Preparation method of nano flower-like titanium dioxide@bismuth trisulfide electrode material

Abstract

The invention provides a preparation method of a nano flower-like titanium dioxide@bismuth trisulfide electrode material, which comprises the following steps: (1) dissolving bismuth chloride in an ethylene glycol solution, carrying out ultrasonic stirring until the bismuth chloride is dissolved, adding water-soluble sulfide into the ethylene glycol solution of bismuth chloride, transferring the prepared solution into a hydrothermal reaction kettle, carrying out ultrasonic stirring to obtain a mixed solution, reacting for 1-15 hours in a constant-temperature box at the temperature of 60-200 DEGC, cooling, filtering, separating, washing with deionized water, washing with absolute ethyl alcohol, and drying, so as to obtain bismuth trisulfide nanoflowers, and (2) dispersing the prepared bismuth trisulfide powder into deionized water, transferring the solution into a three-neck flask, adding tetrabutyl titanate, carrying out oil bath reaction for 1-24 hours at the temperature of 60-90 DEGC, cooling, carrying out centrifugal separation, washing with deionized water, and drying to obtain the nano flower-shaped titanium dioxide@bismuth trisulfide electrode material. The invention also provides an application of the nano flower-like titanium dioxide@bismuth trisulfide electrode material as a sodium ion battery negative electrode material.

Description

technical field [0001] The invention belongs to the technical field of preparation of electrode materials for sodium-ion batteries, and in particular relates to a method for preparing nano-flower-shaped titanium dioxide@bismuth trisulfide electrode materials and its application in negative electrode materials for sodium-ion batteries. Background technique [0002] Lithium-ion batteries have the advantages of flexible application and long service life, but the shortage of Li resources greatly limits the long-term development and application of lithium-ion batteries. Compared with lithium-ion batteries, sodium-ion batteries have a similar energy storage mechanism, but the relative abundance of sodium in the earth's crust is much greater than that of lithium (2.75% vs 0.0065%). Therefore, sodium-ion batteries, as the best substitute for lithium-ion batteries, have attracted the attention of researchers all over the world. [0003] At present, the anode materials for sodium-ion...

AI Technical Summary

Problems solved by technology

However, based on Sb 2 S 3 There are some disadvantages in the negative electrode materials, and its inherent low conductivity easily leads to large impedance and poor rate performance; at the same time, the huge volume expansion caused during the transformation and further alloying reactions will inevitably lead to large mechanical Internal stress, resulting in the crushing and aggregation of nanoparticles, metal Sb 0 and Na 2 The active reaction interface between S is greatly reduced, resulting in poor reversibility of electrochemical reactions and low capacity retention for long-term cycling.

At the same time, as a negative electrode material, the intercalation and deintercalation of sodium ions during the charge and discharge process will lead to a change in the volume of the material, resulting in a decrease in its specific capacity (100-200mAhg -1 ), poor cycle stability (0.1Ag -1 The specific capacitance retention rate is less than 60% after 100 cycles at a certain current density)

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