TiO2(B) Preparation and application of @ RGO aerogel negative electrode material
阅读说明：本技术 TiO2(B)@RGO气凝胶负极材料的制备与应用 (TiO2(B) Preparation and application of @ RGO aerogel negative electrode material ) 是由 王强 何峻 于 2020-07-02 设计创作，主要内容包括：本发明公开了一种TiO<Sub>2</Sub>(B)@RGO气凝胶复合材料作为锂离子电池负极材料的制备与应用。用溶剂热法和改进的Hummers法制备花球状TiO2(B)和氧化石墨烯,使用超声辅助混合法将花球状TiO2(B)与氧化石墨烯混合均匀,在还原剂的作用下合成TiO<Sub>2</Sub>(B)@RGO水凝胶复合材料。冷冻干燥后得到TiO<Sub>2</Sub>(B)@RGO气凝胶复合材料,将TiO<Sub>2</Sub>(B)@RGO气凝胶作为锂离子电池负极材料进行电化学测试。本发明制得的TiO<Sub>2</Sub>(B)@RGO气凝胶具有良好的比容量和倍率性能。(The invention discloses a TiO2 2 (B) Preparation and application of a @ RGO aerogel composite material as a lithium ion battery cathode material. Preparing flower-ball-shaped TiO2(B) and graphene oxide by a solvothermal method and an improved Hummers method, uniformly mixing the flower-ball-shaped TiO2(B) with the graphene oxide by using an ultrasonic-assisted mixing method, and synthesizing the TiO under the action of a reducing agent 2 (B) @ RGO hydrogel composites. Freeze drying to obtain TiO 2 (B) @ RGO aerogel composite material prepared by mixing TiO 2 (B) And the @ RGO aerogel is used as a lithium ion battery cathode material for electrochemical test. TiO prepared by the invention 2 (B) The @ RGO aerogel has good specific capacity and rate capability.)
1. TiO22(B) The preparation of @ RGO aerogel composite material as lithium ion battery cathode material is characterized in that: the method comprises the following steps:
1) a certain amount of titanium trichloride solution TiCl3Deionized water is added into the ethylene glycol solution in sequenceStirring for 2min to obtain a uniformly mixed light purple solution;
2) transferring the light purple solution into a 50ml polytetrafluoroethylene high-pressure reaction kettle for solvothermal reaction;
3) after the reaction is finished, centrifugally washing, and then drying in an oven to obtain TiO2(B) Powder;
4) the obtained TiO is2(B) Putting the powder into a tube furnace for heating treatment to remove residual organic molecules on the surface;
5) weighing a certain amount of graphite powder, K2S2O8And P2O5Adding the concentrated sulfuric acid into a 50ml beaker, slowly adding a certain amount of concentrated sulfuric acid into the beaker, continuously stirring, and drying in a vacuum drying oven to obtain pre-oxidized graphite powder;
6) centrifugally washing pre-oxidized graphite powder to be neutral, and drying in a drying box;
7) pouring the dried pre-oxidized graphite powder into a 500ml beaker, carrying out ice bath, adding a certain amount of concentrated sulfuric acid into the beaker, and then slowly adding a certain amount of potassium permanganate to carry out low-temperature oxidation;
8) heating the mixture to room temperature, reacting for a certain time, and carrying out medium-temperature oxidation;
9) slowly adding a certain amount of deionized water into the mixture, heating the mixture to a high temperature, reacting for a certain time, and carrying out high-temperature oxidation;
10) adding a certain amount of deionized water and a certain amount of hydrogen peroxide into the mixture until the solution is golden yellow;
11) centrifuging and washing the golden yellow solution to be neutral, and drying to obtain graphene oxide;
12) weighing a certain amount of graphene oxide, placing the graphene oxide in a glass bottle, adding a certain amount of deionized water, and carrying out ultrasonic treatment for 10min to obtain a graphene oxide dispersion liquid;
13) weighing a certain amount of TiO2(B) Putting the powder into the graphene oxide dispersion liquid, and carrying out ultrasonic treatment for 5 minutes to uniformly mix the powder to obtain the powder containing TiO2(B) And a brownish yellow dispersion of graphene oxide;
14) adding into the TiO-containing compound obtained in step (13)2(B) Adding a certain amount of ascorbic acid into the brown yellow dispersion liquid of the graphene oxide as a reducing agent, and reacting in a vacuum drying oven to obtain TiO2(B) Reducing graphene oxide hydrogel;
15) freeze drying the hydrogel to obtain TiO2(B) an/RGO aerogel;
16) adding TiO into the mixture2(B) the/RGO aerogel is used as a lithium ion battery cathode material for electrochemical test.
2. The preparation of the TiO2(B) @ RGO aerogel composite material as the negative electrode material of the lithium ion battery according to claim 1, wherein the preparation method comprises the following steps: the solvothermal reaction temperature in the step 2) is 150 ℃, and the reaction time is 24 hours.
3. The preparation of the TiO2(B) @ RGO aerogel composite material as the negative electrode material of the lithium ion battery according to claim 1, wherein the preparation method comprises the following steps: the temperature rise rate of the temperature rise treatment of the middle-tube furnace in the step 4) is 3 ℃/min, the temperature rises to 350 ℃, and the heat preservation time is 2 h.
4. The preparation of the TiO2(B) @ RGO aerogel composite material as the negative electrode material of the lithium ion battery according to claim 1, wherein the preparation method comprises the following steps: the ice bath temperature in the step 7) is 3-7 ℃, and the reaction time is 30 min.
5. The preparation of the TiO2(B) @ RGO aerogel composite material as the negative electrode material of the lithium ion battery according to claim 1, wherein the preparation method comprises the following steps: the temperature of room temperature in the step 8) is 35 ℃, and the reaction time is 2 h.
6. The preparation of the TiO2(B) @ RGO aerogel composite material as the negative electrode material of the lithium ion battery according to claim 1, wherein the preparation method comprises the following steps: the temperature of the high temperature in the step 9) is 95 ℃, and the reaction time is 30 min.
7. The preparation of the TiO2(B) @ RGO aerogel composite material as the negative electrode material of the lithium ion battery according to claim 1, wherein the preparation method comprises the following steps: the concentration of the graphene oxide dispersion liquid in the step 12) is more than 2.5 mg/ml.
8. The preparation of the TiO2(B) @ RGO aerogel composite material as the negative electrode material of the lithium ion battery according to claim 1, wherein the preparation method comprises the following steps: the step 13) contains TiO2(B) And the mass ratio of TiO2(B) to graphene oxide in the brownish yellow dispersion liquid of graphene oxide is 9: 1.
9. The preparation of the TiO2(B) @ RGO aerogel composite material as the negative electrode material of the lithium ion battery according to claim 1, wherein the preparation method comprises the following steps: the reaction temperature of the vacuum drying oven in the step 14) is 95 ℃, and the reaction time is 6 h.
Technical Field
The invention relates to preparation and application of a TiO2(B) @ RGO aerogel composite material as a lithium ion battery cathode material.
Background
Along with the development of society, the demand of people for energy is increasing day by day. On one hand, the reserves of fossil energy are less and less, and the exhaustion of the fossil energy can be caused by excessive exploitation; on the other hand, in the process of using fossil energy, greenhouse gases are generated, which causes climate problems such as global warming, and the like, and the development of a sustainable pollution-free clean energy is urgent. Currently, lithium ion batteries have received extensive research and attention as energy supply devices.
Lithium ion batteries, as a representative of new energy, have incomparable advantages compared with traditional fossil energy, namely: the lithium is rich in the earth crust, and can meet the requirement of long-time use of people; the lithium ion battery does not cause pollution to the environment in the use process; the lithium ion battery can be repeatedly used for a long time. The lithium ion battery has a good prospect in future energy development, and the key for restricting the performance of the lithium ion battery lies in the performance of an electrode material. Today, rapid charge and discharge is becoming more important as it is highly efficient, and it is required to develop a negative electrode material having a high capacity for charge and discharge at a high rate. TiO2(B) has higher specific capacity as the negative electrode material of the lithium ion battery, good cycling stability and good rate capability after modification.
Disclosure of Invention
Based on the problems, the invention provides preparation and application of a TiO2(B) @ RGO aerogel composite material, and the prepared TiO2(B) @ RGO aerogel composite material can improve the capacity of a lithium ion battery and has the advantages of low cost and no pollution.
The preparation method of the TiO2(B) @ RGO aerogel composite material as the lithium ion battery negative electrode material is characterized by comprising the following steps:
1) a certain amount of titanium trichloride solution TiCl3Sequentially adding deionized water into the ethylene glycol solution, and stirring for 2min to obtain a uniformly mixed light purple solution;
2) transferring the light purple solution into a 50ml polytetrafluoroethylene high-pressure reaction kettle for solvothermal reaction;
3) after the reaction is finished, centrifugally washing, and then drying in an oven to obtain TiO2(B) Powder;
4) the obtained TiO is2(B) Putting the powder into a tube furnace for heating treatment to remove residual organic molecules on the surface;
5) weighing a certain amount of graphite powder, K2S2O8And P2O5Adding into 50ml beaker, and concentratingSlowly adding sulfuric acid into a beaker, continuously stirring, and drying in a vacuum drying oven to obtain pre-oxidized graphite powder;
6) centrifugally washing pre-oxidized graphite powder to be neutral, and drying in a drying box;
7) pouring the dried pre-oxidized graphite powder into a 500ml beaker, carrying out ice bath, adding a certain amount of concentrated sulfuric acid into the beaker, and then slowly adding a certain amount of potassium permanganate to carry out low-temperature oxidation;
8) heating the mixture to room temperature, reacting for a certain time, and carrying out medium-temperature oxidation;
9) slowly adding a certain amount of deionized water into the mixture, heating the mixture to a high temperature, reacting for a certain time, and carrying out high-temperature oxidation;
10) adding a certain amount of deionized water and a certain amount of hydrogen peroxide into the mixture until the solution is golden yellow;
11) centrifuging and washing the golden yellow solution to be neutral, and drying to obtain graphene oxide;
12) weighing a certain amount of graphene oxide, placing the graphene oxide in a glass bottle, adding a certain amount of deionized water, and carrying out ultrasonic treatment for 10min to obtain a graphene oxide dispersion liquid;
13) weighing a certain amount of TiO2(B) Putting the powder into the graphene oxide dispersion liquid, and carrying out ultrasonic treatment for 5 minutes to uniformly mix the powder to obtain the powder containing TiO2(B) And a brownish yellow dispersion of graphene oxide;
14) adding into the TiO-containing compound obtained in step (13)2(B) Adding a certain amount of ascorbic acid into the brown yellow dispersion liquid of the graphene oxide as a reducing agent, and reacting in a vacuum drying oven to obtain TiO2(B) Reducing graphene oxide hydrogel;
15) freeze drying the hydrogel to obtain TiO2(B) an/RGO aerogel;
16) adding TiO into the mixture2(B) the/RGO aerogel is used as a lithium ion battery cathode material for electrochemical test.
Further, the solvothermal reaction temperature in the step 2) is 150 ℃, and the reaction time is 24 hours.
Further, the temperature rise rate of the temperature rise treatment of the tubular furnace in the step 4) is 3 ℃/min, the temperature rises to 350 ℃, and the heat preservation time is 2 h.
Further, the ice bath temperature in the step 7) is 3-7 ℃, and the reaction time is 30 min.
Further, the temperature of the room temperature in the step 8) is 35 ℃, and the reaction time is 2 h.
Further, the temperature of the high temperature in the step 9) is 95 ℃, and the reaction time is 30 min.
Further, the concentration of the graphene oxide dispersion liquid in the step 12) is more than 2.5 mg/ml.
Further, the step 13) contains TiO2(B) And the mass ratio of TiO2(B) to graphene oxide in the brownish yellow dispersion liquid of graphene oxide is 9: 1.
Further, the reaction temperature of the vacuum drying oven in the step 14) is 95 ℃, and the reaction time is 6 hours.
The invention has the beneficial effects that: the invention utilizes an ultrasonic auxiliary method and a hydrothermal method to mix TiO2(B) Successfully prepare TiO with GO2(B) @ RGO aerogel. The resulting TiO2(B) @ RGO aerogel composites enable TiO2(B) Uniformly dispersed in an RGO aerogel three-dimensional network structure, and beneficial to reducing nano TiO2(B) The contact area of the electrolyte is increased, and the diffusion distance of lithium ions is reduced; the aerogel structure is beneficial to relieving the volume expansion of lithium ions in the de-intercalation process; the good conductivity of RGO enhances the electronic conductivity of the electrode. TiO prepared by the invention2(B) The @ RGO aerogel has higher specific capacity and good rate capability, and can effectively promote the quick charge and discharge capacity and the service time of the lithium ion battery.
Drawings
For purposes of clarity and clarity of the objects and advantages of the invention, the following detailed description of the invention is provided in conjunction with the accompanying drawings, in which:
FIG. 1 shows TiO obtained in example 12(B) The field emission scanning electron microscope image of the @ RGO aerogel.
FIG. 2 shows TiO obtained in example 12(B) The XRD pattern of the @ RGO aerogel.
FIG. 3 shows TiO obtained in example 12(B) XPS plots of @ RGO aerogels.
FIG. 4 shows TiO described in example 22(B) The charging and discharging curve chart of @ RGO aerogel.
FIG. 5 shows TiO described in example 22(B) Rate performance graph of @ RGO aerogel.
Detailed Description
Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.