Sodium-ion battery negative electrode material and preparation method thereof

Abstract

The application discloses a kind of sodium ion battery negative electrode materials, including spherical inner layer and the coating outer layer of coating in the outer part of spherical inner layer.The application provides a kind of sodium ion battery negative electrode materials, through the development of the negative electrode material, through silicon doped titanium dioxide, it can be used in the actual sodium extraction sodium ion fast through in the process, so as to prevent sodium ion battery specific capacity reduction when actually applied in sodium ion battery, through carbon-coated silicon doped titanium dioxide, improve the cycle stability of the negative electrode material;The application also provides a kind of preparation method of sodium ion battery negative electrode material, through the setting of the method, the prepared sodium ion negative electrode material stability is good, cost is low, capacity retention is high.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of sodium ion batteries, and particularly relates to a sodium ion battery negative electrode material and a preparation method thereof. BACKGROUND

[0002] Energy is a big problem in today's society, and lithium ion batteries have developed rapidly due to their advantages of being clean, efficient and stable. However, due to the limited resources of lithium, as a substitute, the development of sodium ion batteries has become a research hotspot.

[0003] Although the composition of sodium ion batteries is similar to that of lithium ion batteries, due to the chemical difference between sodium and lithium, the materials of sodium ion batteries need to be developed according to the actual situation.

[0004] At present, the negative electrode material is divided into carbon-based material and titanium-based material according to the embedding energy storage mechanism, and has stable structure and low cost, but the stability of specific capacity is difficult to guarantee. SUMMARY

[0005] The purpose of the present application is to overcome the above problems existing in the prior art, and to provide a sodium ion battery negative electrode material. Through the development of the negative electrode material, silicon-doped titanium dioxide can be used for the rapid passage of sodium ions in the actual de-embedding sodium process, thereby preventing the specific capacity of the sodium ion battery from being reduced when the negative electrode material is actually applied to the sodium ion battery. The carbon-coated silicon-doped titanium dioxide improves the cycle stability of the negative electrode material. The present application also provides a preparation method of a sodium ion battery negative electrode material. Through the setting of the method, the prepared sodium ion negative electrode material has good stability, low cost and high capacity retention rate.

[0006] In order to achieve the above technical purposes and achieve the above technical effects, the present application realizes the following technical solutions:

[0007] A sodium ion battery negative electrode material comprises a spherical inner layer and a coated outer layer coated on the outside of the spherical inner layer.

[0008] Further, the material of the spherical inner layer is silicon-doped titanium dioxide.

[0009] The material of the coated outer layer is carbon.

[0010] A preparation method of a sodium ion battery negative electrode material, the method comprising the following steps:

[0011] Step a: pretreatment of titanium dioxide

[0012] A mixed solution is configured, and methanol and water are mixed in a mixing ratio of 4:1.

[0013] A certain amount of titanium dioxide is placed in a mixed solution to obtain a mixed liquid, wherein the mass ratio of titanium dioxide to the mixed solution is 1:1;

[0014] A silane coupling agent is added to the mixed liquid, wherein the ratio of the added mass of the silane coupling agent to the added volume of the mixed solution is 1:1, to obtain a mixed substance;

[0015] The obtained mixed substance is placed in an ultrasonic machine for ultrasonic treatment, the ultrasonic frequency is set to 200 kHz, and the ultrasonic time is 5 min, to obtain treated titanium dioxide;

[0016] Step b: preparation of silicon-doped titanium dioxide

[0017] The treated titanium dioxide is washed and centrifuged multiple times with anhydrous ethanol, and after drying, silicon-doped titanium dioxide is obtained;

[0018] Step c: preparation of carbon-coated silicon-doped titanium dioxide

[0019] A certain amount of a carbon source and a certain amount of concentrated hydrochloric acid are placed in deionized water and stirred on a magnetic stirrer to obtain a transparent solution;

[0020] A certain amount of silicon-doped titanium dioxide is placed in 0.5 mol / L ethanol, wherein the mass-volume ratio of silicon-doped titanium dioxide to ethanol is 1:100;

[0021] The silicon-doped titanium dioxide solution is added dropwise to the transparent solution to obtain a precursor solution, wherein the volume ratio is 1:4, and water bath heating and stirring are performed, the water bath temperature is set to 50 DEG C, and the stirring rate is 120 r / min;

[0022] The precursor solution is vacuum freeze-dried, and the dried sample is sintered in argon, the sintering temperature is 700 DEG C, and the sintering time is 4 h, to obtain carbon-coated silicon-doped titanium dioxide.

[0023] Further, the silane coupling agent is KH560.

[0024] Further, the carbon source is one of carboxymethyl cellulose, sodium alginate, chitosan, and polyacrylic acid sodium.

[0025] The beneficial effects of the present application are:

[0026] 1. The present application provides a sodium ion battery negative material, through the preparation of the negative material, through silicon-doped titanium dioxide, it can be used for the rapid passing of sodium ions in the actual de-intercalation sodium process, so as to prevent the specific capacity of the sodium ion battery from being reduced when actually applied to the sodium ion battery, and the cycle stability of the negative material is improved by carbon-coated silicon-doped titanium dioxide.

[0027] 2. The present invention also provides a method for preparing sodium-ion battery anode material. The sodium-ion anode material prepared by this method has good stability, low cost and high capacity retention. Attached Figure Description

[0028] The accompanying drawings, which are included to provide a further understanding of the invention and form part of this application, illustrate exemplary embodiments of the invention and, together with their description, serve to explain the invention and do not constitute an undue limitation thereof. In the drawings:

[0029] Figure 1 This is a flowchart illustrating the preparation process of the sodium-ion battery anode material provided by the present invention. Detailed Implementation

[0030] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0031] Example 1

[0032] A sodium-ion battery anode material includes a spherical inner layer and a coating outer layer covering the outside of the spherical inner layer;

[0033] The inner spherical layer is made of silicon-doped titanium dioxide;

[0034] The outer layer is made of carbon.

[0035] This embodiment provides a sodium-ion battery anode material. Through the development of this anode material, silicon-doped titanium dioxide can be used to facilitate the rapid passage of sodium ions during the actual sodium insertion / extraction process, thereby preventing the specific capacity of the sodium-ion battery from decreasing when it is actually applied to sodium-ion batteries. The cycle stability of this anode material is improved by carbon-coating silicon-doped titanium dioxide.

[0036] A method for preparing a sodium-ion battery anode material, the method comprising the following steps:

[0037] Step a: Pretreatment of titanium dioxide

[0038] Prepare a mixed solution by mixing methanol and water in a ratio of 4:1;

[0039] A certain amount of titanium dioxide is placed in a mixed solution to obtain a mixed liquid, wherein the mass ratio of titanium dioxide to the mixed solution is 1:1;

[0040] Add a silane coupling agent to the above mixed liquid, wherein the ratio of the mass of the silane coupling agent added to the volume of the mixed solution added is 1:1, to obtain a mixed substance;

[0041] The silane coupling agent is KH560;

[0042] The mass unit for the added silane coupling agent is g, and the volume unit for the added mixed solution is mL.

[0043] The obtained mixture was placed in an ultrasonic machine for ultrasonic treatment. The ultrasonic frequency was set to 200 kHz and the ultrasonic time was 5 min to obtain treated titanium dioxide.

[0044] Step b: Preparation of silicon-doped titanium dioxide

[0045] The treated titanium dioxide was washed with anhydrous ethanol and centrifuged multiple times. After drying, silicon-doped titanium dioxide was obtained.

[0046] Step c: Preparation of carbon-coated silicon-doped titanium dioxide

[0047] Take a certain amount of carbon source and a certain amount of concentrated hydrochloric acid and place them in deionized water. Stir on a magnetic stirrer to obtain a transparent solution.

[0048] The carbon source is one of carboxymethyl cellulose, sodium alginate, chitosan, and sodium polyacrylate.

[0049] The ratio of the added mass of carbon source to the added volume of concentrated hydrochloric acid is 1:1.

[0050] The ratio of the added carbon source mass to the added deionized water volume is 1:200;

[0051] The unit for the mass of added carbon source is g, and the unit for the volume of added deionized water is mL.

[0052] A certain amount of silicon-doped titanium dioxide was placed in 0.5 mol / L ethanol, wherein the mass-volume ratio of silicon-doped titanium dioxide to ethanol was 1:100.

[0053] A silicon-doped titanium dioxide solution was added dropwise to a transparent solution to obtain a precursor solution with a volume ratio of 1:4. The solution was heated and stirred in a water bath at a temperature of 50°C and a stirring rate of 120 r / min.

[0054] The precursor solution was freeze-dried under vacuum, and the dried sample was sintered in argon at a temperature of 700℃ for 4 hours to obtain carbon-coated silicon-doped titanium dioxide.

[0055] This embodiment provides a method for preparing a sodium-ion battery anode material. The sodium-ion anode material prepared by this method has good stability, low cost, and high capacity retention.

[0056] This invention provides a sodium-ion battery anode material and its preparation method. The sodium-ion battery anode material provides a basis for sodium-ion batteries with higher cycle stability, and the preparation method provides operational instructions for the preparation of sodium-ion battery anode materials.

[0057] In the description of this specification, references to terms such as "an embodiment," "example," "specific example," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0058] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claimed invention.

Claims

1. A method for preparing a sodium-ion battery anode material, characterized by: The method comprises the following steps: Step a: pretreatment of titanium dioxide A mixed solution is configured by mixing methanol and water in a ratio of 4:1; A certain amount of titanium dioxide is placed in the mixed solution to obtain a mixed liquid, wherein the mass ratio of titanium dioxide to the mixed solution is 1:1; A silane coupling agent is added to the mixed liquid, wherein the ratio of the added mass of the silane coupling agent to the added volume of the mixed solution is 1:1, and a mixed substance is obtained; The obtained mixed substance is placed in an ultrasonic machine for ultrasonic treatment, the ultrasonic frequency is set to 200 kHz, and the ultrasonic time is 5 min, and treated titanium dioxide is obtained; Step b: preparation of silicon-doped titanium dioxide The treated titanium dioxide is washed and centrifuged with anhydrous ethanol for multiple times, and after drying, silicon-doped titanium dioxide is obtained; Step c: preparation of carbon-coated silicon-doped titanium dioxide A certain amount of carbon source and a certain amount of concentrated hydrochloric acid are placed in deionized water and stirred on a magnetic stirrer to obtain a transparent solution; A certain amount of silicon-doped titanium dioxide is placed in 0.5 mol / L ethanol, wherein the mass-volume ratio of silicon-doped titanium dioxide to ethanol is 1:100; The silicon-doped titanium dioxide solution is added dropwise to the transparent solution to obtain a precursor solution, wherein the volume ratio is 1:4, and water bath heating and stirring are performed, the water bath temperature is set to 50°C, and the stirring rate is 120 r / min; The precursor solution is vacuum freeze-dried, and the dried sample is sintered in argon, the sintering temperature is 700°C, and the sintering time is 4 h, to obtain a sodium ion battery negative electrode material, which comprises a spherical inner layer of silicon-doped titanium dioxide and a carbon coating layer coated on the outside of the spherical inner layer.

2. The method of claim 1, wherein the method further comprises: The silane coupling agent is KH560.

3. The method for preparing a sodium-ion battery negative electrode material according to claim 1, characterized in that: The carbon source is one of carboxymethyl cellulose, sodium alginate, chitosan, and sodium polyacrylate.

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