High-entropy conversion-alloy-based anode material in potassium / sodium ion battery and preparation method thereof

Abstract

The application discloses a high-entropy conversion-alloy-based negative electrode material in a potassium / sodium ion battery and a preparation method thereof. The material preparation steps are as follows: a certain amount of antimony salt, bismuth salt, tin salt, cobalt salt, manganese salt and nickel salt are weighed according to the stoichiometric ratio and dissolved in deionized water containing tartaric acid to form a uniform solution A; then a certain amount of sodium tellurite is dissolved in ammonia water containing hydrazine hydrate to form a uniform solution B; the solutions A and B are uniformly mixed and subjected to a hydrothermal reaction; and the target "medium-high-entropy" material is obtained through centrifugation, washing and drying. The medium-high-entropy component design can significantly enhance the potassium / sodium storage electrochemical kinetics of the conversion-alloy-based negative electrode material, effectively inhibit the large volume expansion problem in the charging and discharging process, and make the material have high reversible specific capacity, excellent cycle stability and rate performance. In addition, the preparation process is simple and easy to operate, and is suitable for large-scale industrial production.

Description

TECHNICAL FIELD

[0001] The application belongs to the field of potassium and sodium ion battery negative electrode materials, and particularly relates to a "medium-high entropy" conversion-alloy dual reaction mechanism negative electrode material and a preparation method thereof. BACKGROUND

[0002] Lithium ion batteries are widely used in portable electronic devices and electric vehicles due to their high energy density, high power density and long cycle life. However, due to the problems of lithium ore raw material shortage and uneven distribution, lithium ion batteries cannot meet the demand of the rapidly growing electric vehicle market and future large-scale energy storage devices. In view of the advantages of sodium ion batteries and potassium ion batteries, such as abundant raw material reserves and low cost, and the similar "rocking chair" electrochemical working principle of the three, sodium / potassium ion batteries are very promising low-cost energy storage devices.

[0003] At present, potassium / sodium ion battery negative electrodes can be divided into three types of materials, namely insertion type, conversion type and alloy reaction mechanism. The insertion type mechanism material has a lower working voltage and excellent cycle stability, but its relatively limited actual specific capacity greatly limits the upper limit development of the energy density of potassium / sodium ion batteries. In contrast, conversion or alloy reaction mechanism materials can provide high theoretical specific capacity through multi-electron transfer reaction, but they have large volume expansion and slow electron and ion transport dynamics during potassium / sodium storage, thus deteriorating cycle stability and rate performance. In recent years, new negative electrode materials based on conversion-alloy dual reaction mechanism can contribute higher theoretical specific capacity because they combine the conversion reaction of cations and the alloying reaction of metal elements. In addition, the participation of alloying reaction can reduce the working voltage of the material, and the conversion product can also act as a buffer area to accommodate the large lattice stress generated during alloying / dealloying. The introduction of medium-high entropy components can further enhance the electrochemical dynamics by reducing the band gap and potassium / sodium ion diffusion barrier of the material, and the increase in disorder degree can effectively enhance the electrode morphology and structural stability during the electrochemical process, thereby improving the rate performance and cycle stability. SUMMARY

[0004] The purpose of the present application is to improve the large volume expansion problem and slow electrochemical dynamics of conversion or alloy reaction mechanism negative electrode materials during potassium / sodium storage, and a "medium-high entropy" conversion-alloy dual reaction mechanism negative electrode material and a preparation method thereof are proposed.

[0005] A medium-high entropy conversion-alloy based negative electrode material for potassium / sodium ion batteries, characterized in that the chemical formula of the negative electrode material is Sb x Bi y Sn z Co m Mn nNi 2-x-y-z-m-n Te3, wherein 0≤x<2, 0≤y<2, 0≤z<2, 0≤m<2, 0≤n<2, and at least three elements of Sb, Bi, Sn, Co, Mn, and Ni are present.

[0006] A preparation method of a high-entropy conversion-alloy-based negative electrode material in a potassium / sodium ion battery, characterized in that it comprises the following steps:

[0007] (1) A certain amount of antimony salt, bismuth salt, tin salt, cobalt salt, manganese salt and nickel salt are weighed according to the stoichiometric ratio and dissolved in deionized water containing tartaric acid to form a uniform solution A; then a certain amount of sodium tellurite is dissolved in ammonia water containing hydrazine hydrate to form a uniform solution B;

[0008] (2) The solution A and the solution B are mixed uniformly under stirring conditions, and then transferred to a reaction kettle with a polytetrafluoroethylene lining, and subjected to hydrothermal reaction under certain temperature and time conditions;

[0009] (3) The precipitate is obtained by centrifugation or filtration, and the precipitate is washed with deionized water and ethanol, and finally the target product Sb x Bi y Sn z Co m Mn n Ni 2-x-y-z-m-n Te3.

[0010] Further technical solutions of the present application: the antimony salt, bismuth salt, tin salt, cobalt salt, manganese salt and nickel salt in step (1) can be one or more of chloride, sulfate and nitrate.

[0011] Further technical solutions of the present application: the molar ratio of the amount of sodium tellurite to the total amount of metal salts in step (1) is 2.5-3.1:2.

[0012] Further technical solutions of the present application: the stirring temperature in step (2) is 20-60℃, and the stirring time is 0.5-4h.

[0013] Further technical solutions of the present application: the hydrothermal reaction temperature in step (2) is 120-220℃, and the hydrothermal reaction holding time is 2-12h.

[0014] Further technical solutions of the present application: the vacuum drying temperature in step (3) is 50-100℃, and the vacuum drying time is 6-36h.

[0015] Compared with the prior art, the present application has the following advantages:

[0016] (1) The prepared potassium / sodium ion battery "medium-high entropy" negative electrode material can effectively inhibit the large volume expansion generated in the charge and discharge process and enhance the electron transmission and ion diffusion dynamics behavior through high entropy and multi-element synergistic effect, so as to ensure excellent rate performance and long cycle life of the material.

[0017] (2) The prepared negative electrode material has the advantages of conversion and alloy reaction, on the one hand, based on multi-electron transfer reaction to ensure high reversible specific capacity, on the other hand, through the coupling effect of double mechanism to enhance the dynamics process and structural stability.

[0018] (3) The preparation process of the present application is simple, the equipment operation is simple and the cost is low, the product preparation success rate is high, and it is green and environmental protection, suitable for large-scale commercial production. BRIEF DESCRIPTION OF DRAWINGS

[0019] Figure 1 is the X-ray diffraction (XRD) spectrum of the Sb 1.4 Bi 0.2 Sn 0.2 Co 0.1 Mn 0.1 Te3 negative electrode material prepared in Example 1 of the present application;

[0020] Figure 2 is the transmission electron microscope (TEM) picture of the Sb 1.4 Bi 0.2 Sn 0.2 Co 0.1 Mn 0.1 Te3 negative electrode material prepared in Example 1 of the present application;

[0021] Figure 3 is the cyclic voltammetry curve of the Sb 1.4 Bi 0.2 Sn 0.2 Co 0.1 Mn 0.1 Te3 negative electrode material prepared in Example 1 of the present application in potassium ion battery;

[0022] Figure 4 is the charge and discharge curve of the Sb 1.4 Bi 0.2 Sn 0.2 Co 0.1 Mn 0.1 Te3 negative electrode material prepared in Example 1 of the present application in potassium ion battery;

[0023] Figure 5 is the charge and discharge curve of the Sb 1.4 Bi 0.2 Sn 0.2 Co0.1 Mn 0.1 Cycle performance plot of Te3 anode material in potassium ion battery at a current density of 20 mA / g.

[0024] Figure 6 Sb prepared in Example 1 of the present application 1.4 Bi 0.2 Sn 0.2 Co 0.1 Mn 0.1 Rate performance plot of Te3 anode material in potassium ion battery.

[0025] Figure 7 Sb prepared in Example 2 of the present application 0.7 Bi 0.7 Sn 0.6 X-ray diffraction (XRD) pattern of Te3 anode material;

[0026] Figure 8 Sb prepared in Example 2 of the present application 0.7 Bi 0.7 Sn 0.6 Scanning electron microscope (SEM) image of Te3 anode material;

[0027] Figure 9 Sb prepared in Example 2 of the present application 0.7 Bi 0.7 Sn 0.6 Cyclic voltammogram of Te3 anode material in potassium ion battery;

[0028] Figure 10 Sb prepared in Example 2 of the present application 0.7 Bi 0.7 Sn 0.6 Charge-discharge curve of Te3 anode material in potassium ion battery;

[0029] Figure 11 Sb prepared in Example 2 of the present application 0.7 Bi 0.7 Sn 0.6 Cycle performance plot of Te3 anode material in potassium ion battery at a current density of 50 mA / g.

[0030] Figure 12 Sb prepared in Example 3 of the present application 0.4 Bi 0.4 Sn 0.3 Co 0.3 Ni 0.3 Mn 0.3 X-ray diffraction (XRD) pattern of Te3 anode material;

[0031] Figure 13 Sb prepared in Example 3 of the present invention 0.4 Bi 0.4 Sn 0.3 Co 0.3 Ni 0.3 Mn 0.3 SEM picture of Te3 anode material;

[0032] Figure 14 Sb prepared in Example 3 of the present invention 0.4 Bi 0.4 Sn 0.3 Co 0.3 Ni 0.3 Mn 0.3 Cyclic voltammogram of Te3 anode material in potassium ion battery;

[0033] Figure 15 Sb prepared in Example 3 of the present invention 0.4 Bi 0.4 Sn 0.3 Co 0.3 Ni 0.3 Mn 0.3 Charge-discharge curve of Te3 anode material in potassium ion battery;

[0034] Figure 16 Sb prepared in Example 3 of the present invention 0.4 Bi 0.4 Sn 0.3 Co 0.3 Ni 0.3 Mn 0.3 Cycle performance graph of Te3 anode material in potassium ion battery at 20 mA / g current density;

[0035] Figure 17 Sb prepared in Example 3 of the present invention 0.4 Bi 0.4 Sn 0.3 Co 0.3 Ni 0.3 Mn 0.3 Rate performance graph of Te3 anode material in potassium ion battery. DETAILED DESCRIPTION

[0036] The present application will be further described with reference to the following specific examples, but the present application is not limited thereto.

[0037] Example 1

[0038] (1) 0.7 mmol of antimony trichloride, 0.1 mmol of bismuth trichloride, 0.1 mmol of stannous chloride, 0.05 mmol of cobalt chloride, and 0.05 mmol of manganese chloride were dissolved in 10 ml of deionized water containing 1.0 g of tartaric acid to form a uniform solution A; 1.4 mmol of sodium tellurite was then dissolved in 40 ml of aqueous hydrazine to form a uniform solution B;

[0039] (2) Solution A was stirred with solution B at 20°C for 1.5 h, and then transferred to a reaction kettle with a polytetrafluoroethylene liner for hydrothermal reaction at 170°C for 6 h;

[0040] (3) After cooling to room temperature, the precipitate was obtained by centrifugation, and then washed with deionized water and ethanol, and finally vacuum dried at 60°C for 12 h to obtain the target product Sb 1.4 Bi 0.2 Sn 0.2 Co 0.1 Mn 0.1 Te3.

[0041] The Sb 1.4 Bi 0.2 Sn 0.2 Co 0.1 Mn 0.1 Te3 prepared in this example was dissolved in N-methyl pyrrolidone together with acetylene black and polyvinylidene fluoride, and then applied on a copper foil current collector after stirring to form a uniform slurry, and then dried at 80°C for 15 h, and then cut into a thin sheet with a diameter of 12 mm. A half-cell was assembled in an argon-filled glove box using potassium / sodium metal as the negative electrode sheet, a glass fiber membrane as the separator, and a 1M KFSI or NaClO4 solution (solvent: EC and DEC in a volume ratio of 1:1) as the electrolyte, and then subjected to constant current charge and discharge tests in a voltage range of 0.01-3.0 V.

[0042] Figure 1 The Rietveld refinement X-ray diffraction (XRD) pattern of the Sb 1.4 Bi 0.2 Sn 0.2 Co 0.1 Mn 0.1 Te3 negative electrode material prepared in this example is given, and the crystal structure thereof corresponds to a hexagonal system of R-3m space group (PDF #97-018-4226).

[0043] Figure 2 The Sb 1.4 Bi 0.2 Sn 0.2 Co 0.1 Mn 0.1The transmission electron microscope (TEM) picture of Te3 anode material can be observed that Sb 1.4 Bi 0.2 Sn 0.2 Co 0.1 Mn 0.1 Te3 is a hexagonal nanosheet with a size of about 300 nm.

[0044] Figure 3 The cyclic voltammogram of Sb 1.4 Bi 0.2 Sn 0.2 Co 0.1 Mn 0.1 Te3 in the process of potassium ion storage is given, the reduction peak at 1.38 V and the oxidation peak at 1.99 V correspond to the insertion and extraction reactions of Sb 1.4 Bi 0.2 Sn 0.2 Co 0.1 Mn 0.1 Te3; the reduction peak at 0.95 V and the oxidation peak at 1.64 V correspond to the conversion and reverse conversion processes of the material; the reduction peak at 0.15 V and the oxidation peak at 0.83 V are alloying and reverse alloying reactions that occur during the potassium storage process.

[0045] Figure 4 The charge-discharge curve of Sb 1.4 Bi 0.2 Sn 0.2 Co 0.1 Mn 0.1 Te3 anode material in the process of potassium storage is given, which presents obvious conversion and alloy charge-discharge platforms, and the first reversible specific capacity of the material is 372.9 mAh / g.

[0046] Figure 5 The cycle performance graph of Sb 1.4 Bi 0.2 Sn 0.2 Co 0.1 Mn 0.1 Te3 anode material at a current density of 20 mA / g is given, the charge specific capacity after 150 cycles is as high as 207.4 mAh / g, and the charge-discharge efficiency is as high as 100%.

[0047] Figure 6 The charge-discharge curve of Sb 1.4 Bi 0.2 Sn 0.2 Co 0.1 Mn 0.1The rate performance graph of Te3 anode material in the process of potassium storage, the reversible specific capacity at current densities of 50, 100, 200, 500, 1000, 2000 mA / g is 387.5, 326.8, 290.3, 236.9, 178.4, 93.9 mAh / g respectively. When the current returns to 50 mA / g, the reversible specific capacity can return to 359.1 mAh / g.

[0048] It can be seen that a pure phase Sb-Bi-Sn-Co-Mn-based high-entropy telluride can be constructed by using a one-step hydrothermal method. Based on high-entropy stabilization and five-element synergistic effect, the electronic and ionic transport kinetics and the structural stability of potassium storage can be effectively enhanced, thus significantly improving the electrochemical performance of the conversion-alloy anode material.

[0049] Example 2

[0050] (1) 0.35 mmol of antimony trichloride, 0.35 mmol of bismuth nitrate, and 0.3 mmol of stannous chloride were dissolved in 10 ml of deionized water containing 1.0 g of tartaric acid to form a uniform solution A; then 1.5 mmol of sodium tellurite was dissolved in 40 ml of aqueous hydrazine containing 16 ml of water to form a uniform solution B;

[0051] (2) Solution A and solution B were stirred at 40°C for 1 h, transferred to a reaction kettle with a polytetrafluoroethylene liner, and subjected to a hydrothermal reaction at 180°C for 4 h;

[0052] (3) After cooling to room temperature, the precipitate was obtained by centrifugation, and the precipitate was washed with deionized water and ethanol, and finally vacuum dried at 80°C for 8 h to obtain the target product Sb 0.7 Bi 0.7 Sn 0.6 Te3.

[0053] The Sb 0.7 Bi 0.7 Sn 0.6 Te3 prepared in this example was dissolved in N-methyl pyrrolidone with acetylene black and polyvinylidene fluoride according to a mass ratio of 8:1:1, and after stirring into a uniform slurry, it was coated on a copper foil current collector, dried at 80°C for 15 h, and then cut into a thin sheet with a diameter of 12 mm. Potassium / sodium metal was used as the negative electrode sheet, glass fiber membrane was used as the separator, and 1M KFSI or NaClO4 solution (solvent: EC and DEC in a volume ratio of 1:1) was used as the electrolyte. The half-cell was assembled in an argon-filled glove box, and constant current charge and discharge tests were carried out in a voltage range of 0.01-3.0 V.

[0054] Figure 7 The Sb 0.7 Bi 0.7 Sn prepared in this example was given.0.6 Rietveld refinement of X-ray diffraction (XRD) pattern of Te3 anode material, crystalline structure belongs to hexagonal system of R-3m space group (PDF #97-018-4226).

[0055] Figure 8 Sb 0.7 Bi 0.7 Sn 0.6 Te3 anode material, Sb 0.7 Bi 0.7 Sn 0.6 Te3 is hexagonal nanoplate with size of about several microns.

[0056] Figure 9 Sb 0.7 Bi 0.7 Sn 0.6 Te3 anode material, the reduction peak at 1.40 V and the oxidation peak at 2.05 V are attributed to the alloying and de-alloying reactions of Sb 0.7 Bi 0.7 Sn 0.6 Te3; the reduction peak at 1.01 V and the oxidation peak at 1.65 V correspond to the conversion and inverse conversion processes of the material; the reduction peak at 0.15 V and the oxidation peak at 0.57 V are the alloying and inverse alloying reactions during the potassium storage process.

[0057] Figure 10 Sb 0.7 Bi 0.7 Sn 0.6 Te3 anode material during the potassium storage process, showing obvious conversion and alloy charge-discharge platforms, and the first reversible specific capacity of the material is 364.1 mAh / g.

[0058] Figure 11 Sb 0.7 Bi 0.7 Sn 0.6 Te3 anode material at a current density of 50 mA / g, the charge specific capacity is as high as 266.0 mAh / g after 50 cycles, and the charge-discharge efficiency is as high as 96.1%.

[0059] It can be seen that the pure phase Sb 0.7 Bi 0.7 Sn 0.6 Te3 entropy anode material is successfully prepared by hydrothermal method. The anode material effectively inhibits the large volume expansion generated during the charge and discharge process through entropy and ternary synergistic effect, and improves the electrochemical kinetic behavior of the material, thus exhibiting excellent electrochemical performance.

[0060] Example 3

[0061] (1) 0.2 mmol of antimony nitrate, 0.2 mmol of bismuth nitrate, 0.15 mmol of stannous chloride, 0.15 mmol of cobalt nitrate, 0.15 mmol of nickel nitrate, and 0.15 mmol of manganese nitrate were dissolved in 10 ml of deionized water containing 1.0 g of tartaric acid to form a uniform solution A; then 1.45 mmol of sodium tellurite was dissolved in 40 ml of aqueous hydrazine to form a uniform solution B;

[0062] (2) Solution A and solution B were stirred at 60°C for 0.5 h, and then transferred to a reaction kettle with a polytetrafluoroethylene liner, and subjected to a hydrothermal reaction at 200°C for 2 h;

[0063] (3) After cooling to room temperature, the precipitate was obtained by centrifugation, and washed with deionized water and ethanol, and finally vacuum dried at 90°C for 6 h to obtain the target product Sb 0.4 Bi 0.4 Sn 0.3 Co 0.3 Ni 0.3 Mn 0.3 Te3.

[0064] The Sb 0.4 Bi 0.4 Sn 0.3 Co 0.3 Ni 0.3 Mn 0.3 Te3 prepared in this example was dissolved in N-methylpyrrolidone according to a mass ratio of 8:1:1 together with acetylene black and polyvinylidene fluoride, and after stirring to form a uniform slurry, it was coated on a copper foil current collector, dried at 80°C for 15 h, and then cut into a thin sheet with a diameter of 12 mm. A half-cell was assembled in an argon-filled glove box using potassium / sodium metal as the negative electrode sheet, a glass fiber membrane as the separator, and a 1M KFSI or NaClO4 solution (solvent: EC and DEC in a volume ratio of 1:1) as the electrolyte, and subjected to constant current charge and discharge tests in a voltage range of 0.01-3.0 V.

[0065] Figure 12 The Rietveld refinement X-ray diffraction (XRD) pattern of the Sb 0.4 Bi 0.4 Sn 0.3 Co 0.3 Ni 0.3 Mn 0.3 Te3 negative electrode material prepared in this example is given, and the crystal structure thereof corresponds to a hexagonal system of R-3m space group (PDF #97-018-4226).

[0066] Figure 13 Sb 0.4 Bi 0.4 Sn 0.3 Co 0.3 Ni 0.3 Mn 0.3 Te3negative electrode material, it can be observed that Sb 0.4 Bi 0.4 Sn 0.3 Co 0.3 Ni 0.3 Mn 0.3 Te3are hexagonal nanosheets with a size of about several microns.

[0067] Figure 14 Sb 0.4 Bi 0.4 Sn 0.3 Co 0.3 Ni 0.3 Mn 0.3 Te3in the process of potassium ion storage, the reduction peak at 1.42 V and the oxidation peak at 2.09 V correspond to the alloying and de-alloying of Sb 0.4 Bi 0.4 Sn 0.3 Co 0.3 Ni 0.3 Mn 0.3 Te3; the reduction peak at 0.26 V and the oxidation peak at 1.75 V correspond to the conversion and reverse conversion processes of the material; the reduction peak at 0.08 V and the oxidation peak at 0.89 V are alloying and de-alloying reactions that occur during the potassium storage process.

[0068] Figure 15 Sb 0.4 Bi 0.4 Sn 0.3 Co 0.3 Ni 0.3 Mn 0.3 Te3negative electrode material in the process of potassium storage, showing obvious conversion and alloy charge-discharge platforms, and the first reversible specific capacity of the material is 397.2 mAh / g.

[0069] Figure 16 Sb 0.4 Bi 0.4 Sn 0.3 Co 0.3 Ni 0.3 Mn 0.3 Te3negative electrode material at a current density of 50 mA / g, the charge specific capacity after 100 cycles is as high as 253.6 mAh / g, and the charge-discharge efficiency is as high as 98.3%.

[0070] Figure 17 Sb 0.4 Bi 0.4 Sn 0.3 Co 0.3 Ni 0.3 Mn 0.3 Te3 negative electrode material in the process of potassium storage. The reversible specific capacity at current densities of 50, 100, 200, 500, 1000, 2000 mA / g is 215.0, 172.4, 148.5, 116.1, 71.9, 36.8 mAh / g, respectively. When the current returns to 50 mA / g, the reversible specific capacity can recover to 195.4 mAh / g.

[0071] It can be seen that, by using the hydrothermal method, pure-phase Sb 0.4 Bi 0.4 Sn 0.3 Co 0.3 Ni 0.3 Mn 0.3 Te3-based six-element high-entropy negative electrode material is successfully prepared. High entropy and cocktail effect significantly improve the electrochemical kinetic behavior and electrode stability, so that the electrode material exhibits high reversible specific capacity, excellent cycle stability and rate performance.

[0072] Example 4

[0073] (1) 0.5 mmol of antimony trichloride, 0.1 mmol of bismuth trichloride, 0.1 mmol of stannous chloride, 0.1 mmol of cobalt sulfate, 0.1 mmol of nickel sulfate, and 0.1 mmol of manganese sulfate were dissolved in 10 ml of deionized water containing 1.0 g of tartaric acid to form a uniform solution A; then 1.3 mmol of sodium tellurite was dissolved in 40 ml of ammonia water containing 16 ml of hydrazine hydrate to form a uniform solution B;

[0074] (2) Solution A and solution B were stirred at 30°C for 3h, and then transferred to a reaction kettle with a polytetrafluoroethylene liner, and hydrothermal reaction was carried out at 150°C for 10h;

[0075] (3) After cooling to room temperature, the precipitate was obtained by centrifugation, and the precipitate was washed with deionized water and ethanol, and finally vacuum dried at 100°C for 6h to obtain the target product Sb 1.0 Bi 0.2 Sn 0.2 Co 0.2 Ni 0.2 Mn 0.2 Te3.

[0076] Example 5

[0077] (1) 0.4 mmol of antimony trichloride, 0.2 mmol of bismuth trichloride, 0.1 mmol of stannous chloride, 0.1 mmol of cobalt chloride, 0.1 mmol of nickel chloride, and 0.1 mmol of manganese chloride were dissolved in 10 ml of deionized water containing 1.0 g of tartaric acid to form a uniform solution A; then 1.55 mmol of sodium tellurite was dissolved in 40 ml of aqueous hydrazine containing 16 ml of hydrazine to form a uniform solution B;

[0078] (2) Solution A was stirred with solution B at 40°C for 2 h, transferred to a reaction kettle with a polytetrafluoroethylene lining, and subjected to a hydrothermal reaction at 120°C for 12 h;

[0079] (3) After cooling to room temperature, the precipitate was obtained by centrifugation, and the precipitate was washed with deionized water and ethanol, and finally vacuum dried at 50°C for 36 h to obtain the target product Sb 0.8 Bi 0.4 Sn 0.2 Co 0.2 Ni 0.2 Mn 0.2 Te3.

[0080] Example 6

[0081] (1) 0.3 mmol of antimony nitrate, 0.2 mmol of bismuth nitrate, 0.2 mmol of stannous chloride, 0.1 mmol of cobalt chloride, 0.1 mmol of nickel chloride, and 0.1 mmol of manganese chloride were dissolved in 10 ml of deionized water containing 1.0 g of tartaric acid to form a uniform solution A; then 1.5 mmol of sodium tellurite was dissolved in 40 ml of aqueous hydrazine containing 16 ml of hydrazine to form a uniform solution B;

[0082] (2) Solution A was stirred with solution B at 50°C for 1.5 h, transferred to a reaction kettle with a polytetrafluoroethylene lining, and subjected to a hydrothermal reaction at 140°C for 10 h;

[0083] (3) After cooling to room temperature, the precipitate was obtained by centrifugation, and the precipitate was washed with deionized water and ethanol, and finally vacuum dried at 60°C for 24 h to obtain the target product Sb 0.6 Bi 0.4 Sn 0.4 Co 0.2 Ni 0.2 Mn 0.2 Te3.

[0084] Example 7

[0085] (1) 0.25 mmol of antimony nitrate, 0.25 mmol of bismuth nitrate, 0.25 mmol of stannous chloride, 0.15 mmol of nickel chloride, and 0.1 mmol of manganese chloride were dissolved in 10 ml of deionized water containing 1.0 g of tartaric acid to form a uniform solution A; then 1.45 mmol of sodium tellurite was dissolved in 40 ml of ammonia water containing 16 ml of hydrazine hydrate to form a uniform solution B;

[0086] (2) Solution A was stirred with solution B at 60°C for 1 h, and then transferred to a reaction kettle with a polytetrafluoroethylene lining, and subjected to a hydrothermal reaction at 150°C for 8 h;

[0087] (3) After cooling to room temperature, the precipitate was obtained by centrifugation, and the precipitate was washed with deionized water and ethanol, and finally vacuum dried at 80°C for 16 h to obtain the target product Sb 0.5 Bi 0.5 Sn 0.5 Ni 0.3 Mn 0.2 Te3.

[0088] Example 8

[0089] (1) 0.2 mmol of antimony nitrate, 0.2 mmol of bismuth nitrate, 0.2 mmol of stannous chloride, 0.2 mmol of cobalt nitrate, and 0.2 mmol of nickel sulfate were dissolved in 10 ml of deionized water containing 1.0 g of tartaric acid to form a uniform solution A; then 1.4 mmol of sodium tellurite was dissolved in 40 ml of ammonia water containing 16 ml of hydrazine hydrate to form a uniform solution B;

[0090] (2) Solution A was stirred with solution B at 60°C for 1 h, and then transferred to a reaction kettle with a polytetrafluoroethylene lining, and subjected to a hydrothermal reaction at 180°C for 6 h;

[0091] (3) After cooling to room temperature, the precipitate was obtained by centrifugation, and the precipitate was washed with deionized water and ethanol, and finally vacuum dried at 70°C for 20 h to obtain the target product Sb 0.4 Bi 0.4 Sn 0.4 Co 0.4 Ni 0.4 Te3.

[0092] It should be noted that the above-described examples are only preferred embodiments of the present application. Those skilled in the art can make several modifications, improvements and equivalent replacements to the present application without departing from the principles of the present application, and these modifications, improvements and equivalent replacements are also considered to fall within the protection scope of the claims of the present application.

Claims

1. A high-entropy conversion-alloy-based anode material for potassium / sodium ion batteries, characterized in that, The chemical formula of the negative electrode material is Sb x Bi y Sn z Co m Mn n Ni 2-x-y-z-m-n Te3, wherein 0≤x<2,0≤y<2,0≤z<2,0≤m<2,0≤n<2, and at least three of the elements Sb, Bi, Sn, Co, Mn, and Ni are present.

2. A method for preparing the high-entropy conversion-alloy-based anode material in a potassium / sodium ion battery according to claim 1, characterized in that, Includes the following steps: (1) Weigh a certain amount of antimony salt, bismuth salt, tin salt, cobalt salt, manganese salt and nickel salt according to the stoichiometric ratio and dissolve them in deionized water containing tartaric acid to form a homogeneous solution A; then dissolve a certain amount of sodium tellurite in ammonia water containing hydrazine hydrate to form a homogeneous solution B. (2) Mix the solution A and the solution B evenly under stirring conditions, transfer them to a reaction vessel with a polytetrafluoroethylene liner, and carry out a hydrothermal reaction under certain temperature and time conditions; (3) The precipitate was obtained by centrifugation or filtration, and the precipitate was washed with deionized water and ethanol. Finally, the target product Sb was obtained by vacuum drying. x Bi y Sn z Co m Mn n Ni 2-x-y-z-m-n Te3.

3. The method for preparing the high-entropy conversion-alloy-based anode material in a potassium / sodium ion battery according to claim 2, characterized in that, The antimony salt, bismuth salt, tin salt, cobalt salt, manganese salt and nickel salt mentioned in step (1) can be one or more of chloride, sulfate and nitrate.

4. The method for preparing the high-entropy conversion-alloy-based anode material in a potassium / sodium ion battery according to claim 2, characterized in that, The molar ratio of sodium tellurite to the total amount of metal salt used in step (1) is 2.5 to 3.1:

2.

5. The method for preparing the high-entropy conversion-alloy-based anode material in a potassium / sodium ion battery according to claim 2, characterized in that, In step (2), the stirring temperature is 20-60℃ and the stirring time is 0.5-4h.

6. The method for preparing the high-entropy conversion-alloy-based anode material in a potassium / sodium ion battery according to claim 2, characterized in that, The hydrothermal reaction temperature in step (2) is 120-220℃, and the hydrothermal reaction holding time is 2-12h.

7. The method for preparing the high-entropy conversion-alloy-based anode material in a potassium / sodium ion battery according to claim 2, characterized in that, The vacuum drying temperature in step (3) is 50-100℃, and the vacuum drying time is 6-36h.

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