CN110304652B

CN110304652B - Synthesis method of magnesium ion electrode material

Info

Publication number: CN110304652B
Application number: CN201910642713.0A
Authority: CN
Inventors: 洪振生; 罗兰; 卢熖忠
Original assignee: Fujian Normal University
Current assignee: Fujian Normal University
Priority date: 2019-07-16
Filing date: 2019-07-16
Publication date: 2022-05-31
Anticipated expiration: 2039-07-16
Also published as: CN110304652A

Abstract

The invention belongs to the technical field of magnesium ion batteries, and particularly relates to a magnesium ion electrode material Na₂Ti₆O₁₃The method of (1). TiOSO is added₄Dissolved in NaOH and H₂And O in the mixed solution. Stirring the solution, heating at 150-180 ℃ for 45-48 hours, washing the precipitate for 5-7 times, drying overnight, collecting to obtain a white titanate nanowire precursor, and finally annealing at 200-280 ℃ in air for 2-5 hours to obtain the final nanowire Na₂Ti₆O₁₃. The material has very high first coulombic efficiency, high specific capacity, low manufacturing cost and development prospect.

Description

Synthesis method of magnesium ion electrode material

Technical Field

The invention belongs to the technical field of magnesium ion batteries, and particularly relates to a magnesium ion electrode material Na₂Ti₆O₁₃The method of (1).

Background

The magnesium ion battery has high capacity (2205 mAh g)^-1And 3833 mAh cm^-3) The low reduction potential (-2.37V vs. SHE), the abundant reserves of magnesium metal and the absence of dendrite formation have attracted much attention from researchers. Due to Mg^{2 +}With strong electrostatic interaction between the two charges and the anion, resulting in Mg²⁺Ions slowly intercalate into the lattice kinetics. There remains a need in the search for new electrode materials with sufficient capacity to exceed current lithium ion battery technologyThe challenge is to be solved. Among all magnesium ion battery electrode materials, Ti-based materials are of great interest due to their low cost, abundance and environmental friendliness.

Disclosure of Invention

The invention aims to provide a magnesium ion electrode material Na₂Ti₆O₁₃The method of (1). The invention is used as the electrode material of the magnesium ion battery for the first time, and the electrode material is found to have very high first coulombic efficiency and higher specific capacity.

In order to achieve the purpose, the invention adopts the following technical scheme:

the Na is₂Ti₆O₁₃The preparation method of the material comprises the following steps:

(1) preparing a titanate nanowire precursor: 1-2 g of TiOSO₄Dissolving in 30-50 ml of 15M NaOH and 18-30 ml of H₂And O in the mixed solution.

(2) After stirring the solution for 7-10 minutes, the solution is transferred to a liner with a capacity of 60-100 ml and heated at 150 ℃ and 180 ℃ for 45-48 hours.

(3) And finally washing the precipitate with deionized water for 5-7 times until the pH value is neutral, and then drying at 60 ℃ overnight to collect the white titanate nanowire precursor.

(4) Finally obtaining the final nano-wire Na after annealing for 2-5 hours at the high temperature of 200-280 ℃ in the air₂Ti₆O₁₃。

Assembling the magnesium ion battery: according to the mass ratio, adding Na₂Ti₆O₁₃: acetylene black: PTFE is 70-75:15-20:5-10, is stirred, mixed and rolled into an electrode film with the thickness of 70-100 mm by a rolling machine, and is cut into small electrode films with the mass of about 1.3-1.8 mg by scissors, and the foamed nickel is used as a current collector. The positive electrode is metal magnesium, and the electrolyte is 0.4M 2 PhMgCl-AlCl₃(APC)/THF solution. All assembly was carried out in an argon filled glove box (oxygen and moisture content below 1 ppm).

The invention has the following remarkable advantages:

the invention provides a novel magnesium ion electrode material Na₂Ti₆O₁₃The preparation method of the synthesis method and finds good application prospect in magnesium ion batteries for the first time. The method has the advantages of simple operation, low cost, excellent performance and capability of being synthesized in large scale.

Drawings

FIG. 1Na₂Ti₆O₁₃XRD pattern of (a);

FIG. 2 Na₂Ti₆O₁₃SEM picture of (1);

FIG. 3 Na₂Ti₆O₁₃At 0.01A g^-1A charge-discharge curve at current density;

FIG. 4 Na₂Ti₆O₁₃Magnification graph of (1);

FIG. 5 Na₂Ti₃O₇At 0.01A g^-1A charge-discharge curve at current density;

FIG. 6 Na₂Ti₃O₇XRD pattern of (a).

Detailed Description

For further disclosure, but not limitation, the present invention is described in further detail below with reference to examples.

Example 1

(1) preparing a titanate nanowire precursor: 1 g of TiOSO₄Dissolved in 40 ml of 15M NaOH and 25 ml of H₂And O in the mixed solution.

(2) After stirring the solution for 7 minutes, the above solution was transferred to a liner having a capacity of 100 ml and heated at 160 ℃ for 46 hours.

(3) And finally washing the precipitate with deionized water for 5 times, and then drying at 60 ℃ overnight to collect the white titanate nanowire precursor.

(4) Finally obtaining the final nano-wire Na after annealing for 3 hours at the high temperature of 220 ℃ in the air₂Ti₆O₁₃。

Example 2

(1) preparing a titanate nanowire precursor: 1.5g of TiOSO₄Dissolved in 45 ml of 15M NaOH and 26 ml of H₂And O in the mixed solution.

(2) After stirring the solution for 8 minutes, the above solution was transferred to a liner having a capacity of 100 ml and heated at 170 ℃ for 47 hours.

(3) And finally washing the precipitate with deionized water for 6 times, and then drying at 60 ℃ overnight to collect a white titanate nanowire precursor.

(4) Finally obtaining the final nano-wire Na after annealing for 3 hours at the high temperature of 230 ℃ in the air₂Ti₆O₁₃。

Example 3

(1) preparing a titanate nanowire precursor: 2 g of TiOSO₄Dissolved in 50 ml of 15M NaOH and 30 ml of H₂And O in the mixed solution.

(2) After stirring the solution for 10 minutes, the above solution was transferred to a liner having a capacity of 100 ml and heated at 180 ℃ for 48 hours.

(3) And finally washing the precipitate with deionized water for 7 times, and then drying at 60 ℃ overnight to collect the white titanate nanowire precursor.

(4) Finally obtaining the final nano-wire Na after high-temperature annealing for 4 hours at 240 ℃ in the air₂Ti₆O₁₃。

Comparative example

The Na is₂Ti₃O₇The preparation method of the material comprises the following steps:

(2) After the solution was stirred for 7 minutes, the solution was transferred to a liner having a capacity of 100 ml, and heated at 160 ℃ for 46 hours.

(3) And finally washing the precipitate with deionized water for 2 times, washing with ethanol twice to remove residual alkali, and drying at 60 ℃ overnight to collect the white titanate nanowire precursor.

(4) Finally obtaining the final nano-wire Na after annealing for 3 hours at the high temperature of 220 ℃ in the air₂Ti₃O₇。

Assembling the magnesium ion battery: according to the mass ratio, adding Na₂Ti₆O₁₃: acetylene black: PTFE is 70-75:15-20:5-10, is stirred, mixed and rolled into an electrode film with the thickness of 70-100 mm by a rolling machine, and is cut into small electrode films with the mass of about 1.3-1.8 mg by scissors, and the foamed nickel is used as a current collector. The positive electrode is metal magnesium, and the electrolyte is 0.4M 2 PhMgCl-AlCl₃(APC)/THF solution. All assembly was carried out in an argon filled glove box (oxygen and moisture content below 1 ppm). Comparative example Na₂Ti₃O₇The assembly is similar.

From the X-ray powder diffraction analysis chart of fig. 1, it can be seen that the diffraction peaks of the prepared samples are all consistent with those of JCPDS standard card (14-0277), while from fig. 6, it can be seen that the diffraction peaks are significantly different from those of fig. 1. The material is clearly seen in the SEM image of fig. 2 as a nanowire structure. As shown in FIG. 3, the current density was 0.01A g at a voltage window of 0.01-2.0V^-1The first discharge specific capacity can reach 165.8 mA h g^-1The first charge capacity is 147.7 mA h g^-1The first efficiency is up to 89.1%. This is the highest efficiency in the present titanium-based magnesium storage electrode material. As shown in FIG. 4, Na₂Ti₆O₁₃Has excellent rate capability, which can be seen at 1A g^-1The reversible capacity is still 30 mAh g under the high current density^-1. Comparative example obtained Na with a higher sodium content₂Ti₃O₇The structure is only the change of a washing mode, but the influence on the magnesium storage performance of the material is great, as shown in figure 5, the first coulombic efficiency is only 41.9 percent, and the reversible charge capacity is only 44.7 mAh g^-1. This further illustrates the materials preparedAdvancement and obvious influence of different sodium titanate structures on magnesium storage performance.

The above description is only a preferred embodiment of the present invention, and all equivalent changes and modifications made in accordance with the claims of the present invention should be covered by the present invention.

Claims

1. Magnesium ion Na₂Ti₆O₁₃The application of the electrode material in the magnesium ion battery is characterized in that: the magnesium ion Na₂Ti₆O₁₃The electrode material synthesis method comprises the following steps:

(1) preparing a titanate nanowire precursor: 1-2 g of TiOSO₄Dissolving in 30-50 ml 15M NaOH and 18-30 ml H₂In a mixed solution of O;

(2) stirring the solution for 7-10 minutes, and transferring the solution to an autoclave liner with the capacity of 60-100 ml for hydrothermal reaction;

(3) finally, washing the precipitate with deionized water for 5-7 times, and then drying at 60 ℃ overnight to collect a white titanate nanowire precursor;

(4) finally obtaining the final nano-wire Na after high-temperature annealing in the air₂Ti₆O₁₃(ii) a The specific conditions of the high-temperature annealing in the step (4) are as follows: annealing at 200 ℃ and 280 ℃ for 2-5 hours;

assembling the magnesium ion battery: according to the mass ratio, adding Na₂Ti₆O₁₃: acetylene black: stirring and mixing PTFE 70-75:15-20:5-10, rolling into electrode films with the thickness of 70-100 mm by a rolling machine, cutting into small electrode films with the mass of 1.3-1.8 mg by using scissors, and taking foamed nickel as a current collector; the positive electrode is metal magnesium, and the electrolyte is 0.4M 2 PhMgCl-AlCl₃(APC)/THF solution; all assembly was carried out in an argon filled glove box with oxygen and moisture levels below 1 ppm.

2. Use according to claim 1, characterized in that: the hydrothermal reaction in the step (2) is specifically as follows: heating at 150-180 deg.C for 45-48 hr.