Preparation method of sulfonated pitch carbon@BiOCl sodium ion battery negative electrode composite material

Abstract

The application relates to a preparation method of a sulfonated asphalt carbon@BiOCl sodium ion battery negative electrode composite material. Bi(NO3)3.5H2O and A are dissolved in ethylene glycol, 3-aminopropyl methoxysilane is added into the ethylene glycol, and stirring is conducted to form a uniform suspension; A is SnCl4.5H2O, SnCl4 or SnCl2; sulfonated asphalt is added into the suspension, and magnetic stirring is conducted; then the suspension is moved into polytetrafluoroethylene and is placed into a high-pressure reaction kettle for constant temperature treatment at 160-200 DEG C for 10-24h; after the reaction kettle is cooled to room temperature, centrifugal separation is conducted, and drying is conducted; 4) the sample is subjected to constant temperature treatment at 600-1000 DEG C for 1-3h in a tubular furnace in an inert atmosphere, and the temperature is reduced to room temperature. Advantages are that the sodium ion battery negative electrode composite material with high performance is prepared through a simple one-step hydrothermal method, and the sodium ion battery negative electrode composite material has high specific capacity and excellent rate performance.

Description

Technical Field

[0001] This invention belongs to the field of sodium-ion battery anode materials, and particularly relates to a method for preparing a sulfonated pitch carbon@BiOCl sodium-ion battery anode composite material. Background Technology

[0002] Sodium ions (Na) + The emergence of battery research was based on the similarity of many electrochemical properties of sodium ions to those of lithium ions. However, in reality, sodium... + The interaction with electrode materials did not exhibit the high-performance characteristics associated with lithium-ion batteries. With the continuous depletion of lithium resources, the practical application of sodium-ion batteries is accelerating, making the development of high-performance electrode materials for sodium-ion batteries an urgent priority.

[0003] Currently, the research and development of anode materials for sodium-ion batteries is a key focus, mainly because the electrode potential of the anode material greatly affects the energy density of sodium-ion batteries. To date, research on anode materials for sodium-ion batteries primarily concentrates on biomass hard carbon. However, hard carbon materials face challenges such as inconsistent sourcing, difficulty in ensuring the uniformity of their properties, and limitations in large-scale production due to geographical, temporal, and spatial constraints.

[0004] Ion-layered semiconductor nanosheets based on alloy reaction systems have attracted considerable attention as anode materials for sodium-ion batteries. Firstly, the unique layered structure, composed of alternating anion and cation layers, provides rapid diffusion channels between the ion layers. Secondly, and more importantly, the layered structural units provide ample space for sodium ion insertion and extraction, fundamentally reducing the volume expansion problem of the electrode material during cycling. BiOCl is such a material, consisting of [Bi₂O₂] with alternating stacks of Cl⁻ ions along the c-axis. 2+ The material consists of multiple layers. However, its conductivity is not excellent, resulting in poor rate performance during energy storage. A common improvement method is to coat its surface with a carbon substrate and then carbonize it to improve its conductivity.

[0005] Sulfonated asphalt's main component is sodium asphalt sulfonate, which is produced by sulfonating, neutralizing, and post-processing asphalt under certain conditions. Sulfonated asphalt is water-soluble, and as a carbon precursor for coating BiOCl, it avoids the use of organic solvents, making the preparation process more energy-efficient and environmentally friendly. Because sulfonated asphalt itself is thermosetting, the coated composite material does not melt during heat treatment, further simplifying the preparation process. Summary of the Invention

[0006] To overcome the shortcomings of the prior art, the purpose of this invention is to provide a method for preparing sulfonated pitch carbon@BiOCl sodium-ion battery anode composite material. The method uses inexpensive and readily available sulfonated pitch to prepare the sulfonated pitch carbon@BiOCl sodium-ion battery anode composite material through a simple one-step hydrothermal method, which gives it high specific capacity and excellent rate performance.

[0007] To achieve the above objectives, the present invention provides the following technical solution:

[0008] The preparation method of sulfonated pitch carbon@BiOCl sodium-ion battery anode composite material includes the following steps:

[0009] 1) Dissolve 0.3-0.6g of Bi(NO3)3·5H2O and 0.1-0.8g of A in 30-60ml of ethylene glycol, and add 100-400μl of 3-aminopropylmethoxysilane and stir for 1-10h to form a homogeneous suspension; wherein A is SnCl4·5H2O, SnCl4 or SnCl2;

[0010] 2) Add 0.1-0.9g of sulfonated asphalt to the suspension and stir magnetically for 0.5-1.5h to form a homogeneous mixed suspension;

[0011] 3) Transfer the mixed suspension into 75-160 ml of polytetrafluoroethylene and place it in a high-pressure reactor. Maintain the temperature at 160-200℃ for 10-24 hours. After the reactor cools to room temperature, centrifuge, remove, and dry.

[0012] 4) After drying, the sample is kept at 600-1000℃ for 1-3 hours in an inert atmosphere tube furnace. When the temperature drops to room temperature, the sample obtained is the sulfonated pitch carbon@BiOCl composite material.

[0013] Compared with the prior art, the beneficial effects of the present invention are:

[0014] This invention utilizes inexpensive and readily available sulfonated asphalt with SnCl4 or SnCl2 and Bi(NO3)3·5H2O to prepare a high-performance sulfonated asphalt carbon@BiOCl sodium-ion battery anode composite material via a simple one-step hydrothermal method. This sodium-ion battery anode composite material exhibits high specific capacity and excellent rate performance. After 100 cycles at a current density of 0.1 A / g, the discharge specific capacity is 411.1-460.2 mAh / g, and simultaneously, it retains a reversible specific capacity of 260.1-300.2 mAh / g at a current density of 2 A / g. Attached Figure Description

[0015] Figure 1 This is the XRD pattern of the sulfonated pitch carbon@BiOCl composite material.

[0016] Figure 2 This is a graph showing the cyclic performance of the sulfonated pitch carbon@BiOCl composite material.

[0017] Figure 3 This is a capacity-voltage diagram of the sulfonated pitch carbon@BiOCl electrode material at 0.1 A / g. Detailed Implementation

[0018] The present invention will now be described in detail with reference to the accompanying drawings, but it should be noted that the implementation of the present invention is not limited to the following embodiments.

[0019] Example 1

[0020] The preparation of the sulfonated pitch carbon@BiOCl sodium-ion battery anode composite material is as follows:

[0021] 1) Dissolve 0.485g Bi(NO3)3·5H2O and 0.35g SnCl4·5H2O in 50ml ethylene glycol, and add 200μl of 3-aminopropylmethoxysilane and stir for 3h to form a homogeneous suspension;

[0022] 2) Add 0.1g of sulfonated asphalt to the above suspension and stir magnetically for 3 hours to form a homogeneous mixed suspension;

[0023] 3) Transfer the mixed suspension into 100 ml of polytetrafluoroethylene and place it in a high-pressure reactor at 180°C for 12 hours. After the reactor cools to room temperature, centrifuge, remove the sample, and dry it.

[0024] 4) After drying, the sample is kept at 800℃ for 1-3 hours in a tube furnace with high-purity nitrogen. After the temperature drops to room temperature, the sample obtained is the sulfonated pitch carbon@BiOCl composite material.

[0025] The XRD pattern of the prepared sulfonated pitch carbon@BiOCl composite material is shown below. Figure 1 As shown, by Figure 1 It can be seen that the prepared composite material contains the BiOCl crystalline phase and the corresponding peak position corresponds to the standard card ICSD 01-073-2060.

[0026] A half-cell was constructed using sulfonated pitch carbon@BiOCl composite material as the electrode material and a sodium sheet. Its cycle performance was then tested. Figure 2 As shown, after 100 cycles at a current density of 0.1 A / g, the capacity is 411.1 mAh / g, and it still exhibits a reversible specific capacity of 281.8 mAh / g at a current density of 2 A / g. Furthermore, the prepared sulfonated pitch carbon@BiOCl composite material has a lower sodium storage potential, indicating that the material has a higher energy density. (See...) Figure 3 .

[0027] Furthermore, the above electrochemical experimental results show that, thanks to the layered structure of BiOCl and the use of carbon as a conductive substrate, the sodium storage capacity of BiOCl is greatly enhanced.

[0028] Example 2

[0029] Sulfonated pitch carbon@BiOCl sodium-ion battery anode composite materials were prepared using different bismuth and chlorine sources:

[0030] 1) Dissolve 0.395g Bi(NO3)3 and 0.190g SnCl2 in 50ml ethylene glycol, and add 200μl of 3-aminopropylmethoxysilane and stir for 3h to form a homogeneous suspension;

[0031] 2) Add 0.1g of sulfonated asphalt to the above suspension and stir magnetically for 3 hours to form a homogeneous mixed suspension;

[0032] 3) Transfer the mixed suspension into 100 ml of polytetrafluoroethylene and place it in a high-pressure reactor at 180°C for 12 hours. After the reactor cools to room temperature, centrifuge, remove the sample, and dry it.

[0033] 4) After drying, the sample is kept at 800℃ for 1-3 hours in a tube furnace with high-purity nitrogen. After the temperature drops to room temperature, the sample obtained is the sulfonated pitch carbon@BiOCl composite material.

[0034] The sulfonated pitch carbon@BiOCl composite material was used as the electrode material to form a half-cell with a sodium sheet. Its cycling performance was tested. After 100 cycles at a current density of 0.1 A / g, the capacity was 432.3 mAh / g, and at the same time, it still had a reversible specific capacity of 293.8 mAh / g when cycling at a current density of 2 A / g.

[0035] Example 3

[0036] Sulfonated pitch carbon@BiOCl sodium-ion battery anode composite materials were prepared using different bismuth and chlorine sources:

[0037] 1) Dissolve 0.395g Bi(NO3)3 and 0.26SnCl4 in 50ml ethylene glycol, and add 200μl of 3-aminopropylmethoxysilane and stir for 3h to form a homogeneous suspension;

[0038] 2) Add 0.1g of sulfonated asphalt to the above suspension and stir magnetically for 3 hours to form a homogeneous mixed suspension;

[0039] 3) Transfer the mixed suspension into 100 ml of polytetrafluoroethylene and place it in a high-pressure reactor at 180°C for 12 hours. After the reactor cools to room temperature, centrifuge, remove the sample, and dry it.

[0040] 4) After drying, the sample is kept at 800℃ for 1-3 hours in a tube furnace with high-purity nitrogen. After the temperature drops to room temperature, the sample obtained is the sulfonated pitch carbon@BiOCl composite material.

[0041] Sulfonated pitch carbon@BiOCl composite material was used as the electrode material to form a half-cell with sodium sheet. Its cycling performance was tested. After 100 cycles at a current density of 0.1 A / g, the capacity was 457.3 mAh / g, and at the same time, it still had a reversible specific capacity of 286.7 mAh / g when cycling at a current density of 2 A / g.

Claims

1. A method for preparing sulfonated pitch carbon@BiOCl sodium-ion battery anode composite material, characterized in that, Includes the following steps: 1) Dissolve 0.3-0.6g of Bi(NO3)3·5H2O and 0.1-0.8g of A in 30-60ml of ethylene glycol, and add 100-400μl of 3-aminopropylmethoxysilane and stir for 1-10h to form a homogeneous suspension; wherein A is SnCl4·5H2O, SnCl4 or SnCl2; 2) Add 0.1-0.9g of sulfonated asphalt to the suspension and stir magnetically for 0.5-1.5h to form a homogeneous mixed suspension; 3) Transfer the mixed suspension into 75-160 ml of polytetrafluoroethylene and place it in a high-pressure reactor. Maintain the temperature at 160-200℃ for 10-24 hours. After the reactor cools to room temperature, centrifuge, remove, and dry. 4) After drying, the sample is kept at 600-1000℃ for 1-3 hours in an inert atmosphere tube furnace. When the temperature drops to room temperature, the sample obtained is the sulfonated pitch carbon@BiOCl composite material.

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