CN102745752A

CN102745752A - Method of synthesizing mesoporous nickel cobalt oxide nanowire using hydrothermal method and application thereof

Info

Publication number: CN102745752A
Application number: CN2012102229162A
Authority: CN
Inventors: 王雪峰; 王雅兰; 王欢文
Original assignee: Tongji University
Current assignee: Tongji University
Priority date: 2012-07-02
Filing date: 2012-07-02
Publication date: 2012-10-24

Abstract

The invention relates to a method of synthesizing nickel cobalt oxide electrode material using a hydrothermal method and an application thereof. The method comprises dissolving CoCl2.6H2O, NiCl2.6H2O and CO(NH2)2 into an appropriate amount of deionized water, wherein the mole ratio of CoCl2.6H2O to NiCl2.6H2O is 1 : 2; uniformly stirring the mixed solution by using a magnetic stirrer, transferring the solution into an autoclave, heating the solution to 100 DEG C and keeping the temperature constant for 10 hours; cooling the solution to room temperature, filtering, washing and drying reactants, and then annealing the reactants for 2 hours in an air atmosphere of 250 DEG C. The method is simple to operate and environmental-friendly. The prepared nickel cobalt oxide nanowire is a spinel-type cubic phase and porous, has high purity and relatively high specific surface area, and can be used as electrode materials for super capacitors, with specific capacitance thereof being 722 F/g.

Description

The method and the application thereof of the synthesising mesoporous cobalt acid of hydrothermal method nickel nano wire

Technical field

The invention belongs to the electrochemical energy storage field, be specifically related to the method and the application thereof of the synthesising mesoporous cobalt acid of a kind of hydro-thermal nickel nano wire.

Background technology

Cobalt acid nickel (NiCo ₂O ₄) be the AB of inverse spinel structure ₂O ₄The type composite oxides, wherein nickel ion occupies octahedral interstices, and cobalt occupies the whole tetrahedron spaces and the octahedral interstices of half.There are Co in its electroconductibility and electrochemical activity far above single nickel, cobalt/cobalt oxide ³⁺/ Co ²⁺And Ni ³⁺/ Ni ²⁺Redox couple has with low costly simultaneously, and advantages of environment protection can be used as electrode material for super capacitor, has huge using value.So NiCo ₂O ₄Application aspect ultracapacitor causes people's attention gradually.Sol-gel process as people such as Wei. [Te-Yu Wei et al., Adv. Mater., 2010,22,347-351.] utilize propylene oxide to drive is successfully prepared NiCo ₂O ₄Gas gel has higher ratio electric capacity (1400 Fg ¹).

The main compound method of cobalt acid nickel has: high temperature solid-state method, mechanochemical synthesis, sol-gel method, the liquid phase chemical precipitator method etc.Wherein the high temperature solid-state chemical reaction method is a cobalt acid nickel prior synthesizing method, though technology is simple, long reaction time, energy consumption is high, product granularity is big; Introduce a large amount of strains and defective, products therefrom bad dispersibility in the mechanochemistry building-up process; Sol-gel method is less and be evenly distributed through the product grain diameter that adds tensio-active agent and obtain, but is prone to introduce impurity; And liquid phase chemical precipitator method synthetic product structure is imperfect, can generate the part metastable phase.

Chinese patent (CN10033497.3,2011) utilizes that sol-gel method has synthesized that pattern is even, specific surface area is big, percent crystallinity is high, the porous cobalt of even aperture distribution acid nickel material.Chinese patent (CN10195864.X, 2011) provides a kind of co-precipitation compound method of nickel cobaltate nano particles, prepared NiCo ₂O ₄Be spinel structure, particle size is about 10nm, and is applied to electrode material for super capacitor.

Summary of the invention

The object of the present invention is to provide the method and the application thereof of the synthesising mesoporous cobalt acid of a kind of hydrothermal method nickel nano wire; This method prepares in the process of cobalt acid nickel material need not add template; Products therefrom purity is high, and specific surface area is bigger, can be used as electrode material for super capacitor.

The method of the synthetic cobalt acid of the hydrothermal method that the present invention proposes nickel nano wire, concrete steps are following:

(1) with 0.64g CoCl ₂6H ₂O, 0.32g NiCl ₂6H ₂O and 1.20g CO (NH ₂) ₂Be dissolved in the 50ml deionized water, magnetic stirring apparatus fully stirs, and solution is mixed.

(2) mixing solutions in the step (1) is transferred to has in the teflon-lined autoclave, be heated to 80 ~ 120 ℃, constant temperature 10h obtains precursor solution.

(3) after the question response still was cooled to room temperature, the precursor solution that filtration step (2) obtains was used the deionized water thorough washing, and dry in 60 ℃ of baking ovens, made presoma.

(4) the dry presoma that step (3) is made places retort furnace at 200 ~ 300 ℃ of annealing of air atmosphere 2h, obtains cobalt acid nickel nano wire.

(5) the cobalt acid nickel nano wire that step (4) is obtained characterizes with electrochemical properties to be tested.

The cobalt acid nickel nano-material that utilizes the inventive method to prepare is applied to electrode material for super capacitor.

Beneficial effect of the present invention is: simple to operate, the environmental friendliness of present method, gained cobalt acid nickel nano wire is spinel type cube phase, purity height, porous, has higher specific surface area, can be used as electrode material for super capacitor, can reach 722Fg than electric capacity ¹

Description of drawings

Fig. 1 is the XRD figure of cobalt acid nickel material.

Fig. 2-5 is sem (SEM) figure (magnification is respectively 6000,15000,30000 and 80000).

Fig. 6-8 is the figure of the transmission electron microscope (TEM) under the different amplification (the scale scale is respectively 50nm, 20nm, 2nm).

Fig. 9 is the nitrogen adsorption-desorption isotherm of cobalt acid nickel material.

Figure 10 is the pore size distribution curve that makes mesoporous cobalt acid nickel nano wire.

Figure 11 is the cyclic voltammetry curve (electrolyte solution be 1M KOH solution) of cobalt acid nickel nano-material under different scanning rates.

Figure 12 is the ratio capacitance of cobalt acid nickel material under different scanning rates.

Figure 13 is the discharge curve of cobalt acid nickel material under the different electric flow density.

Figure 14 is the ratio capacitance of cobalt acid nickel material under the different electric flow density.

Figure 15 is the cycle life figure of cobalt acid nickel material.

Embodiment

Further specify the present invention through embodiment below.

Embodiment 1:

(2) mixing solutions in the step (1) is transferred to has in the teflon-lined autoclave, be heated to 100 ℃, constant temperature 10h obtains precursor solution.

(3) after the question response still was cooled to room temperature, the precursor solution that filtration step (2) obtains was collected presoma.Use the deionized water thorough washing, and dry in 60 ℃ of baking ovens, make presoma.

(4) the dry presoma that step (3) is made places retort furnace at 250 ℃ of annealing of air atmosphere 2h, obtains cobalt acid nickel nano wire.

(5) the cobalt acid nickel nano wire that step (4) is obtained characterizes with electrochemical properties to be tested.The result shows that this method synthetic cobalt acid nickel nano wire has higher specific surface area (101.6 m ²g ^-1), can reach 722Fg than electric capacity ¹, have good cyclical stability, be merely 8% through 1000 circulation backs than capacitance fade rate.

Embodiment 2:

(4) the dry presoma that step (3) is made places retort furnace at 200 ℃ of annealing of air atmosphere 2h, obtains cobalt acid nickel nano wire.

Embodiment 3:

(4) the dry presoma that step (3) is made places retort furnace at 300 ℃ of annealing of air atmosphere 2h, obtains cobalt acid nickel nano wire.

Embodiment 4:

(2) mixing solutions in the step (1) is transferred to has in the teflon-lined autoclave, be heated to 120 ℃, constant temperature 10h obtains precursor solution.

Embodiment 5:

(2) mixing solutions in the step (1) is transferred to has in the teflon-lined autoclave, be heated to 80 ℃, constant temperature 10h obtains precursor solution.

Claims

1. the method for the synthesising mesoporous cobalt acid of hydrothermal method nickel nano wire is characterized in that operation steps is following:

(1) with 0.64g CoCl ₂6H ₂O, 0.32g NiCl ₂6H ₂O and 1.20g CO (NH ₂) ₂Be dissolved in the 50ml deionized water, magnetic stirring apparatus fully stirs, and solution is mixed;

(2) mixing solutions in the step (1) is transferred to has in the teflon-lined autoclave, be heated to 80 ~ 120 ℃, constant temperature 10h obtains precursor solution;

(3) after the question response still was cooled to room temperature, the precursor solution that filtration step (2) obtains was used the deionized water thorough washing, and dry in 60 ℃ of baking ovens, made presoma;

(4) the dry presoma that step (3) is made places retort furnace at 200 ~ 300 ℃ of annealing of air atmosphere 2h, obtains cobalt acid nickel nano wire;

2. the cobalt acid nickel nano-material that obtains according to the said preparation method of claim 1 is applied to electrode material for super capacitor.