Potassium ion battery dual binary alloy negative electrode and preparation method and application thereof

Abstract

The invention discloses a potassium ion battery dual-binary alloy negative electrode and a preparation method and application thereof. The dual binary alloy negative electrode is obtained by dissolving commercial SbCl3, BiCl3 and CuSO4 in an acidic aqueous solution and then carrying out one-step substitution reaction through iron powder. The method is simple in process, low in cost and good in operability and repeatability, and the prepared material is high in parameter proportion adjustability. When used as the negative electrode of the potassium ion battery, the material has the advantages of improving volume expansion in an alloying process, accelerating transmission of potassium ions in a charging and discharging process and the like, and can be potentially applied to the negative electrode of the potassium ion battery in a large scale.

Description

Technical Field

[0001] This invention relates to a dual binary alloy anode for potassium-ion batteries, its preparation method, and its application, belonging to the technical field of alloyed anode materials. Background Technology

[0002] The development of advanced energy storage devices based on lithium-ion batteries (LIBs) is of great scientific significance for achieving the "dual carbon" goal and advancing new energy strategies. LIBs have broad application potential in portable electronics and the emerging electric vehicle market. LIB development faces two main challenges. The first challenge is developing high-capacity LIBs, especially structurally stable high-capacity anodes. Furthermore, with the ever-increasing demand for lithium, there is an urgent need to replace LIBs with new scalable electrochemical energy storage devices to ensure simple and low-cost energy storage. It is well known that K... + It has more than Li + Larger ionic radius, in K + The insertion / extraction process causes significant volume changes, which severely impacts the actual cycle life. Therefore, a simple and structurally stable negative electrode design is crucial for the commercial application of potassium-ion batteries (PIBs).

[0003] Currently, graphite anodes are commercially used in LIBs. When applied to PIB anodes, the capacity is <300 mAh g⁻¹. -1 (KC8) is far lower than in practical applications. The antimony (Sb) and bismuth (Bi) anode has a capacity of 660 mAh g. -1 and 384 mAh g -1 With its high theoretical capacity, Cu₂Sb is a promising next-generation anode material. However, during charge and discharge, elemental Sb and Bi anodes experience severe volume expansion (>400%) during potassium ion insertion and extraction, and may even detach from the current collector and lose activity. Furthermore, their slow potassium ion kinetics severely limit their cycle stability. Currently, incorporating highly conductive and low-volume-expansion Cu₂Sb into antimony-bismuth alloys is one effective method to reduce volume expansion and accelerate ion transport. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to overcome the problem that when Sb and Bi are used as negative electrode materials of potassium ion batteries, they will undergo severe volume expansion during charging and discharging, and then pulverize and fall off, resulting in rapid performance degradation. The present invention provides a dual binary alloy negative electrode, its preparation method and application.

[0005] The purpose of this invention is to provide a method for preparing a binary alloy.

[0006] Another object of the present invention is to provide a binary alloy material prepared by the above method.

[0007] Another object of the present invention is to provide the application of the above-mentioned binary alloy anode.

[0008] The above-mentioned objective of this invention is achieved through the following technical solution: a dual binary alloy negative electrode for potassium-ion batteries, wherein SbCl3, BiCl3, and CuSO4 are dissolved in an acidic solution, and then Sb is obtained through a one-step substitution reaction with iron powder. 0.5 Bi 0.5 @Cu2Sb is then mixed evenly with conductive carbon black and polyacrylic acid binder, and water is used as a solvent to prepare a potassium electrode negative electrode.

[0009] The acidic aqueous solution is an ethanolic solution of hydrochloric acid with a concentration of 0.3–0.6 mol / L. -1 .

[0010] Sb 0.5 Bi 0.5 The mass ratio of Cu2Sb to conductive carbon black and polyacrylic acid binder is 6-8:1-3:1.

[0011] The method for preparing the potassium-ion battery dual binary alloy anode includes the following specific steps:

[0012] S1. Dissolve SbCl3, BiCl3 and CuSO4 in an ethanol solution containing hydrochloric acid in proportion, and stir to obtain a homogeneous solution;

[0013] S2. Excess iron powder is slowly added to solution S1, and the reaction proceeds completely at room temperature to obtain Sb. 0.5 Bi 0.5 @Cu2Sb dual alloy suspension;

[0014] S3. The product obtained in S2 is washed, filtered, and freeze-dried to finally obtain Sb. 0.5 Bi 0.5 @Cu2Sb binary alloy material;

[0015] S4. The material obtained in S3 is mixed uniformly with conductive carbon black and polyacrylic acid binder in a certain proportion, and water is used as a solvent to prepare a potassium electrode negative electrode.

[0016] The application of the aforementioned binary alloy anode material in potassium-ion batteries.

[0017] Beneficial effects:

[0018] This invention prepares a dual binary alloy anode material that can buffer the volume expansion of Sb and Bi and improve K. + One effective method to improve diffusion rate is to alloy antimony and bismuth and introduce highly conductive Cu, thereby improving the cycle life and capacity of lithium-ion batteries.

[0019] This preparation process is simple, low-cost, allows for controllable content of each element, and is easy to scale up for production. Attached Figure Description

[0020] Figure 1 The dual binary alloy Sb prepared in Example 1 0.5 Bi 0.5 Scanning electron microscope (SEM) images of Cu2Sb. In the images, 'a' represents the macroscopic nanoparticle stacking structure; 'b' represents a more clearly defined nanoparticle structure under magnification.

[0021] Figure 2 The dual binary alloy Sb prepared in Example 1 0.5 Bi 0.5 X-ray diffraction pattern of Cu2Sb. Among them, Sb... 0.5 Bi 0.5 The standard XRD pattern of Cu2Sb (PDF#97-061-7054) and the standard XRD pattern of Cu2Sb (PDF#97-062-8984).

[0022] Figure 3 The dual binary alloy Sb prepared in Example 1 0.5 Bi 0.5 Charge-discharge curves of @Cu2Sb as a negative electrode material for potassium-ion batteries under different cycles.

[0023] Figure 4 The charge-discharge curves of the dual binary alloy Sb@Cu2Sb prepared in Example 1 as the negative electrode material of potassium-ion batteries under different cycles are shown. Detailed Implementation

[0024] The present invention will be further described below with reference to the accompanying drawings and specific embodiments, but this should not be construed as limiting the present invention. Simple modifications or substitutions made to the methods, steps, or conditions of the present invention without departing from the spirit and substance of the invention are all within the scope of the present invention; unless otherwise specified, the reagents, methods, and equipment used in the present invention are conventional reagents, methods, and equipment in this technical field.

[0025] The purpose of this invention is to provide a method for preparing a binary alloy.

[0026] Another object of the present invention is to provide a binary alloy material prepared by the above method.

[0027] Another object of the present invention is to provide the application of the above-mentioned binary alloy anode.

[0028] The above-mentioned objective of this invention is achieved through the following technical solutions:

[0029] A method for preparing a binary alloy involves a one-step co-substitution reaction to obtain Sb.0.5 Bi 0.5 @Cu2Sb alloy. This invention features a simple process, low cost, good repeatability and operability. The reaction temperature is room temperature, and the alloy ratio is controlled by adjusting the amounts of SbCl3, BiCl3 and CuSO4. The prepared material can solve the problem of material pulverization and detachment caused by volume expansion during the Sb and Bi alloying process, and has the potential for large-scale application in potassium-ion batteries.

[0030] Specifically, the preparation method of the above-mentioned binary alloy includes the following steps:

[0031] A method for preparing a binary alloy includes the following specific steps:

[0032] S1. Dissolve 0.4 mmol SbCl3, 0.2 mmol BiCl3, and 0.4 mmol CuSO4 in 200 ml of ethanol solution containing hydrochloric acid, and stir to obtain a homogeneous solution;

[0033] S2. Excess iron powder is slowly added to the S1 solution, and the reaction is carried out at room temperature for 6 hours to obtain Sb. 0.5 Bi 0.5 @Cu2Sb bimetallic suspension.

[0034] S3. The product obtained in S2 is washed, filtered, and freeze-dried to finally obtain Sb. 0.5 Bi 0.5 @Cu2Sb binary alloy material.

[0035] S4. The material obtained in S3 is uniformly mixed with conductive carbon black and polyacrylic acid binder at a mass ratio of 7:2:1, and water is used as a solvent to prepare a potassium electrode.

[0036] In step S1, the concentration of hydrochloric acid is 0.5 mol / L. -1 ;

[0037] The amount of iron powder in step S2 is 1.4 mmol;

[0038] Furthermore, the binary alloy materials prepared by the above method and their application in potassium-ion batteries are also within the scope of protection of this invention.

[0039] This invention employs a one-step co-substitution method to replace Sb. 0.5 Bi 0.5 The Cu2Sb alloy is reacted at room temperature, and the alloy ratio is controlled by adjusting the amounts of SbCl3, BiCl3, and CuSO4.

[0040] Example 1

[0041] 1. Preparation:

[0042] S1. Dissolve 0.4 mmol SbCl3, 0.2 mmol BiCl3 and 0.4 mmol CuSO4 in 200 ml of ethanol solution containing hydrochloric acid, and stir to obtain a homogeneous solution;

[0043] S2. Excess iron powder is slowly added to the S1 solution, and the reaction is carried out at room temperature for 6 hours to obtain Sb. 0.5 Bi 0.5 @Cu2Sb dual alloy suspension;

[0044] S3. The product obtained in S2 is washed, filtered, and freeze-dried to finally obtain Sb. 0.5 Bi 0.5 @Cu2Sb binary alloy material;

[0045] S4. The material obtained in S3 is uniformly mixed with conductive carbon black and polyacrylic acid binder at a mass ratio of 7:2:1, and water is used as a solvent to prepare a potassium anode.

[0046] In step S1, the concentration of hydrochloric acid is 0.5 mol / L. -1 ;

[0047] The amount of iron powder in step S2 is 1.4 mmol;

[0048] Sb was replaced by a one-step co-substitution method. 0.5 Bi 0.5 @Cu2Sb alloy, the reaction temperature is room temperature, and the alloy ratio is controlled by controlling the amount of SbCl3, BiCl3 and CuSO4.

[0049] 2. Characterization and performance testing:

[0050] The aforementioned binary alloy Sb 0.5 Bi 0.5 The Cu2Sb was characterized and its performance was tested. Figure 1 Sb is a binary alloy 0.5 Bi 0.5 SEM images of @Cu2Sb, where a represents the macroscopic nanoparticle stacking structure; b represents the nanoparticle structure that is clearer after local magnification; Figure 2 Sb is a binary alloy 0.5 Bi 0.5 X-ray diffraction pattern of Cu2Sb. Among them, Sb... 0.5 Bi 0.5The standard XRD pattern of Cu2Sb (PDF#97-061-7054) and the standard XRD pattern of Cu2Sb (PDF#97-062-8984). Figure 3 and Figure 4 Sb is a binary alloy 0.5 Bi 0.5 Charge-discharge curves of @Cu2Sb and Sb@Cu2Sb as anode materials in potassium-ion batteries under different cycles, with the first-cycle discharge capacity reaching 682.4 mA hg. -1 and 939.4 mA hg -1 The discharge capacity in the second cycle reached 462.6 mA hg. -1 and 562.8 mA hg -1 The coulomb efficiency reached 76.3% and 60.1% in the first cycle, and the capacity remained at 480.21 mA hg after 200 cycles. -1 and 376.5 mA hg -1 The good cycling stability indicates that the binary alloy Sb exhibits good performance. 0.5 Bi 0.5 @Cu2Sb can buffer the volume expansion of Sb and Bi and increase K. + One effective method to improve diffusion rate is to alloy antimony and bismuth and introduce highly conductive Cu, thereby improving the cycle life and capacity of lithium-ion batteries.

[0051] Example 2

[0052] preparation:

[0053] S1. Dissolve 0.5 mmol SbCl3, 0.2 mmol BiCl3 and 0.4 mmol CuSO4 in 200 ml of ethanol solution containing hydrochloric acid, and stir to obtain a homogeneous solution;

[0054] S2. Excess iron powder is slowly added to the S1 solution, and the reaction is carried out at room temperature for 6 hours to obtain Sb. 0.6 Bi 0.4 @Cu2Sb bimetallic suspension.

[0055] S3. The product obtained in S2 is washed, filtered, and freeze-dried to finally obtain Sb. 0.6 Bi 0.4 @Cu2Sb binary alloy material.

[0056] S4. The material obtained in S3 is uniformly mixed with conductive carbon black and polyacrylic acid binder at a mass ratio of 7:2:1, and water is used as a solvent to prepare a potassium electrode.

[0057] In step S1, the concentration of hydrochloric acid is 0.5 mol / L. -1;

[0058] The amount of iron powder in step S2 is 1.7 mmol.

[0059] Example 3

[0060] preparation:

[0061] S1. Dissolve 0.4 mmol of commercially available SbCl3, 0.3 mmol of BiCl3 and 0.4 mmol of CuSO4 in 200 ml of ethanol solution containing hydrochloric acid, and stir to obtain a homogeneous solution;

[0062] S2. Excess iron powder is slowly added to the S1 solution, and the reaction is carried out at room temperature for 6 hours to obtain Sb. 0.4 Bi 0.6 @Cu2Sb suspension.

[0063] S3. The product obtained in S2 is washed, filtered, and freeze-dried to finally obtain Sb. 0.4 Bi 0.6 @Cu2Sb material.

[0064] S4. The material obtained in S3 is uniformly mixed with conductive carbon black and polyacrylic acid binder at a mass ratio of 7:2:1, and water is used as a solvent to prepare a potassium electrode.

[0065] In step S1, the concentration of hydrochloric acid is 0.5 mol / L. -1 ;

[0066] The amount of iron powder in step S2 is 1.7 mmol.

[0067] Comparative Example

[0068] preparation:

[0069] S1. Dissolve 0.4 mmol of commercially available SbCl3, 0 mmol of BiCl3 and 0.4 mmol of CuSO4 in 150 ml of ethanol solution containing hydrochloric acid, and stir to obtain a homogeneous solution;

[0070] S2. Slowly add excess iron powder to the S1 solution and react at room temperature for 6 h to obtain Sb@Cu2Sb suspension.

[0071] S3. The product obtained in S2 is washed, filtered, and freeze-dried to finally obtain Sb@Cu2Sb material.

[0072] S4. The material obtained in S3 is uniformly mixed with conductive carbon black and polyacrylic acid binder at a mass ratio of 7:2:1, and water is used as a solvent to prepare a potassium electrode.

[0073] In step S1, the concentration of hydrochloric acid is 0.5 mol / L. -1 ;

[0074] The amount of iron powder in step S2 is 1.2 mmol.

[0075] The above embodiments are merely illustrative examples to clearly illustrate the present invention and are not intended to limit the implementation of the invention. Those skilled in the art can make other variations based on the above description. It is neither necessary nor possible to exhaustively describe all possible implementations. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A potassium-ion battery dual-binary alloy anode, characterized in that, SbCl3, BiCl3, CuSO4 were dissolved in acid solution, and then Sb was obtained by one-step displacement reaction with iron powder 0.5 Bi 0.5 @Cu2Sb, and then mixed with conductive carbon black and polyacrylic acid binder to prepare a potassium negative electrode with water as the solvent.

2. The potassium-ion battery dual-binary alloy anode of claim 1, wherein, The acidic aqueous solution is an ethanol solution of hydrochloric acid with a concentration of 0.3-0.6 mol L -1 .

3. The potassium-ion battery dual-binary alloy anode of claim 1, wherein, Sb 0.5 Bi 0.5 @Cu2Sb, with a mass ratio of 6-8:1-3:1 of Cu2Sb, conductive carbon black and polyacrylic acid binder.

4. Process for the preparation of the potassium-ion battery bi-binary alloy anode according to any one of claims 1 to 3, characterized in that, Comprise the following specific steps: S1. Dissolve SbCl3, BiCl3 and CuSO4 in the ethanol solution containing hydrochloric acid in proportion, and obtain a uniform solution after stirring; S2. Slowly add excess iron powder to the solution of S1 and allow the reaction to proceed at room temperature until complete. The resulting product is Sb 0.5 Bi 0.5 @Cu2Sb double alloy suspension S3. The product obtained in S2 is washed, suction filtered, and freeze-dried to obtain Sb 0.5 Bi 0.5 @Cu2Sb binary alloy material; S4. Homogeneously mix the material obtained in S3 with conductive carbon black and polyacrylic acid binder in proportion, and prepare a potassium negative electrode with water as solvent.

5. The application of the dual binary alloy negative material in any one of claims 1-3 in a potassium ion battery.

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