| Solid oxide fuel cells(SOFCs)are environmentally efficient energy devices,but are partially limited by the complicated fabrication procedures.The development of the digital light processing(DLP)technology on ceramics makes it possible to reduce the fabrication procedures especially manual assembly and multiple joints.At present,there are few papers on DLP 3D printing SOFCs because of the lack of ceramic UV resin slurries of related materials.So,in order to solve this problem,the feasibility of DLP3D printing electrolyte-supported SOFC has been discussed in this thesis from the aspects of ceramic UV resin slurry,the sintering characteristics of the printed electrolyte samples and the structure design of the electrolytes by using the state-of-the-art 8 mol%yttria-stabilized zirconia(8YSZ)powder.The main conclusions are as following:Firstly,the effect of different kinds of dispersant,different dispersant concentrations and different solid-phase contents of the slurries on the rheological properties of 8YSZ UV resin slurries was studied.The results showed that when the alkanolamine salt of copolymer containing acid group is used as dispersant,the viscosity of slurry is the lowest with the highest fluidity index and barely a little yield stress,which indicated that the carboxylic functional groups can absorbed on the surface of the powder as anchor groups and the long chains of the dispersants can provide the steric force for the dispersion of powders.When the dispersant concentration is 3 wt%and the solid-phase content is 50 vol%,a low viscosity(<5Pa·s at a shear rate of10 s-1)was remained for an acceptable printing performance with the DLP technology.Secondly,by using the prepared 8YSZ UV resin slurry,the sintering characteristics of the printed 8YSZ samples and the electrochemical performance of the printed flat electrolyte-supported primary cell were studied.The results showed that a fully dense ceramic can be achieved at a temperature of 1450°C and the total conductivity of the sintered 8YSZ can reach 2.18×10-2 S·cm-1 at a test temperature of 800°C,which is acceptable for practical application.Besides,by using printed 8YSZ electrolyte membrane,a self-supported fuel cell fabricated with Ni-8YSZ cermet and LSM as anode and cathode respectively had a power density of 114.3 m W·cm-2,It was demonstrated that 3D printing is a promising processing technique to build up electrolyte self-supported SOFCs with desired structure for the future development.Thirdly,8YSZ ripple-shaped and honeycomb-like electrolytes have been prepared by DLP 3D printing and the electrochemical performances of assembled primary cells supported by these two kinds of electrolytes have been investigated.At a test temperature of 800°C,Compared with the reference flat cell,an improvement of?20%was achieved in the power density of the honeycomb-like elelctrolyte-supported primary cell due to the reduction of the condutive area thickness and an improvement of?32%was achieved in the power density of the ripple-shaped elelctrolyte-supported primary cell due to the increase of the electrode-electrolyte interface(36%).Finally,the 8YSZ electrolyte with three-dimensional toplogical structure was prepared by DLP 3D printing and the effect of the structure on the electrochemical performance of the assembled primary cell by slip casting of the electrode slurries with different solid-phase contents.The results showed that when the solid-phase content of electode slurries is 35 vol%,the power of the primary cell is the highest,which is 260.1W.However,due to the low utilization rate of the area of the channel of the electrolyte,the power density of the cell could not reach that of the flat cell as prepared before.But,this strategy can really simplify the cell assembly processing. |
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