cameras, electric tools, and the like, and gradually expanded to the fields of new energy automobiles, energy storage, and the like, because of their outstanding advantages of high energy density, high working voltage, long cycle life, low self-discharge efficiency, environmental friendliness, and the like. The growing market of lithium ion batteries inevitably brings about the problems of shortage of lithium resources and rising lithium prices. Therefore, there is a need to develop new energy storage systems that are abundant in resources and inexpensive. Sodium ion battery systems are considered promising large-scale energy storage devices due to their abundant resources, low cost, environmental friendliness, and electrochemical properties similar to those of lithium ion batteries. Heretofore, as a negative electrode material for a sodium ion battery, there are carbonaceous materials, titanium-based materials, metal alloys, metal sulfides, transition metal oxides, and the like. Of these, transition metal oxides are of great interest due to their higher theoretical capacity. Particularly, materials based on ferrite compounds have been widely developed due to their abundant resources, low cost, environmental friendliness, and the like. FeOOH has a manganese barium ore type tunnel structure, and is beneficial to intercalation and transmission of sodium ions. At the same time, Fe³⁺The weak ionic bond between OH-and OH-also favors the conversion reaction. Although FeOOH has a higher theoretical capacity (903mAh g)^-1) But have poor cycle and rate performance, which is associated with particle cracking and irreversible phase transformation. Compared with the theoretical capacity, the cycle performance and rate performance of FeOOH still need to be improved. Currently, FeOOH is improved to be used as sodium ion batteryThe main method adopted for the cycling stability of the cell cathode is to reduce the particle size of FeOOH so as to shorten the diffusion distance of sodium ions. Nanocrystallization can provide high surface area and low ion transmission resistance, thereby generating high specific capacity and rate capability, the nanoparticles shorten the transport path of sodium ions, and promote the contact of electrodes and electrolyte; thereby improving its electrochemical performance. Therefore, a simple and efficient method for preparing the sodium-ion battery cathode material with good performance is needed to be found.

Disclosure of Invention

In order to overcome the defects and shortcomings in the prior art, the invention mainly aims to provide a method for preparing nano strip-shaped or rod-shaped FeOOH.

The invention also aims to provide the nano strip-shaped or rod-shaped FeOOH prepared by the preparation method; the material has a nanobelt or nanorod structure with uniform size, the nanostructure can provide high surface area and low ion transmission resistance, so that high specific capacity and speed capability are generated, the thin nanobelt or nanorod shortens the sodium ion transmission path, and the contact between an electrode and an electrolyte is promoted; thereby improving its electrochemical performance.

The invention also aims to provide application of the nano-belt-shaped or rod-shaped FeOOH.

The purpose of the invention is realized by the following technical scheme:

a preparation method of nano-ribbon or bar-shaped FeOOH comprises the following operation steps:

(1) dissolving ferric trichloride hexahydrate in deionized water, adding urea solid into the deionized water, and stirring to dissolve the urea solid to prepare a mixed solution of ferric trichloride and urea;

(2) adding a surfactant into the mixed solution of ferric trichloride and urea obtained in the step (1), heating to 70-90 ℃, stirring simultaneously, and stirring until the mixture is completely dissolved to obtain a mixed solution; the surfactant is sodium dodecyl sulfate, polyacrylic acid (PAA), polyvinylpyrrolidone (PVP) or Sodium Dodecyl Benzene Sulfonate (SDBS); when the surfactant is sodium dodecyl sulfate, heating to 70-90 ℃ while stirring;

(3) transferring the mixed solution obtained in the step (2) to a reaction kettle for hydrothermal reaction;

(4) and (3) carrying out suction filtration on a final product obtained by the hydrothermal reaction, sequentially washing for 2-3 times by using deionized water and ethanol, and drying to obtain the nano band-shaped or rod-shaped FeOOH.

When the surfactant in the step (2) is Sodium Dodecyl Sulfate (SDS), the nano-strip FeOOH is obtained in the step (4); and (3) when the surfactant in the step (2) is polyacrylic acid (PAA), polyvinylpyrrolidone (PVP) or Sodium Dodecyl Benzene Sulfonate (SDBS), obtaining the nano-rod-shaped FeOOH in the step (4).

The mass ratio of the ferric trichloride hexahydrate in the step (1) to the surfactant in the step (2) is 1:0.22: 0.06.

In the step (1), the concentration of the ferric trichloride hexahydrate in the deionized water is 0.5 mol/L.

The heating in step (2) is heating to 90 ℃.

The temperature of the hydrothermal reaction in the step (3) is 80-100 ℃, and the reaction time is 5-30 h; the hydrothermal reaction was carried out under a closed condition and then cooled to room temperature.

In the step (3), the washing is respectively carried out for 3 times by using deionized water and ethanol, and the drying conditions are as follows: drying at 60 deg.C for 10-20 hr.

The nano band-shaped or rod-shaped FeOOH prepared by the preparation method.

The nano strip-shaped or rod-shaped FeOOH is applied to preparing the cathode material of the sodium ion battery.

The specific implementation of the application is as follows:

fully and uniformly mixing the prepared nano banded or rodlike FeOOH with conductive carbon black and CMC-Na (sodium carboxymethylcellulose), adding deionized water, stirring to obtain uniformly mixed paste, coating the paste on a copper foil substrate to be used as a test electrode, assembling a button cell by using metal sodium as a counter electrode, and using 1M NaPF as electrolyte₆(sodium hexafluorophosphate) was dissolved in diethylene glycol dimethyl ether.

Compared with the prior art, the invention has the following advantages and effects:

(1) the nano-belt or rod-shaped FeOOH has a nano-belt structure, the nano-belt can provide high surface area and low ion transmission resistance, so that high specific capacity and rate capability are generated, the thin nano-belt shortens the sodium ion transmission path, and promotes the contact between an electrode and an electrolyte, so that the electrochemical performance of the electrode is improved.

(2) In the preparation process of the nano strip-shaped or rod-shaped FeOOH, the raw material source is rich, the production cost is low, the reaction condition is easy to control, the operation is simple, and the industrial production is easy to realize.

Drawings

FIG. 1 is an X-ray powder diffraction pattern of FeOOH prepared in example 1, example 2, example 3 and example 4, which shows that the products prepared by adding different surfactants, Sodium Dodecyl Sulfate (SDS), polyacrylic acid (PAA), polyvinylpyrrolidone (PVP) and Sodium Dodecylbenzenesulfonate (SDBS), are pure crystals of FeOOH.

FIG. 2 is a scanning electron microscope picture of FeOOH prepared in example 1, example 2, example 3 and example 4, wherein a and b are scanning electron microscope pictures of FeOOH product obtained in example 1, and are nanoribbon structures with a width of 50-150nm and a length of 250-590 nm; c is a scanning electron microscope picture of the FeOOH product obtained in the embodiment 2, and is a nanorod structure with the width of 70-150 nm; d is a scanning electron microscope picture of the FeOOH product obtained in the embodiment 3, and is a nanorod structure with the width of 70-150 nm; e is the scanning electron microscope picture of the FeOOH product obtained in example 4, and is a nanorod structure with the width of 10-50 nm.

FIG. 3 is a transmission electron micrograph of FeOOH prepared in example 1, wherein a shows that it is a nanoribbon structure with a width of 50-150nm and a length of 250-590 nm; the lattice spacing measured in b is 0.33nm corresponding to the (130) plane of FeOOH.

FIG. 4 is a graph of charge and discharge rate performance measured after FeOOH prepared in example 1, example 2, example 3 and example 4 is assembled into a battery as a negative electrode material of a sodium ion battery; as shown in the figure, FeOOH-PAA has a current density of 0.1, 0.2, 0.5, 1, 2 A.g^-1The first charge specific capacity is 765.71, 578.57, 532.08, 500.76, 468.71mAh g^-1When the current density again decreases to 0.1A · g^-1When the charge capacity is higher than the predetermined value, the charge specific capacity can return to 560.11mAh g^-1The good rate performance is shown; the first charge specific capacity of FeOOH-PVP at the current density of 0.1, 0.2, 0.5, 1, 2A g-1 is 730.79, 518.60, 454.43, 385.73, 308.25mAh g-1, when the current density is reduced to 0.1A g^-1When the charge capacity is higher than the predetermined value, the charge specific capacity can return to 530.79mAh g^-1(ii) a FeOOH-SDBS has a current density of 0.1, 0.2, 0.5, 1, 2 A.g^-1The first charge specific capacity is 626.76, 483.20, 455.61, 432.89, 405.33mAh g^-1When the current density again decreases to 0.1A · g^-1When the charge capacity is higher than the predetermined value, the charge specific capacity can return to 484.5mAh g^-1(ii) a FeOOH-SDS at a current density of 0.1, 0.2, 0.5, 1, 2A. multidot.g^-1The first charge specific capacity is 632.52, 495.07, 458.12, 425.38, 383.47mAh g^-1When the current density again decreases to 0.1A · g^-1When the charge capacity is higher than the predetermined value, the charge specific capacity can return to 492.75mAh g^-1The good rate performance is shown;

FIG. 5 shows the FeOOH obtained in example 1, example 2, example 3 and example 4 as the negative electrode material of sodium ion battery after assembling into battery at 0.1 A.g^-1The charge-discharge cycle stability performance chart tested at the current density of (1).

FIG. 6 shows the results of assembling FeOOH prepared in examples 1, 2, 3 and 4 as a negative electrode material of sodium ion battery into a battery at 1A · g^-1The charge-discharge cycle stability performance chart tested at the current density of (1).

Detailed Description

The present invention will be described in further detail with reference to examples, but the embodiments of the present invention are not limited thereto.

Example 1: the FeOOH nano material is prepared by the following steps:

(1) 9.4605g of iron chloride hexahydrate (FeCl)₃ ^.6H₂O) and 2.1014g of urea are added into 70mL of deionized water and stirred to obtain a transparent solution;

(2) adding 0.5768g Sodium Dodecyl Sulfate (SDS) into the transparent solution, heating to 70-90 deg.C, stirring, and stirring to dissolve completely to obtain mixed solution;

(3) transferring the mixed solution obtained in the step (2) into a reaction kettle, carrying out hydrothermal reaction for 20h at 90 ℃, carrying out suction filtration after the reaction, washing the product obtained by suction filtration with deionized water and absolute ethyl alcohol for three times respectively, and drying at the temperature of 60 ℃ for 10h to obtain a final product;

the X-ray diffraction data of the product obtained in this example are shown in FIG. 1, from which it can be seen that the product is pure FeOOH crystals.

The scanning electron micrograph and the transmission electron micrograph of the product obtained in the example are shown in a and b in FIG. 2 and FIG. 3, and as can be seen from the electron micrograph, the obtained product is a nanoribbon structure with the width of between 50 and 150nm and the length of between 250 and 590 nm.

The electrochemical properties of the product obtained in this example are shown in fig. 4, 5 and 6.

Example 2: the FeOOH nano material is prepared by the following steps:

(1) 9.4605g of iron chloride hexahydrate (FeCl)₃ ^.6H₂O) and 2.1014g of urea are added into 70mL of deionized water and stirred to obtain a transparent solution;

(2) 0.5768g of polyacrylic acid (PAA) is added into the transparent solution, and stirring is carried out simultaneously until the polyacrylic acid (PAA) is completely dissolved, so as to prepare a mixed solution;

(3) and (3) transferring the mixed solution obtained in the step (2) into a reaction kettle, carrying out hydrothermal reaction for 20h at 90 ℃, carrying out suction filtration after the reaction, washing the product obtained by suction filtration for three times by using deionized water and absolute ethyl alcohol respectively, and drying for 20h at the temperature of 60 ℃ to obtain the final product.

The X-ray diffraction data of the product obtained in this example are shown in FIG. 1, from which it can be seen that the product is pure FeOOH crystals.

The scanning electron micrograph of the product obtained in the example is shown in fig. 2 c, and the scanning electron micrograph shows that the obtained product is a nanorod structure with the width of 70-150 nm.

The electrochemical properties of the product obtained in this example are shown in fig. 4, 5 and 6.

Example 3: the FeOOH nano material is prepared by the following steps:

(1) 9.4605g of iron chloride hexahydrate (FeCl)₃ ^.6H₂O) and 2.1014g of urea are added into 70ml of deionized water and stirred to obtain a transparent solution;

(2) 0.5768g of polyvinylpyrrolidone (PVP) is added into the transparent solution, and stirring is carried out simultaneously until the polyvinylpyrrolidone is completely dissolved, so as to obtain a mixed solution;

(3) and (3) transferring the mixed solution obtained in the step (2) into a reaction kettle, carrying out hydrothermal reaction for 20h at 90 ℃, carrying out suction filtration after the reaction, washing the product obtained by suction filtration for three times by using deionized water and absolute ethyl alcohol respectively, and drying for 15h at the temperature of 60 ℃ to obtain the final product.

The X-ray diffraction data of the product obtained in this example are shown in FIG. 1, from which it can be seen that the product is pure FeOOH crystals.

The scanning electron micrograph of the product obtained in this example is shown in d of FIG. 2, and it can be seen from the electron micrograph that the obtained product is a nanorod structure with a width of between 100 and 200 nm.

The electrochemical properties of the product obtained in this example are shown in fig. 4, 5 and 6.

Example 4: the FeOOH nano material is prepared by the following steps:

(1) 9.4605g of iron chloride hexahydrate (FeCl)₃ ^.6H₂O) and 2.1014g of urea are added into 70ml of deionized water and stirred to obtain a transparent solution;

(2) 0.5768g of Sodium Dodecyl Benzene Sulfonate (SDBS) is added into the transparent solution, and stirring is carried out simultaneously until the Sodium Dodecyl Benzene Sulfonate (SDBS) is completely dissolved, so as to prepare a mixed solution;

(3) and (3) transferring the mixed solution obtained in the step (2) into a reaction kettle, carrying out hydrothermal reaction for 20h at 90 ℃, carrying out suction filtration after the reaction, washing the product obtained by suction filtration for three times by using deionized water and absolute ethyl alcohol respectively, and drying the product at the temperature of 60 ℃ for 18h in a common way to obtain the final product.

The X-ray diffraction data of the product obtained in this example are shown in FIG. 1. It can be seen from the figure that the product is obtained as pure FeOOH crystals.

The scanning electron micrograph of the product obtained in the example is shown as e in FIG. 2, and the electron micrograph shows that the obtained product is a nanorod structure with the width of 10-50 nm.

The electrochemical properties of the product obtained in this example are shown in fig. 4, 5 and 6.

The above embodiments are preferred embodiments of the present invention, but the present invention is not limited to the above embodiments, and any other changes, modifications, substitutions, combinations, and simplifications which do not depart from the spirit and principle of the present invention should be construed as equivalents thereof, and all such changes, modifications, substitutions, combinations, and simplifications are intended to be included in the scope of the present invention.