CN110571500B - Lithium-sulfur semi-flow battery - Google Patents

Abstract

The invention discloses a lithium-sulfur semi-liquid flow battery, which comprises a liquid flow sulfur positive electrode area, a lithium metal negative electrode area, and a diaphragm; the liquid flow sulfur positive electrode area includes a working electrode and lithium polysulfide catholyte; the working electrode includes an active material, a conductive agent, binder and current collector; the active material is Ni/C composite material, Pt/C composite material or Pt ₃ Ni/C composite material; lithium polysulfide catholyte is composed of lithium polysulfide dissolved in lithium sulfur electrolyte The lithium metal negative pole area comprises a lithium metal negative pole and a lithium-sulfur electrolyte, and the lithium metal negative pole is lithium metal or a lithium metal alloy; the diaphragm is a single-ion membrane; the lithium-sulfur semi-flow battery of the present invention has high energy density, Due to its high power density and long life, it can be widely used not only as a power source for various devices such as electric vehicles or hybrid electric vehicles, but also as a large-scale energy storage device for power grids.

Description

A lithium-sulfur semi-flow battery

technical field

The invention relates to the field of electrochemical energy, in particular to a lithium-sulfur semi-liquid flow battery with high energy density, high power density and long cycle life.

Background technique

In recent decades, the use of solar, tidal and wind power has increased, and electric vehicles with low CO2 emissions have been promoted. Therefore, in order to effectively utilize renewable energy, it is imperative to develop high-performance, safe, inexpensive, and environmentally friendly energy conversion and storage systems. Lithium-ion batteries and supercapacitors are the most developed of these energy storage systems. Lithium-ion batteries are common electrochemical devices used to store electrical energy. However, despite their commercial success, lithium-ion batteries cannot meet the high power demands required for applications such as power tools, electric vehicles, and efficient storage devices for renewable energy. In contrast, supercapacitors, in addition to offering higher energy densities than conventional dielectric capacitors, also show promise for applications in high-power systems because they can instantaneously deliver higher power densities than batteries. However, the energy density of supercapacitors is still insufficient for novel applications requiring high energy and high power densities.

To overcome these disadvantages, research on Li-ion batteries has focused on improving electrode materials, for example, using silicon anodes and Li-rich cathodes. However, these materials inherently suffer from several drawbacks, including low first-cycle Coulombic efficiencies, unsatisfactory rate performance, poor cycle life, poor thermal characteristics, and significant voltage decay. In fact, alternative battery systems, such as lithium-air batteries, lithium-sulfur batteries, and sodium/magnesium-ion batteries, have been shown to outperform lithium-ion batteries in terms of energy/power density, safety, and cost. However, these systems also have their own disadvantages. For example, during the charging and discharging process of a lithium-sulfur battery, due to the dissolution and shuttling of its intermediates, the utilization rate of the active material of the battery is reduced and the cycle life is shortened; at the same time, due to the poor conductivity of the active material sulfur and lithium sulfide, the rate performance of the battery is relatively low. Poor, in order to improve the conductivity, it is necessary to add a large amount of conductive additives, resulting in a decrease in the content of active materials, so that the volumetric energy density of the battery is low and it is difficult to exert the high energy density of the lithium-sulfur battery. Therefore, to address these issues, a new class of lithium-sulfur flow battery systems has recently been proposed. This system involves the use of an electrocatalytically active working electrode, a lithium polysulfide catholyte, a separator, and an anode region comprising a lithium metal anode and a conventional lithium-sulfur electrolyte. Although this lithium-sulfur semi-flow battery has high energy density and power density, it is necessary to solve the catalytic activity and stability of the working electrode and the selectivity of the separator to realize its commercial application.

Contents of the invention

The invention provides a lithium-sulfur semi-liquid flow battery with high energy density, high power density and long life, which comprises a liquid flow sulfur positive electrode region, a lithium metal negative electrode region, and a diaphragm.

The liquid flow sulfur cathode region includes a working electrode and lithium polysulfide catholyte.

The working electrode includes an active material that can catalyze the conversion of lithium polysulfide, a conductive agent, a binder and a current collector; the mass ratio of the active material that can catalyze the conversion of lithium polysulfide, the conductive agent and the binder is 8:1 : 1; the conductive agent and the binding agent are commonly used products for commercial batteries, preferably Super p is used as the conductive agent, and preferably polyvinylidene fluoride (PVDF) is used as the binding agent; the current collector is aluminum foil, stainless steel mesh and carbon One of the commonly used current collectors such as paper or self-supporting, preferably stainless steel mesh.

The active material capable of catalyzing the conversion of lithium polysulfide is Ni/C composite material, Pt/C composite material, Pt ₃ Ni/C composite material, and other conductive carriers loaded with Ni, Pt, and Pt ₃ Ni.

The lithium polysulfide catholyte is composed of lithium polysulfide dissolved in lithium-sulfur electrolyte, the concentration of lithium polysulfide is 0.1mol/L～2mol/L, preferably 1mol/L; the solvent of lithium-sulfide electrolyte is molecular formula: Polyethers of R(CH ₂ CH ₂ O)n-R', wherein, n=1-6, R and R' are methyl or ethyl, and the solute is lithium difluorooxalate borate, bistrifluoromethylsulfonate Lithium imide, lithium bisfluorosulfonyl imide, lithium difluorophosphate or lithium hexafluorophosphate, the concentration of lithium sulfur electrolyte is 1mol/L.

The lithium metal negative pole area includes a lithium metal negative pole and a lithium-sulfur electrolyte, the lithium metal negative pole is lithium metal or a lithium metal alloy, and the lithium metal alloy is a lithium-tin alloy, a lithium-silicon alloy or a lithium-copper alloy; the solvent of the lithium-sulfur electrolyte is Polyethers with the molecular formula R(CH ₂ CH ₂ O)n-R', wherein, n=1-6, R and R' are methyl or ethyl, and the solute is lithium difluorooxalate borate, bistrifluoromethane Lithium sulfonyl imide, lithium bisfluorosulfonyl imide, lithium difluorophosphate or lithium hexafluorophosphate, the concentration of lithium sulfur electrolyte is 1mol/L.

The separator includes one of single-ion membranes such as PP or PE, and three-layer membranes such as PP/PE/PP.

The preparation method of described Ni/C composite material, concrete steps are as follows:

(1) Sonicate the C conductive carrier and deionized water for 1 to 5 hours to obtain a carbon-based carrier dispersion with a concentration of 1 to 10 mg/mL; the C conductive carrier is graphene, Super p, carbon black, acetylene black and One of CNT, etc.;

(2) Add nickel acetate or nickel nitrate to the carbon-based carrier dispersion in step (1) at a mass ratio of C:Ni of 5 to 15:1, and sonicate for 1 to 5 hours to obtain a mixed dispersion;

(3) Quickly freeze the mixed dispersion in step (2) with liquid nitrogen, and freeze-dry with a freeze dryer to obtain a mixed powder;

(4) Under the protection of Ar gas, place the mixed powder in step (3) in a tube furnace, heat up to 700-900°C for 1-3 hours at a heating rate of 5°C/min, and then cool naturally to obtain Ni/C composite material.

The preparation method of the Pt/C composite material is the same as that of the Ni/C composite material, replacing the nickel acetate or nickel nitrate in step (2) with platinum acetate or platinum nitrate.

The preparation method of the Pt ₃ Ni/C composite material, the specific steps are as follows:

(1) Add the C conductive carrier into a round bottom flask filled with DMF, and sonicate for 1~5 hours to obtain a carbon-based carrier dispersion with a concentration of 1~10mg/mL; the C conductive carrier is graphene, Super p, carbon black , acetylene black and CNT, etc.;

(2) Put platinum diacetylacetonate (Pt(acac) ₂ ) and nickel diacetylacetonate (Ni(acac) ₂ ) at a mass ratio of Pt(acac) ₂ :Ni(acac) ₂ :C of 8:8:20~ The ratio of 24:8:60 is added to the carbon-based carrier dispersion in step (1), and then benzoic acid is added. The benzoic acid is added according to the ratio of platinum diacetylacetonate: benzoic acid mass ratio of 8:50~70, and ultrasonically 1 to 5 hours to obtain a mixed dispersion;

(3) The mixed dispersion in step (2) is heated in a constant temperature water bath at 150~170°C, and reacted for 20~24 hours;

(4) centrifuging the product of step (3) to obtain a Pt ₃ Ni/C composite material.

The preparation method of described working electrode, concrete steps are as follows:

(1) Mix and grind 80 parts by weight of an active material capable of catalyzing the conversion of lithium polysulfide and 10 parts by weight of a conductive agent to obtain a mixed powder;

(2) Stir and mix the mixed powder in step (1) and 10 parts by weight of the binder solution, and coat the mixed slurry on the current collector; the thickness of the slurry coated to the current collector is preferably 10 to 500 microns, 60 ℃ vacuum drying for 10 to 24 hours to remove the solvent to obtain a working electrode.

The lithium-sulfur semi-liquid flow battery of the present invention uses the working electrode and the lithium polysulfide catholyte as the liquid flow sulfur positive electrode area, uses the lithium metal negative electrode and the lithium-sulfur electrolyte as the lithium metal negative electrode area, and uses the diaphragm as a commercial liquid The assembly method of the flow battery is assembled into a battery, that is, a lithium-sulfur semi-flow battery is obtained; the electrochemical redox of lithium polysulfide occurs at the positive electrode area of the liquid flow sulfur, the stripping/deposition of lithium occurs at the negative electrode area of lithium metal, and the lithium-sulfur positive electrode area of the liquid flow sulfur The lithium polysulfide catholyte also plays the role of providing the active material lithium polysulfide. The electrolyte between the working electrode and the counter electrode mainly plays the role of transporting charge by conducting lithium ions. At the same time, the solute lithium salt has a Very good solubility and ionic conductivity, which have an important impact on the working temperature, specific energy, cycle efficiency, safety performance, etc. of the battery. The middle diaphragm separates the positive and negative active materials of the battery, allowing only lithium ions to pass through, avoiding Any electron flow between the positive and negative electrodes passes directly to avoid short circuit of the battery; the resistance of the ion flow should be as small as possible, which has high energy density and power density.

Beneficial effects of the present invention:

1. The lithium-sulfur semi-flow battery of the present invention has the performance of high energy density, high power density and long life at the same time. It can not only be used as a secondary battery for driving power in mobile information equipment such as mobile phones and notebook computers, but also It can be widely used as a power source for various equipment such as electric vehicles and hybrid electric vehicles.

2. The lithium-sulfur semi-flow battery of the present invention exhibits strong energy and power density and excellent cycle performance. The lithium-sulfur semi-flow battery uses the working electrode to catalyze the mutual transformation between lithium polysulfides. At the same time, lithium polysulfides The conversion between them is a liquid-liquid reaction, so the utilization rate and reaction rate of the active material are improved, and the sulfur active material has a high theoretical specific capacity (such as sulfur: 1675mAh/g), so the lithium-sulfur semi-flow battery It will be able to overcome the challenges posed by conventional lithium-sulfur batteries, and finally achieve high capacity, good rate characteristics, and excellent cycle performance, thus serving as an advanced energy storage device.

3. The implementation cost of the present invention is low and has the potential of large-scale application.

Description of drawings

Fig. 1 is the structural representation of embodiment 1 lithium-sulfur semi-flow battery;

Fig. 2 is the SEM figure of Pt in embodiment ₉ Ni/C composite material;

Fig. 3 is the charging and discharging curve diagram of the lithium-sulfur semi-flow battery in which the Pt Ni/C composite material is used as _the working electrode in Example 9;

Fig. 4 is a diagram of the cycle performance of the lithium-sulfur semi-flow battery with the Pt ₃ Ni/C composite material used as the working electrode in Example 9.

Detailed ways

The present invention will be further described below in conjunction with the accompanying drawings through the examples, but it should be understood that the examples are used to explain the implementation of the present invention, and within the scope not exceeding the theme of the present invention, the protection scope of the present invention is not limited by the examples limit.

Other objects and advantages of the present invention will be partly set forth in the following description, and the remaining parts can be easily known from the description, or comprehended through the practice of the present invention. In addition, in the following description, "%" is a mass basis unless otherwise specified.

Example 1

A lithium-sulfur semi-flow battery with high energy density, high power density and long life, including a liquid flow sulfur positive electrode region, a lithium metal negative electrode region, and a diaphragm; the liquid flow sulfur positive electrode region includes a working electrode, lithium polysulfide catholyte The working electrode includes an active material capable of catalyzing the conversion of lithium polysulfide, a conductive agent, a binder and a current collector; the mass ratio of the active material capable of catalyzing the conversion of lithium polysulfide, the conductive agent and the binder is 8:1:1; The conductive agent and binder are commonly used products in commercial batteries. Superp is preferred as the conductive agent, and polyvinylidene fluoride (PVDF) is preferred as the binder; the current collector is stainless steel mesh; the active material that can catalyze the conversion of lithium polysulfide is Ni /C composite material; lithium polysulfide catholyte is composed of lithium polysulfide dissolved in lithium sulfur electrolyte, the concentration of lithium polysulfide is 1mol/L; lithium metal negative electrode area includes lithium metal negative electrode, lithium sulfur electrolyte, lithium metal The negative electrode is lithium metal, and the diaphragm is a three-layer porous membrane made of PP/PE/PP material; the solvent of the lithium-sulfur electrolyte in this embodiment is a polyether with a molecular formula of R(CH ₂ CH ₂ O)n-R', wherein, n=1, both R and R' are methyl groups, the solute is lithium difluorooxalate borate, and the concentration of the lithium-sulfur electrolyte is 1mol/L.

The preparation process of the lithium-sulfur semi-flow battery in this embodiment, the specific steps are as follows:

The preparation of A, Ni/C composite material, concrete steps are as follows:

(1) Add the C conductive carrier graphene dispersion (3wt%) into a beaker filled with deionized water, and sonicate for 1 hour to obtain a carbon-based carrier dispersion with a concentration of 1 mg/mL;

(2) adding nickel nitrate to the carbon-based carrier dispersion in step (1) at a ratio of C:Ni mass ratio of 5:1, and ultrasonicating for 5 hours to obtain a mixed dispersion;

(3) Quickly freeze the mixed dispersion in step (2) with liquid nitrogen, and freeze-dry with a freeze dryer to obtain a mixed powder;

(4) Under the protection of Ar gas, place the mixed powder in step (3) in a tube furnace, heat up to 800°C for 2 hours at 5°C/min, and calcine for 2 hours, then cool naturally to obtain a Ni/C composite material;

B, the preparation of working electrode, concrete steps are as follows:

(1) 80 parts by weight of the active material Ni/C composite material capable of catalyzing the conversion of lithium polysulfide prepared in step A and 10 parts by weight of the conductive agent Super p are mixed and ground to obtain a mixed powder;

(2) Stir and mix the mixed powder in step (1) and 10 parts by weight of the binder polyvinylidene fluoride (PVDF), and coat the mixed slurry on the current collector; the slurry is coated to the thickness of the current collector 10 microns, vacuum drying at 60°C for 24 hours to remove the solvent to obtain a working electrode;

C, the preparation of the lithium-sulfur semi-flow battery, as shown in Figure 1, the working positive electrode obtained in step B and the lithium polysulfide catholyte are used as the liquid flow sulfur positive electrode area, and the lithium metal negative electrode and the lithium-sulfur electrolyte are used as the The lithium metal negative electrode area, together with the diaphragm, is assembled into a battery according to the assembly method of a commercial flow battery. In an argon atmosphere glove box, the working electrode, catholyte, PP/PE/PP three-layer porous membrane, lithium sulfur The sequential superposition of the electrolyte solution and the lithium metal negative electrode yields a lithium-sulfur semi-flow battery.

The performance of the battery is tested in the battery test system, the charge and discharge cut-off voltage is 1.8V~2.6V, and the charge and discharge current density is 0.50mA/cm.

Example 2

A lithium-sulfur semi-flow battery with high energy density, high power density and long life, including a liquid flow sulfur positive electrode region, a lithium metal negative electrode region, and a diaphragm; the liquid flow sulfur positive electrode region includes a working electrode, lithium polysulfide catholyte The working electrode includes an active material capable of catalyzing the conversion of lithium polysulfide, a conductive agent, a binder and a current collector; the mass ratio of the active material capable of catalyzing the conversion of lithium polysulfide, the conductive agent and the binder is 8:1:1; The conductive agent and binder are commonly used products in commercial batteries, preferably Superp is used as the conductive agent, and polyvinylidene fluoride (PVDF) is preferred as the binder; the current collector is aluminum foil; the active material that can catalyze the conversion of lithium polysulfide is Pt/ C composite material; lithium polysulfide catholyte is composed of lithium polysulfide dissolved in lithium sulfur electrolyte, the concentration of lithium polysulfide is 1mol/L; lithium metal negative electrode area includes lithium metal negative electrode, lithium sulfur electrolyte, lithium metal negative electrode Extremely lithium metal, the separator is a three-layer porous membrane made of PP/PE/PP material; the solvent of the lithium-sulfur electrolyte in this embodiment is a polyether with the molecular formula R(CH ₂ CH ₂ O)n-R', wherein, n =2, both R and R' are ethyl, the solute is lithium bistrifluoromethanesulfonimide, and the concentration of the lithium-sulfur electrolyte is 1mol/L.

The preparation process of the lithium-sulfur semi-flow battery in this embodiment, the specific steps are as follows:

The preparation of A, Ni/C composite material, concrete steps are as follows:

(1) Add the C conductive carrier graphene dispersion (3wt%) into a beaker filled with deionized water, and sonicate for 2 hours to obtain a carbon-based carrier dispersion with a concentration of 5 mg/mL;

(2) Adding nickel acetate to the carbon-based carrier dispersion in step (1) at a mass ratio of C:Ni of 10:1, and ultrasonicating for 3 hours to obtain a mixed dispersion;

(3) Quickly freeze the mixed dispersion in step (2) with liquid nitrogen, and freeze-dry with a freeze dryer to obtain a mixed powder;

(4) Under the protection of Ar gas, place the mixed powder in step (3) in a tube furnace, heat up to 700°C for 3 hours at 5°C/min, and then cool naturally to obtain a Ni/C composite material;

B, the preparation of working electrode, concrete steps are as follows:

(1) 80 parts by weight of the active material Ni/C composite material capable of catalyzing the conversion of lithium polysulfide prepared in step A and 10 parts by weight of the conductive agent Super p are mixed and ground to obtain a mixed powder;

(2) Stir and mix the mixed powder in step (1) and 10 parts by weight of the binder polyvinylidene fluoride (PVDF), and coat the mixed slurry on the current collector; the slurry is coated to the thickness of the current collector 30 microns, vacuum drying at 60°C for 24 hours to remove the solvent to obtain a working electrode;

C, the preparation of the lithium-sulfur semi-flow battery, the working positive electrode obtained in step B and the lithium polysulfide catholyte are used as the liquid flow sulfur positive electrode area, and the lithium metal negative electrode and the lithium sulfur electrolyte are used as the lithium metal negative electrode area, and The diaphragm is assembled into a battery according to the assembly method of a commercial flow battery. In an argon atmosphere glove box, the working electrode, catholyte, PP/PE/PP three-layer porous membrane, lithium-sulfur electrolyte and lithium metal anode The sequential superposition of lithium-sulfur semi-flow battery is obtained.

The performance of the battery is tested in the battery test system, the charge and discharge cut-off voltage is 1.8V~2.6V, and the charge and discharge current density is 0.50mA/cm.

Example 3

A lithium-sulfur semi-flow battery with high energy density, high power density and long life, including a liquid flow sulfur positive electrode region, a lithium metal negative electrode region, and a diaphragm; the liquid flow sulfur positive electrode region includes a working electrode, lithium polysulfide catholyte The working electrode includes an active material capable of catalyzing the conversion of lithium polysulfide, a conductive agent, a binder and a current collector; the mass ratio of the active material capable of catalyzing the conversion of lithium polysulfide, the conductive agent and the binder is 8:1:1; Conductive agents and binders are commonly used products in commercial batteries. Superp is preferred as the conductive agent, and polyvinylidene fluoride (PVDF) is preferred as the binder; the current collector is carbon paper; the active material that can catalyze the conversion of lithium polysulfide is Ni /C composite material; lithium polysulfide catholyte is composed of lithium polysulfide dissolved in lithium sulfur electrolyte, the concentration of lithium polysulfide is 0.1mol/L; lithium metal negative electrode area includes lithium metal negative electrode, lithium sulfur electrolyte, lithium The metal negative electrode is a lithium-tin alloy (Li0.9Sn0.1), and the separator is a three-layer porous separator (PP/PE/PP); the solvent of the lithium-sulfur electrolyte in this example is R(CH ₂ CH ₂ O)n- Polyethers of R', where n=6, R is ethyl, R' is methyl, the solute is lithium bisfluorosulfonimide, and the concentration of the lithium-sulfur electrolyte is 1mol/L.

The preparation process of the lithium-sulfur semi-flow battery in this embodiment, the specific steps are as follows:

The preparation of A, Ni/C composite material, concrete steps are as follows:

(1) Add the C conductive carrier graphene dispersion (3wt%) into a beaker filled with deionized water, and ultrasonicate for 5 hours to obtain a carbon-based carrier dispersion with a concentration of 10mg/mL;

(2) Nickel acetate is added to the carbon-based carrier dispersion in step (1) at a mass ratio of C:Ni of 15:1, and ultrasonicated for 1 hour to obtain a mixed dispersion;

(3) Quickly freeze the mixed dispersion in step (2) with liquid nitrogen, and freeze-dry with a freeze dryer to obtain a mixed powder;

(4) Under the protection of Ar gas, place the mixed powder in step (3) in a tube furnace, heat up to 900°C for 1 hour at 5°C/min, and then cool naturally to obtain a Ni/C composite material;

B, the preparation of working electrode, concrete steps are as follows:

(1) 80 parts by weight of the active material Ni/C composite material capable of catalyzing the conversion of lithium polysulfide prepared in step A and 10 parts by weight of the conductive agent Super p are mixed and ground to obtain a mixed powder;

(2) Stir and mix the mixed powder in step (1) and 10 parts by weight of the binder polyvinylidene fluoride (PVDF), and coat the mixed slurry on the current collector; the slurry is coated to the thickness of the current collector 50 microns, vacuum drying at 60°C for 10 hours to remove the solvent to obtain a working electrode;

C, the preparation of the lithium-sulfur semi-flow battery, the working positive electrode obtained in step B and the lithium polysulfide catholyte are used as the liquid flow sulfur positive electrode area, and the lithium metal negative electrode and the lithium sulfur electrolyte are used as the lithium metal negative electrode area, and The diaphragm is assembled into a battery according to the assembly method of a commercial flow battery. In an argon atmosphere glove box, the working electrode, catholyte, three-layer porous diaphragm (PP/PE/PP), lithium-sulfur electrolyte and lithium Sequential stacking of metal negative electrodes yields a lithium-sulfur semi-flow battery.

The performance of the battery is tested in the battery test system, the charge and discharge cut-off voltage is 1.8V~2.6V, and the charge and discharge current density is 0.50mA cm ^-2 .

Example 4

A lithium-sulfur semi-flow battery with high energy density, high power density and long life, including a liquid flow sulfur positive electrode region, a lithium metal negative electrode region, and a diaphragm; the liquid flow sulfur positive electrode region includes a working electrode, lithium polysulfide catholyte The working electrode includes an active material capable of catalyzing the conversion of lithium polysulfide, a conductive agent, a binder and a current collector; the mass ratio of the active material capable of catalyzing the conversion of lithium polysulfide, the conductive agent and the binder is 8:1:1; The conductive agent and binder are commonly used products in commercial batteries. Superp is preferred as the conductive agent, and polyvinylidene fluoride (PVDF) is preferred as the binder; the current collector is stainless steel mesh; the active material that can catalyze the conversion of lithium polysulfide is Pt /C composite material; lithium polysulfide catholyte is composed of lithium polysulfide dissolved in lithium sulfur electrolyte, the concentration of lithium polysulfide is 1mol/L; lithium metal negative electrode area includes lithium metal negative electrode, lithium sulfur electrolyte, lithium metal The negative electrode is a lithium-silicon alloy (Li0.9Si0.1), and the separator is a three-layer porous separator (PP/PE/PP); the solvent of the lithium-sulfur electrolyte in this example is R(CH ₂ CH ₂ O)n-R 'The polyether, wherein, n=6, R and R' are both methyl, the solute is lithium hexafluorophosphate, and the concentration of the lithium-sulfur electrolyte is 1mol/L.

The preparation process of the lithium-sulfur semi-flow battery in this embodiment, the specific steps are as follows:

The preparation of A, Pt/C composite material, concrete steps are as follows:

(1) Add the C conductive carrier graphene dispersion (3wt%) into a beaker filled with deionized water, and ultrasonicate for 3 hours to obtain a carbon-based carrier dispersion with a concentration of 10 mg/mL;

(2) adding platinum acetate to the carbon-based carrier dispersion in step (1) at a mass ratio of C:Pt of 15:1, and ultrasonicating for 5 hours to obtain a mixed dispersion;

(3) Quickly freeze the mixed dispersion in step (2) with liquid nitrogen, and freeze-dry with a freeze dryer to obtain a mixed powder;

(4) Under the protection of Ar gas, place the mixed powder in step (3) in a tube furnace, heat up to 800°C for 2 hours at 5°C/min, and then cool naturally to obtain a Pt/C composite material;

B, the preparation of working electrode, concrete steps are as follows:

(1) 80 parts by weight of the active material Pt/C composite material capable of catalyzing the conversion of lithium polysulfide prepared in step A and 10 parts by weight of the conductive agent Super p are mixed and ground to obtain a mixed powder;

(2) Stir and mix the mixed powder in step (1) and 10 parts by weight of the binder polyvinylidene fluoride (PVDF), and coat the mixed slurry on the current collector; the slurry is coated to the thickness of the current collector 30 microns, vacuum-dried at 60°C for 15 hours to remove the solvent, and obtained the working electrode;

C, the preparation of the lithium-sulfur semi-flow battery, the working positive electrode obtained in step B and the lithium polysulfide catholyte are used as the liquid flow sulfur positive electrode area, and the lithium metal negative electrode and the lithium sulfur electrolyte are used as the lithium metal negative electrode area, and The diaphragm is assembled into a battery according to the assembly method of a commercial flow battery. In an argon atmosphere glove box, the working electrode, catholyte, three-layer porous diaphragm (PP/PE/PP), lithium-sulfur electrolyte and lithium Sequential stacking of metal negative electrodes yields a lithium-sulfur semi-flow battery.

The performance of the battery is tested in the battery test system, the charge and discharge cut-off voltage is 1.8V~2.6V, and the charge and discharge current density is 0.50mA/cm.

Example 5

A lithium-sulfur semi-flow battery with high energy density, high power density and long life, including a liquid flow sulfur positive electrode region, a lithium metal negative electrode region, and a diaphragm; the liquid flow sulfur positive electrode region includes a working electrode, lithium polysulfide catholyte The working electrode includes an active material capable of catalyzing the conversion of lithium polysulfide, a conductive agent, a binder and a current collector; the mass ratio of the active material capable of catalyzing the conversion of lithium polysulfide, the conductive agent and the binder is 8:1:1; The conductive agent and binder are commonly used products in commercial batteries. Superp is preferred as the conductive agent, and polyvinylidene fluoride (PVDF) is preferred as the binder; the current collector is stainless steel mesh; the active material that can catalyze the conversion of lithium polysulfide is Pt /C composite material; lithium polysulfide catholyte is composed of lithium polysulfide dissolved in lithium sulfur electrolyte, the concentration of lithium polysulfide is 2mol/L; lithium metal negative electrode area includes lithium metal negative electrode, lithium sulfur electrolyte, lithium metal The negative electrode is a lithium copper alloy (Li0.9Cu0.1), and the separator is a three-layer porous separator (PP/PE/PP); the solvent of the lithium-sulfur electrolyte in this example is R(CH ₂ CH ₂ O)n-R 'The polyethers, wherein, n=2, R and R' are both ethyl, the solute is lithium bistrifluoromethanesulfonimide, and the concentration of the lithium-sulfur electrolyte is 1mol/L.

The preparation process of the lithium-sulfur semi-flow battery in this embodiment, the specific steps are as follows:

The preparation of A, Pt/C composite material, concrete steps are as follows:

(1) Add the C conductive carrier acetylene black dispersion (3wt%) into a beaker filled with deionized water, and sonicate for 1 hour to obtain a carbon-based carrier dispersion with a concentration of 4 mg/mL;

(2) adding platinum nitrate to the carbon-based carrier dispersion in step (1) at a ratio of C:Pt mass ratio of 10:1, and ultrasonicating for 3 hours to obtain a mixed dispersion;

(3) Quickly freeze the mixed dispersion in step (2) with liquid nitrogen, and freeze-dry with a freeze dryer to obtain a mixed powder;

(4) Under the protection of Ar gas, place the mixed powder in step (3) in a tube furnace, heat up to 900°C for 1 hour at 5°C/min, and then cool naturally to obtain a Pt/C composite material;

B, the preparation of working electrode, concrete steps are as follows:

(1) 80 parts by weight of the active material Pt/C composite material capable of catalyzing the conversion of lithium polysulfide prepared in step A and 10 parts by weight of the conductive agent Super p are mixed and ground to obtain a mixed powder;

(2) Stir and mix the mixed powder in step (1) and 10 parts by weight of the binder polyvinylidene fluoride (PVDF), and coat the mixed slurry on the current collector; the slurry is coated to the thickness of the current collector 10 microns, vacuum drying at 60°C for 12 hours to remove the solvent to obtain a working electrode;

C, the preparation of the lithium-sulfur semi-flow battery, the working positive electrode obtained in step B and the lithium polysulfide catholyte are used as the liquid flow sulfur positive electrode area, and the lithium metal negative electrode and the lithium sulfur electrolyte are used as the lithium metal negative electrode area, and The diaphragm is assembled into a battery according to the assembly method of a commercial flow battery. In an argon atmosphere glove box, the working electrode, catholyte, three-layer porous diaphragm (PP/PE/PP), lithium-sulfur electrolyte and lithium Sequential stacking of metal negative electrodes yields a lithium-sulfur semi-flow battery.

The performance of the battery is tested in the battery test system, the charge and discharge cut-off voltage is 1.8V~2.6V, and the charge and discharge current density is 0.50mA/cm.

Example 6

A lithium-sulfur semi-flow battery with high energy density, high power density and long life, including a liquid flow sulfur positive electrode region, a lithium metal negative electrode region, and a diaphragm; the liquid flow sulfur positive electrode region includes a working electrode, lithium polysulfide catholyte The working electrode includes an active material capable of catalyzing the conversion of lithium polysulfide, a conductive agent, a binder and a current collector; the mass ratio of the active material capable of catalyzing the conversion of lithium polysulfide, the conductive agent and the binder is 8:1:1; The conductive agent and binder are commonly used products in commercial batteries. Superp is preferred as the conductive agent, and polyvinylidene fluoride (PVDF) is preferred as the binder; the current collector is stainless steel mesh; the active material that can catalyze the conversion of lithium polysulfide is Pt /C composite material; lithium polysulfide catholyte is composed of lithium polysulfide dissolved in lithium sulfur electrolyte, the concentration of lithium polysulfide is 1mol/L; lithium metal negative electrode area includes lithium metal negative electrode, lithium sulfur electrolyte, lithium metal The negative electrode is lithium metal, and the diaphragm is a three-layer porous diaphragm (PP/PE/PP); the solvent of the lithium-sulfur electrolyte in this example is a polyether with the molecular formula R(CH ₂ CH ₂ O)n-R', wherein, n=5, R is methyl, R' is ethyl, the solute is lithium difluorophosphate, and the concentration of lithium-sulfur electrolyte is 1mol/L.

The preparation process of the lithium-sulfur semi-flow battery in this embodiment, the specific steps are as follows:

The preparation of A, Pt/C composite material, concrete steps are as follows:

(1) Add the C conductive carrier graphene dispersion (3wt%) into a beaker filled with deionized water, and ultrasonicate for 5 hours to obtain a carbon-based carrier dispersion with a concentration of 1 mg/mL;

(2) Adding platinum nitrate to the carbon-based carrier dispersion in step (1) at a mass ratio of C:Pt of 5:1, and ultrasonicating for 1 hour to obtain a mixed dispersion;

(3) Quickly freeze the mixed dispersion in step (2) with liquid nitrogen, and freeze-dry with a freeze dryer to obtain a mixed powder;

(4) Under the protection of Ar gas, place the mixed powder in step (3) in a tube furnace, heat up to 700°C for 3 hours at 5°C/min, and then cool naturally to obtain a Pt/C composite material;

B, the preparation of working electrode, concrete steps are as follows:

(1) 80 parts by weight of the active material Pt/C composite material capable of catalyzing the conversion of lithium polysulfide prepared in step A and 10 parts by weight of the conductive agent Super p are mixed and ground to obtain a mixed powder;

(2) Stir and mix the mixed powder in step (1) and 10 parts by weight of the binder polyvinylidene fluoride (PVDF), and coat the mixed slurry on the current collector; the slurry is coated to the thickness of the current collector 500 microns, vacuum-dried at 60°C for 24 hours to remove the solvent to obtain a working electrode;

C, the preparation of the lithium-sulfur semi-flow battery, the working positive electrode obtained in step B and the lithium polysulfide catholyte are used as the liquid flow sulfur positive electrode area, and the lithium metal negative electrode and the lithium sulfur electrolyte are used as the lithium metal negative electrode area, and The diaphragm is assembled into a battery according to the assembly method of a commercial flow battery. In an argon atmosphere glove box, the working electrode, catholyte, three-layer porous diaphragm (PP/PE/PP), lithium-sulfur electrolyte and lithium Sequential stacking of metal negative electrodes yields a lithium-sulfur semi-flow battery.

The performance of the battery is tested in the battery test system, the charge and discharge cut-off voltage is 1.8V~2.6V, and the charge and discharge current density is 0.50mA/cm.

Example 7

A lithium-sulfur semi-flow battery with high energy density, high power density and long life, including a liquid flow sulfur positive electrode region, a lithium metal negative electrode region, and a diaphragm; the liquid flow sulfur positive electrode region includes a working electrode, lithium polysulfide catholyte The working electrode includes an active material capable of catalyzing the conversion of lithium polysulfide, a conductive agent, a binder and a current collector; the mass ratio of the active material capable of catalyzing the conversion of lithium polysulfide, the conductive agent and the binder is 8:1:1; The conductive agent and binder are commonly used products in commercial batteries. Superp is preferred as the conductive agent, and polyvinylidene fluoride (PVDF) is preferred as the binder; the current collector is stainless steel mesh; the active material that can catalyze the conversion of lithium polysulfide is Pt ₃ Ni/C composite material; lithium polysulfide catholyte is composed of lithium polysulfide dissolved in lithium sulfur electrolyte, the concentration of lithium polysulfide is 1mol/L; lithium metal negative electrode area includes lithium metal negative electrode, lithium sulfur electrolyte, The lithium metal negative electrode is lithium metal, and the separator is a three-layer porous separator (PP/PE/PP); the solvent of the lithium-sulfur electrolyte in this example is a polyether with the molecular formula R(CH ₂ CH ₂ O)n-R', Wherein, n=2, both R and R' are ethyl groups, the solute is lithium bistrifluoromethanesulfonimide, and the concentration of the lithium-sulfur electrolyte is 1mol/L.

The preparation process of the lithium-sulfur semi-flow battery in this embodiment, the specific steps are as follows:

The preparation method of A, Pt ₃ Ni/C composite material, concrete steps are as follows:

(1) Add 10 mg of C conductive carrier Super p into a round-bottomed flask filled with 10 mL of DMF, and sonicate for 1 hour to obtain a carbon-based carrier dispersion with a concentration of 1 mg/mL;

(2) Put platinum diacetylacetonate (Pt(acac) ₂ ) and nickel diacetylacetonate (Ni(acac) ₂ ) in a mass ratio of Pt(acac) ₂ :Ni(acac) ₂ :C of 8:8:20 Ratio, add to the carbon-based carrier dispersion in step (1), then add benzoic acid, benzoic acid is added according to the ratio of platinum diacetylacetonate: benzoic acid mass ratio of 8:50, and ultrasonically for 1 hour to obtain a mixed dispersion;

(3) The mixed dispersion in step (2) was heated in a constant temperature water bath at 150°C and reacted for 24 hours;

(4) centrifuging the product of step (3) to obtain a Pt ₃ Ni/C composite material;

B, the preparation of working electrode, concrete steps are as follows:

(1) 80 parts by weight of the active material Pt ₃ Ni/C composite material capable of catalyzing the conversion of lithium polysulfide prepared in step A and 10 parts by weight of the conductive agent Super p are mixed and ground to obtain a mixed powder;

(2) Stir and mix the mixed powder of step (1) and 10 parts by weight of the binder polyvinylidene fluoride (PVDF) solution, and coat the mixed slurry on the current collector; The thickness is 50 microns, and the solvent is removed by vacuum drying at 60°C for 24 hours to obtain a working electrode;

C, the preparation of the lithium-sulfur semi-flow battery, the working positive electrode obtained in step B and the lithium polysulfide catholyte are used as the liquid flow sulfur positive electrode area, and the lithium metal negative electrode and the lithium sulfur electrolyte are used as the lithium metal negative electrode area, and The diaphragm is assembled into a battery according to the assembly method of a commercial flow battery. In an argon atmosphere glove box, the working electrode, catholyte, three-layer porous diaphragm (PP/PE/PP), lithium-sulfur electrolyte and lithium Sequential stacking of metal negative electrodes yields a lithium-sulfur semi-flow battery.

The performance of the battery is tested in the battery test system, the charge and discharge cut-off voltage is 1.8V~2.6V, and the charge and discharge current density is 0.50mA/cm.

Example 8

A lithium-sulfur semi-flow battery with high energy density, high power density and long life, including a liquid flow sulfur positive electrode region, a lithium metal negative electrode region, and a diaphragm; the liquid flow sulfur positive electrode region includes a working electrode, lithium polysulfide catholyte The working electrode includes an active material capable of catalyzing the conversion of lithium polysulfide, a conductive agent, a binder and a current collector; the mass ratio of the active material capable of catalyzing the conversion of lithium polysulfide, the conductive agent and the binder is 8:1:1; The conductive agent and binder are commonly used products in commercial batteries. Superp is preferred as the conductive agent, and polyvinylidene fluoride (PVDF) is preferred as the binder; the current collector is stainless steel mesh; the active material that can catalyze the conversion of lithium polysulfide is Pt ₃ Ni/C composite material; lithium polysulfide catholyte is composed of lithium polysulfide dissolved in lithium sulfur electrolyte, the concentration of lithium polysulfide is 1mol/L; lithium metal negative electrode area includes lithium metal negative electrode, lithium sulfur electrolyte, The lithium metal negative electrode is lithium metal, and the separator is a three-layer porous separator (PP/PE/PP); the solvent of the lithium-sulfur electrolyte in this example is a polyether with the molecular formula R(CH ₂ CH ₂ O)n-R', Wherein, n=1, both R and R' are methyl groups, the solute is lithium difluorooxalate borate, and the concentration of the lithium-sulfur electrolyte is 1mol/L.

The preparation process of the lithium-sulfur semi-flow battery in this embodiment, the specific steps are as follows:

The preparation method of A, Pt ₃ Ni/C composite material, concrete steps are as follows:

(1) Add 200 mg of C conductive carrier CNT into a round bottom flask filled with 20 mL of DMF, and ultrasonicate for 5 hours to obtain a carbon-based carrier dispersion with a concentration of 10 mg/mL;

(2) Platinum diacetylacetonate (Pt(acac) ₂ ) and nickel diacetylacetonate (Ni(acac) ₂ ) were mixed according to the mass ratio of Pt(acac) ₂ :Ni(acac) ₂ :C of 24:8:60 ratio, added to the carbon-based carrier dispersion in step (1), and then added benzoic acid, the benzoic acid was added according to the ratio of platinum diacetylacetonate: benzoic acid mass ratio of 8:60, and ultrasonicated for 5 hours to obtain a mixed dispersion;

(3) The mixed dispersion in step (2) was heated in a constant temperature water bath at 160°C, and reacted for 22 hours;

(4) centrifuging the product of step (3) to obtain a Pt ₃ Ni/C composite material;

B, the preparation of working electrode, concrete steps are as follows:

(1) 80 parts by weight of the active material Pt ₃ Ni/C composite material capable of catalyzing the conversion of lithium polysulfide prepared in step A and 10 parts by weight of the conductive agent Super p are mixed and ground to obtain a mixed powder;

(2) Stir and mix the mixed powder in step (1) and 10 parts by weight of the binder polyvinylidene fluoride (PVDF), and coat the mixed slurry on the current collector; the slurry is coated to the thickness of the current collector 500 microns, vacuum-dried at 60°C for 24 hours to remove the solvent to obtain a working electrode;

C, the preparation of the lithium-sulfur semi-flow battery, the working positive electrode obtained in step B and the lithium polysulfide catholyte are used as the liquid flow sulfur positive electrode area, and the lithium metal negative electrode and the lithium sulfur electrolyte are used as the lithium metal negative electrode area, and The diaphragm is assembled into a battery according to the assembly method of a commercial flow battery. In an argon atmosphere glove box, the working electrode, catholyte, three-layer porous diaphragm (PP/PE/PP), lithium-sulfur electrolyte and lithium Sequential stacking of metal negative electrodes yields a lithium-sulfur semi-flow battery.

The performance of the battery is tested in the battery test system, the charge and discharge cut-off voltage is 1.8V~2.6V, and the charge and discharge current density is 0.50mA/cm.

Example 9

A lithium-sulfur semi-flow battery with high energy density, high power density and long life, including a liquid flow sulfur positive electrode region, a lithium metal negative electrode region, and a diaphragm; the liquid flow sulfur positive electrode region includes a working electrode, lithium polysulfide catholyte The working electrode includes an active material capable of catalyzing the conversion of lithium polysulfide, a conductive agent, a binder and a current collector; the mass ratio of the active material capable of catalyzing the conversion of lithium polysulfide, the conductive agent and the binder is 8:1:1; The conductive agent and binder are commonly used products in commercial batteries. Superp is preferred as the conductive agent, and polyvinylidene fluoride (PVDF) is preferred as the binder; the current collector is stainless steel mesh; the active material that can catalyze the conversion of lithium polysulfide is Pt ₃ Ni/C composite material; lithium polysulfide catholyte is composed of lithium polysulfide dissolved in lithium sulfur electrolyte, the concentration of lithium polysulfide is 1mol/L; lithium metal negative electrode area includes lithium metal negative electrode, lithium sulfur electrolyte, The lithium metal negative electrode is lithium metal, and the separator is a three-layer porous separator (PP/PE/PP); the solvent of the lithium-sulfur electrolyte in this example is a polyether with the molecular formula R(CH ₂ CH ₂ O)n-R', Wherein, n=2, both R and R' are ethyl groups, the solute is lithium difluorophosphate, and the concentration of the lithium-sulfur electrolyte is 1mol/L.

The preparation process of the lithium-sulfur semi-flow battery in this embodiment, the specific steps are as follows:

The preparation method of A, Pt ₃ Ni/C composite material, concrete steps are as follows:

(1) Add 40 mg of C conductive carrier carbon black into a round-bottomed flask filled with 20 mL of DMF, and sonicate for 2 hours to obtain a carbon-based carrier dispersion with a concentration of 2 mg/mL;

(2) Put platinum diacetylacetonate (Pt(acac) ₂ ) and nickel diacetylacetonate (Ni(acac) ₂ ) at a mass ratio of Pt(acac) ₂ :Ni(acac) ₂ :C of 16:8:40 ratio, added to the carbon-based carrier dispersion in step (1), and then added benzoic acid, which was added according to the ratio of platinum diacetylacetonate: benzoic acid mass ratio of 8:61, and ultrasonicated for 3 hours to obtain a mixed dispersion;

(3) The mixed dispersion in step (2) was heated in a constant temperature water bath at 170°C, and reacted for 20 hours;

(4) centrifuging the product of step (3) to obtain a Pt ₃ Ni/C composite material;

B, the preparation of working electrode, concrete steps are as follows:

(1) 80 parts by weight of the active material Pt ₃ Ni/C composite material capable of catalyzing the conversion of lithium polysulfide prepared in step A and 10 parts by weight of the conductive agent Super p are mixed and ground to obtain a mixed powder;

(2) Stir and mix the mixed powder in step (1) and 10 parts by weight of the binder polyvinylidene fluoride (PVDF), and coat the mixed slurry on the current collector; the slurry is coated to the thickness of the current collector 50 microns, vacuum drying at 60°C for 24 hours to remove the solvent to obtain a working electrode;

C, the preparation of the lithium-sulfur semi-flow battery, the working positive electrode obtained in step B and the lithium polysulfide catholyte are used as the liquid flow sulfur positive electrode area, and the lithium metal negative electrode and the lithium sulfur electrolyte are used as the lithium metal negative electrode area, and The diaphragm is assembled into a battery according to the assembly method of a commercial flow battery. In an argon atmosphere glove box, according to the working electrode, catholyte, three-layer porous diaphragm (PP/PE/PP), conventional lithium-sulfur electrolyte and Sequential stacking of lithium metal negative electrodes yields a lithium-sulfur semi-flow battery.

The performance of the battery is tested in the battery test system, the charge and discharge cut-off voltage is 1.8V~2.6V, and the charge and discharge current density is 0.50mA/cm.

Fig. 2 is the SEM figure of Pt ₃ Ni/C composite material in embodiment 9, can find out from Fig. 1 that the Pt ₃ Ni of several nanometers size is evenly supported on the carbon black, and this is conducive to increasing the electrical conductivity and property of composite material The contact area with lithium polysulfide is increased, thereby enhancing the ability of the composite material to promote the transformation of lithium polysulfide.

Fig. 3 is the charge-discharge curve of the lithium-sulfur semi-flow battery with the Pt ₃ Ni/C composite material as the working electrode in Example 9. It can be seen from the figure that it shows the same charge-discharge platform as the lithium-sulfur battery .

Fig. 4 is the cycle performance diagram of the lithium-sulfur semi-flow battery in which the Pt ₃ Ni/C composite material is used as the working electrode in Example 9. As can be seen from the figure, the lithium-sulfur semi-flow battery made of the Pt ₃ Ni/C composite material The sulfur semi-flow battery has a high specific capacity, which is maintained at around 550mAh/g, and the cycle is stable, which is due to the excellent and stable catalytic activity of the Pt ₃ Ni/C composite for the conversion of lithium polysulfide.

Claims (5)

1. A lithium-sulfur semi-flow battery, characterized in that it comprises a liquid flow sulfur positive electrode region, a lithium metal negative electrode region, and a diaphragm; The liquid flow sulfur cathode region includes a working electrode and a lithium polysulfide catholyte; The working electrode includes an active material, a conductive agent, a binder, and a current collector; the mass ratio of the active material, the conductive agent, and the binder is 8:1:1; The active material is Ni/C composite material, Pt/C composite material or Pt ₃ Ni/C composite material; the current collector is aluminum foil, stainless steel mesh or carbon paper; The preparation method of Ni/C composite material, concrete steps are as follows: (1) Sonicate the C conductive carrier and deionized water for 1-5 hours to obtain a carbon-based carrier dispersion with a concentration of 1-10 mg/mL; the C conductive carrier is one of graphene, carbon black and CNT; (2) Add nickel acetate or nickel nitrate to the carbon-based carrier dispersion in step (1) at a mass ratio of C:Ni of 5 to 15:1, and sonicate for 1 to 5 hours to obtain a mixed dispersion; (3) Freeze the mixed dispersion in step (2) with liquid nitrogen, and freeze-dry to obtain a mixed powder; (4) Under the protection of Ar gas, heat up the mixed powder in step (3) to 700-900°C for 1-3 hours at a heating rate of 5°C/min, and then cool naturally to obtain a Ni/C composite material; The lithium polysulfide catholyte is obtained by dissolving lithium polysulfide in a lithium-sulfur electrolyte; The lithium metal negative electrode area includes a lithium metal negative electrode and a lithium-sulfur electrolyte; the lithium metal negative electrode in the lithium metal negative electrode area is lithium metal or a lithium metal alloy; The solvent of the lithium-sulfur electrolyte is a polyether with the molecular formula R(CH ₂ CH ₂ O)n-R', wherein n=1-6, R and R' are methyl or ethyl, and the solute is di Lithium fluorine oxalate borate, lithium bistrifluoromethylsulfonimide, lithium bisfluorosulfonimide, lithium difluorophosphate or lithium hexafluorophosphate, the concentration of the lithium-sulfur electrolyte is 1mol/L. 2 . The lithium-sulfur semi-flow battery according to claim 1 , wherein the concentration of lithium polysulfide in the lithium polysulfide catholyte is 0.1 mol/L˜2 mol/L. 3. The lithium-sulfur semi-flow battery according to claim 1, wherein the lithium metal alloy is lithium-tin alloy, lithium-silicon alloy or lithium-copper alloy. 4. according to the described lithium-sulfur semi-flow battery of claim 1, it is characterized in that, the preparation method of Pt/C composite material is the same as the preparation method of Ni/C composite material, nickel acetate or nickel nitrate in step (2) Replace with platinum acetate or platinum nitrate. 5. The lithium-sulfur semi-liquid flow battery according to claim 1, characterized in that, the preparation method of the _Pt3Ni /C composite material, the specific steps are as follows: (1) Add the C conductive carrier to DMF, and ultrasonicate for 1-5 hours to obtain a carbon-based carrier dispersion with a concentration of 1-10 mg/mL; the C conductive carrier is one of graphene, carbon black and CNT; (2) Add platinum diacetylacetonate and nickel diacetylacetonate to the ratio of platinum diacetylacetonate:nickel diacetylacetonate:C in the ratio of 8:8:20~24:8:60 in step (1) In the carbon-based carrier dispersion, add benzoic acid, and the benzoic acid is added according to the ratio of platinum diacetylacetonate: benzoic acid mass ratio of 8:50 to 70, and ultrasonically for 1 to 5 hours to obtain a mixed dispersion; (3) The mixed dispersion in step (2) is heated in a constant temperature water bath at 150~170°C, and reacted for 20~24 hours; (4) The product of step (3) is centrifuged and dried to obtain a Pt ₃ Ni/C composite material.

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