CN-121990610-A - Preparation method and low-temperature application of Te-doped tungsten-niobium-oxygen/molybdenum-niobium-oxygen heterojunction material

Abstract

A preparation method and low-temperature application of Te doped tungsten-niobium-oxygen/molybdenum-niobium-oxygen heterojunction belong to the technical field of secondary batteries. The method comprises the steps of carrying out high-energy ball milling alloying on WO 3 、Nb 2 O 5 and Te 2 O 5 to obtain amorphous Te-doped tungsten-niobium oxide, carrying out high-energy ball milling alloying on MoO 3 、Nb 2 O 5 and Te 2 O 5 to obtain amorphous Te-doped molybdenum-niobium oxide, uniformly mixing and compacting the amorphous Te-doped tungsten-niobium oxide and the amorphous Te-doped molybdenum-niobium oxide, and carrying out spark plasma sintering under inert atmosphere to obtain the ceramic crystal-form Te-doped tungsten-niobium oxide/molybdenum-niobium oxide heterojunction material. The Te doped tungsten-niobium-oxygen/molybdenum-niobium-oxygen two-phase heterojunction material designed by the invention has the advantages of short synthesis time, short synthesis period, convenient regulation and control of grain size, very good material crystallinity, extremely high promotion of lithium ion diffusion rate of heterojunction interface, and electronic conductivity improvement in cooperation with Te doping, and can be used as a lithium ion negative electrode material with quick charge characteristic and good low-temperature performance.

Inventors

• LOU SHUAIFENG
• WEI LIHUA
• ZHANG YAN
• Geng Shenglu
• DONG SHENGWEI
• NING YANBIN

Assignees

• 哈尔滨工业大学

Dates

Publication Date

20260508

Application Date

20260202

Claims (10)

1. 1. The preparation method of the Te doped tungsten-niobium-oxygen/molybdenum-niobium-oxygen heterojunction material is characterized by comprising the following steps of: Step one, performing high-energy ball milling alloying on WO 3 、Nb 2 O 5 and Te 2 O 5 to obtain amorphous Te-doped tungsten niobium oxide, and performing high-energy ball milling alloying on MoO 3 、Nb 2 O 5 and Te 2 O 5 to obtain amorphous Te-doped molybdenum niobium oxide; And step two, uniformly mixing and compacting the amorphous Te-doped tungsten-niobium oxide and the amorphous Te-doped molybdenum-niobium oxide, and performing spark plasma sintering in an inert atmosphere to obtain the ceramic crystal form Te-doped tungsten-niobium oxide/molybdenum-niobium oxide heterojunction material.
2. 2. The method of claim 1, wherein in the first step, the molar ratio of the raw materials WO 3 、Nb 2 O 5 and Te 2 O 5 used for preparing the amorphous Te-doped tungsten-niobium oxide is 3:7:X, wherein X=0.0425-0.85, and the molar ratio of the raw materials MoO 3 、Nb 2 O 5 and Te 2 O 5 used for preparing the amorphous Te-doped molybdenum-niobium oxide is 3:1:Y, wherein Y=0.0125-0.25.
3. 3. The method of claim 1, wherein in the first step, the Te-doped tungsten-niobium oxide and the amorphous Te-doped molybdenum-niobium oxide are prepared by a high-energy ball milling method, the ball milling speed is equal to or higher than 1800rpm, and the ball milling time is 6-12 hours.
4. 4. The method of claim 1, wherein in the second step, the amorphous Te-doped tungsten-niobium oxide and the amorphous Te-doped molybdenum-niobium oxide are uniformly mixed by adopting a mortar grinding or low-energy ball milling mode, wherein the mortar grinding time is 10-20 min, the low-energy ball milling rotating speed is 150-400 rpm, and the time is 1-5 h.
5. 5. The method of claim 1, wherein the pressure of the spark plasma sintering is 50-100 MPa, the temperature is 700-1100 ℃ and the time is 1-10 min.
6. 6. The application of the Te-doped tungsten-niobium-oxygen/molybdenum-niobium-oxygen heterojunction material prepared by the preparation method of any one of claims 1-5 is characterized in that the prepared Te-doped tungsten-niobium-oxygen/molybdenum-niobium-oxygen heterojunction material is used as a negative electrode active material to be applied to a negative electrode of a fast-charge and low-temperature lithium ion battery.
7. 7. The method according to claim 6, wherein the Te-doped tungsten-niobium-oxygen/molybdenum-niobium-oxygen heterojunction material is crushed into powder.
8. 8. The method of claim 7, wherein the crushing is grinding or low-energy ball milling, and the rotation speed of the low-energy ball milling is 150-400 rpm for 1-5 hours.
9. 9. The application of the preparation method of the negative electrode material, which is characterized in that the prepared Te-doped tungsten-niobium-oxygen/molybdenum-niobium-oxygen heterojunction material is taken as a negative electrode active material, is dispersed in a solvent together with a conductive agent and a binder to obtain a negative electrode slurry, the negative electrode slurry is coated on a negative electrode current collector, and a negative electrode plate is obtained through drying, rolling and punching.
10. 10. The application of the lithium ion battery according to claim 6, wherein the stable cycle rate of the fast-charge and low-temperature lithium ion battery is up to 200 ℃, and the working temperature range is-50 ℃ to 25 ℃.

Description

Preparation method and low-temperature application of Te-doped tungsten-niobium-oxygen/molybdenum-niobium-oxygen heterojunction material Technical Field The invention belongs to the technical field of secondary batteries, and particularly relates to a preparation method of a Te-doped tungsten-niobium-oxygen/molybdenum-niobium-oxygen heterojunction material and application of the Te-doped tungsten-niobium-oxygen/molybdenum-niobium-oxygen heterojunction material in a fast-charge and low-temperature lithium ion battery negative electrode. Background In order to achieve both environment-friendly development and economic sustainable development, the lithium ion battery-driven electric automobile market is continuously developing. Under the trend, iterative upgrading of the rapid charging technology and research and development innovation of the high-energy-density battery have become core keys for promoting the sustainable development in the field of electric automobiles. The improvement of the rapid electric storage capacity is essentially dependent on the optimization and improvement of the ion diffusion rate and the electron conductivity. Niobium-based oxides offer a very potential viable solution for the landing of fast charge technologies by virtue of their unique crystal structure and excellent electrochemical properties. This advantage stems from its inherent three-dimensional (3D) tunnel structure, which gives the material two major core electrochemical advantages, namely a low migration energy barrier for lithium ions and a safe and stable operating voltage window. The nature of these properties can be traced back to its typical Wadsley-Roth phase structure, the Wadsley-Roth phase of the tungsten-niobium-oxide (W-Nb-O) system belonging to the monoclinic system, whose crystal structure has n×m co-angular linked MO 6 (m= W, nb) octahedral formations like rectangular blocks of ReO 3 structure, with typical crystallographic shear structures formed by co-edge octahedral co-edge linking and tetrahedral co-angular linking between the rectangular blocks. The tungsten-niobium-oxygen block body with the structure has an open tunnel space, not only can provide sufficient sites for lithium ion storage, but also more importantly, the interconnected three-dimensional tunnels form a high-efficiency transmission channel for rapid diffusion of Li +, so that the risk of blocking the ion channel during charging and discharging under high current density is remarkably reduced, and a structural foundation is laid for realizing rapid charging characteristics of materials. However, due to the existence of a crystal shearing surface with a higher lithium ion diffusion barrier, the long-cycle performance of tungsten-niobium oxide at high current density and low temperature is limited, the rapid charging characteristic of tungsten-niobium oxide is limited due to the fact that the crystal grain size is larger (micron-sized), and meanwhile, more active metal elements are always lost due to higher calcining temperature and longer calcining time in a conventional synthesis method, so that the concentration of electrons participating in reaction is reduced, and the capacity of the tungsten-niobium oxide is remarkably reduced. Therefore, it is highly desirable to invent a method that can improve the high current density and long cycle performance and capacity of tungsten niobium oxide materials at low temperatures. Disclosure of Invention Based on the background technology, the invention provides a preparation method and application of a Te doped tungsten-niobium-oxygen/molybdenum-niobium-oxygen two-phase heterojunction material, which aims to reduce the lithium ion diffusion barrier, the material band gap width, the grain size and the volatilization of active elements of the tungsten-niobium-oxygen material and improve the electrochemical properties such as long cycle performance, capacity and the like of the tungsten-niobium-oxygen material at high current density and low temperature. In order to achieve the above purpose, the present invention adopts the following technical scheme: a preparation method of a Te doped tungsten-niobium-oxygen/molybdenum-niobium-oxygen heterojunction material comprises the following steps: Step one, performing high-energy ball milling alloying on WO 3、Nb2O5 and Te 2O5 to obtain amorphous Te-doped tungsten niobium oxide, and performing high-energy ball milling alloying on MoO 3、Nb2O5 and Te 2O5 to obtain amorphous Te-doped molybdenum niobium oxide; Uniformly mixing the amorphous Te doped tungsten-niobium oxide and the amorphous Te doped molybdenum-niobium oxide, grinding for 10-20 min by using a mortar or ball milling for 1-5 h at low energy (150-400 rpm) to obtain a heterojunction precursor, placing the heterojunction precursor into a graphite mold for compaction, and performing discharge plasma sintering under inert atmosphere (Ar gas) to obtain a ceramic crystal form Te doped tungsten-niobium oxide/m