Air electrode material, preparation method of air electrode material, proton ceramic battery and preparation method of proton ceramic battery

Abstract

The invention provides an air electrode material and a preparation method thereof, and a proton ceramic battery and a preparation method thereof, and the preparation method of the air electrode material comprises the following steps: firstly, uniformly mixing a water-soluble barium salt, a water-soluble non-barium metal salt and deionized water according to a stoichiometric ratio, then adding a complexing agent, and carrying out pH value adjustment treatment to obtain a mixed solution; secondly, carrying out oil bath heating treatment on the mixed solution to obtain precursor gel; thirdly, heating and drying the precursor gel, and crushing to obtain precursor powder; and finally, performing high-temperature calcination treatment on the precursor powder to obtain the air electrode material. When the air electrode material prepared by the sol-gel method is applied to the prepared proton ceramic battery, the air electrode layer and the electrolyte layer are only adjacent and are not in close contact before assembly and formal work, so that the proton ceramic battery can subsequently induce the air electrode layer to realize self-sintering through thermoelectric coupling; therefore, the preparation steps are simplified and the manufacturing cost is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of solid oxide batteries, and in particular to an air electrode material and a preparation method thereof, a proton ceramic battery and a preparation method thereof. Background Art

[0002] Currently, fossil fuels such as coal, oil, and natural gas still dominate the world's energy mix. However, with the rapid development of the global economy, energy crises and environmental pollution are becoming increasingly prominent. Clean energy sources such as wind, hydro, and solar energy have attracted widespread attention as promising alternatives to fossil fuels. However, their availability is limited by environmental and geographical factors. Therefore, the development of low-carbon, clean, and pollution-free energy conversion devices has become an effective strategy to address current environmental and energy challenges.

[0003] Solid oxide batteries (SOCs) have attracted widespread attention due to their high energy conversion rate, flexible fuel selectivity and low environmental pollution characteristics. According to the different electrolyte carriers, SOCs can be divided into oxygen ion conducting solid oxide batteries (O-SOCs) and proton conducting solid oxide batteries (H-SOCs). O-SOCs use oxygen ion conducting oxides as electrolytes, such as fluorite-structured yttria-stabilized zirconia (YSZ), doped CeO2 and perovskite-structured LaGaO3. H-SOCs, also known as proton ceramic batteries (PCCs), use proton conducting oxides as electrolytes, and the most commonly used electrolyte material is BaZr. 0.1 Ce 0.7 Y 0.1 Yb 0.1 O 3-δ (BZCYYb). Due to the small ionic radius of protons, their migration energy barrier is lower than that of oxygen ions. Even under medium- and low-temperature operating conditions (400-700°C), PCCs still have good proton conductivity. This feature of PCCs that can operate at medium and low temperatures can effectively avoid reactions between battery components at high temperatures, making the battery microstructure more stable and extending the battery life. In addition, the product water of the proton ceramic battery is only generated on the air electrode side, which can avoid Ni oxidation on the fuel electrode side and improve fuel utilization.

[0004] As a key component of PCCs, the performance of the air electrode material directly determines the overall performance and stability of the battery. Perovskite materials are considered to be ideal candidate materials for the preparation of high-performance air electrodes due to their unique electronic structure and excellent physical and chemical properties. However, the preparation of traditional air electrode layers is formed through screen printing and high-temperature sintering processes to ensure the formation of the electrode / electrolyte interface and achieve close contact, which significantly increases the preparation process and cost and prolongs the battery production cycle. In addition, the electrode particles are easily coarsened in high-temperature environments, which reduces the catalytic activity, which limits the practical application of PCCs. Summary of the Invention

[0005] In response to the above-mentioned defects or improvement needs of the prior art, the present invention provides an air electrode material, a proton ceramic battery and a preparation method to solve the technical problems of the proton ceramic battery prepared by the prior art, such as high cost, long production cycle and reduced catalytic activity due to the formation of electrode / electrolyte interface by high-temperature sintering of the air electrode material to be prepared.

[0006] To solve the above technical problems, the present invention first provides a method for preparing an air electrode material, comprising: S10, uniformly mixing a water-soluble barium salt, a water-soluble non-barium metal salt, and deionized water according to a stoichiometric ratio, adding a complexing agent, and adjusting the pH to obtain a mixed solution; S20, heating the mixed solution in an oil bath to obtain a precursor gel; S30, heating and drying the precursor gel to obtain precursor powder after crushing; S40, calcining the precursor powder at a high temperature to obtain an air electrode material.

[0007] Preferably, in step S10, the water-soluble non-barium metal salt includes any one of a water-soluble cobalt salt, a water-soluble iron salt, a water-soluble manganese salt, a water-soluble cerium salt, a water-soluble bismuth salt, a water-soluble nickel salt, a water-soluble erbium salt and a water-soluble ruthenium salt.

[0008] Preferably, in step S10, ammonia water is used to adjust the pH value, and the pH value of the mixed solution is 7-9.

[0009] Preferably, in step S20, the heating temperature of the oil bath heating treatment is 75-100°C.

[0010] Preferably, in step S30, the temperature of the heating and drying treatment is 220-260° C., and the drying time is 4-8 hours; in step S40, the temperature of the high-temperature calcination treatment is 800-1000° C., and the calcination time is 4-7 hours.

[0011] Preferably, in step S40, the chemical formula of the air electrode material is Ba5Xn5O 14-δ, 0 ≤ δ ≤ 1; Among them, the structural general formula of Xn is (Xn1) 5-x (Xn2) x , 0 < x < 2.5; Xn1 includes Co, and Xn2 includes at least one of Fe, Mn, Ce, Bi, Ni, Er, Ru.

[0012] Correspondingly, the present invention also provides an air electrode material, which is prepared by the sol-gel method from the preparation method of the air electrode material in any one of the above, and the chemical general formula of the air electrode material is Ba5Xn5O 14-δ , 0 ≤ δ ≤ 1; Among them, the structural general formula of Xn is (Xn1) 5-x (Xn2) x , 0 < x < 2.5; Xn1 includes Co, and Xn2 includes at least one of Fe, Mn, Ce, Bi, Ni, Er, Ru.

[0013] Preferably, the air electrode material includes Ba5Co3Fe2O 14-δ , Ba5Co 2.85 Fe 1.9 Ni 0.25 O 14-δ and Ba5Co 2.85 Fe 1.9 Er 0.25 O 14-δ any one of them.

[0014] Correspondingly, the present invention further provides a proton ceramic battery, which includes a fuel electrode layer, a functional layer, an electrolyte layer, and an air electrode layer stacked from bottom to top; Among them, the air electrode layer includes the air electrode material prepared by the preparation method of the air electrode material in any one of the above, or includes the air electrode material in any one of the above.

[0015] Correspondingly, the present invention further provides a preparation method of the above proton ceramic battery, including: S10, preparing a functional layer and an electrolyte layer on the surface of the fuel electrode layer by the drop coating method in sequence, and obtaining a fuel electrode-electrolyte support after co-sintering; S20, mixing the air electrode material with a binder and screen-printing it on one side surface of the electrolyte layer of the fuel electrode-electrolyte support to obtain a proton ceramic battery; wherein, the air electrode material can achieve self-sintering after being induced by thermoelectric coupling.

[0016] The beneficial effects of the present invention are as follows: Different from the prior art, the present invention provides an air electrode material and a preparation method thereof, a proton ceramic battery and a preparation method thereof, wherein the preparation method of the air electrode material comprises: first, uniformly mixing a water-soluble barium salt, a water-soluble non-barium metal salt and deionized water according to a stoichiometric ratio, adding a complexing agent, and adjusting the pH value to obtain a mixed solution; secondly, heating the mixed solution in an oil bath to obtain a precursor gel; thirdly, heating and drying the precursor gel, and crushing it to obtain a precursor powder; and finally, calcining the precursor powder at a high temperature. The air electrode material is prepared by a sol-gel method. After the proton ceramic battery prepared with the air electrode material is assembled and before formal operation, the air electrode layer and the electrolyte layer are only adjacent to each other but not in close contact, so that the proton ceramic battery can induce the air electrode layer to self-sinter through thermoelectric coupling within the temperature range of assembly operation, forming a clear air electrode layer / electrolyte layer interface, thereby simplifying the preparation steps of the proton ceramic battery and reducing the production cost, while avoiding the coarsening of electrode particles during high-temperature sintering, thereby maintaining the high catalytic activity of the proton ceramic battery. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 A flow chart of a method for preparing an air electrode material according to an embodiment of the present invention; Figure 2 A schematic diagram of the cross-sectional structure of a proton ceramic battery provided in an embodiment of the present invention; Figure 3 A flow chart of a method for preparing a proton ceramic battery according to an embodiment of the present invention; Figure 4 Ba5Co3Fe2O provided in Example 1 of the present invention 14-δ XRD pattern of the material; Figure 5a Ba5Co3Fe2O provided in Example 1 of the present invention 14-δ Electrochemical impedance spectroscopy results of the material under fuel cell mode at 700°C and 0.9V; Figure 5b Ba5Co3Fe2O provided in Example 1 of the present invention 14-δ Electrochemical impedance spectroscopy (EIS) test results of the material in electrolytic cell mode at 700°C and 0.9V. Figure 5c Ba5Co3Fe2O provided in Example 1 of the present invention 14-δ IVP curve of the material in fuel cell mode at 700°C and 0.9V; Figure 5d Ba5Co3Fe2O provided in Example 1 of the present invention 14-δThe IV curve of the material in electrolytic cell mode at 700°C and 0.9V. Figure 6a Ba5Co3Fe2O provided in Example 1 of the present invention 14-δ Microscopic morphology of the battery cross section after the material was thermoelectrically induced self-sintering at 700°C and 0.9V; Figure 6b Ba5Co3Fe2O provided in Example 1 of the present invention 14-δ Microscopic morphology of the air electrode after thermoelectrically induced self-sintering at 700°C and 0.9V. DETAILED DESCRIPTION

[0018] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0019] In response to the above-mentioned defects or improvement needs of the prior art, the present invention provides an air electrode material and a preparation method thereof, a proton ceramic battery and a preparation method thereof, the purpose of which is to simplify the preparation steps of the proton ceramic battery, reduce the production cost, and at the same time maintain high electrochemical performance, so as to solve the technical problems of the proton ceramic battery prepared by the prior art, such as high cost, long production cycle and reduced catalytic activity, caused by the high-temperature sintering of the air electrode material to form an electrode / electrolyte interface.

[0020] See also Figure 1 The present invention first provides a method for preparing an air electrode material (unless otherwise specified, the raw materials used are conventional commercially available products in the art), comprising: S10, uniformly mixing a water-soluble barium salt, a water-soluble non-barium metal salt and deionized water according to a stoichiometric ratio, adding a complexing agent, and adjusting the pH value to obtain a mixed solution.

[0021] Specifically, step S10 further includes: First, a water-soluble barium salt, a water-soluble non-barium metal salt, and deionized water are uniformly mixed according to a stoichiometric ratio; the water-soluble non-barium metal salt includes any one of a water-soluble cobalt salt, a water-soluble iron salt, a water-soluble manganese salt, a water-soluble cerium salt, a water-soluble bismuth salt, a water-soluble nickel salt, a water-soluble erbium salt, and a water-soluble ruthenium salt; Secondly, after mixing evenly, add the complexing agent; the complexing agent reacts with the metal ions (Ba 2+ 、Co 3+ 、Fe 3+etc.) to form a stable complex, inhibiting the hydrolysis and precipitation of metal ions, ensuring the uniformity of the solution, and providing a precursor uniformity basis for the subsequent sol-gel process; Finally, after adding the complexing agent, the pH value is adjusted with ammonia water to obtain a mixed solution with a pH value of 7-9.

[0022] Specifically, pH adjustment treatment can promote the coordination reaction between the complexing agent and the metal ions, avoid excessive release of metal ions under acidic conditions, or generate hydroxide precipitation under strong alkaline conditions, which is conducive to the formation of thermoelectrically induced self-sintering air electrode materials.

[0023] In step S10, the water-soluble barium salt is preferably at least one of barium nitrate, barium carbonate, and barium acetate; the water-soluble cobalt salt is preferably at least one of cobalt nitrate hexahydrate, cobalt carbonate, and cobalt acetate; the water-soluble iron salt is preferably at least one of ferric nitrate nonahydrate, ferric carbonate, and ferric acetate; the water-soluble nickel salt is preferably at least one of nickel nitrate hexahydrate, nickel carbonate, and nickel acetate; and the water-soluble erbium salt is preferably at least one of erbium nitrate hexahydrate, erbium carbonate, and erbium acetate.

[0024] In step S10, the complexing agent is preferably one or more of acetic acid, citric acid monohydrate, and ethylenediaminetetraacetic acid, more preferably citric acid monohydrate and ethylenediaminetetraacetic acid.

[0025] In one embodiment, the water-soluble non-barium metal salt includes a water-soluble cobalt salt, a water-soluble iron salt, a water-soluble nickel salt and a water-soluble erbium salt, and the complexing agent includes citric acid monohydrate and ethylenediaminetetraacetic acid; wherein the ratio of the total molar number of metal ions in the water-soluble barium salt, the water-soluble cobalt salt, the water-soluble iron salt, the water-soluble nickel salt and the water-soluble erbium salt to the molar number of citric acid monohydrate and ethylenediaminetetraacetic acid is 1:(0.8~4):(0.8~4), more preferably 1:(1~2):(1~2).

[0026] S20, heating the mixed solution in an oil bath to obtain a precursor gel.

[0027] Specifically, step S20 further includes: The mixed solution is heated in an oil bath at 75-100°C and stirred for 7-12 hours to obtain a precursor gel. The oil bath medium can be silicone oil. By precisely controlling the temperature, stirring speed and complexing agent concentration, the microstructure and composition uniformity of the precursor gel can be regulated, laying the foundation for subsequent calcination to obtain high-performance air electrode materials.

[0028] S30, heating and drying the precursor gel, and crushing it to obtain precursor powder.

[0029] Specifically, step S30 further includes: The precursor gel (gel-like liquid) is heated and dried at 220 - 260 °C. After drying for 4 - 8 h, it is pulverized to obtain the precursor powder (fluffy black solid). The heat drying treatment can promote the full volatilization of the solvent in the precursor gel and the complete decomposition of the complexing agent, forming a precursor powder with abundant pores, effectively avoiding impurity residues and metal ion hydrolysis; this treatment method can accurately control the powder particle size and dispersibility, optimize its microstructure, reduce the temperature and shorten the time for the subsequent calcination process, significantly improve the reaction activity and uniformity of the material, and ultimately improve the performance and stability of related products such as proton ceramic batteries.

[0030] In step S30, the drying temperature is preferably 230 - 250 °C, the drying time is preferably 6 - 8 h, and the pulverization method is preferably grinding.

[0031] S40. The precursor powder is subjected to high-temperature calcination treatment to obtain the air electrode material.

[0032] Specifically, step S40 further includes: The precursor powder is subjected to high-temperature calcination treatment at 800 - 1000 °C. After calcination for 4 - 7 h, the air electrode material is obtained. Among them, the high-temperature calcination treatment can promote the full reaction of metal ions in the precursor powder, form a highly crystalline and structurally stable target phase, effectively eliminate the carbon impurities and organic substances remaining in the drying process, and form a thermoelectrically induced self-sintered air electrode material.

[0033] Specifically, the chemical general formula of the air electrode material is Ba5Xn5O 14-δ , 0 ≤ δ ≤ 1; Among them, the structural general formula of Xn is (Xn1) 5-x (Xn2) x , 0 < x < 2.5; Xn1 includes Co, and Xn2 includes at least one of Fe, Mn, Ce, Bi, Ni, Er, Ru.

[0034] Correspondingly, the present invention also provides an air electrode material, which is prepared by the sol-gel method from the preparation method of the air electrode material as described in any one of the above, and the chemical general formula of the air electrode material is Ba5Xn5O 14-δ , 0 ≤ δ ≤ 1; Among them, the structural general formula of Xn is (Xn1) 5-x (Xn2) x , 0 < x < 2.5; Xn1 includes Co, and Xn2 includes at least one of Fe, Mn, Ce, Bi, Ni, Er, Ru.

[0035] In some embodiments, Xn2 is Fe.

[0036] In some embodiments, Xn2 is Fe, Ni.

[0037] In some embodiments, Xn2 is Fe, Er.

[0038] Specifically, the air electrode material includes Ba5Co3Fe2O 14-δ 、Ba5Co 2.85 Fe 1.9 Ni 0.25 O 14-δ and Ba5Co 2.85 Fe 1.9 Er 0.25 O 14-δ Any one of .

[0039] In the first embodiment, Ba5Co3Fe2O was prepared by sol-gel method. 14-δ The preparation method of the thermoelectrically induced self-sintering air electrode material is as follows: Step (1) mixing a water-soluble barium salt, a water-soluble cobalt salt, a water-soluble iron salt and deionized water in a stoichiometric ratio, adding a complexing agent, adjusting the pH with ammonia water and heating and stirring in sequence to obtain a precursor gel; wherein the pH value is adjusted to 7-9 with ammonia water, and the temperature of heating and stirring is 75-100°C; Step (2) drying, crushing and calcining the precursor gel obtained in step (1) in sequence to obtain a thermoelectrically induced self-sintered air electrode material; wherein the drying temperature is 240° C. and the drying time is 6 to 8 hours; the calcination temperature is 800 to 1000° C. and the calcination time is 4 to 7 hours.

[0040] In the second embodiment, Ba5Co was prepared by sol-gel method. 2.85 Fe 1.9 Ni 0.25 O 14-δ The preparation method of the thermoelectrically induced self-sintering air electrode material is as follows: Step (1) mixing a water-soluble barium salt, a water-soluble cobalt salt, a water-soluble iron salt, a water-soluble nickel salt and deionized water in a stoichiometric ratio, adding a complexing agent, adjusting the pH with ammonia water and heating and stirring in sequence to obtain a precursor gel; wherein the pH value is adjusted to 7-9 with ammonia water, and the temperature of heating and stirring is 75-100°C; Step (2) drying, crushing and calcining the precursor gel obtained in step (1) in sequence to obtain a thermoelectrically induced self-sintered air electrode material; wherein the drying temperature is 240° C. and the drying time is 6 to 8 hours; the calcination temperature is 800 to 1000° C. and the calcination time is 4 to 7 hours.

[0041] In the third embodiment, Ba5Co was prepared by sol-gel method. 2.85 Fe 1.9 Er0.25 O 14-δ The preparation method of the air electrode material by thermoelectric induced self-sintering is as follows: Step (1): According to the stoichiometric ratio, mix a water-soluble barium salt, a water-soluble cobalt salt, a water-soluble iron salt, a water-soluble erbium salt and deionized water, then add a complexing agent, adjust the pH with ammonia water and heat with stirring in sequence to obtain a precursor gel; wherein, the pH value is adjusted to 7-9 with ammonia water, and the temperature of heating with stirring is 75-100 °C; Step (2): Dry, crush and calcine the precursor gel obtained in step (1) in sequence to obtain the air electrode material by thermoelectric induced self-sintering; wherein, the drying temperature is 240 °C and the drying time is 6-8 h; the calcination temperature is 800-1000 °C and the calcination time is 4-7 h.

[0042] Correspondingly, the present invention further provides a proton ceramic battery, which includes a fuel electrode layer, a functional layer, an electrolyte layer and an air electrode layer stacked from bottom to top; wherein, the air electrode material used in the air electrode layer is prepared by the sol-gel method, and the chemical general formula of the air electrode material is Ba5Xn5O 14-δ , 0≤δ≤1; the structural general formula of Xn is (Xn1) 5-x (Xn2) x , 0<x<2.5; Xn1 includes Co, and Xn2 includes at least one of Fe, Mn, Ce, Bi, Ni, Er, Ru.

[0043] Specifically, the fuel electrode layer is used to directly contact fuels (such as hydrogen, methane), release electrons and protons through catalytic oxidation reactions, and the material of the fuel electrode layer is preferably NiO-BZCYYb material; the functional layer is between the fuel electrode layer and the electrolyte layer, and can optimize proton transport or interfacial compatibility, and the material of the functional layer is preferably NiO-BZCYYb material; the electrolyte layer uses a proton-conducting ceramic (such as BaZrO3-based, BaCeO3-based materials), which only allows protons (H⁺) to pass through, blocks electrons and gases, and its density and proton conductivity directly determine the open-circuit voltage and power density of the battery, and the material of the electrolyte layer is preferably BZCYYb material; the air electrode layer is used to contact air / oxygen, and it receives protons and electrons through catalytic reduction reactions, and needs to have high oxygen reduction reaction (ORR) activity and stability.

[0044] Please refer to Figure 3 , Figure 3 which is the flowchart of the preparation method of the proton ceramic battery provided by the embodiment of the present invention; wherein, the preparation method of the proton ceramic battery includes: S10, sequentially prepare the functional layer and the electrolyte layer on the surface of the fuel electrode layer by the drop coating method, and obtain a fuel electrode-electrolyte support after co-sintering.

[0045] Specifically, step S10 further includes: First, a NiO-BZCYYb precursor was prepared by a tabletting method and then calcined to obtain a fuel electrode layer (anode support). Secondly, a functional layer of NiO-BZCYYb material and an electrolyte layer of BZCYYb material are sequentially prepared on the surface of the fuel electrode layer by a drop coating method, and a fuel electrode-electrolyte support is obtained after co-sintering.

[0046] S20, mixing the air electrode material with the binder and screen printing the mixed material onto the surface of one side of the electrolyte layer of the fuel electrode-electrolyte support to obtain a proton ceramic battery; wherein the air electrode material can be self-sintered after being induced by thermoelectric coupling.

[0047] Specifically, step S20 further includes: The above-mentioned thermoelectrically induced self-sintered air electrode material (Ba5Xn5O 14-δ ) is coated on one side of the electrolyte layer of the fuel electrode-electrolyte support by screen printing to obtain a proton ceramic battery; wherein, the proton ceramic battery is not sintered after preparation, and the air electrode layer and the electrolyte layer are only adjacent but not in close contact. In the subsequent constant voltage polarization process, the air electrode layer is induced to self-sinter by thermoelectric coupling.

[0048] Furthermore, under the conditions of an operating temperature of 700°C and an applied voltage of 0.9V, the proton ceramic battery was directly subjected to constant voltage polarization treatment without sintering. With the help of the local temperature at the interface between the air electrode layer and the electrolyte layer and the high energy of the current, the air electrode material was in situ self-sintered on the surface of the electrolyte layer, forming a clear Ba5Xn5O 14-δ / BZCYYb interface, and then the corresponding charge-discharge electrochemical performance test can be carried out The technical solutions of the present invention will be described in further detail below with reference to specific examples. It should be understood that the following examples are merely illustrative and explain the present invention and should not be construed as limiting the scope of protection of the present invention. All technologies implemented based on the above content of the present invention are encompassed within the scope of protection intended by the present invention. Unless otherwise stated, the raw materials and reagents used in the following examples are all commercially available products or can be prepared by known methods.

[0049] Example 1: This embodiment 1 provides a Ba5Co3Fe2O 14-δ The preparation method of the material includes: Step (1) Weigh barium nitrate, cobalt nitrate hexahydrate, and ferric nitrate nonahydrate in a stoichiometric ratio of Ba:Co:Fe=5:3:2, add them to deionized water and mix them evenly. Add complexing agents citric acid monohydrate and ethylenediaminetetraacetic acid in a ratio of total molar number of metal ions: molar number of citric acid: molar number of EDTA=1:1.5:1 to the solution, then add ammonia water to adjust the pH value of the solution to 7, and finally heat to 90°C and stir magnetically for 10 hours to obtain Ba5Co3Fe2O 14-δ Precursor gel.

[0050] Step (2) The obtained precursor gel was placed in an oven at 240°C and dried for 6 hours. The gel-like liquid gradually turned into a fluffy black solid. The black solid was ground into powder in a mortar to obtain Ba5Co3Fe2O 14-δ Precursor powder.

[0051] Step (3) The obtained black precursor powder sample is placed in a 100 mL corundum crucible and kept at 900-950 ° C for 5 h to remove the residual organic matter and form a thermoelectrically induced self-sintered air electrode for proton ceramic batteries. The solid powder obtained is Ba5Co3Fe2O 14-δ .

[0052] Accordingly, this embodiment 1 provides a proton ceramic battery, which includes a fuel electrode layer, a functional layer, an electrolyte layer and an air electrode layer stacked from bottom to top, wherein the air electrode layer is Ba5Co3Fe2O 14-δ Material.

[0053] Specifically, the preparation method of the proton ceramic battery provided in this embodiment 1 includes: Ba5Co3Fe2O 14-δ The slurry obtained by mixing and stirring the material, the binder and the organic solvent is screen-printed onto the electrolyte layer side of the fuel electrode-electrolyte support to prepare a conductive proton ceramic battery.

[0054] Furthermore, the above-mentioned fuel electrode-electrolyte support was prepared by a co-pressing method, and the specific process was as follows: 0.4 g of dry and uniform fuel electrode powder was placed in a cylindrical mold, a pressure of 6 MPa was applied and maintained for 1 minute to form a fuel electrode embryo, and pre-fired at 1150°C for 2.5 hours to obtain a pre-fired NiO-BZCYYb fuel electrode; then the electrolyte powder was mixed with an organic solvent and ball-milled, and then drop-coated on the pre-fired NiO-BZCYYb fuel electrode to make it evenly dispersed, and co-sintered at 1450°C for 5 hours to form an electrolyte-fuel electrode support.

[0055] Example 2: This embodiment 2 provides a Ba5Co 2.85Fe 1.9 Ni 0.25 O 14-δ The preparation method of the material includes: Step (1) Weigh barium nitrate, cobalt nitrate hexahydrate, iron nitrate nonahydrate, and nickel nitrate hexahydrate in a stoichiometric ratio of Ba:Co:Fe:Ni=5:2.85:1.9:0.25, add them to deionized water and mix them evenly. Add complexing agents citric acid monohydrate and ethylenediaminetetraacetic acid in a ratio of total molar number of metal ions: molar number of citric acid: molar number of EDTA=1:1.5:1 to the solution, and then add ammonia water to adjust the pH value of the solution to 7. Finally, heat to 90°C and stir magnetically for 10 hours to obtain Ba5Co 2.85 Fe 1.9 Ni 0.25 O 14-δ Precursor gel.

[0056] Step (2) The obtained precursor gel was placed in an oven at 240°C and dried for 6 hours. The gel-like liquid gradually turned into a fluffy black solid. The black solid was ground into powder in a mortar to obtain Ba5Co 2.85 Fe 1.9 Ni 0.25 O 14-δ Precursor powder.

[0057] Step (3) The obtained black precursor powder sample is placed in a 100 mL corundum crucible and kept at 900-950 ° C for 5 hours to remove the residual organic matter and form a thermoelectrically induced self-sintered air electrode for proton ceramic batteries. The solid powder obtained is Ba5Co 2.85 Fe 1.9 Ni 0.25 O 14-δ .

[0058] Accordingly, this embodiment 2 provides a proton ceramic battery, which includes a fuel electrode layer, a functional layer, an electrolyte layer and an air electrode layer stacked from bottom to top, and the air electrode layer is Ba5Co 2.85 Fe 1.9 Ni 0.25 O 14-δ Material.

[0059] Specifically, the preparation method of the proton ceramic battery provided in this embodiment 2 includes: Ba5Co 2.85 Fe 1.9 Ni 0.25 O 14-δ The slurry obtained by mixing and stirring the material, the binder and the organic solvent is screen-printed onto the electrolyte layer side of the fuel electrode-electrolyte support to prepare a conductive proton ceramic battery.

[0060] Furthermore, the above-mentioned fuel electrode-electrolyte support was prepared by a co-pressing method, and the specific process was as follows: 0.4 g of dry and uniform fuel electrode powder was placed in a cylindrical mold, a pressure of 6 MPa was applied and maintained for 1 minute to form a fuel electrode embryo, and pre-fired at 1150°C for 2.5 hours to obtain a pre-fired NiO-BZCYYb fuel electrode; then the electrolyte powder was mixed with an organic solvent and ball-milled, and then drop-coated on the pre-fired NiO-BZCYYb fuel electrode to make it evenly dispersed, and co-sintered at 1450°C for 5 hours to form an electrolyte-fuel electrode support.

[0061] Example 3: This embodiment 3 provides a Ba5Co 2.85 Fe 1.9 Er 0.25 O 14-δ The preparation method of the material includes: Step (1) Weigh barium nitrate, cobalt nitrate hexahydrate, iron nitrate nonahydrate and erbium nitrate hexahydrate in a stoichiometric ratio of Ba:Co:Fe:Er = 5:2.85:1.9:0.25, add them to deionized water and mix them evenly. Add complexing agents citric acid monohydrate and ethylenediaminetetraacetic acid in a ratio of total molar number of metal ions: molar number of citric acid: molar number of EDTA = 1:1.5:1 to the solution, and then add ammonia water to adjust the pH value of the solution to 7. Finally, heat to 90 ° C and stir magnetically for 10 hours to obtain Ba5Co 2.85 Fe 1.9 Er 0.25 O 14-δ Precursor gel.

[0062] Step (2) The obtained precursor gel was placed in an oven at 240°C and dried for 6 hours. The gel-like liquid gradually turned into a fluffy black solid. The black solid was ground into powder in a mortar to obtain Ba5Co 2.85 Fe 1.9 Er 0.25 O 14-δ Precursor powder.

[0063] Step (3) The obtained black precursor powder sample is placed in a 100 mL corundum crucible and kept at 900-950 ° C for 5 h to remove the residual organic matter and form a thermoelectrically induced self-sintered air electrode for proton ceramic batteries. The solid powder obtained is Ba5Co 2.85 Fe 1.9 Er 0.25 O 14-δ .

[0064] Accordingly, this embodiment 3 provides a proton ceramic battery, which includes a fuel electrode layer, a functional layer, an electrolyte layer and an air electrode layer stacked from bottom to top, and the air electrode layer is Ba5Co 2.85 Fe 1.9 Er 0.25 O 14-δ Material.

[0065] Specifically, the preparation method of the proton ceramic battery provided in this embodiment 3 includes: Ba5Co 2.85 Fe 1.9 Er 0.25 O 14-δ The slurry obtained by mixing and stirring the material, the binder and the organic solvent is screen-printed onto the electrolyte layer side of the fuel electrode-electrolyte support to prepare a conductive proton ceramic battery.

[0066] Furthermore, the above-mentioned fuel electrode-electrolyte support was prepared by a co-pressing method, and the specific process was as follows: 0.4 g of dry and uniform fuel electrode powder was placed in a cylindrical mold, a pressure of 6 MPa was applied and maintained for 1 minute to form a fuel electrode embryo, and pre-fired at 1150°C for 2.5 hours to obtain a pre-fired NiO-BZCYYb fuel electrode; then the electrolyte powder was mixed with an organic solvent and ball-milled, and then drop-coated on the pre-fired NiO-BZCYYb fuel electrode to make it evenly dispersed, and co-sintered at 1450°C for 5 hours to form an electrolyte-fuel electrode support.

[0067] Now take Example 1 as an example to analyze Ba5Co3Fe2O 14-δ The materials were characterized and the Ba5Co3Fe2O 14-δ The electrochemical performance of the proton ceramic battery prepared with the material was tested.

[0068] See also Figure 4 , Figure 4 Ba5Co3Fe2O provided in Example 1 of the present invention 14-δ XRD (X-ray diffraction) diagram of the material; wherein, the thermoelectrically induced self-sintering air electrode material (Ba5Co3Fe2O 14-δ The XRD analysis of the material was carried out. Figure 4 It can be seen that Ba5Co3Fe2O 14-δ The material does not contain any impurities.

[0069] The corresponding thermoelectrically induced self-sintered air electrode material Ba5Co3Fe2O prepared in Example 1 was 14-δThe proton ceramic battery prepared as raw materials was loaded into the test furnace, air was introduced into the air electrode side, hydrogen was introduced into the fuel electrode side, the furnace temperature was raised to 700℃, and the electrochemical workstation was connected to perform constant voltage polarization at a voltage of 0.9V. The electrochemical performance of the battery was recorded after different polarization times. In the fuel cell mode, the electrochemical impedance spectroscopy test was performed with an applied perturbation of 20mV and a test frequency range of 10 5 ~0.1Hz; perform volt-ampere characteristic curve test with a sweep rate of 5mV·s -1 , the scanning range is 1.1~0.2V. In the electrolytic cell mode, humid air (wherein the water content is 3%) is introduced into the air electrode side, and the electrochemical impedance spectroscopy test is performed. The applied perturbation is 20mV, the applied bias voltage is 1.1V, and the test frequency range is 10 5 ~0.1Hz; perform volt-ampere characteristic curve test with a sweep rate of 5mV·s -1 , the scanning range is 1.4~0.8V.

[0070] According to the above method, the electrochemical performance of the proton ceramic battery measured in Example 1 after polarization for different times at an operating temperature of 700°C and a polarization voltage of 0.9V was compared to obtain a comparison chart of the electrochemical performance test of the proton ceramic battery prepared using the corresponding thermoelectrically induced self-sintered air electrode material prepared in Example 1 as a raw material. Figures 5a to 5d shown.

[0071] Specifically, Figure 5a Ba5Co3Fe2O provided in Example 1 of the present invention 14-δ Electrochemical impedance spectroscopy results of the material in fuel cell mode at 700°C and 0.9V (Z' is the real part of the impedance, and Z'' is the imaginary part of the impedance); Figure 5b Ba5Co3Fe2O provided in Example 1 of the present invention 14-δ Electrochemical impedance spectroscopy (EIS) results of the material in electrolytic cell mode at 700°C and 0.9V (Z' is the real part of the impedance, and Z'' is the imaginary part of the impedance). Figure 5c Ba5Co3Fe2O provided in Example 1 of the present invention 14-δ IVP curve of the material in fuel cell mode at 700°C and 0.9V; Figure 5d Ba5Co3Fe2O provided in Example 1 of the present invention 14-δ The IV curve of the material in electrolytic cell mode at 700°C and 0.9V.

[0072] Among them, Figures 5a to 5dIt can be seen that with the increase of polarization time, the peak power density of the proton ceramic battery prepared in Example 1 steadily increases, the ohmic impedance and polarization impedance gradually decrease, and the electrolysis current density corresponding to 1.3V in the electrolytic cell mode also gradually increases. The above test results show that: during the constant voltage polarization process of the battery, a violent electrochemical reaction occurs at the interface of the air electrode layer / electrolyte layer. Under the action of local high temperature and current, the air electrode layer grows in situ on the surface of the electrolyte layer through thermoelectric induction without the need for prior high-temperature sintering (1000°C and above). While ensuring the interfacial bonding strength of the air electrode layer / electrolyte layer, it also simplifies the preparation process of the proton ceramic battery and reduces the preparation cost.

[0073] See also Figure 6a and Figure 6b , Figure 6a Ba5Co3Fe2O provided in Example 1 of the present invention 14-δ Microscopic morphology of the battery cross section after the material was thermoelectrically induced self-sintering at 700°C and 0.9V; Figure 6b Ba5Co3Fe2O provided in Example 1 of the present invention 14-δ The microscopic morphology of the air electrode after the material was thermoelectrically induced self-sintering at 700°C and 0.9V. Figure 6a and Figure 6b It can be seen that after constant voltage polarization, the air electrode layer and the electrolyte layer of the proton ceramic battery are tightly combined, with a clear air electrode layer / electrolyte layer interface, indicating that direct thermoelectrically induced self-sintering without high-temperature sintering can also significantly improve the bonding force between the air electrode layer and the electrolyte layer, thereby optimizing the catalytic conversion efficiency of the battery.

[0074] The present invention discloses a thermoelectrically induced self-sintered air electrode material for proton ceramic batteries and its preparation method and application, which relates to the field of proton conductive ceramic batteries (PCC). The air electrode material is A5B5O 14 type material, whose general structural formula is Ba5Xn5O 14-δ , 0≤δ≤1, Xn is (Xn1) 5-x (Xn2) x, Xn1 is Co, Xn2 is at least one of Fe, Mn, Ce Ce, Bi, Ni, Er, Ru, and 0 < x < 2.5. In the present invention, the air electrode material is coated on the fuel electrode - electrolyte substrate by screen printing. Before the proton ceramic battery is assembled and officially operates, the air electrode layer and the electrolyte layer have not been sintered, and there is no close contact between them. Within the temperature range of the operation of the proton ceramic battery assembly, the air electrode layer and the electrolyte layer surface are further combined by thermoelectric coupling to form a clear air electrode layer / electrolyte layer interface. The constant voltage polarization-induced self-sintering air electrode proposed in the present invention can simplify the process flow, save the cost of battery preparation, avoid the phenomenon of electrode particle coarsening during the high-temperature sintering process, and at the same time maintain high electrochemical performance.

[0075] Compared with the prior art, the beneficial effects of the present invention are as follows: The present invention provides an air electrode material and its preparation method, a proton ceramic battery and its preparation method. The thermoelectrically induced self-sintering air electrode material can be used to prepare proton ceramic batteries (PCCs). It does not go through the high-temperature sintering process of the electrode, reduces the steps of battery preparation, lowers the preparation cost, and at the same time avoids the coarsening of electrode particles after high-temperature sintering, maintaining the high catalytic activity of the battery.

[0076] It should be noted that the above embodiments all belong to the same inventive concept. The descriptions of each embodiment have their own focuses. For the parts not described in detail in individual embodiments, reference can be made to the descriptions in other embodiments.

[0077] [[ID=

Claims

1. A method for preparing an air electrode material, characterized in that: include: S10, uniformly mixing a water-soluble barium salt, a water-soluble non-barium metal salt, and deionized water according to a stoichiometric ratio, adding a complexing agent, and adjusting the pH to obtain a mixed solution; S20, heating the mixed solution in an oil bath to obtain a precursor gel; S30, heating and drying the precursor gel to obtain precursor powder after crushing; S40, performing a high-temperature calcination treatment on the precursor powder to obtain an air electrode material.

2. The method for preparing an air electrode material according to claim 1, wherein: In the step S10, the water-soluble non-barium metal salt includes any one of a water-soluble cobalt salt, a water-soluble iron salt, a water-soluble manganese salt, a water-soluble cerium salt, a water-soluble bismuth salt, a water-soluble nickel salt, a water-soluble erbium salt and a water-soluble ruthenium salt.

3. The method for preparing an air electrode material according to claim 1, wherein: In the step S10, ammonia water is used to adjust the pH value, and the pH value of the mixed solution is 7-9.

4. The method for preparing an air electrode material according to claim 1, wherein: In the step S20, the heating temperature of the oil bath heating treatment is 75-100°C.

5. The method for preparing an air electrode material according to claim 1, wherein: In the step S30, the temperature of the heating and drying treatment is 220-260°C, and the drying time is 4-8 hours; in the step S40, the temperature of the high-temperature calcination treatment is 800-1000°C, and the calcination time is 4-7 hours.

6. The method for preparing an air electrode material according to claim 1, wherein: In the step S40, the chemical formula of the air electrode material is Ba5Xn5O 14-δ , 0≤δ≤1; Among them, the structural general formula of Xn is (Xn1) 5-x (Xn2) x , where 0 < x < 2.5; Xn1 includes Co, and Xn2 includes at least one of Fe, Mn, Ce, Bi, Ni, Er, and Ru.

7. An air electrode material, characterized in that The air electrode material is prepared by the sol-gel method according to any one of claims 1 to 6, wherein the chemical formula of the air electrode material is Ba5Xn5O 14-δ , 0≤δ≤1; Among them, the structural general formula of Xn is (Xn1) 5-x (Xn2) x , where 0 < x < 2.5; Xn1 includes Co, and Xn2 includes at least one of Fe, Mn, Ce, Bi, Ni, Er, Ru.

8. The air electrode material according to claim 7, characterized in that The air electrode material includes Ba5Co3Fe2O 14-δ 、Ba5Co 2.85 Fe 1.9 Ni 0.25 O 14-δ and Ba5Co 2.85 Fe 1.9 Er 0.25 O 14-δ Any one of .

9. A proton ceramic battery, characterized in that: The proton ceramic battery comprises a fuel electrode layer, a functional layer, an electrolyte layer and an air electrode layer stacked from bottom to top; The air electrode layer comprises an air electrode material prepared by the method for preparing an air electrode material according to any one of claims 1 to 6, or comprises the air electrode material according to any one of claims 7 to 8.

10. A method for preparing a proton ceramic battery according to claim 9, characterized in that: include: S10, sequentially preparing the functional layer and the electrolyte layer on the surface of the fuel electrode layer by a drop coating method, and obtaining a fuel electrode-electrolyte support after co-sintering; S20, mixing the air electrode material with a binder and screen printing the mixture onto the surface of one side of the electrolyte layer of the fuel electrode-electrolyte support to obtain the proton ceramic battery; wherein the air electrode material can be self-sintered after being induced by thermoelectric coupling.

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