CN-116207225-B - Vanadium-based positive electrode material, and preparation method and application thereof

CN116207225BCN 116207225 BCN116207225 BCN 116207225BCN-116207225-B

Abstract

The invention discloses a vanadium-based positive electrode material, and a preparation method and application thereof. The vanadium-based positive electrode material comprises a nitrogen-doped carbon matrix, and vanadium nitride and vanadium trioxide with quantum dot sizes loaded on the nitrogen-doped carbon matrix, wherein heterogeneous interfaces are formed between the nitrogen-doped carbon matrix and the quantum dots, heterojunction is formed between the vanadium nitride quantum dots and the vanadium trioxide quantum dots, and the nitrogen-doped carbon matrix is formed by calcining melamine. The preparation method comprises the steps of adding ammonium metavanadate and melamine into a dimethyl sulfoxide aqueous solution according to a molar ratio of 1:2-4, stirring to obtain a homogeneous solid solution, centrifuging, drying, sintering at 555-1555 ℃ for 1-5 h in an inert atmosphere, and naturally cooling to obtain the catalyst. The vanadium-based positive electrode material has rich heterojunction, simple preparation process and easily-controlled conditions, and is used as a positive electrode of a zinc ion battery, and the positive electrode material has long-cycle stability, high specific capacity, excellent multiplying power performance and outstanding zinc ion storage performance.

Inventors

XIAO PEITAO
YUAN XIAORU
LI ZHONGZHE
GAO HONGJING
CHEN YUFANG
ZHENG CHUNMAN

Assignees

中国人民解放军国防科技大学

Dates

Publication Date: 20260512
Application Date: 20230117

Claims (10)

1. The vanadium-based positive electrode material is characterized by being a vanadium nitride/vanadium trioxide heterojunction quantum dot positive electrode material and comprising a nitrogen-doped carbon matrix, and vanadium nitride and vanadium trioxide with quantum dot sizes loaded on the nitrogen-doped carbon matrix, wherein a heterogeneous interface is formed between the nitrogen-doped carbon matrix and the quantum dots, a heterojunction is formed between the vanadium nitride quantum dots and the vanadium trioxide quantum dots, and the nitrogen-doped carbon matrix is formed by calcining melamine.
2. The vanadium-based positive electrode material according to claim 1, wherein the quantum dots have a particle size of 5 nm or less.
3. The preparation method of the vanadium-based positive electrode material is characterized by comprising the following steps of: (1) Adding ammonium metavanadate and melamine into a mixed solution of dimethyl sulfoxide and water according to the mol ratio of 1:2-4, and stirring to obtain a homogeneous solid solution; (2) Centrifuging and drying the homogeneous solid solution obtained in the step (1) to obtain mixed powder; (3) And (3) sintering the mixed powder obtained in the step (2) in an inert gas atmosphere, wherein the sintering temperature is 500-1000 ℃, the sintering time is 1-5 h, and naturally cooling to room temperature after sintering to obtain the vanadium-based anode material, namely the vanadium nitride/vanadium trioxide heterojunction quantum dot anode material.
4. The method for preparing a vanadium-based positive electrode material according to claim 3, wherein in the step (1), the melamine is first dissolved in a mixed solution of dimethyl sulfoxide and water, and is mixed by first stirring to obtain a mixed solution, and ammonium metavanadate is added into the mixed solution, and is mixed by second stirring to obtain a homogeneous solid solution of melamine and ammonium metavanadate.
5. The method of claim 3, wherein in the step (1), the molar ratio of the ammonium metavanadate to the melamine is 1:3.
6. The method for preparing a vanadium-based positive electrode material according to claim 3, wherein in the step (1), the volume ratio of dimethyl sulfoxide to water is 1:2-5.
7. The method for preparing a vanadium-based positive electrode material according to claim 3, wherein in the step (2), the centrifugal speed is 8000r/min to 9500 r/min.
8. The method for preparing a vanadium-based cathode material according to claim 3, wherein in the step (2), the drying is vacuum drying, the temperature of the vacuum drying is 60-100 ℃, and the time of the vacuum drying is 12-24 h.
9. The method of claim 3, wherein in step (3), the inert gas is nitrogen or argon.
10. The application of the vanadium-based positive electrode material as set forth in claim 1 or 2 or the vanadium-based positive electrode material prepared by the preparation method as set forth in any one of claims 3 to 9 in a water-based zinc ion battery.

Description

Vanadium-based positive electrode material, and preparation method and application thereof Technical Field The invention belongs to the technical field of electrochemical energy storage materials, and particularly relates to a vanadium-based positive electrode material, and a preparation method and application thereof. Background With the continuous increase of consumer electronics demands, the steady development of electric automobiles and the increasing requirements of people on the safety and environmental protection of energy storage systems, water-based energy storage devices show great potential in the new generation battery market. Among the numerous aqueous batteries, rechargeable zinc ion batteries are receiving wide attention due to their high theoretical capacity (820 mA h/g), abundant zinc resources, high safety, environmental friendliness, but still face a controversial complex energy storage mechanism and non-ideal performance challenges, impeding their practical application. In order to solve these problems, it is important to develop advanced cathode materials such as manganese-based oxides, prussian blue analogues, organic compounds, vanadium-based compounds, and the like. The vanadium-based compound has a typical layered structure, rich valence states, higher energy density and theoretical capacity, effectively improves the zinc ion storage performance, and becomes a proper choice of the positive electrode material of the water-based zinc ion battery. However, at high depth of discharge cycling, the rate performance and cycling stability are generally poor because of their inherent ionic/electronic conductivity and structural stability which cannot be matched to the rapid, large number of Zn 2+ insertions/removals. In order to solve these problems, it is necessary to develop a novel aqueous zinc ion battery positive electrode material having excellent performance and stable structure. Vanadium nitride has higher theoretical specific capacity and belongs to the gap compound or alloy family. The incorporation of nitrogen into the transition metal lattice increases the d electron density, having an electron structure similar to that of noble metals. However, vanadium nitride obtained by the conventional preparation method is generally a clustered particle, and seriously affects the exertion of electrochemical properties thereof. Disclosure of Invention The technical problem to be solved by the invention is to overcome the defects of the prior art, provide a vanadium-based positive electrode material with large specific surface area, more active sites and rich heterojunction, and also provide a preparation method and application with simple process and easily controlled conditions, which are beneficial to realizing large-scale production. In order to solve the technical problems, the invention adopts the following technical scheme. The vanadium-based positive electrode material is a vanadium nitride/vanadium trioxide heterojunction quantum dot positive electrode material, and comprises a nitrogen-doped carbon matrix, and vanadium nitride and vanadium trioxide with quantum dot sizes loaded on the nitrogen-doped carbon matrix, wherein a heterogeneous interface is formed between the nitrogen-doped carbon matrix and the quantum dots, a heterojunction is formed between the vanadium nitride quantum dots and the vanadium trioxide quantum dots, and the nitrogen-doped carbon matrix is formed by calcining melamine. In the vanadium-based positive electrode material, preferably, the particle size of the quantum dots is less than or equal to 5nm. As a general technical concept, the invention also provides a preparation method of the vanadium-based positive electrode material, which comprises the following steps: (1) Adding ammonium metavanadate and melamine into a mixed solution of dimethyl sulfoxide and water according to the mol ratio of 1:2-4, and stirring to obtain a homogeneous solid solution; (2) Centrifuging and drying the homogeneous solid solution obtained in the step (1) to obtain mixed powder; (3) And (3) sintering the mixed powder obtained in the step (2) in an inert gas atmosphere, wherein the sintering temperature is 500-1000 ℃, the sintering time is 1-5 h, and naturally cooling to room temperature after sintering to obtain the vanadium-based anode material, namely the vanadium nitride/vanadium trioxide heterojunction quantum dot anode material. In the preparation method of the vanadium-based positive electrode material, preferably, in the step (1), the melamine is firstly dissolved in a mixed solution of dimethyl sulfoxide and water, and is subjected to first stirring and mixing to obtain a mixed solution, and ammonium metavanadate is added into the mixed solution, and is subjected to second stirring and mixing to obtain a homogeneous solid solution in which the melamine and the ammonium metavanadate are mixed. In the above preparation method of vanadium-based cathode material, preferably, i