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CN-121983591-A - Solid oxide fuel cell full cell and preparation method thereof

CN121983591ACN 121983591 ACN121983591 ACN 121983591ACN-121983591-A

Abstract

The invention belongs to the technical field of solid oxide fuel cells, and discloses a solid oxide fuel cell full cell and a preparation method thereof. The problem that the cell piece bending deformation is serious in the prior art for manufacturing the SOFC full cell by a layer-by-layer preparation method is solved. The invention realizes the matching of the contraction behaviors of all layers by optimizing the slurry formula and the solvent system of all functional layers, obviously improves the interface bonding strength between all functional layers by adopting a hot-pressing composite process, reduces the layering risk, reduces the sintering times by adopting a co-sintering process, shortens the preparation period and reduces the energy consumption. The full cell prepared by the method has the advantages of high flatness, good interface bonding strength, excellent electrochemical performance, excellent thermal stability and the like, can remarkably improve the assembly efficiency and the operation stability of the SOFC stack, reduces the production cost and has wide market prospect.

Inventors

  • ZHANG YAZHOU
  • XIAO FULAI
  • ZHANG YIFAN

Assignees

  • 山东新寰清科技发展有限公司

Dates

Publication Date
20260505
Application Date
20260126

Claims (6)

  1. 1. The preparation method of the solid oxide fuel cell full cell is characterized by comprising the following steps: firstly, preparing anode support layer slurry by adopting a solvent S1 system, ball-milling and uniformly mixing the anode support layer slurry, and then carrying out tape casting molding and drying to obtain an anode support layer green body; The solvent S1 is a mixed solvent of ethanol and butanone, and the mass ratio of the ethanol to the butanone in the solvent S1 is 1:1 or 1:3; The anode support layer slurry comprises, by mass, 35% -45% of NiO,20% -30% of 8YSZ,8% -12% of graphite, 1% -2% of triethyl phosphate, 5% -8% of polyvinyl butyral, 4% -7% of dibutyl phthalate and the balance of solvent S1; preparing anode functional layer slurry by adopting a solvent S2 system, uniformly grinding the anode functional layer slurry, performing tape casting and forming, and drying to obtain an anode functional layer green body; The solvent S2 is terpineol; the anode functional layer slurry comprises, by mass, 25% -35% of NiO,25% -35% of 8YSZ,1% -2% of polyvinylpyrrolidone, 4% -6% of ethylcellulose, 3% -5% of polyethylene glycol and the balance of solvent S2; preparing electrolyte layer slurry by adopting a solvent S3 system, ball-milling the electrolyte layer slurry uniformly, casting and forming, and drying to obtain an electrolyte layer green body; The solvent S3 is a mixed solvent of ethanol and butanone, and the mass ratio of the ethanol to the butanone in the solvent S3 is 1:1 or 2:1; The electrolyte layer slurry comprises, by mass, 40% -50% of 8YSZ,1.5% -2.5% of polyacrylic acid, 3% -5% of polyvinyl alcohol, 2% -4% of polyethylene glycol and the balance of solvent S3; Step four, stacking the green compact of the anode supporting layer, the green compact of the anode functional layer and the green compact of the electrolyte layer in sequence, carrying out hot pressing and compounding at the temperature of 80-120 ℃ and the pressure of 50-100MPa, and carrying out heat preservation and pressure maintaining for 30-60 minutes to obtain a green compact of the half cell; Step five, performing glue discharging treatment on the half-cell green body, wherein the glue discharging temperature is 300-500 ℃, and the heat preservation is performed for 1-3 hours, and then sintering for 2-5 hours at 1350-1450 ℃ to obtain the half-cell; Preparing GDC blocking layer slurry on the surface of an electrolyte layer of the half cell, printing the GDC blocking layer slurry on the surface of the electrolyte layer by adopting a screen printing method, and sintering at 1250-1350 ℃ for 2-4 hours; the GDC barrier layer slurry comprises 50-60% of GDC powder, 3-5% of ethyl cellulose and the balance of terpineol by mass percent; preparing LSCF cathode slurry on the surface of the GDC barrier layer, printing the LSCF cathode slurry on the surface of the GDC barrier layer by adopting a screen printing method, and sintering for 1-3 hours at 1050-1150 ℃ to obtain the solid oxide fuel cell full cell; the LSCF cathode slurry comprises, by mass, 50% -60% of LSCF powder, 3% -5% of ethyl cellulose and the balance terpineol.
  2. 2. The method for preparing a full cell of a solid oxide fuel cell according to claim 1, wherein in the fourth step, a step-up pressure is adopted in the hot-pressing compounding process, the initial pressure is 10-20MPa, the final pressure is increased to 50-100MPa, and the pressure-up rate is 5-10MPa/min.
  3. 3. The method for preparing a full cell of a solid oxide fuel cell according to claim 1, wherein in the fifth step, a multi-stage temperature rise system is adopted for the glue discharging and sintering: The first stage comprises room temperature to 300 ℃, heating rate of 1-2 ℃ per min, the second stage comprises 300-600 ℃, heating rate of 0.5-1 ℃ per min, heat preservation for 2 hours for discharging glue, the third stage comprises 600-1000 ℃, heating rate of 2-3 ℃ per min, and the fourth stage comprises 1000-1350-1450 ℃, heating rate of 3-5 ℃ per min, and heat preservation for 3 hours.
  4. 4. A solid oxide fuel cell full cell prepared by the method of any one of claims 1 to 3, having a tortuosity of not more than 1.0%, comprising an anode support layer, an anode functional layer, an electrolyte layer, a GDC barrier layer and an LSCF cathode layer laminated in this order.
  5. 5. The solid oxide fuel cell full cell of claim 4, wherein the anode support layer has a thickness of 500-800 μm, the anode functional layer has a thickness of 10-30 μm, the electrolyte layer has a thickness of 5-15 μm, the GDC barrier layer has a thickness of 3-8 μm, and the LSCF cathode layer has a thickness of 20-40 μm.
  6. 6. The solid oxide fuel cell full cell of claim 5, wherein the tortuosity is no more than 0.3%.

Description

Solid oxide fuel cell full cell and preparation method thereof Technical Field The invention belongs to the technical field of solid oxide fuel cells, and particularly relates to a solid oxide fuel cell full cell and a preparation method thereof. Background A Solid Oxide Fuel Cell (SOFC) is an efficient, environmentally friendly energy conversion device that can directly convert chemical energy into electrical energy. Flat plate SOFCs are of great interest because of their high power density and relatively simple manufacturing processes. However, in the process of preparing the SOFC full cell, bending deformation of the cell sheet is often caused due to the difference of thermal expansion coefficients of the materials of the functional layers and mismatch of shrinkage behavior in the sintering process. In the prior art, an anode support is generally prepared by casting and shaping an SOFC full cell, and then an anode functional layer, an electrolyte layer and a cathode layer are sequentially prepared by screen printing, spraying and other modes. The layer-by-layer preparation method is relatively mature in process, but has the problems that (1) bending deformation is serious, internal stress is generated on the battery piece due to different shrinkage rates of materials of all layers in the drying and sintering processes, bending deformation is caused, the bending degree is usually between 2% and 4%, interface bonding is poor, when the layer-by-layer preparation is carried out, the interface bonding strength between the layers is insufficient, layering of the battery is easily caused in the thermal cycle process, the preparation period is long, multiple times of drying and sintering are needed, the energy consumption is high, the production efficiency is low, and (4) the performance consistency is poor, the contact of the battery piece is poor when the battery piece is assembled in a galvanic pile due to bending deformation, and the stability and consistency of the performance of the battery are affected. Therefore, the development of the preparation method capable of effectively controlling the flatness of the whole SOFC, improving the interface bonding strength and shortening the preparation period has important practical significance. Disclosure of Invention The invention aims to provide a preparation method of a solid oxide fuel cell full cell, which effectively solves the problem that in the prior art, cell bending deformation is serious when an SOFC full cell is manufactured by a layer-by-layer preparation method. The preparation method of the solid oxide fuel cell full cell comprises the following steps of adopting a solvent S1 system to prepare anode support layer slurry, ball-milling and mixing the anode support layer slurry uniformly, then casting and forming the anode support layer slurry, and drying the anode support layer slurry to obtain an anode support layer green body, wherein the solvent S1 is a mixed solvent of ethanol and butanone, the mass ratio of the ethanol to the butanone in the solvent S1 is 1:1 or 1:3, and the anode support layer slurry comprises, by mass, 35% -45% of NiO,20% -30% of 8YSZ,8% -12% of graphite, 1% -2% of triethyl phosphate, 5% -8% of polyvinyl butyral, 4% -7% of dibutyl phthalate, and the balance of the solvent S1. Step two, preparing anode functional layer slurry by adopting a solvent S2 system, uniformly grinding the anode functional layer slurry, carrying out tape casting and forming, and drying to obtain an anode functional layer green body, wherein the solvent S2 is terpineol, and the anode functional layer slurry comprises, by mass, 25% -35% of NiO,25% -35% of 8YSZ,1% -2% of polyvinylpyrrolidone, 4% -6% of ethylcellulose, 3% -5% of polyethylene glycol and the balance of solvent S2. Step three, preparing electrolyte layer slurry by adopting a solvent S3 system, carrying out ball milling on the electrolyte layer slurry uniformly, then carrying out tape casting molding, and drying to obtain an electrolyte layer green compact, wherein the solvent S3 is a mixed solvent of ethanol and butanone, the mass ratio of the ethanol to the butanone in the solvent S3 is 1:1 or 2:1, and the electrolyte layer slurry comprises, by mass, 40% -50% of 8YSZ,1.5% -2.5% of polyacrylic acid, 3% -5% of polyvinyl alcohol, 2% -4% of polyethylene glycol, and the balance of the solvent S3. And fourthly, stacking the green body of the anode supporting layer, the green body of the anode functional layer and the green body of the electrolyte layer in sequence, hot-pressing and compounding at the temperature of 80-120 ℃ and the pressure of 50-100MPa, and preserving heat and pressure for 30-60 minutes to obtain the green body of the half cell. And fifthly, performing glue discharging treatment on the half-cell green body, wherein the glue discharging temperature is 300-500 ℃, the heat preservation is performed for 1-3 hours, and then sintering is performed for 2-5 hours at 1350-1450 ℃ to obtain