Battery cell, symmetrical battery, battery stack and energy conversion device

Abstract

The present application relates to battery cell, symmetric battery, battery stack and energy conversion device, the solid oxide battery includes a plurality of battery units, each battery unit includes a fuel electrode, an electrolyte unit and an air electrode; the electrolyte units of a plurality of battery units are connected to form an electrolyte layer of the solid oxide battery cell, the fuel electrode is located on the first surface of the electrolyte layer, the air electrode is located on the second surface of the electrolyte layer, and the projection of the fuel electrode and the air electrode of each battery unit on the electrolyte layer. By arranging a large-size battery cell into several small-size battery units, the size of the battery is optimized, and the problem of poor uniformity of large-size batteries is overcome.

Description

Technical Field

[0001] This invention relates to the field of solid oxide battery technology, and in particular to a battery cell, a symmetrical battery, a battery stack, and an energy conversion device. Background Technology

[0002] Solid oxide batteries are all-solid-state energy conversion devices with promising applications in future energy and environmental protection. Solid oxide batteries typically consist of a fuel electrode, an electrolyte, and an air electrode. However, when the size of a solid oxide battery cell is large, the stringent manufacturing process of large cells makes it difficult to guarantee the consistency and reliability of the cells. Summary of the Invention

[0003] Based on this, the present invention provides a battery cell, a symmetrical battery, a battery stack, and an energy conversion device to solve the problems of poor consistency and reliability of large-size single cells.

[0004] In a first aspect, the present invention provides a solid oxide battery cell comprising a plurality of battery cells, each battery cell comprising a fuel electrode, an electrolyte cell, and an air electrode; the electrolyte cells of the plurality of battery cells are connected integrally to form an electrolyte layer of the solid oxide battery cell, the fuel electrode is located on a first surface of the electrolyte layer, the air electrode is located on a second surface of the electrolyte layer, and the projections of the fuel electrode and the air electrode of each battery cell on the electrolyte layer coincide.

[0005] In some embodiments, each of the battery cells further includes a barrier layer located between the electrolyte layer and the air electrode, wherein the projections of the fuel electrode, the barrier layer, and the air electrode onto the electrolyte layer coincide.

[0006] In some embodiments, each of the battery cells is provided with a receiving groove on a first surface and a second surface of the electrolyte layer, and the receiving grooves on the first surface and the second surface of each battery cell are arranged opposite to each other; the fuel electrode is located in the receiving groove on the first surface, and the barrier layer is located in the receiving groove on the second surface.

[0007] In some embodiments, adjacent battery cells are arranged at equal intervals.

[0008] In some embodiments, the air electrode is provided with an air passage, and the fuel electrode is provided with a fuel gas passage.

[0009] In some embodiments, the thickness of the electrolyte layer is 50 μm to 1000 μm; and / or the thickness of the fuel electrode is 1 μm to 200 μm; and / or the thickness of the air electrode is 1 μm to 200 μm; and / or the thickness of the barrier layer is 0.1 μm to 50 μm.

[0010] In some embodiments, the ends of the plurality of fuel electrodes on the first surface of the electrolyte layer that are away from the electrolyte layer are at the same height relative to the electrolyte layer; the ends of the plurality of air electrodes on the second surface of the electrolyte layer that are away from the electrolyte layer are at the same height relative to the electrolyte layer.

[0011] In some embodiments, the electrolyte layer comprises a doped zirconium oxide material;

[0012] Optionally, the doped zirconium oxide material includes one or more of yttrium-stabilized zirconium oxide and scandium-stabilized zirconium oxide.

[0013] In some embodiments, the fuel electrode comprises a composite metal-ceramic material, which includes nickel oxide and ceramic material, wherein the mass ratio of nickel oxide to ceramic material is (0.25–4):1.

[0014] Optionally, the ceramic material includes one or more of yttrium-stabilized zirconium oxide, scandium-stabilized zirconium oxide, gadolinium-doped cerium oxide, samarium-doped cerium oxide, and lanthanum-doped cerium oxide.

[0015] In some embodiments, the barrier layer comprises a cerium oxide-doped material;

[0016] Optionally, the doped cerium oxide material includes one or more of gadolinium-doped cerium oxide, samarium-doped cerium oxide, and lanthanum-doped cerium oxide;

[0017] Optionally, the barrier layer further includes a sintering aid, which includes one or more of copper oxide, bismuth oxide, lithium oxide, and cobalt oxide, and the sintering aid is present in the barrier layer at a mass percentage of 0.2% to 5%.

[0018] In some embodiments, the air electrode includes a composite air electrode material, which includes an electronic conductivity phase and an ionic conductivity phase, wherein the mass ratio of the electronic conductivity phase to the ionic conductivity phase is (3 / 7 to 4): 1;

[0019] Optionally, the electronic conductivity phase includes one or more of lanthanum-strontium-cobalt-iron, lanthanum-strontium-cobalt, and lanthanum-strontium-manganese; and / or the ionic conductivity phase includes one or more of yttrium-stabilized zirconium oxide, scandium-stabilized zirconium oxide, gadolinium-doped cerium oxide, samarium-doped cerium oxide, and lanthanum-doped cerium oxide.

[0020] A second aspect of the present invention provides a method for preparing the solid oxide battery cell described in the first aspect of the present invention, comprising the following steps:

[0021] Preparation of electrolyte layer;

[0022] Multiple fuel electrodes are prepared on the first surface of the electrolyte layer;

[0023] A plurality of air electrodes are formed on the second surface of the electrolyte layer;

[0024] Alternatively, a plurality of barrier layers may be prepared on the second surface of the electrolyte layer, and an air electrode may be prepared on each of the barrier layers.

[0025] In some embodiments, the sintering temperature for preparing the electrolyte layer is 800–1600°C and the sintering time is 1–5 h; and / or the sintering temperature for preparing the barrier layer is 800–1400°C and the sintering time is 1–5 h.

[0026] In some embodiments, a fuel electrode is prepared using a composite metal-ceramic material and a pore-forming agent, and an air electrode is prepared using a composite air electrode material and a pore-forming agent.

[0027] Preferably, the sintering temperature for preparing the fuel electrode is 800–1500°C and the sintering time is 1–6 h, and the sintering temperature for preparing the air electrode is 600–1400°C and the sintering time is 1–5 h.

[0028] More preferably, the pore-forming agent includes one or more of carbon black, starch, polymethyl methacrylate microspheres and polystyrene microspheres, and the pore-forming agent accounts for 1% to 15% of the total raw materials when preparing the fuel electrode and / or the air electrode.

[0029] A third aspect of the present invention provides a symmetrical battery comprising two solid oxide battery cells as described in the first aspect of the present invention, arranged opposite to each other, wherein the fuel electrodes of the two solid oxide battery cells are close to each other, the electrolyte layers of the two solid oxide battery cells are sealed together, and a fuel gas inlet / outlet channel and a conductive connection device are provided between the electrolyte layers of the two solid oxide battery cells.

[0030] A fourth aspect of the present invention provides a battery stack comprising a plurality of solid oxide battery cells as described in the first aspect of the present invention or a plurality of sets of symmetrical batteries as described in the third aspect of the present invention.

[0031] A fifth aspect of the present invention provides an energy conversion device comprising a solid oxide battery cell as described in the first aspect of the present invention, a symmetrical battery as described in the third aspect of the present invention, or a battery stack as described in the fourth aspect of the present invention.

[0032] The present invention provides a battery cell, a symmetrical battery, a battery stack, and an energy conversion device. The solid oxide battery cell is composed of several small-sized battery units, and each battery unit includes an electrolyte unit, an air electrode, and a fuel electrode. Multiple electrolyte units are connected together to form an electrolyte layer of the solid oxide battery cell. By setting a large-sized battery cell into several small-sized battery units, the size of the battery is optimized, and the problems of poor consistency and reliability of large-sized batteries are effectively overcome. Attached Figure Description

[0033] Figure 1 A cross-sectional schematic diagram of the solid oxide battery cell 10 provided in an embodiment of the present invention;

[0034] Figure 2 A cross-sectional schematic diagram of the solid oxide battery cell 20 provided in an embodiment of the present invention;

[0035] Figure 3 A cross-sectional schematic diagram of a symmetrical battery 200 provided in an embodiment of the present invention;

[0036] Figure 4 A cross-sectional schematic diagram of the solid oxide battery cell 30 provided in an embodiment of the present invention;

[0037] Figure 5 A cross-sectional schematic diagram of a symmetrical battery 300 provided in an embodiment of the present invention;

[0038] Figure 6 A perspective view of a symmetrical battery provided in an embodiment of the present invention;

[0039] Figure 7 This is a schematic diagram of the consistency test results of the battery cell provided in the embodiment of the present invention; wherein the horizontal axis in the figure represents the current density, the left vertical axis represents the potential, and the right vertical axis represents the power density. Detailed Implementation

[0040] To make the above-mentioned objects, features, and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of the present invention. However, the present invention can be practiced in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0041] In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0042] In this invention, numerical ranges are involved. Unless otherwise specified, the numerical ranges are considered continuous and include the minimum and maximum values ​​of the range, as well as every value between the minimum and maximum values. Furthermore, when the range refers to integers, it includes every integer between the minimum and maximum values ​​of the range. Additionally, when multiple ranges are provided to describe features or characteristics, the ranges may be merged. In other words, unless otherwise specified, all ranges disclosed herein should be understood to include any and all subranges to which they are included.

[0043] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the specification of this invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0044] Solid oxide batteries are all-solid-state energy conversion devices. They can function as solid oxide fuel cells (SOFCs) to efficiently convert the chemical energy stored in fuel and oxidant into electrical energy, characterized by high power generation efficiency and environmental friendliness. Alternatively, they can function as solid oxide electrolyzers (SOECs) to efficiently and environmentally convert thermal and electrical energy directly into the chemical energy in fuel. SOECs can be seen as the reverse operation of SOFCs. Solid oxide battery technology has a bright future in energy and environmental protection.

[0045] Solid oxide batteries typically consist of a fuel electrode, an electrolyte, and an air electrode. When the size of a solid oxide battery cell is large, the stringent manufacturing process makes it difficult to guarantee the consistency and reliability of the cells. Solid oxide batteries generally operate at temperatures between 700 and 1000°C. High-temperature operating environments place even higher demands on sealing components, as failure of these components or element diffusion can reduce the battery's lifespan.

[0046] In addition, current common battery stacks are usually made up of individual cells stacked together by connectors. If any problem occurs with an individual cell, it will lead to a significant reduction in the lifespan of the entire battery stack or even render it inoperable.

[0047] Please refer to Figure 1 This invention provides a solid oxide battery cell 10, which includes multiple battery cells. Each battery cell includes a fuel electrode 11, an electrolyte cell, and an air electrode 13. The electrolyte cells of the multiple battery cells are connected to form an electrolyte layer 12 of the solid oxide battery cell 10. The fuel electrode 11 is located on a first surface of the electrolyte layer 12, and the air electrode 13 is located on a second surface of the electrolyte layer 12. The projections of the fuel electrode 11 and the air electrode 13 of each battery cell on the electrolyte layer 12 coincide.

[0048] Please see Figure 2 This invention provides a solid oxide battery cell 20, comprising multiple battery cells, each battery cell including a fuel electrode 21, an electrolyte cell, a barrier layer 24, and an air electrode 23. The electrolyte cells of the multiple battery cells are connected integrally to form an electrolyte layer 22 of the solid oxide battery cell 20. The fuel electrode 21 is located on a first surface of the electrolyte layer 22, the barrier layer 24 is located on a second surface of the electrolyte layer 22, and the air electrode 23 is located on the surface of the barrier layer 24. The projections of the fuel electrode 21, the barrier layer 24, and the air electrode 23 on the electrolyte layer 22 coincide. By providing the barrier layer, a reaction between the air electrode and the electrolyte layer can be prevented, providing safety and durability to the solid oxide battery cell.

[0049] Please see Figure 4 The solid oxide battery cell 30 provided in this embodiment of the invention includes multiple battery cells, each battery cell including a fuel electrode 31, an electrolyte cell, a barrier layer 34, and an air electrode 33; the electrolyte cells of the multiple battery cells are connected to form an electrolyte layer 32 of the solid oxide battery cell 30; the fuel electrode 31 is located in a receiving groove on the first surface of the electrolyte layer 32, the barrier layer 34 is located in a receiving groove on the second surface of the electrolyte layer 32, and the air electrode 33 is located on the surface of the barrier layer 34; the projections of the fuel electrode 31, the barrier layer 34, and the air electrode 33 on the electrolyte layer 32 coincide. By providing receiving grooves on the first surface and / or the second surface of the electrolyte layer, the thickness of the solid oxide battery cell can be further reduced.

[0050] It should be noted that the fuel electrode being located within the receiving groove on the first surface of the electrolyte layer can mean that the fuel electrode is partially located within the receiving groove on the first surface of the electrolyte layer, and the thickness of the fuel electrode in the direction perpendicular to the surface of the electrolyte layer is greater than the depth of the receiving groove on the first surface of the electrolyte layer; or it can mean that the fuel electrode is completely located within the receiving groove on the first surface of the electrolyte layer, and the thickness of the fuel electrode in the direction perpendicular to the surface of the electrolyte layer is less than or equal to the depth of the receiving groove on the first surface of the electrolyte layer.

[0051] The barrier layer is located within the receiving groove on the second surface of the electrolyte layer. This can mean that the barrier layer is completely located within the receiving groove on the second surface of the electrolyte layer, and the thickness of the barrier layer in the direction perpendicular to the surface of the electrolyte layer is less than or equal to the depth of the receiving groove on the second surface of the electrolyte layer; or it can mean that the barrier layer is partially located within the receiving groove on the second surface of the electrolyte layer, and the thickness of the barrier layer in the direction perpendicular to the surface of the electrolyte layer is greater than the depth of the receiving groove on the second surface of the electrolyte layer.

[0052] The overlapping projections of the fuel electrode, barrier layer, and air electrode onto the electrolyte layer can include cases where the projected cross-sectional sizes of the fuel electrode, barrier layer, and air electrode onto the electrolyte layer are the same, or cases where one of the projected cross-sections is located within the range of the other two projected cross-sections, or cases where two of the projected cross-sections are located within the range of another projected cross-section.

[0053] The solid oxide battery unit mentioned in this invention can be a solid oxide fuel cell unit or a solid oxide electrolyzer unit, and there is no specific limitation.

[0054] The solid oxide battery cell provided by this invention is composed of several small-sized battery cells, and each battery cell includes an electrolyte cell, an air electrode, and a fuel electrode. Multiple electrolyte cells are connected together to form an electrolyte layer of the solid oxide battery cell. By setting a large-sized battery cell into several small-sized battery cells, the size of the battery is optimized, and the problems of poor consistency and reliability of large-sized batteries are effectively overcome.

[0055] In some embodiments, adjacent battery cells can be arranged at equal intervals, which can further improve the consistency and reliability of solid oxide battery cells and facilitate the fabrication of symmetrical batteries.

[0056] In some embodiments, an air channel is provided in the air electrode and a fuel gas channel is provided in the fuel electrode; this facilitates the flow of fuel and gas during the operation of the solid oxide battery.

[0057] In some embodiments, the ends of the plurality of fuel electrodes on the first surface of the electrolyte layer that are away from the electrolyte layer are at the same height relative to the electrolyte layer; the ends of the plurality of air electrodes on the second surface of the electrolyte layer that are away from the electrolyte layer are at the same height relative to the electrolyte layer; this can further improve the consistency of solid oxide battery cells and facilitate the subsequent fabrication of symmetrical batteries.

[0058] In some embodiments, the thickness of the electrolyte layer can be any value between 50 μm and 1000 μm; for example, it can be 50 μm, 100 μm, 200 μm, 300 μm, 400 μm, 500 μm, 600 μm, 700 μm, 800 μm, 900 μm or 1000 μm, etc., preferably 200 μm.

[0059] In some embodiments, the thickness of the fuel electrode can be any value between 1 μm and 200 μm; for example, it can be 1 μm, 20 μm, 50 μm, 80 μm, 100 μm, 125 μm, 150 μm, 180 μm or 200 μm, etc., and there is no specific limitation.

[0060] In some embodiments, the thickness of the air electrode can be any value between 1 μm and 200 μm; for example, it can be 1 μm, 30 μm, 55 μm, 75 μm, 100 μm, 130 μm, 150 μm, 170 μm or 200 μm, etc., and there is no specific limitation.

[0061] In some embodiments, the thickness of the barrier layer can be any value between 0.1 μm and 50 μm; for example, it can be 0.1 μm, 5 μm, 10 μm, 20 μm, 30 μm, 35 μm, or 40 μm, etc., and there is no specific limitation.

[0062] In some embodiments, the electrolyte layer may include a doped zirconium oxide material; in some embodiments, the doped zirconium oxide material may include one or more of yttrium-stabilized zirconium oxide and scandium-stabilized zirconium oxide.

[0063] In some embodiments, the fuel electrode may include a composite metal-ceramic material, which may include nickel oxide and a ceramic material. The mass ratio of the nickel oxide to the ceramic material may be (0.25–4):1, for example, 0.25:1, 0.5:1, 1:1, 1.5:1, 2:1, 2.5:1, 3:1, 3.5:1, or 4:1, preferably 1.5:1. In some embodiments, the ceramic material may include one or more of yttrium-stabilized zirconium oxide, scandium-stabilized zirconium oxide, gadolinium-doped cerium oxide, samarium-doped cerium oxide, and lanthanum-doped cerium oxide.

[0064] In some embodiments, the barrier layer may include a doped cerium oxide material; in some embodiments, the doped cerium oxide material may include one or more of gadolinium-doped cerium oxide, samarium-doped cerium oxide, and lanthanum-doped cerium oxide.

[0065] In some embodiments, the barrier layer may further include a sintering aid. In some embodiments, the sintering aid may include one or more of copper oxide, bismuth oxide, lithium oxide, and cobalt oxide. The mass percentage of the sintering aid in the barrier layer may be 0.2% to 5%, for example, 0.2%, 0.5%, 1%, 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, or 5%, preferably 2%.

[0066] In some embodiments, the air electrode may include a composite air electrode material comprising an electronic conductivity phase and an ionic conductivity phase, wherein the mass ratio of the electronic conductivity phase to the ionic conductivity phase is (3 / 7 to 4):1, for example, it can be 3 / 7:1, 1:1, 1.5:1, 2:1, 2.5:1, 3:1, 3.5:1 or 4:1, preferably 1:1; in some embodiments, the electronic conductivity phase may include one or more of lanthanum-strontium-cobalt-iron, lanthanum-strontium-cobalt, and lanthanum-strontium-manganese; the ionic conductivity phase may include one or more of yttrium-stabilized zirconium oxide, scandium-stabilized zirconium oxide, gadolinium-doped cerium oxide, samarium-doped cerium oxide, and lanthanum-doped cerium oxide.

[0067] The present invention also provides a method for preparing a solid oxide battery cell, which may include the following steps:

[0068] Preparation of electrolyte layer;

[0069] Multiple fuel electrodes are prepared on the first surface of the electrolyte layer;

[0070] A plurality of air electrodes are formed on the second surface of the electrolyte layer;

[0071] Alternatively, a plurality of barrier layers may be prepared on the second surface of the electrolyte layer, and an air electrode may be prepared on each of the barrier layers.

[0072] The solid oxide battery cell provided by this invention has a simple preparation process, saves manufacturing costs, and can promote the mass production and commercialization of solid oxide battery cells.

[0073] In this invention, the electrolyte layer can be prepared using a casting method or a conventional method known in the art. The preparation method of the electrolyte layer in this invention is as follows: the electrolyte layer is prepared using a casting method, and then sintered. The sintering temperature can be 800–1600℃, for example, 800℃, 900℃, 1000℃, 1100℃, 1200℃, 1300℃, 1400℃, 1500℃, or 1600℃, etc., without specific limitation; the sintering time can be 1–5 hours, for example, 1 hour, 2 hours, 3 hours, 4 hours, or 5 hours, etc., without specific limitation, to form a dense electrolyte layer.

[0074] The fuel electrode can be prepared by screen printing or by conventional methods known in the art. The method for preparing the fuel electrode of the present invention can be specifically as follows: when the first surface of the electrolyte layer is not provided with a receiving groove, multiple fuel electrodes are prepared on the first surface of the electrolyte layer according to a planned first position or first pattern using a screen printing method, and then sintered. The sintering temperature can be 800-1500℃, for example, 800℃, 900℃, 1000℃, 1100℃, 1200℃, 1300℃, 1400℃ or 1500℃, etc., and is not specifically limited; the sintering time can be 1-6 hours, for example, 1 hour, 2 hours, 3 hours, 4 hours, 5 hours or 6 hours, etc., and is not specifically limited; among the raw materials used, the pore-forming agent can include one or more of carbon black, starch, polymethyl methacrylate microspheres and polystyrene microspheres, and the pore-forming agent accounts for 1%-15% of the total raw materials by mass, for example, 1%, 3%, 5%, 7%, 10%, 12% or 15%, etc., preferably 7%. Adding a pore-forming agent during the preparation of the fuel electrode can create fuel gas channels.

[0075] In this invention, the barrier layer can be prepared using screen printing or conventional methods known in the art. The preparation method of the barrier layer in this invention is as follows: when the second surface of the electrolyte layer does not have a receiving groove, multiple barrier layers are prepared on the second surface of the electrolyte layer according to a planned second position or second pattern using screen printing, and then sintered. The sintering temperature can be 800–1400℃, for example, 800℃, 900℃, 1000℃, 1100℃, 1200℃, 1300℃, or 1400℃, etc., without specific limitation; the sintering time can be 1–6 hours, for example, 1 hour, 2 hours, 3 hours, 4 hours, or 5 hours, etc., without specific limitation; wherein, the first position or first pattern corresponds to the second position or second pattern respectively.

[0076] In some embodiments, the raw materials used to prepare the barrier layer may also include sintering aids.

[0077] In this invention, the air electrode can be prepared using screen printing or conventional methods known in the art. The preparation method of the air electrode of this invention is as follows: The air electrode is prepared on the surface of multiple barrier layers using screen printing, and then sintered. The sintering temperature can be 600–1400℃, for example, 600℃, 700℃, 800℃, 900℃, 1000℃, 1100℃, 1200℃, 1300℃, or 1400℃, etc., without specific limitation; the sintering time can be 1–5 hours, for example, 1 hour, 2 hours, 3 hours, 4 hours, or 5 hours, without specific limitation. Among the raw materials used, the pore-forming agent can include one or more of carbon black, starch, polymethyl methacrylate microspheres, and polystyrene microspheres. The pore-forming agent accounts for 1%–15% of the total raw materials by mass, for example, 1%, 3%, 5%, 7%, 10%, 12%, or 15%, preferably 8%. Adding a pore-forming agent during air preparation can create air channels.

[0078] In some embodiments, the barrier layer and the air electrode on the surface of the barrier layer can be prepared by screen printing, and then co-sintered at 800–1400°C.

[0079] In some embodiments, current collector layers may be formed on the outer surfaces of the air electrode and the fuel electrode, respectively, and the current collector layers may be made of conductive materials such as silver or platinum.

[0080] Please refer to Figure 3 or Figure 5 This disclosure also provides a symmetrical battery, comprising two opposing solid oxide battery cells, with the fuel electrodes of the two solid oxide battery cells close to each other, the electrolyte layers of the two solid oxide battery cells sealed together, and a fuel gas inlet / outlet channel and a conductive connection device provided between the electrolyte layers of the two solid oxide battery cells. Wherein, Figure 3 To adopt Figure 2 The symmetrical battery 200 is prepared from a solid oxide battery cell shown in the figure. Figure 5 To adopt Figure 4 The solid oxide battery cell shown is a symmetrical battery 300.

[0081] A symmetrical battery consists of two symmetrical solid oxide battery cells, each of which comprises several small-sized battery units. This facilitates control over the consistency of the small-sized battery units and the reliability of the solid oxide battery cells, thereby simplifying the structure of the symmetrical battery and improving its uniformity. In some embodiments, a glass or ceramic sealant can be used to seal the electrolyte layers between the two solid oxide battery cells.

[0082] Please refer to Figure 6 This is a 3D diagram of a symmetrical battery, constructed from... Figure 6 As can be seen, in a symmetrical battery, the area where several battery cells are located is the high-temperature zone 51, and the surrounding area is the low-temperature zone 52. The high-temperature zone 51 ensures the operation of the battery, while the low-temperature zone 52 is used for sealing. The low-temperature zone 52 is filled with sealing material (such as glass or ceramic sealant) to seal the electrolyte layer between the two solid oxide battery cells, which can reduce the requirements for sealing materials and improve the selectivity and stability of sealing materials.

[0083] This invention also provides a battery stack, comprising multiple solid oxide battery cells or multiple groups of symmetrical cells. The battery stack is composed of parallel symmetrical cells, eliminating the need for connectors. The symmetrical cells are independent of each other, offering advantages such as ease of maintenance and replacement. The symmetrically arranged solid oxide battery cells within the symmetrical cells are flexible, reliable, and easy to replace, thus improving the overall lifespan of the battery stack.

[0084] The present invention also provides an energy conversion device, including a solid oxide battery cell, a symmetrical battery, or a battery stack as described above.

[0085] The following are specific embodiments. They are intended to provide a more detailed description of the present invention to help those skilled in the art and researchers to better understand it. The technical conditions described do not constitute any limitation on the present invention. Any modifications made within the scope of the claims of this invention are protected within the scope of the claims.

[0086] Example 1

[0087] An electrolyte layer with a thickness of 200 μm was prepared by casting using yttrium-stabilized zirconium oxide. The layer was then sintered at 1500 °C for 2 hours to form a dense electrolyte sheet.

[0088] Multiple fuel electrodes were fabricated on the first surface of the electrolyte sheet. The fuel electrodes were made of a composite metal-ceramic material composed of nickel oxide and yttrium-stabilized zirconium oxide, with a mass ratio of nickel oxide to yttrium-stabilized zirconium oxide of 3:2. Multiple circles with a diameter of 12 mm and a thickness of 10 μm were screen-printed at planned positions using a screen printing method. The electrodes were then sintered at 1400 °C for 2 hours to obtain the fuel electrodes.

[0089] A barrier layer, with the same number of fuel electrodes as the first and second surfaces, is prepared on the second surface of the electrolyte sheet, with the first and second surfaces positioned opposite each other. The barrier layer is made of gadolinium-doped cerium oxide. Circular shapes with a diameter of 15 mm and a thickness of 2 μm are screen-printed at positions corresponding to the fuel electrodes, and sintered at 1200 °C for 2 hours to obtain the barrier layer.

[0090] Air electrodes were fabricated on the surfaces of multiple barrier layers. The air electrodes were composite materials consisting of an electronically conductive phase and an ionicly conductive phase. The electronically conductive phase was composed of lanthanum-strontium-cobalt-iron, and the ionicly conductive phase was composed of gadolinium-doped cerium oxide. The mass ratio of lanthanum-strontium-cobalt-iron to gadolinium-doped cerium oxide was 1. Circular shapes with a diameter of 12 mm and a thickness of 10 μm were screen-printed at positions corresponding to the fuel electrode. The resulting air electrodes were sintered at 1000 °C for 2 hours.

[0091] The prepared solid oxide battery cells are spliced ​​together with the fuel electrode side as the axis of symmetry. The electrolyte sheets are sealed with glass glue, and the inlet and outlet channels for fuel gas and conductive connection devices are reserved to obtain a symmetrical battery.

[0092] Example 2

[0093] An electrolyte layer with a thickness of 200 μm was prepared by casting using yttrium-stabilized zirconium oxide. The layer was then sintered at 1500 °C for 2 hours to form a dense electrolyte sheet.

[0094] Multiple fuel electrodes were fabricated on the first surface of the electrolyte sheet. The fuel electrodes were made of a composite metal-ceramic material composed of nickel oxide and yttrium-stabilized zirconium oxide, with a mass ratio of nickel oxide to yttrium-stabilized zirconium oxide of 3:2. Multiple circles with a diameter of 12 mm and a thickness of 10 μm were screen-printed at planned positions using a screen printing method. The electrodes were then sintered at 1400 °C for 2 hours to obtain the fuel electrodes.

[0095] Air electrodes, with the same number as fuel electrodes, are prepared on the second surface of the electrolyte sheet. The air electrodes are composite materials consisting of an electronically conductive phase and an ionicly conductive phase. The electronically conductive phase is lanthanum-strontium-manganese, and the ionicly conductive phase is yttrium-stabilized zirconium oxide. The mass ratio of lanthanum-strontium-manganese to yttrium-stabilized zirconium oxide is 1. Circular shapes with a diameter of 12 mm and a thickness of 10 μm are screen-printed at positions corresponding to the fuel electrodes. The resulting air electrodes are sintered at 1200 °C for 2 hours.

[0096] The prepared solid oxide battery cells are spliced ​​together with the fuel electrode side as the axis of symmetry. The electrolyte sheets are sealed with glass glue, and the inlet and outlet channels for fuel gas and conductive connection devices are reserved to obtain a symmetrical battery.

[0097] Example 3

[0098] An electrolyte layer with a thickness of 150 μm was prepared by casting using scandium-stabilized zirconium oxide. The layer was then sintered at 1400 °C for 5 hours to form a dense electrolyte sheet.

[0099] Multiple fuel electrodes are fabricated on the first surface of an electrolyte sheet. The fuel electrodes are made of a composite metal-ceramic material composed of nickel oxide and gadolinium-doped cerium oxide, along with carbon black. The mass ratio of nickel oxide to gadolinium-doped cerium oxide is 1:1, and the carbon black accounts for 1% of the total raw material mass. Multiple circles with a diameter of 12 mm and a thickness of 30 μm are screen-printed at planned positions using a screen printing method. The electrodes are then sintered at 1300 °C for 2 hours to obtain the fuel electrodes.

[0100] A barrier layer, the same number as the fuel electrodes, is prepared on the second surface of the electrolyte sheet, with the first and second surfaces positioned opposite each other. The barrier layer is made of samarium-doped cerium oxide and cobalt oxide, with cobalt oxide accounting for 2% of the total raw material by mass. Circular shapes with a diameter of 15 mm and a thickness of 5 μm are screen-printed at positions corresponding to the fuel electrodes, and sintered at 1000 °C for 1 hour to obtain the barrier layer.

[0101] Air electrodes were fabricated on the surfaces of multiple barrier layers. The air electrodes were made from a composite air electrode material consisting of an electronically conductive phase and an ionicly conductive phase, along with starch, with starch accounting for 8% of the total raw material mass. The electronically conductive phase was lanthanum-strontium-cobalt, and the ionicly conductive phase was samarium-doped cerium oxide, with a mass ratio of lanthanum-strontium-cobalt to samarium-doped cerium oxide of 1. Circular shapes with a diameter of 12 mm and a thickness of 30 μm were screen-printed at positions corresponding to the fuel electrode, and sintered at 1100 °C for 1 hour to obtain the air electrodes.

[0102] The prepared solid oxide battery cells are spliced ​​together with the fuel electrode side as the axis of symmetry. The electrolyte sheets are sealed with ceramic sealant, and the inlet and outlet channels for fuel gas and conductive connection devices are reserved to obtain a symmetrical battery.

[0103] Example 4

[0104] An electrolyte layer with a thickness of 100 μm was prepared by casting using scandium-stabilized zirconium oxide. The layer was then sintered at 1600 °C for 1 hour to form a dense electrolyte sheet.

[0105] Multiple fuel electrodes were fabricated on the first surface of an electrolyte sheet. The fuel electrodes were constructed using a composite metal-ceramic material consisting of nickel oxide and lanthanum-doped cerium oxide, along with polystyrene microspheres. The polystyrene microspheres comprised 15% of the total raw material by mass, and the mass ratio of nickel oxide to lanthanum-doped cerium oxide was 4. Multiple 10mm diameter, 50μm thick circles were screen-printed at planned locations using a screen printing method. The resulting electrodes were sintered at 1400℃ for 1 hour to obtain the fuel electrodes.

[0106] A barrier layer, the same number as the fuel electrodes, is prepared on the second surface of the electrolyte sheet, with the first and second surfaces positioned opposite each other. The barrier layer is made of lanthanum-doped cerium oxide. Circular shapes with a diameter of 10 mm and a thickness of 2 μm are screen-printed at positions corresponding to the fuel electrodes, and sintered at 800 °C for 5 hours to obtain the barrier layer.

[0107] Air electrodes were fabricated on the surfaces of multiple barrier layers. The air electrodes were constructed using a composite air electrode material consisting of an electronically conductive phase and an ionicly conductive phase, along with polymethyl methacrylate (PMMA) microspheres. The PMMA microspheres comprised 8% of the total raw material by mass. The electronically conductive phase was composed of lanthanum-strontium-cobalt-iron (LMOS), and the ionicly conductive phase was composed of lanthanum-doped cerium oxide. The mass ratio of LMOS to LMOS to lanthanum-doped cerium oxide was 3 / 7. Circular shapes with a diameter of 10 mm and a thickness of 1 μm were screen-printed at positions corresponding to the fuel electrode. The resulting air electrodes were sintered at 900 °C for 5 hours.

[0108] The prepared solid oxide battery cells are spliced ​​together with the fuel electrode side as the axis of symmetry. The electrolyte sheets are sealed with ceramic sealant, and the inlet and outlet channels for fuel gas and conductive connection devices are reserved to obtain a symmetrical battery.

[0109] Performance testing

[0110] Battery cell consistency test: Scandium-stabilized zirconium oxide was used to prepare electrolyte cells by casting method. The cells were 100 μm thick and 20 mm in diameter, and sintered at 1500 °C for 2 hours.

[0111] A fuel electrode is fabricated on the first surface of the electrolyte unit. The fuel electrode is made of a composite metal-ceramic material composed of nickel oxide and gadolinium-doped cerium oxide, and carbon black. The carbon black accounts for 5% of the total raw material by mass, and the mass ratio of nickel oxide to gadolinium-doped cerium oxide is 13 / 7. A circular electrode with a diameter of 10 mm and a thickness of 20 μm is screen-printed at the planned position, and sintered at 1400 °C for 2 hours to obtain the fuel electrode.

[0112] An air electrode is fabricated on the second surface of the electrolyte sheet. The air electrode is composed of a composite air electrode material consisting of an electronic conductivity phase and an ionic conductivity phase, along with carbon black, which accounts for 8% of the total raw material mass. The electronic conductivity phase is lanthanum-strontium-cobalt-iron, and the ionic conductivity phase is gadolinium-doped cerium oxide, with a mass ratio of lanthanum-strontium-cobalt-iron to gadolinium-doped cerium oxide of 1. A circular shape with a diameter of 10 mm and a thickness of 20 μm is screen-printed at the position corresponding to the fuel electrode. The electrode is then sintered at 1050 °C for 2 hours to obtain the air electrode, thus completing the fabrication of battery cell 1.

[0113] Repeat the above process to obtain battery cell 2.

[0114] The prepared battery cells 1 and 2 were used for current collection using silver conductive paste and tested at 800℃. The performance comparisons of battery cells 1 and 2 are as follows: Figure 6 As shown.

[0115] Depend on Figure 6 It can be seen that battery cell 1 and battery cell 2 have a high degree of consistency, and the performance of a solid oxide battery cell is a multiple of the number of battery cells.

[0116] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0117] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims, and the specification and drawings can be used to interpret the content of the claims.

Claims

1. A symmetrical battery, characterized in that, It includes two solid oxide battery cells arranged opposite each other; The solid oxide battery cell includes multiple battery cells, each battery cell including a fuel electrode, an electrolyte cell, and an air electrode; the electrolyte cells of the multiple battery cells are connected to form an electrolyte layer of the solid oxide battery cell, the fuel electrode is located on a first surface of the electrolyte layer, the air electrode is located on a second surface of the electrolyte layer, each battery cell also includes a barrier layer located between the electrolyte layer and the air electrode, the projections of the fuel electrode, the barrier layer, and the air electrode of each battery cell on the electrolyte layer coincide, the barrier layer includes a cerium oxide doped material and a sintering aid, the sintering aid including one or more of copper oxide, bismuth oxide, lithium oxide, and cobalt oxide, the mass percentage of the sintering aid in the barrier layer being 0.2% to 5%; Each of the battery cells has a receiving groove on the first surface and the second surface of the electrolyte layer, and the receiving grooves on the first surface and the second surface of each battery cell are arranged opposite to each other; the fuel electrode is located in the receiving groove on the first surface, and the barrier layer is located in the receiving groove on the second surface. In the symmetrical battery, the fuel electrodes of the two solid oxide battery cells are close to each other, the electrolyte layers of the two solid oxide battery cells are sealed together, and a fuel gas inlet / outlet channel and a conductive connection device are provided between the electrolyte layers of the two solid oxide battery cells.

2. The symmetrical battery according to claim 1, characterized in that, In the solid oxide battery cell, adjacent battery cells are arranged at equal intervals.

3. The symmetrical battery according to claim 1, characterized in that, In the solid oxide battery cell, an air channel is provided in the air electrode, and a fuel gas channel is provided in the fuel electrode.

4. The symmetrical battery according to claim 1, characterized in that, The thickness of the electrolyte layer is 50 μm to 1000 μm; And / or the thickness of the fuel electrode is 1 μm to 200 μm; And / or the thickness of the air electrode is 1 μm to 200 μm; And / or the thickness of the barrier layer is 0.1 μm to 50 μm.

5. The symmetrical battery according to any one of claims 1 to 4, characterized in that, In the solid oxide battery cell, the ends of the plurality of fuel electrodes on the first surface of the electrolyte layer that are away from the electrolyte layer are at the same height relative to the electrolyte layer; the ends of the plurality of air electrodes on the second surface of the electrolyte layer that are away from the electrolyte layer are at the same height relative to the electrolyte layer.

6. The symmetrical battery according to any one of claims 1 to 4, characterized in that, The electrolyte layer comprises a doped zirconium oxide material.

7. The symmetrical battery according to claim 6, characterized in that, The doped zirconium oxide material includes one or more of yttrium-stabilized zirconium oxide and scandium-stabilized zirconium oxide.

8. The symmetrical battery according to any one of claims 1 to 4, characterized in that, The fuel electrode comprises a composite metal-ceramic material, which includes nickel oxide and ceramic material, wherein the mass ratio of nickel oxide to ceramic material is (0.25~4):

1.

9. The symmetrical battery according to claim 8, characterized in that, The ceramic material includes one or more of yttrium-stabilized zirconium oxide, scandium-stabilized zirconium oxide, gadolinium-doped cerium oxide, samarium-doped cerium oxide, and lanthanum-doped cerium oxide.

10. The symmetrical battery according to claim 1, characterized in that, The doped cerium oxide material includes one or more of gadolinium-doped cerium oxide, samarium-doped cerium oxide, and lanthanum-doped cerium oxide.

11. The symmetrical battery according to any one of claims 1 to 4, characterized in that, The air electrode outer surface and the fuel electrode outer surface each independently include a current collector layer, which includes one or more of silver and platinum.

12. The symmetrical battery according to any one of claims 1 to 4, characterized in that, The air electrode includes a composite air electrode material, which comprises an electronic conductivity phase and an ionic conductivity phase, wherein the mass ratio of the electronic conductivity phase to the ionic conductivity phase is (3 / 7~4):

1.

13. The symmetrical battery according to claim 12, characterized in that, The electronic conductivity phase includes one or more of lanthanum-strontium-cobalt-iron, lanthanum-strontium-cobalt, and lanthanum-strontium-manganese; and / or the ionic conductivity phase includes one or more of yttrium-stabilized zirconium oxide, scandium-stabilized zirconium oxide, gadolinium-doped cerium oxide, samarium-doped cerium oxide, and lanthanum-doped cerium oxide.

14. A method for preparing a symmetrical battery as described in any one of claims 1 to 13, characterized in that, The symmetrical battery comprises two oppositely arranged solid oxide battery cells, and the preparation of the solid oxide battery cells includes the following steps: Preparation of electrolyte layer; Multiple fuel electrodes are prepared on the first surface of the electrolyte layer; A plurality of air electrodes are formed on the second surface of the electrolyte layer; Alternatively, a plurality of barrier layers may be prepared on the second surface of the electrolyte layer, and an air electrode may be prepared on each of the barrier layers.

15. The method for preparing a symmetrical battery according to claim 14, characterized in that, The sintering temperature for preparing the electrolyte layer is 800~1600℃ and the sintering time is 1~5h; and / or the sintering temperature for preparing the barrier layer is 800~1400℃ and the sintering time is 1~5h.

16. The method for preparing a symmetrical battery according to claim 14, characterized in that, The fuel electrode is prepared using composite metal-ceramic materials and a pore-forming agent, and the air electrode is prepared using composite air electrode materials and a pore-forming agent.

17. The method for preparing a symmetrical battery according to claim 16, characterized in that, The sintering temperature for preparing the fuel electrode is 800~1500℃ and the sintering time is 1~6h. The sintering temperature for preparing the air electrode is 600~1400℃ and the sintering time is 1~5h.

18. The method for preparing a symmetrical battery according to claim 16, characterized in that, The pore-forming agent includes one or more of carbon black, starch, polymethyl methacrylate microspheres and polystyrene microspheres, and the pore-forming agent accounts for 1% to 15% of the total raw materials when preparing the fuel electrode and / or the air electrode.

19. A battery stack, characterized in that, It includes multiple sets of symmetrical batteries as described in any one of claims 1 to 13, or symmetrical batteries prepared by any one of claims 14 to 18.

20. An energy conversion device, characterized in that, Includes the symmetrical battery as described in any one of claims 1 to 13 or the battery stack as described in claim 19.

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