CN111063898B

CN111063898B - Battery anode reforming layer material, preparation method and power generation method of battery anode reforming layer material for solid oxide fuel battery

Info

Publication number: CN111063898B
Application number: CN201911324881.1A
Authority: CN
Inventors: 凌意瀚; 王鑫鑫; 杨洋; 吴雨杰; 周世杰
Original assignee: China University of Mining and Technology CUMT
Current assignee: China University of Mining and Technology CUMT
Priority date: 2019-12-20
Filing date: 2019-12-20
Publication date: 2021-03-30
Anticipated expiration: 2039-12-20
Also published as: CN111063898A

Abstract

The invention discloses a battery anode reforming layer material, a preparation method and a power generation method for a solid oxide fuel battery, wherein the battery anode reforming layer material has a chemical formula of Ni₂Mo_2xTi_2‑3xO_6‑2δIn the formula, x is Mo⁶⁺Doped with Ti⁴⁺The molar ratio of the sites, x is more than or equal to 0.001 and less than or equal to 0.05; will contain Ni²⁺Compound of (2), Mo⁶⁺Compound of (2), Ti⁴⁺The compound is sequentially added into water, then a complexing agent is added, the pH value of the solution is adjusted to 6-7 after stirring, and the powder obtained after heating, concentration and combustion is calcined in the air atmosphere. The power generation method of the material comprises the following steps: adding terpineol-ethyl cellulose into the reforming layer powder material to prepare slurry, coating the slurry on the surface of the anode of the battery, sintering in the air, and reducing in the hydrogen atmosphere; and respectively introducing low-concentration gas and external air into an anode air passage and a cathode air passage of the battery. The invention can avoid carbon deposition of the anode and improve the power generation power and stability of the solid oxide fuel cell.

Description

Battery anode reforming layer material, preparation method and power generation method of battery anode reforming layer material for solid oxide fuel battery

Technical Field

The invention relates to the technical field of gas utilization and fuel cells, in particular to a cell anode reforming layer material, a preparation method and a power generation method of the cell anode reforming layer material for a solid oxide fuel cell.

Background

Coal mine gas is a clean energy with abundant reserves, and the coal mine gas resource amount in China reaches 31 billion cubic meters. However, due to the influence of the excavation activity, the coal mine gas is mixed with a large amount of air, so that the methane content is low, and the difficulty of gas utilization is increased. At present, the utilization rate of extracted gas in coal mines in China is less than 40%, more than 100 billionth cubic meters of extracted gas is directly emptied every year, and serious energy waste and atmospheric greenhouse effect are caused. The existing gas power generation technology is mainly combustion power generation technology of an internal combustion engine, a gas turbine and the like, but the power generation efficiency of the technology is low (< 30%), and a large amount of air pollutants such as nitrogen oxides and solid particles and noise pollution are generated, so that clean and efficient utilization of coal mine gas is of great significance for increasing clean energy supply and avoiding environmental pollution.

The patent with publication number CN108232206A discloses a method and system for direct power generation using ventilation air methane or low-concentration gas, in which the ventilation air methane or low-concentration gas extracted by a gas extraction vacuum pump discharged by a mine ventilator is desulfurized and dedusted, part of oxygen in the gas is removed by a gas separation device, and then the gas enters an anode gas passage of a solid oxide fuel cell to participate in an electrochemical reaction, meanwhile, outside air is delivered to a cathode gas passage of the solid oxide fuel cell to participate in the electrochemical reaction, and the solid oxide fuel cell outputs direct current to the outside to realize direct conversion of chemical energy of the ventilation air methane or the low-concentration gas into electric energy. Although the method solves the problem of utilization of low-concentration gas, the problems of carbon deposition, sintering and growth of nickel particles and the like can occur when the traditional nickel-based anode is used for catalyzing oxygen-containing coal mine gas under certain working conditions, and the catalytic reforming efficiency of the traditional nickel-based anode on the low-concentration gas is also low, so that a new technical method is urgently needed to be developed to solve the problems, so that the electrochemical performance and the stability of the coal mine gas fuel cell are improved.

Disclosure of Invention

The invention aims to provide a cell anode reforming layer material, a preparation method and a power generation method for a solid oxide fuel cell by using the cell anode reforming layer material.

To achieve the above object, a material for anode reforming layer of battery has a chemical formula of Ni₂Mo_2xTi_2-3xO_6-2δIn the formula, x is Mo⁶⁺Doped with Ti⁴⁺The molar ratio of x is more than or equal to 0.001 and less than or equal to 0.05. Preferably, the chemical formula of the doped material is Ni₂Mo_0.05Ti_1.925O_6-2δ。

The preparation method of the battery anode reforming layer material comprises the following steps:

(1) to contain nickel ions Ni²⁺Compound of (2), Mo containing molybdenum ion⁶⁺Compound of (2), containing titanium ion Ti⁴⁺Is prepared from compound of formula (II) and has molecular formula of Ni₂Mo_2xTi_2-3xO_6-2δWeighing the raw materials according to the stoichiometric ratio of the corresponding elements, wherein x is Mo⁶⁺Doped with Ti⁴⁺The molar ratio of the sites, and x is more than or equal to 0.001 and less than or equal to 0.05; weighing nickel ions Ni²⁺Compound of (2), molybdenum ion Mo⁶⁺Compound of (2), titanium ion Ti⁴⁺The compounds of (a) are sequentially added into water to obtain a solution containing each ion;

(2) adding a complexing agent into the solution obtained in the step (1), wherein the addition amount of the complexing agent is 1-2 times of the mole number of metal ions in the solution, the complexing agent is one or two of ethylenediamine tetraacetic acid and citric acid, stirring until the complexing agent is dissolved, and adding ammonia water to adjust the pH value of the solution to 6-7;

(3) heating and concentrating the solution to generate spontaneous combustion, and calcining the powder obtained after combustion in an air atmosphere at 600-1000 ℃ to obtain Ni₂Mo_2xTi_2-3xO_6-2δReforming layer powder material.

Preferably, the nickel ion Ni²⁺The compound of (a) is nickel nitrate; the Mo containing molybdenum ions⁶⁺The compound of (1) is ammonium molybdate; the titanium ion-containing Ti⁴⁺The compound of (a) is n-butyl titanate; the molar ratio of nickel nitrate to ammonium molybdate to n-butyl titanate is 1: 0.025: 0.9625.

the use of a cell anode reforming layer material as described above for a solid oxide fuel cell.

The power generation method of the cell anode reforming layer material for the solid oxide fuel cell comprises the following steps:

(1) has a molecular formula of Ni₂Mo_2xTi_2-3xO_6-2δAdding a certain amount of terpineol-ethyl cellulose into the reforming layer powder material to prepare reforming layer slurry, wherein x is Mo⁶⁺Doped with Ti⁴⁺The molar ratio of the sites, x is more than or equal to 0.001 and less than or equal to 0.05; coating the reforming layer slurry on the surface of the anode-supported solid oxide fuel cell for 4-6 times, and sintering in the air at 900-1000 ℃ for 3-5 hours to prepare the Ni-containing composite material₂Mo_2xTi_2-3xO_6-2δA solid oxide fuel cell reforming layer;

(2) the belt made in step (1) is provided with Ni₂Mo_2xTi_2-3xO_6-2δReducing the solid oxide fuel cell of the reforming layer for 3-5 h at 700-800 ℃ in a hydrogen atmosphere;

(3) preparing a low-concentration gas component as a fuel;

(4) and introducing the fuel into an anode air passage of the solid oxide fuel cell, introducing outside air into a cathode air passage of the solid oxide fuel cell, and outputting direct current to the outside through electrons obtained by the cathode and the anode to convert the chemical energy of the low-concentration gas into electric energy.

Preferably, Ni in step (1)₂Mo_2xTi_2-3xO_6-2δThe thickness of the reforming layer is 40 to 50 μm.

Preferably, Ni₂Mo_2xTi_2-3xO_6-2δThe mass ratio of the reforming layer powder material to the terpineol-ethyl cellulose is 1: 1.5, the mass fraction of ethyl cellulose in the terpineol-ethyl cellulose is 10%.

Preferably, the fuel in the step (3) is oxygen-containing wet gas with methane concentration of 5-30%; the concentration ratio of methane to oxygen in the fuel is not less than 2, the concentration content of oxygen in the fuel is less than 8%, and the moisture content in the fuel is 3%.

Compared with the prior art, the Mo-doped NiTiO in the invention_3-δThe reforming layer material can be decomposed into metal Ni phase and Mo-doped TiO under the high-temperature reducing atmosphere of the battery anode_2-δPhase Ni phase havingElectrochemically catalytic active, Mo-doped TiO_2-δThe phase has strong water absorption, can promote methane wet reforming, and avoid carbon deposition on the anode of the battery, thereby improving the electrochemical performance and stability of the battery; mo-doped TiO_2-δMo in the phase has multiple valence states, so that the redox activity of the catalyst is improved; ni phase and Mo-doped TiO formed after reduction_2-δThe phase has a continuous nano-network structure, so that the reaction interface area is greatly increased. In conclusion, the reforming layer has high electrochemical catalytic activity, strong water absorption, strong oxidation-reduction activity and rich reaction interface after reduction; in addition, the reforming layer material adopts an EDTA-citric acid complexing method to synthesize Mo-doped NiTiO in one step_3-δThe reforming layer powder has simple preparation process, low cost and good application prospect.

Drawings

FIG. 1 shows the chemical formula of Ni₂Mo_0.05Ti_1.925O_6-2δX-ray diffraction pattern of reforming layer material: (a) before reduction; (b) after reduction;

FIG. 2 shows a chemical formula of Ni₂Mo_0.05Ti_1.925O_6-2δA high-resolution transmission electron microscope image of the reformed layer material after reduction;

FIG. 3 shows a chemical formula of Ni₂Mo_0.05Ti_1.925O_6-2δPhotoelectron spectrum of the reformed layer material after reduction: (a) ti2 p; (b) mo3 d;

FIG. 4 shows Ni₂Mo_0.05Ti_1.925O_6-2δThe cells with and without the reforming layer were treated with low concentration gas (3% H)₂O-11％CH₄) I-V, I-P curve for fuel;

FIG. 5 shows Ni content₂Mo_0.05Ti_1.925O_6-2δThe cells with and without the reforming layer were treated with low concentration gas (3% H)₂O-25％CH₄) Long term stability test results for the fuel;

FIG. 6 shows a single cell Ni-YSZ anode and anode Ni after long term stability testing₂Mo_0.05Ti_1.925O_6-2δScanning electron microscope image of reforming layer interface;

FIG. 7 shows anode Ni after long-term stability test₂Mo_0.05Ti_1.925O_6-2δScanning electron microscope photographs of the reformed layer;

FIG. 8 is a schematic view of the structure of a solid oxide fuel cell of the present invention;

in the figure: 1. cathode, 2, electrolyte; 3. an anode; 4. Ni/Mo-TiO_2-δAnd (4) reforming the layer.

Detailed Description

The present invention will be described in further detail with reference to examples.

Example 1

A material for anode reforming layer of battery is disclosed, whose chemical formula is Ni₂Mo_0.05Ti_1.925O_6-2δIn the formula, x is Mo⁶⁺Doped with Ti⁴⁺Molar ratio of the sites. The preparation method of the battery anode reforming layer material comprises the following steps: nickel nitrate, ammonium molybdate and tetrabutyl titanate are mixed according to a molar ratio of 1: 0.025: 0.9625 are sequentially added into water, complexing agents of ethylene diamine tetraacetic acid and citric acid are added, and the molar ratio of metal ions, citric acid and ethylene diamine tetraacetic acid in the solution is 1: 1: 0.8, stirring until the complexing agent is dissolved, and then adding ammonia water to adjust the pH value of the solution to 6-7; pouring the solution into a crucible for heating, concentrating and evaporating the solution to dryness, then generating spontaneous combustion, calcining the powder obtained after combustion in an air atmosphere at 600-1000 ℃ for 3-5 h, and thus obtaining Ni₂Mo_0.05Ti_1.925O_6-2δReforming layer powder material.

The power generation method of the anode reforming layer material of the battery used for the solid oxide fuel battery comprises the following steps:

(1) has a molecular formula of Ni₂Mo_0.05Ti_1.925O_6-2δAdding a certain amount of terpineol-ethyl cellulose into the reforming layer powder material to prepare reforming layer slurry, wherein x is Mo⁶⁺Doped with Ti⁴⁺The molar ratio of the sites; the Ni₂Mo_0.05Ti_1.925O_6-2δThe mass ratio of the reforming layer powder material to the terpineol-ethyl cellulose is 1: 1.5, mass fraction of ethyl cellulose in the terpineol-ethyl cellulose10 percent; coating the reforming layer slurry on the surface of the anode-supported solid oxide fuel cell for 4-6 times, and sintering in the air at 900-1000 ℃ for 3-5 hours to prepare the Ni-containing composite material₂Mo_0.05Ti_1.925O_6-2δA solid oxide fuel cell reforming layer; the Ni₂Mo_0.05Ti_1.925O_6-2δThe thickness of the reforming layer is 40-50 μm;

(2) the belt made in step (1) is provided with Ni₂Mo_0.05Ti_1.925O_6-2δReducing the solid oxide fuel cell of the reforming layer for 3-5 h at 700-800 ℃ in a hydrogen atmosphere;

(3) preparing a low-concentration gas component as a fuel; the fuel is oxygen-containing wet gas with methane concentration of 5-30%; in order to prevent the anode from being oxidized, the concentration ratio of methane to oxygen in the fuel is not lower than 2; in order to make the interior of the anode in a suffocation state and improve the safety, the oxygen concentration content in the fuel is lower than 8 percent; in order to effectively prevent anodic oxidation and promote partial oxidation reforming and water reforming reactions of methane and improve the performance of the battery, the prepared fuel gas is humidified by a water bath kettle at 30 ℃ so that the low-concentration gas contains 3% of water;

As shown in FIG. 8, the solid oxide fuel cell with an anode reforming layer has a structure comprising a cathode 1, an electrolyte 2, an anode 3 and Ni/Mo-TiO in this order_2-δThe reforming layer 4.

For Ni, X-ray diffractometer (Bruker model D8)₂Mo_0.05Ti_1.925O_6-2δThe structural analysis of the reformed layer powder material gave FIG. 1(a), which shows that 2.5% Mo doping did not alter NiTiO_3-δThe structure of (1), no new phase is generated; doping Mo with NiTiO_3-δReducing the powder in hydrogen for 3h at 800 ℃, and reducing the reduced Ni₂Mo_0.05Ti_1.925O_6-2δThe reformed layer powder material was subjected to X-ray diffraction analysis to obtain FIG. 1(b), and the sample was decomposed into Ni phase and Mo-doped TiO phase_2-δPhase, no other phase was found.

The reduced Ni was observed with a high-resolution transmission electron microscope (Tecnai G2F 20, USA)₂Mo_0.05Ti_1.925O_6-2δReforming the layered powder material, resulting in FIG. 2, it can be seen from FIG. 2 that Ni₂Mo_0.05Ti_1.925O_6-2δThe powder material of the reforming layer presents a continuous nano-network structure.

Observing reduced Ni by a photoelectron spectrometer₂Mo_0.05Ti_1.925O_6-2δReforming the layer powder material, FIG. 3 is obtained, showing that the Ti in the reduced powder includes Ti⁴⁺And Ti³⁺，Ti⁴⁺Is reduced to Ti³⁺Meanwhile, a large amount of oxygen vacancies are generated, and the oxygen vacancies are helpful for absorbing moisture, so that the wet reforming reaction of methane is promoted; mo in the reduced powder⁶⁺、Mo⁵⁺、M⁴⁺And Mo in multiple valence states, wherein the Mo in the multiple valence states can promote the redox activity of the catalyst, thereby promoting the methane reforming reaction.

Testing of single cells in simulated low-concentration gas atmosphere (3% H) using an electrochemical workstation (Zennium, Zahner, Germany)₂O-11％CH₄) IV and IP curves below, FIG. 4 is obtained, and the results show that Ni is contained₂Mo_0.05Ti_1.925O_6-2δThe performance of the reforming layer (NTM reforming layer) cell is significantly better than the cell without the reforming layer.

Testing of single cells in simulated low-concentration gas atmosphere (3% H) using an electrochemical workstation (Zennium, Zahner, Germany)₂O-25％CH₄) The long-term discharge stability is shown in fig. 5, and the results show that the performance of the cell containing the NTM reforming layer is not obviously attenuated in the long-term discharge process of 50h, and the stability of the cell is obviously superior to that of the cell without the reforming layer.

The microstructure of the anode and the reformed layer was observed by a scanning electron microscope (Quanta 250 in U.S. Pat. No. 6) to obtain FIG. 6, and as a result, the surface anode and the reformed layer were tightly bonded and no significant carbon deposition was observed.

By scanning electricityMicroscopic examination of the high-magnification microstructure of the reformed layer (Quanta 250, USA) resulted in FIG. 7, which shows that a large number of nanoparticles are distributed in the reformed layer, and the nanoparticles are NiTiO doped with Mo_3-δReducing the mixture into a nano Ni phase and nano Mo-doped TiO_2-δThe phase formed is in a nano-net structure, and the catalyst with the nano-structure has a large amount of reaction interfaces, so that the methane reforming reaction is promoted, and carbon deposition is avoided.

Example 2

A material for anode reforming layer of battery is disclosed, whose chemical formula is Ni₂Mo_0.1Ti_1.85O_6-2δIn the formula, x is Mo⁶⁺Doped with Ti⁴⁺Molar ratio of the sites. The preparation method of the battery anode reforming layer material comprises the following steps: nickel nitrate, ammonium molybdate and tetrabutyl titanate are mixed according to a molar ratio of 1: 0.05: 0.925, adding the mixture into water in sequence, adding complexing agents of ethylenediamine tetraacetic acid and citric acid, wherein the molar ratio of metal ions, citric acid and ethylenediamine tetraacetic acid in the solution is 1: 1: 0.8, stirring until the complexing agent is dissolved, and then adding ammonia water to adjust the pH value of the solution to 6-7; pouring the solution into a crucible for heating, concentrating and evaporating the solution to dryness, then generating spontaneous combustion, calcining the powder obtained after combustion in an air atmosphere at 600-1000 ℃ for 3-5 h, and thus obtaining Ni₂Mo_0.1Ti_1.85O_6-2δReforming layer powder material.

The reforming layer powder material prepared in this example was used in a solid oxide fuel cell, and the power generation method was the same as in example 1.

The X-ray powder diffraction pattern, TEM image, photoelectron spectrum, IV and IP curves, long-term stability pattern, and SEM image of the reformed-layer powder material prepared in this example were consistent with those of the sample prepared in example 1.

Example 3

A material for anode reforming layer of battery is disclosed, whose chemical formula is Ni₂Mo_0.002Ti_1.997O_6-2δIn the formula, x is Mo⁶⁺Doped with Ti⁴⁺Molar ratio of the sites. The preparation method of the battery anode reforming layer material comprises the following steps: nickel nitrate, ammonium molybdate and tetrabutyl titanate are mixed according to a molar ratio of 1: 0.001:0.9985, adding into water in sequence, adding complexing agent ethylenediamine tetraacetic acid and citric acid, wherein the molar ratio of metal ions, citric acid and ethylenediamine tetraacetic acid in the solution is 1: 1: 0.8, stirring until the complexing agent is dissolved, and then adding ammonia water to adjust the pH value of the solution to 6-7; pouring the solution into a crucible for heating, concentrating and evaporating the solution to dryness, then generating spontaneous combustion, calcining the powder obtained after combustion in an air atmosphere at 600-1000 ℃ for 3-5 h, and thus obtaining Ni₂Mo_0.1Ti_1.85O_6-2δReforming layer powder material.

Claims

1. A power generation method of a cell anode reforming layer material for a solid oxide fuel cell is characterized by comprising the following steps:

(3) preparing a low-concentration gas component as a fuel;

2. The method for generating power of a solid oxide fuel cell using a cell anode reforming layer material as defined in claim 1, wherein Ni in the step (1)₂Mo_2xTi_2-3xO_6-2δThe thickness of the reforming layer is 40 to 50 μm.

3. The method for generating power of a solid oxide fuel cell using a cell anode reforming layer material as defined in claim 1 or 2, wherein Ni is Ni₂Mo_2xTi_2-3xO_6-2δThe mass ratio of the reforming layer powder material to the terpineol-ethyl cellulose is 1: 1.5, the mass fraction of ethyl cellulose in the terpineol-ethyl cellulose is 10%.

4. The method for generating power of a solid oxide fuel cell using a cell anode reforming layer material as defined in claim 1 or 2, wherein the fuel in the step (3) is oxygen-containing wet gas having a methane concentration of 5 to 30%; the concentration ratio of methane to oxygen in the fuel is not less than 2, the concentration content of oxygen in the fuel is less than 8%, and the moisture content in the fuel is 3%.