CN-121988366-A - Solid sulfur anode catalytic material, preparation method and application

CN121988366ACN 121988366 ACN121988366 ACN 121988366ACN-121988366-A

Abstract

The solid sulfur anode catalytic material comprises a carrier, and a first transition metal atom and a second transition metal atom which are loaded on the carrier, wherein the carrier is a nitrogen-doped carbon material, and the electronegativity difference delta EN between the first transition metal atom and the second transition metal atom is more than or equal to 0.01 and less than or equal to 0.5. The solid sulfur anode catalytic material can generate a dynamic electron buffer effect in the sulfur conversion reaction process of the all-solid-state battery, is beneficial to regulating the charge state of a metal center through reversible electron migration among diatomic atoms in charge and discharge, thereby inhibiting the excessive oxidation or reduction of an active site and improving the structural stability and valence reversibility of the active site in long-term circulation. Meanwhile, the synergistic effect of the diatomic can also enhance the electron interaction with sulfur substances, which is beneficial to lowering the solid-solid interface reaction energy barrier and improving the sulfur conversion reaction kinetics.

Inventors

LV WEI
SHI JIWEI
GAN LIN
JIANG MINGYANG
Geng Chuannan
HU ZHONGHAO

Assignees

清华大学深圳国际研究生院

Dates

Publication Date: 20260508
Application Date: 20260130

Claims (10)

1. A solid sulfur anode catalytic material is characterized by comprising a carrier, and first transition metal atoms and second transition metal atoms which are jointly supported on the carrier in an atomically dispersed form, wherein the carrier comprises a nitrogen-doped carbon material, and the electronegativity difference delta EN between the first transition metal atoms and the second transition metal atoms is more than or equal to 0.01 and less than or equal to 0.5.
2. The solid sulfur cathode catalytic material of claim 1, wherein the first transition metal atom and the second transition metal atom are each independently selected from one of copper, nickel, cobalt, iron, and zinc elements; and the first transition metal atom and the second transition metal atom are different elements from each other.
3. The solid sulfur positive electrode catalytic material according to claim 1, wherein the electronegativity difference Δen of the first transition metal atom and the second transition metal atom satisfies 0.01≤Δen≤0.05.
4. The solid sulfur cathode catalytic material of claim 1, wherein the molar ratio of the first transition metal atoms to the second transition metal atoms is from 0.7:1 to 1:0.7.
5. The solid sulfur cathode catalytic material of any of claims 1-4, wherein the atomic spacing between the first transition metal atom and the second transition metal atom is 0.3nm to 0.4nm.
6. A method of preparing a solid sulfur positive electrode catalytic material according to any one of claims 1 to 5, comprising: providing the carrier; mixing a first metal salt containing a first transition metal atom and a second metal salt containing a second transition metal atom with the carrier in a solvent to obtain a mixture; Drying said mixture, and And carrying out heat treatment on the dried mixture in a protective atmosphere, so that the first metal salt and the second metal salt respectively react on the carrier in situ to generate the first transition metal atom and the second transition metal atom, thereby obtaining the solid sulfur anode catalytic material.
7. The method for producing a solid sulfur positive electrode catalytic material according to claim 6, wherein the first metal salt comprises at least one of a chloride salt, a nitrate salt, and an acetate salt containing the first transition metal atom; the second metal salt includes at least one of chloride, nitrate, and acetate containing the second transition metal atom.
8. The method for producing a solid sulfur positive electrode catalytic material according to claim 6, wherein the heat treatment comprises a first heat treatment stage which is conducted at 200 to 350 ℃ for 2 to 6 hours and a second heat treatment stage which is conducted at 500 to 600 ℃ for 2 to 6 hours, and/or, The mixing treatment is carried out under ultrasonic conditions, the frequency of the ultrasonic wave is 50KHZ to 100KHZ, the ultrasonic time is 20min to 30min, and/or, The drying treatment is performed by rotary evaporation at 50 to 60 ℃ for 30 to 40 minutes.
9. A positive electrode material for an all-solid-state lithium-sulfur battery, characterized in that the positive electrode material comprises a sulfur active substance, a conductive additive, a solid electrolyte and the solid sulfur positive electrode catalytic material as claimed in any one of claims 1 to 4.
10. An all-solid-state lithium-sulfur battery comprising a positive electrode, a negative electrode, and a solid electrolyte layer between the positive electrode and the negative electrode, the positive electrode being made of the positive electrode material of claim 9.

Description

Solid sulfur anode catalytic material, preparation method and application Technical Field The application relates to the technical field of new energy, in particular to a solid sulfur anode catalytic material, a preparation method and application. Background With the development of sustainable energy systems and the improvement of high-safety energy storage demands, all-solid-state lithium sulfur batteries become an important research direction of new generation high-energy-density energy storage devices by virtue of the fact that the lithium sulfur batteries do not contain flammable liquid electrolytes and have high theoretical energy density. However, in practical applications of all-solid-state lithium sulfur batteries, sulfur and its discharge product lithium sulfide are solid materials with low electronic and ionic conductivity, and the conversion reaction mainly occurs in the solid-solid interface region composed of sulfur active material, conductive phase and solid electrolyte. Due to the lack of mass transfer and interface wetting of the liquid electrolyte, the cooperative transmission of electrons and ions in the sulfur conversion process is limited, so that the reaction polarization is increased, the sulfur utilization rate is reduced, the capacity is rapidly attenuated in the long-cycle process, and the practical application of the all-solid-state lithium sulfur battery is severely restricted. Disclosure of Invention In view of this, in order to solve at least one of the above drawbacks, it is necessary to propose a solid sulfur positive electrode catalytic material. In addition, the application also provides a preparation method of the solid sulfur anode catalytic material, an anode material using the solid sulfur anode catalytic material and an all-solid lithium sulfur battery. In a first aspect, the application provides a solid sulfur anode catalytic material, which comprises a carrier, and first transition metal atoms and second transition metal atoms which are jointly supported on the carrier in an atomically dispersed form, wherein the carrier is a nitrogen-doped carbon material, and the electronegativity difference delta EN between the first transition metal atoms and the second transition metal atoms is more than or equal to 0.01 and less than or equal to 0.5. Based on the first aspect, in some embodiments of the present application, the first transition metal atom and the second transition metal atom are each independently selected from one of copper, nickel, cobalt, iron, and zinc elements, and the first transition metal atom and the second transition metal atom are elements different from each other. Based on the first aspect, in some embodiments of the application, the electronegativity difference ΔEN between the first transition metal atom and the second transition metal atom satisfies 0.01 ΔEN≤0.05. Based on the first aspect, the first transition metal atom and the second transition metal atom are each independently selected from one of copper and nickel. Based on the first aspect, in some embodiments of the application, the molar ratio of the first transition metal atoms to the second transition metal atoms is from 0.7:1 to 1:0.7. Based on the first aspect, in some embodiments of the application, the molar ratio of the first transition metal atoms to the second transition metal atoms is 1:1. Based on the first aspect, in some embodiments of the application, an atomic distance between the first transition metal atom and the second transition metal atom is 0.3nm to 0.4nm. In a second aspect, the application provides a preparation method of the solid sulfur anode catalytic material, which comprises the steps of providing the carrier, mixing a first metal salt containing a first transition metal atom and a second metal salt containing a second transition metal atom with the carrier in a solvent to obtain a mixture, drying the mixture, and carrying out heat treatment on the dried material under a protective atmosphere to obtain the solid sulfur anode catalytic material. In some embodiments of the present application, the first metal salt comprises at least one of a chloride, nitrate, and acetate containing the first transition metal atom, and the second metal salt comprises at least one of a chloride, nitrate, and acetate containing the second transition metal atom. Based on the second aspect, in some embodiments of the application, the heat treatment comprises a first heat treatment stage and a second heat treatment stage, wherein the first heat treatment stage is used for treating for 2 to 6 hours at 200 to 350 ℃, the second heat treatment stage is used for treating for 2 to 6 hours at 500 to 600 ℃, and/or the mixing treatment is carried out under ultrasonic conditions, the ultrasonic frequency is 50 to 100KHZ, the ultrasonic time is 20 to 30min, and/or the drying treatment is used for treating for 30 to 40min through rotary evaporation at 50 to 60 ℃. Based on the second aspect, in so