阅读说明：本技术 锂镧锆钽氧作为固体氧化物燃料电池电解质材料的应用 (Application of lithium lanthanum zirconium tantalum oxygen as solid oxide fuel cell electrolyte material ) 是由 陆玉正 杨静静 颜森林 于 2021-08-13 设计创作，主要内容包括：本发明公开了锂镧锆钽氧作为固体氧化物燃料电池电解质材料的应用；所述固体氧化物燃料电池的结构为泡沫镍-NCAL/LLZTO/NCAL-泡沫镍；其中,电解质材料LLZTO中各元素配比为Li-(6.4)La-(3)Zr-(1.4)Ta-(0.6)O-(12)；NCAL的化学式为：Ni-(0.8)Co-(0.15)Al-(0.05)LiO-(2-δ)。锂镧锆钽氧作为燃料电池的电解质材料,能够在燃料电池操作气氛下通过质子占据锂离子位置的方式,形成质子传输通道,因此采用锂镧锆钽氧作为燃料电池的电解质材料,能够实现燃料电池在低温段也具有良好的输出功率密度。(The invention discloses an application of lithium lanthanum zirconium tantalum oxygen as an electrolyte material of a solid oxide fuel cell; the structure of the solid oxide fuel cell is foam nickel-NCAL/LLZTO/NCAL-foam nickel; wherein, the electrolyte material LLZTO contains Li in each element proportion 6.4 La 3 Zr 1.4 Ta 0.6 O 12 (ii) a The chemical formula of NCAL is: ni 0.8 Co 0.15 Al 0.05 LiO 2‑δ . The lithium lanthanum zirconium tantalum oxygen is used as the electrolyte material of the fuel cell, and a proton transmission channel can be formed in a way that protons occupy lithium ion positions under the operation atmosphere of the fuel cell, so that the fuel cell can have good output power density at a low temperature section by adopting the lithium lanthanum zirconium tantalum oxygen as the electrolyte material of the fuel cell.)

1. The application of lithium lanthanum zirconium tantalum oxygen as a solid oxide fuel cell electrolyte material.

2. The use of lithium lanthanum zirconium tantalum oxygen as a solid oxide fuel cell electrolyte material according to claim 1, characterized in that: the structure of the solid oxide fuel cell is foam nickel-NCAL/LLZTO/NCAL-foam nickel.

3. The use of lithium lanthanum zirconium tantalum oxygen as a solid oxide fuel cell electrolyte material according to claim 2, characterized in that: the application process is as follows: the anode of the fuel cell generates protons at the working temperature of 450-500 ℃, the protons generated by the anode replace lithium ions in the electrolyte material LLZTO, and a proton transmission channel is formed in the electrolyte material LLZTO to transmit the protons from the anode to the cathode.

4. The use of lithium lanthanum zirconium tantalum oxygen as a solid oxide fuel cell electrolyte material according to claim 2, characterized in that: the electrolyte material LLZTO contains Li as each element_6.4La₃Zr_1.4Ta_0.6O₁₂。

5. The use of lithium lanthanum zirconium tantalum oxygen as a solid oxide fuel cell electrolyte material according to claim 1, characterized in that: the chemical formula of NCAL is: ni_0.8Co_0.15Al_0.05LiO_2-δ。

6. The use of the li-la-zr-ta-o according to claim 1 as a solid oxide fuel cell electrolyte materialThe method is characterized in that: the cathode of the solid oxide fuel cell adopts foamed nickel-LSCF to replace foamed nickel-NCAL; wherein the LSCF has the formula: la_0.6Sr_0.4Co_0.2Fe_0.8O_3-δ。

7. The use of lithium lanthanum zirconium tantalum oxygen as a solid oxide fuel cell electrolyte material according to claim 6, characterized in that: the preparation method of the foamed nickel-NCAL comprises the following steps: mixing 10 g of NCAL powder with 5mL of terpineol to obtain a mixed material; adding a bonding agent polyvinylidene fluoride accounting for 5% of the mass ratio of the mixture into the mixture, and fully grinding to obtain slurry; and uniformly coating the slurry on the foamed nickel to obtain the foamed nickel-NCAL.

Technical Field

The invention relates to application of lithium lanthanum zirconium tantalum oxygen as an electrolyte material of a solid oxide fuel cell.

Background

A Solid Oxide Fuel Cell (SOFC) is a device which generates electricity by adopting electrochemical reaction, has no Carnot cycle, has far higher efficiency than other power generation equipment, and has the main product of CO₂And H₂And O. The SOFC has high power generation efficiency (the power generation efficiency per se is close to 60 percent, and the combined efficiency with the hot gas turbine can reach more than 80 percent), high waste heat quality, wide fuel selection range (natural gas, coal gas, biomass gas, methanol and the like can be used), and no need of using natural gas, coal gas, biomass gas, methanol and the likeNeeds noble metal catalyst, has strong adaptability and is a fuel cell with high application prospect. The method is mainly applied to the fields of portable power supplies, power stations, data centers, communication base stations, distributed power supply and heating and the like. However, the SOFC has an excessively high operation temperature, generally about 800 ℃, and an excessively high operation or operating temperature makes a cell sealing process difficult, a reaction easily occurs between an electrode and an electrolyte, a material selection range is limited, and the like, which limit the commercialization process of the SOFC.

Disclosure of Invention

The purpose of the invention is as follows: the invention provides a low-temperature solid oxide fuel cell adopting lithium lanthanum zirconium tantalum oxygen as an electrolyte material, aiming at the problem of overhigh operation temperature of the solid oxide fuel cell in the prior art.

The technical scheme is as follows: the application of lithium lanthanum zirconium tantalum oxygen as a solid oxide fuel cell electrolyte material.

Wherein the structure of the solid oxide fuel cell is nickel foam-NCAL/LLZTO/NCAL-nickel foam.

Wherein, the application process is as follows: the anode of the fuel cell generates protons at the working temperature of 450-500 ℃, the protons generated by the anode replace lithium ions in the electrolyte material LLZTO, and a proton transmission channel is formed in the electrolyte material LLZTO to transmit the protons from the anode to the cathode. Electrolyte material LLZTO (Li)_6.4La₃Zr_1.4Ta_0.6O₁₂) Under the operating atmosphere of the fuel cell (the temperature is over 200 ℃), lithium ions have high activity and are unstable, and hydrogen gas of an anode generates a large amount of protons (H) under the catalytic action of a cathode electrode material NCAL⁺) And simultaneously releases electrons, and the generated protons gradually occupy lithium ions (Li) in LLZTO under the drive of concentration difference⁺) The lithium ions at the occupied positions are volatilized at high temperature, so that proton transmission channels are formed in the electrolyte material LLZTO, the protons pass through the electrolyte and reach the cathode, electrons released by the anode reach the cathode from an external circuit, and the protons, oxygen molecules of the cathode and the electrons are subjected to electrochemical reaction at the cathode, so that the power generation function of the fuel cell is realized; the chemical reaction formula of the cathode is as follows: o is₂+4H⁺+4e^-→2H₂O。

Wherein, the electrolyte material LLZTO contains Li in each element proportion_6.4La₃Zr_1.4Ta_0.6O₁₂。

Wherein the chemical formula of NCAL is: ni_0.8Co_0.15Al_0.05LiO_2-δ。

Wherein, the cathode of the solid oxide fuel cell can adopt foam nickel-LSCF to replace foam nickel-NCAL; wherein the LSCF has the formula: la_0.6Sr_0.4Co_0.2Fe_0.8O_3-δ。

Wherein, the preparation method of the foam nickel-NCAL comprises the following steps: mixing 10 g of NCAL powder with 5mL of terpineol to obtain a mixed material; adding a bonding agent polyvinylidene fluoride accounting for 5% of the mass ratio of the mixture into the mixture, and fully grinding to obtain slurry; and uniformly coating the slurry on the foamed nickel to obtain the foamed nickel-NCAL.

The preparation method of the solid oxide fuel cell comprises the following steps: the prepared anode and cathode foamed nickel-NCAL and electrolyte material Li_6.4La₃Zr_1.4Ta_0.6O₁₂And pressing the cell piece by adopting a hot-pressing die with a heating function, wherein the pressure is 250Mpa, the hot-pressing temperature is 500 ℃, the hot-pressing time is 2 hours, and taking out the cell piece after the hot-pressing die is completely cooled to obtain the low-temperature solid oxide fuel cell.

Has the advantages that: the lithium lanthanum zirconium tantalum oxygen is used as the electrolyte material of the fuel cell, and a proton transmission channel can be formed in a way that protons occupy lithium ion positions in the operating atmosphere of the fuel cell, so that the operating temperature of the fuel cell can be reduced to below 500 ℃ by using the lithium lanthanum zirconium tantalum oxygen as the electrolyte material of the fuel cell, and the fuel cell has good output power density in a low-temperature section. When the operating temperature of the solid oxide fuel cell is 500 ℃, the output power reaches 690mW/cm²。

Drawings

FIG. 1 is a schematic view of the structure of a fuel cell according to the present invention;

FIG. 2 shows H in a fuel cell according to the present invention⁺And Li⁺Schematic diagram of the permutation;

FIG. 3 is X-ray diffraction results of LLZTO before and after fuel cell reaction;

FIG. 4 is a refined plot of the X-ray diffraction results of LLZTO prior to fuel cell reaction;

FIG. 5 is a refined plot of the X-ray diffraction results of LLZTO after the fuel cell reaction;

FIG. 6 is a graph of the output performance of a low temperature fuel cell of the present invention;

FIG. 7 is a plot of the electrochemical AC impedance spectrum of a low temperature fuel cell in accordance with the present invention;

FIG. 8 is a schematic diagram of a fuel cell with a proton filter;

fig. 9 is a graph of fuel cell performance with a proton filter.

Detailed Description

As shown in FIG. 1, the fuel cell of the present invention has a structure of nickel foam-NCAL/LLZTO/NCAL-nickel foam. Wherein the cathode and anode materials are both prepared by coating NCAL3 on foamed nickel 2, and the electrolyte material 1 is LLZTO (Li)_6.4La₃Zr_1.4Ta_0.6O₁₂). Wherein the chemical formula of NCAL is: ni_0.8Co_0.15Al_0.05LiO_2-δNCAL may be purchased commercially directly. The electrolyte material LLZTO can also be purchased commercially directly.

The preparation method of the foamed nickel-NCAL comprises the following steps: mixing 10 g of NCAL powder with 5mL of terpineol to obtain a mixed material; adding a bonding agent polyvinylidene fluoride accounting for 5% of the mass ratio of the mixture into the mixture, and fully grinding to obtain slurry; and uniformly coating the slurry on the foamed nickel to obtain the foamed nickel-NCAL.

The preparation method of the fuel cell comprises the following steps: the prepared anode and cathode foamed nickel-NCAL and electrolyte material Li_6.4La₃Zr_1.4Ta_0.6O₁₂Pressing the battery piece by adopting a hot-pressing die with a heating function, wherein the pressure is 250Mpa, the hot-pressing temperature is 500 ℃, the hot-pressing time is 2 hours, and after the hot-pressing die is finishedAnd after full cooling, taking out the cell piece to obtain the low-temperature solid oxide fuel cell.

As shown in FIG. 2, the electrolyte material LLZTO has a garnet structure, and under the operation atmosphere of the fuel cell, the space group of the garnet structure changes, namely, the space group Ia-3d in the initial state is converted to the space group I-43d in the termination state, and the space group is converted from Ia-3d to I-43d, so that the process that protons occupy lithium ion positions is realized, and the fast transmission of the protons in the electrolyte LLZTO is further realized.

As shown in FIG. 3, X-ray diffraction (XRD) analysis of LLZTO before and after the participation in the chemical reaction revealed that: the electrolyte material LLZTO keeps good garnet shape before and after the chemical reaction of the fuel cell, and the comparison with PDF standard (39-0898) card shows that the X-ray diffraction peaks before and after the reaction are basically not changed.

As shown in FIGS. 4 to 5, the XRD results were further refined, and it was found that although the LLZTO before and after the reaction was kept in good garnet form, the space group changed from Ia-3d before the reaction to I-43d after the reaction, i.e., LLZTO before the fuel cell reaction was in space group Ia-3d, and the space group changed to I-43d after the fuel cell reaction, which proved the lithium ion position behavior (i.e., H) occupied by protons (i.e., H⁺And Li⁺Displacement behavior) to form a proton transfer channel, thereby realizing the power generation function of the fuel cell; a detailed schematic of the behavior of protons occupying lithium ions is shown in fig. 2.

As shown in FIG. 6, the output power density of the low temperature fuel cell using LLZTO as the electrolyte material reaches 690mW/cm at an operation temperature of 500 deg.C²(ii) a The output power density reaches 300mW/cm at the operation temperature of 450 DEG C². The corresponding electrochemical alternating-current impedance results are shown in fig. 7, and the ohmic impedance and the electrode polarization impedance are very small under the low-temperature condition, which proves that the electrolyte material has good electrochemical performance.

To further verify proton transport in LLZTO, the present invention further constructs a proton Filter (BaZr)_0.8Y_0.2O₃BZY), namely a layer of BZY is added between the electrode and the electrolyte,the BZY only allows proton transmission, can effectively filter oxygen ion transmission, and has a cell structure as shown in figure 8. the experimental result shows that after the BZY proton filter is used, the cell still has very high output, and the output power density reaches 612mW/cm at 500 DEG C²As shown in fig. 9, the experimental results fully demonstrate the proton transport properties of LLZTO.