Proton conductor and preparation method and application thereof

Abstract

The invention belongs to an advanced material technology, and relates to a proton conductor and a preparation method thereof. The invention discloses a novel medium and low temperature perovskite type proton conductor, which is a barium-based perovskite type proton conductor, and is specifically BaN < 1-x > M < x > O < 3-delta >, N is a pentavalent metal including one or more of Nb < 5 + > and Ta < 5 + >; m is one or more of trivalent metals including Al < 3 + >, Ga < 3 + >, In < 3 + >, Sc < 3 + >, Y < 3 + >, Sm < 3 + >, Eu < 3 + >, Gd < 3 + >, Dy < 3 + >, Ho < 3 + >, Er < 3 + >, Tm < 3 + >, Yb < 3 + > and Lu < 3 + >; 0.5 lt; xlt; 1, the electrolyte material has low proton conduction activation energy in a medium-low temperature region. According to the invention, the high-concentration trivalent metal element with the concentration of 50-100% is utilized to form seepage conduction in the electrolyte and reduce the proton capture effect caused by the low-valence metal element, and the pentavalent element is utilized to reduce excessive generation of oxygen vacancies and maintain the structural stability, so that the material with good ionic conductivity in the medium-low temperature region is finally obtained.

Description

Technical Field

[0001] The invention belongs to advanced material technology and relates to a proton conductor and a preparation method thereof. Background Art

[0002] Solid oxide fuel cells (SOFCs), as an energy conversion device, have the advantages of high energy conversion efficiency, wide range of fuel selection and environmental friendliness. Proton conductive ceramic fuel cells (PCFCs), as a type of SOFC, use protons as carriers and have lower carrier conduction activation energy. In the current field of proton conductors, there is a lack of suitable materials with both high ionic conductivity and high chemical stability in the temperature range of 200 to 500 °C. This area is named the "Norby gap" by scholars in this field [see: Solid-state protonic conductors: principles, properties, progress and prospects]. Taking the traditional perovskite proton conductor BaZr as an example, the conventional perovskite proton conductor BaZr is a kind of proton conductor with high ionic conductivity and high chemical stability. 1- x Y x O 3-δ Taking BZY as an example, low-valent metal elements (Y 3+ ) to form oxygen vacancies, and then introduce carrier protons through hydration reaction to produce proton conductivity. However, it is difficult to increase the concentration of doping elements in the above materials by conventional methods. For Y-doped BaZrO3, the solid phase reaction method can only introduce a Y doping concentration of 0.3 (BaZr 0.7 Y 0.3 O 3-δ ), and when the Y doping concentration exceeds 0.2, the ionic conductivity of the material will be significantly reduced. Even if the oxygen vacancy concentration and proton concentration are increased by increasing the Y concentration, the effective proton concentration actually involved in the transmission is not significantly increased due to the capture effect of the capture center on the proton. A considerable part of the protons are captured by the capture center and cannot move freely, which significantly reduces the proton conductivity [see: Carrier-Carrier Interaction in Proton Conducting Perovskites: Carrier Blocking vs Trap-Site Filling]. Therefore, it is necessary to develop new electrolytes to weaken the proton capture effect and reduce the activation energy of proton conduction to meet the performance requirements of medium and low temperature fuel cells at 200-500°C. Summary of the invention

[0003] It is difficult to increase the concentration of doping elements through conventional methods in the prior art. Even if the oxygen vacancy concentration and proton concentration are increased by increasing the element doping concentration, the effective proton concentration actually involved in the transmission is not significantly increased due to the capture effect of the capture center on protons. The present invention adopts a new technical idea to overcome the technical bias of the prior art to improve the performance of proton conductors by doping, and discloses a barium-based perovskite (ABO3) proton conductor containing pentavalent and trivalent elements. The capture area is greatly increased and connected to each other to form a pathway. The protons in the entire pathway will move with a lower migration energy, and finally achieve high proton conductivity. The present invention develops a new electrolyte, which uses the percolation conduction mechanism to weaken the proton capture effect and reduce the proton conduction activation energy to meet the performance requirements of medium and low temperature fuel cells at 200 to 700°C.

[0004] The present invention adopts the following technical scheme.

[0005] A proton conductor is a perovskite-type proton conductor ABO3, characterized in that the B-site element includes a pentavalent element N and a trivalent element M; and the A-site element includes barium.

[0006] In the present invention, the B-site metal includes pentavalent element N and trivalent element M; the total ratio is 100%, calculated by molar ratio.

[0007] Preferably, the proportion of trivalent elements is 50-100%, preferably not including 100%; further preferably, the proportion of trivalent elements is 50-95%; still more preferably, the proportion of trivalent elements is 55-90%; more preferably, the proportion of trivalent elements is 60-85%; still more preferably, the proportion of trivalent elements is 60-80%, such as 60%, 65%, 70%, 75%, 80% or any proportion within the range.

[0008] Preferably, N includes one or more of Nb and Ta, and M includes one or more of Al, Ga, In, Sc, Y, Sm, Eu, Gd, Dy, Ho, Er, Tm, Yb, and Lu.

[0009] The present invention discloses a new medium-low temperature perovskite proton conductor, specifically a barium-based perovskite proton conductor. As an example, the proton conductor is BaN 1-x M x O 3-δ (N includes Nb 5+ , 5+ One or more of; M includes Al 3+ , Ga 3+ , In 3+ ,Sc 3+ , Y 3+ , Sm 3+ , Eu 3+ , Gd3+ , Dy 3+ , Ho 3+ , Er 3+ , Tm 3+ , Yb 3+ , Lu 3+ One or more of; x = 0.5, 0.55, 0.6, 0.65, 0.7, 0.75, 0.8, 0.85, 0.9, 0.95 or any value within 0.5 to 0.95, δ is 0 to 0.45), is an electrolyte material with low proton conduction activation energy in the medium and low temperature region. The present invention utilizes a high concentration of trivalent metal elements, the concentration of which is greater than 50%, to form percolation conduction in the electrolyte, reduce the proton capture effect caused by the valence metal elements, and use pentavalent elements to reduce the excessive generation of oxygen vacancies, maintain structural stability, and finally obtain a material with good ionic conductivity in the medium and low temperature region.

[0010] The invention discloses a method for preparing the proton conductor, which comprises the following steps: using an A-site element precursor and a B-site element precursor as raw materials and utilizing a solid phase reaction method to prepare the proton conductor.

[0011] Preferably, the proton conductor is obtained by the solid phase reaction method through the coexistence of pentavalent metal elements and trivalent metal elements; further, the solid phase reaction method is ball milling followed by calcination.

[0012] In the present invention, the proton conductor is prepared by using A-site element precursor and B-site element precursor as raw materials, ball milling and calcination, wherein the precursor includes metal oxide, metal carbonate, etc., and the metal is barium, pentavalent metal and trivalent metal.

[0013] Preferably, the ball milling time is 1 to 100 hours; more preferably, the ball milling time is 10 to 80 hours.

[0014] Preferably, the calcination temperature is 600° C. to 2000° C., and the time is 5 to 50 hours; more preferably, the calcination temperature is 800° C. to 1800° C., and the time is 10 to 30 hours.

[0015] Preferably, the above-mentioned proton conductor is prepared by using the A-site element precursor and the B-site element precursor as raw materials, ball milling for 5 to 50 hours, calcining at 800 to 1000° C. for 8 to 12 hours, then calcining at 1000 to 1400° C. for 8 to 12 hours, and then calcining at 1400 to 1700° C. for 10 to 30 hours. As common sense, a sacrificial agent can be added during the last step of calcination to maintain the product element ratio and prevent volatilization.

[0016] In the present invention, during calcination, the sample is amorphous or has a shape; wherein the amorphous is obtained by ball milling, and the shape is obtained by tableting, which is a conventional technique, and the powder can be made into tablets. Preferably, the A-site element precursor and the B-site element precursor are used as raw materials, ball milled for 5 to 50 hours, calcined at 800 to 1000°C for 8 to 12 hours, and then tableted at 1000 to 1400°C for 8 to 12 hours, and then tableted at 1400 to 1700°C for 10 to 30 hours to prepare the above-mentioned proton conductor. More preferably, the A-site element precursor and the B-site element precursor are used as raw materials, ball-milled for 5 to 50 hours and then calcined at 800 to 1000° C. for 8 to 12 hours, then ball-milled and pressed into tablets and calcined at 1000 to 1400° C. for 8 to 12 hours, and then ball-milled and pressed into tablets and calcined at 1400 to 1700° C. for 10 to 30 hours. A sacrificial agent can be added in this step to prepare the above-mentioned proton conductor.

[0017] The present invention provides a preparation method and application of a novel proton conductor electrolyte, which is a barium-based perovskite-type proton conductor, and is a cubic perovskite-phase proton conductor. The present invention uses pentavalent N (including Nb 5+ , 5+ One or more of them) and trivalent M (including Al 3+ , Ga 3+ , In 3+ , Sc 3+ , Y 3+ , Sm 3+ , Eu 3+ ,Gd 3+ , Dy 3+ , Ho 3+ , Er 3+ , Tm 3+ , Yb 3+ , Lu 3+ One or more of the above); wherein the trivalent element is in high concentration, forms percolation conduction inside the material, improves the proton conductivity of the electrolyte in the medium and low temperature zone, reduces the activation energy of proton conduction, and can meet the needs of working in the medium and low temperature zone; using pentavalent elements with higher valence is conducive to reducing the excessive generation of oxygen vacancies and maintaining structural stability. The medium and low temperature zone is common knowledge in the art, and the present invention refers to 200-700°C, such as 300°C, 400°C, 500°C, 600°C or any temperature within the range.

[0018] The invention discloses an electrolyte material prepared from the above-mentioned proton conductor.

[0019] The invention discloses a fuel cell, comprising the above electrolyte material.

[0020] The invention discloses an electrolytic hydrogen production system, comprising the above electrolyte material.

[0021] The present invention discloses the application of the above proton conductor in the preparation of electrolyte materials, electrolytic hydrogen production materials or fuel cell materials.

[0022] The present invention discloses the application of the above electrolyte material in the preparation of fuel cells or in electrolytic hydrogen production.

[0023] The present invention discloses a new medium and low temperature perovskite type proton conductor, specifically a barium-based perovskite type proton conductor. As an example: the proton conductor is BaN 1-x M x O 3-δ (N includes one or more of Nb 5+ , Ta 5+ ; M includes one or more of Al 3+ , Ga 3+ , In 3+ , Sc 3+ , Y 3+ , Sm 3+ , Eu 3+ , Gd 3+ , Dy 3+ , Ho 3+ , Er 3+ , Tm 3+ , Yb 3+ , Lu 3+ ; 0.5 < x < 1), which is an electrolyte material with a low proton conduction activation energy in the medium and low temperature region. In the present invention, the concentration of trivalent elements is high (for example, occupying more than half), the capture regions are significantly increased and connected to each other, thereby forming a path. Protons in the entire path will move with a lower migration energy, and finally high proton conductivity is achieved. The present invention develops a new electrolyte, utilizes the percolation conduction mechanism to weaken the proton capture effect and reduce the proton conduction activation energy to meet the performance requirements of medium and low temperature fuel cells at 200-700 °C. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 For the powder XRD patterns of (a) BaNb 0.4 In 0.6 O 3-δ and (b) BaNb 0.3 In 0.7 O 3-δ sintered at 1600 °C by the solid-phase reaction method.

[0025] Figure 2 For BaNb 0.4 In 0.6 O 3-δ and BaNb0.3 In 0.7 O 3-δ The proton concentration per unit cell.

[0026] Figure 3 Under humidified hydrogen conditions, BaNb 0.4 In 0.6 O 3-δ (BNI46) and BaNb 0.3 In 0.7 O 3-δ (BNI37) Arrhenius plot of total conductivity. DETAILED DESCRIPTION

[0027] It is difficult to increase the concentration of doping elements by conventional methods in the prior art. Even if the oxygen vacancy concentration and proton concentration are increased by increasing the doping concentration of the element, the effective proton concentration actually involved in the transmission is not significantly increased due to the capture effect of the capture center on the protons; and doping requires the existence of a stable parent phase. The present invention discloses a new medium- and low-temperature perovskite proton conductor, specifically a barium-based perovskite proton conductor. As an example: the proton conductor is BaN 1-x M x O 3-δ (N includes Nb 5+ , 5+ One or more of; M includes Al 3+ , Ga 3+ , In 3+ , Sc 3+ , Y 3+ , Sm 3+ , Eu 3+ , Gd 3+ , Dy 3 + , Ho 3+ , Er 3+ , Tm 3+ , Yb 3+ , Lu 3+ One or more of; 0.5 < x <1), is an electrolyte material with low proton conduction activation energy in the medium and low temperature region. In the present invention, the concentration of trivalent elements is high (for example, occupying more than half), the capture area is greatly increased and connected to each other, thereby forming a pathway, and the protons in the entire pathway will move with a lower migration energy, ultimately achieving high proton conductivity. The present invention develops a new electrolyte that utilizes the percolation conduction mechanism to weaken the proton capture effect and reduce the proton conduction activation energy to meet the performance requirements of medium and low temperature fuel cells at 200 to 700°C.

[0028] The present invention uses metal oxide compounds as raw materials, ball milling and then calcining to prepare the above-mentioned proton conductor. The metal oxides include metal oxides, metal carbonates, etc., and the metals are barium, pentavalent metals and trivalent metals.

[0029] The preparation method of the proton conductor disclosed in the present invention comprises the following steps: (1) Weighing the raw metal oxygen compound according to the stoichiometric ratio; (2) Wet-milling the raw materials at a speed of 100 to 500 rpm for 20 to 30 h; then, calcining them in air at 800 to 1000 °C for 8 to 12 h, with a heating and cooling rate of 4 to 6 °C / min; (3) The product calcined in step (2) is wet-milled at a speed of 100 to 500 rpm for 5 to 15 hours, and then tableted, and calcined in air at 1000 to 1400°C for 8 to 12 hours, with a heating and cooling rate of 4 to 6°C / min; and then ball-milled at a speed of 100 to 500 rpm for 35 to 65 hours, and then tableted, and calcined in air at 1500 to 1700°C for 10 to 30 hours, with a heating and cooling rate of 3 to 5°C / min, to obtain a proton conductor, or crushed to obtain a proton conductor.

[0030] Specifically, the preparation method of the proton conductor disclosed in the present invention comprises the following steps: (1) Weigh the raw materials according to the stoichiometric ratio: BaCO3, N2O5 (N = Nb or Ta) and M2O3 (M = Al, Ga, In, Sc, Y, Sm, Eu, Gd, Dy, Ho, Er, Tm, Yb or Lu); (2) Put the weighed raw materials into a bottle, add solvent (such as alcohol) and ball milling balls, such as (zirconia balls); (3) Ball milling at 100-500 rpm for 20-30 h; (4) Recover the solvent by rotary evaporation, transfer the obtained powder to a crucible, and then place it in a box furnace, raise the temperature to 800-1000°C in air, and maintain it for 8-12 hours, with the heating and cooling rate being 4-6°C / min; (5) Place the sample in a bottle, add a solvent (such as alcohol) and a ball for ball milling, such as a zirconia ball; and ball mill at a speed of 100 to 500 rpm for 5 to 15 hours. (6) recovering the solvent by rotary evaporation and pressing the obtained powder into tablets; (7) Transfer the flake sample to a crucible, then place it in a box furnace, heat it to 1000-1400°C in air, and maintain it for 8-12 h. The heating and cooling rates are 4-6°C / min. (8) The sintered sample is crushed in a mortar and then ball-milled at a speed of 100 to 500 rpm for 50 h, and the solvent is recovered by rotary evaporation to obtain a powder product; then the product is pressed into tablets and sintered in a box furnace (air) at 1500 to 1700 °C for 10 to 30 hours to obtain a dense sample, with a heating and cooling rate of 3 to 5 °C / min; a proton conductor is obtained. As a common sense, a sacrificial agent can be added in this step, which is a mixture of the sample crushed in a mortar and a barium salt.

[0031] As a common sense, for performance testing, the above step (8) is adjusted as follows: (9) crushing the sintered sample (step (7)) in a mortar, ball milling at a speed of 100 to 500 rpm for 50 h, and recovering the solvent by rotary evaporation to obtain a powder product; mixing the sample powder and the binder in a weight ratio of powder to binder = (6 to 8) : 1, and then sieving and tableting; (10) Mixing the sample powder and BaCO3 in a weight ratio of powder:BaCO3 = 100:(1-10) to prepare a sacrificial powder (sacrificial agent); (11) The sheet sample obtained in step (9) above is placed on an alumina plate, embedded with an alumina tube and sacrificial powder, and then sintered in a box furnace (in air) at 1500-1700°C for 10-30 hours to obtain a dense sample for testing. The heating and cooling rates are 3-5°C / min.

[0032] The technical scheme and technical effects of the present invention are explained below through specific experiments. The raw materials used in the present invention are all existing products, and the specific preparation operations and performance tests are conventional techniques.

[0033] Test Method: X-ray diffraction (XRD) was used to analyze the phase structure or structural evolution of the synthesized material, and the 2θ range of the material of the present invention was 20 ~ 80 °. The morphology of the electrolyte cross section was observed by scanning electron microscopy (SEM). The electrolyte water content was calibrated using a MKC-710S titrator from Kyoto Electronics Industry Co., Ltd., Japan. Silver electrodes were coated on the surface of the sheet sample. The conductivity was measured by AC impedance spectroscopy using a frequency response analyzer (Solartron SI 1260) in the frequency range of 10 Hz - 7 MHz by applying an AC voltage of 1 V rms. The sample was first kept in a humidified atmosphere (20% H2 + 80% Ar, water partial pressure of 0.05 atm) at 700 ° C for 10 hours to achieve hydration equilibrium, and impedance spectra were collected from 200 to 700 ° C under humidified atmosphere conditions, with intervals of 50 ° C, and the equilibrium time for each interval was at least 1.5 hours. The collected AC impedance spectra were analyzed by ZView software. The humidified atmosphere is a gas bubbled in deionized water at 33° C. to obtain a water partial pressure of 0.05 atm. Unless otherwise specified, the test atmosphere of the present invention refers to a mixture of 20% H2+80% Ar. Example

[0034] The preparation method of the novel proton conductor for proton ceramic fuel cell electrolyte disclosed in the present invention is completed in the following steps in sequence: (1) Weigh the raw materials according to the stoichiometric ratio: BaCO3, N2O5 (N = Nb or Ta) and M2O3 (M = Al, Ga, In, Sc, Y, Sm, Eu, Gd, Dy, Ho, Er, Tm, Yb or Lu); (2) Put the weighed raw materials into a PET bottle, add alcohol and zirconium oxide balls for ball milling; (3) Ball milling at 100-500 rpm for 20-30 h; (4) Recover the alcohol by rotary evaporation, transfer the obtained powder to a crucible, and then place it in a box furnace (in air), raise the temperature to 800-1000 °C, and maintain it for 8-12 h, with the heating and cooling rate being 4-6 °C / min; (5) Ball milling at 100-500 rpm for 5-15 h; (6) Recovering the alcohol by rotary evaporation, and pressing the obtained powder into tablets with a die size of 1 inch and a pressure of 20 to 100 MPa; (7) Transfer the flake sample to a crucible, then place it in a box furnace (in air), heat it to 1000-1400°C, and keep it for 8-12 h; the heating and cooling rates are both 4-6°C / min; (8) The sintered sample was crushed in a mortar and pestle, ball-milled at 100-500 rpm for 50 h, and the solvent was recovered by rotary evaporation to obtain a powder product; The sample powder and BaCO3 were mixed in a weight ratio of powder:BaCO3 = 100:(1-10) to prepare a sacrificial powder; The sample is then pressed into a sheet and sintered in a box furnace (in air) at 1500-1700°C for 10-30 hours to obtain a dense sample. The heating and cooling rates are 3-5°C / min and sacrificial powder is used for protection to obtain a proton conductor.

[0035] Further: (9) crushing the sample sintered in step (7) in a mortar and pestle, ball-milling at a speed of 100 to 500 rpm for 50 h, and recovering the alcohol by rotary evaporation to obtain a powder product; mixing the sample powder and the binder in a weight ratio of powder to binder = (6 to 8) : 1, then sieving, and pressing into tablets using a 1 / 2 inch die at a pressure of 400 to 800 MPa; heat-treating the obtained sheet sample to remove the binder; (10) Mixing the sample powder and BaCO3 in a weight ratio of powder:BaCO3 = 100:(1-10) to prepare a sacrificial powder; (11) The obtained sheet sample is placed on an alumina plate, embedded with an alumina tube and sacrificial powder. The specific embedding method is conventional technology, and then sintered in a box furnace (air) at 1500-1700 °C for 10-30 hours to obtain a dense sample for testing. It can also be conventionally crushed to obtain a proton conductor; the heating and cooling rates are all 3-5 °C / min.

[0036] Binder: 50 g deionized water + 2 g PVA + 0.25 ml glycerol + 2.5 ml glycerol, mix and stir at 50 °C for 30 minutes.

[0037] Take N = Nb, M = In, x = 0.6 or 0.7 as an example.

[0038] Synthesis example 1: BaNb 0.3 In 0.7 O 2.8 (BNI37) (1) Weigh the raw materials: BaCO3, Nb2O5 and In2O3 according to the stoichiometric ratio; the raw material amounts required to prepare 10 g of sample are BaCO3: 6.7994 g, Nb2O5: 1.3745 g, In2O3: 3.3468 g, in molar ratio, In concentration is 70%, Nb concentration is 30%; (2) Put the weighed raw materials into a PET bottle, add alcohol and zirconium oxide balls for ball milling; (3) Ball milling at 300 rpm for 24 h; (4) Recover the alcohol by rotary evaporation, transfer the obtained powder to a crucible, and then put it into a box furnace, heat it to 1000°C, and keep it at 1000°C for 10 hours, with a heating and cooling rate of 5°C / min; (5) Ball milling at 300 rpm for another 10 h; (6) Recovering the alcohol by rotary evaporation, and pressing the obtained powder into tablets with a die size of 1 inch and a pressure of 50 MPa; (7) Transfer the flake sample to a crucible, then place it in a box furnace, heat it to 1300°C, keep it at 1300°C for 10 h, and then cool it down. The heating and cooling rates are both 5°C / min. (8) The sintered sample was crushed in a mortar, ball-milled at 300 rpm for 50 h, and the alcohol was recovered by rotary evaporation. (9) The sample powder was sieved (110 mesh) and pressed into tablets using a 1 / 2 inch die at a pressure of 570 MPa; (10) mixing the powder (step (8)) with BaCO3 in a weight ratio of powder to BaCO3 = 100:1 to prepare a sacrificial powder; (11) The obtained flake samples were placed on an alumina plate, embedded with an alumina tube and sacrificial powder, and then sintered in a box furnace (in air) at 1600 °C for 24 h to obtain a dense sample for testing. The heating and cooling rates were 4.17 °C / min (0 to 1000 °C) and 3.33 °C / min (1000 to 1600 °C), and the product BNI37 was obtained.

[0039] Synthesis Example 2: BaNb 0.4 In 0.6 O 2.9 (BNI46) (1) Weigh the raw materials: BaCO3, Nb2O5 and In2O3 according to the stoichiometric ratio; the raw material amounts required to prepare 10 g of sample are BaCO3: 6.8133 g, Nb2O5: 1.8346 g, In2O3: 2.8746 g, in molar ratio, In concentration is 60%, Nb concentration is 40%; Steps (2) to (11) are carried out with reference to Synthesis Example 1.

[0040] Example 1: BaNb 0.3 In 0.7 O 2.8 (BNI37) (1) Weigh the raw materials: BaCO3, Nb2O5 and In2O3 according to the stoichiometric ratio; the raw material amounts required to prepare 10 g of sample are BaCO3: 6.7994 g, Nb2O5: 1.3745 g, In2O3: 3.3468 g, in molar ratio, In concentration is 70%, Nb concentration is 30%; (2) Put the weighed raw materials into a PET bottle, add alcohol and zirconium oxide balls for ball milling; (3) Ball milling at 300 rpm for 24 h; (4) Recover the alcohol by rotary evaporation, transfer the obtained powder to a crucible, and then put it into a box furnace, heat it to 1000°C, and keep it at 1000°C for 10 hours, with a heating and cooling rate of 5°C / min; (5) Ball milling at 300 rpm for another 10 h; (6) Recovering the alcohol by rotary evaporation, and pressing the obtained powder into tablets with a die size of 1 inch and a pressure of 50 MPa; (7) Transfer the sheet sample to a crucible, then place it in a box furnace, heat it to 1300°C, keep it at 1300°C for 10 h, and then cool it down. The heating and cooling rates are both 5°C / min. (8) The sintered sample was crushed in a mortar, ball-milled at 300 rpm for 50 h, and the alcohol was recovered by rotary evaporation. (9) The sample powder and the binder were mixed in a weight ratio of powder to binder = 7:1, then sieved (110 mesh), and pressed into tablets using a 1 / 2 inch die at a pressure of 570 MPa. The obtained sheet sample was heat treated at 600 °C for 2 h to remove the binder; (10) Mixing the sample powder (step (8)) with BaCO3 in a weight ratio of powder to BaCO3 = 100:1 to prepare a sacrificial powder; (11) The obtained flake samples were placed on an alumina plate, embedded with an alumina tube and sacrificial powder, and then sintered in a box furnace (in air) at 1600 °C for 24 h to obtain a dense sample for testing. The heating and cooling rates were 4.17 °C / min (0 to 1000 °C) and 3.33 °C / min (1000 to 1600 °C), and the product BNI37 was obtained.

[0041] Example 2: BaNb 0.4 In 0.6 O 2.9 (BNI46) (1) Weigh the raw materials: BaCO3, Nb2O5 and In2O3 according to the stoichiometric ratio; the raw material amounts required to prepare 10 g of sample are BaCO3: 6.8133 g, Nb2O5: 1.8346 g, In2O3: 2.8746 g, in molar ratio, In concentration is 60%, Nb concentration is 40%; Steps (2) to (11) refer to Example 1.

[0042] like Figure 1 As shown, the synthesized BaNb 0.4 In 0.6 O3-δ (BNI46) 、BaNb 0.3 In 0.7 O 3-δ In the (BNI37) sample, all peaks correspond to the cubic perovskite phase peaks of the standard card (97-018-7803), and no obvious impurity peaks are observed, indicating that a cubic perovskite single phase is obtained.

[0043] After the sample was hydrated in humidified argon with a water partial pressure of 0.05 atm, the proton concentration was measured as Figure 2 As shown in Figure 2, the proton concentrations of BNI37 and BNI46 decreased with increasing temperature. At the same time, BNI37 showed a higher proton concentration, which promoted the hydration reaction and was beneficial to the introduction of protons.

[0044] Figure 3 The Arrhenius diagram of the material of the present invention in humidified hydrogen at 200-700°C is shown. At 700°C, the total conductivity of the BNI37 material is about 1.2×10 -3 S cm -1 , higher than BNI46 (9×10 -4 S cm -1 ), indicating that BNI37 has a higher proton concentration than BNI46.

[0045] In a 0.05 atm water pressure atmosphere, the activation energy E of BNI46 and BNI37 in the range of 200-500℃ is a 0.49 and 0.38 eV respectively. BNI37 has a higher concentration of low-valent metal elements (0.7) and obtains a lower activation energy. BNI37 has a consistent activation energy (0.38 eV) in the low temperature range of 200-300°C and the range of 400-500°C, which is consistent with the inhibitory effect of percolation conduction on proton capture, so that more protons participate in the transmission under low temperature conditions, thus obtaining a higher proton conductivity.

[0046] Comparison example BZ 0.8 Y 0.2 O 3-δ (BZY20) is a classic Y-doped barium zirconate proton conductor material, which is considered to have good application performance. Its activation energy is 0.30 eV at 370°C, which is less than 0.47 eV at 200°C, indicating that proton capture occurs in BZY20 at low temperatures, reducing proton conductivity. 0.3 In 0.7 O 2.8The activation energy (0.38 eV) is consistent in the low temperature range of 200 ~ 300℃ and the range of 400 ~ 500℃, which is consistent with the inhibitory effect of percolation conduction on proton capture and can obtain higher proton conductivity.

[0047] In the present invention, a new electrolyte material BaN is prepared 1-x M x O 3-δ (N includes Nb 5+ , 5+ One or more of; M includes Al 3+ , Ga 3+ , In 3+ , Sc 3+ , Y 3+ , Sm 3+ , Eu 3+ , Gd 3+ , Dy 3+ , Ho 3+ , Er 3+ , Tm 3+ , Yb 3+ ,Lu 3+ One or more of; x = 0.5, 0.55, 0.6, 0.65, 0.7, 0.75, 0.8, 0.85, 0.9,0.95). The material design strategy is to use trivalent elements and pentavalent elements at the same time, and make the total concentration of trivalent elements in the material ≥ 0.5, thereby stimulating the percolation conduction mechanism and weakening the capture effect of low-valent elements on protons in the low-temperature region. Specifically, the present invention successfully synthesized BaNb 0.4 In 0.6 O 2.9 and BaNb 0.3 In 0.7 O 2.8 Single-phase material, and the microstructure of the sintered material is dense. 0.3 In 0.7 O 2.8 The activation energy at 200-300°C is 0.38 eV, which is consistent with the activation energy at 400-500°C, indicating that a high concentration of trivalent elements can suppress the proton capture effect of the material in the low temperature region.

Claims

1. A proton conductor, which is a perovskite-type proton conductor ABO3, characterized in that: The B-site elements include pentavalent elements N and trivalent elements M.

2. The proton conductor according to claim 1, characterized in that: N includes one or more of Nb and Ta, M includes one or more of Al, Ga, In, Sc, Y, Sm, Eu, Gd, Dy, Ho, Er, Tm, Yb, and Lu; the A-site element includes barium.

3. The proton conductor according to claim 1, characterized in that: In terms of molar ratio, the total ratio of pentavalent element N and trivalent element M is 100%; the ratio of trivalent element is 50-100%.

4. The method for preparing the proton conductor according to claim 3, characterized in that: The proton conductor is prepared by using A-site element precursor and B-site element precursor as raw materials through solid phase reaction method.

5. The method for preparing a proton conductor according to claim 4, characterized in that: Among the B-site elements, the molar amount of the trivalent element M is greater than the molar amount of the pentavalent element N.

6. The method for preparing a proton conductor according to claim 4, characterized in that: The solid phase reaction method is ball milling followed by calcination.

7. An electrolyte material prepared from the proton conductor according to claim 1.

8. A fuel cell or an electrolytic hydrogen production system, comprising an electrolyte material prepared from the proton conductor according to claim 1.

9. Use of the proton conductor according to claim 1 in the preparation of electrolyte materials, electrolytic hydrogen production materials or fuel cell materials.

10. Use of the electrolyte material according to claim 7 in the preparation of a fuel cell, or in the production of hydrogen by electrolysis.

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