Preparation Of LSCF Cathode Thin Layer Of Solid Oxide Fuel Cell By Ink Jet Printing And Its Properties

Energy is the foundation of human survival and social development.The development of high-quality new energy and the development of advanced new energy technologies are important ways to solve today’s energy crisis and environmental pollution.Solid oxide fuel cell（SOFC）is a power generation device that can directly convert chemical energy into electrical energy.It has high energy conversion efficiency,stable reliability and environmental friendliness.Inkjet printing technology is a promising non-contact maskless manufacturing method,which has a wide application in the manufacturing fields of electronic components,optical devices and micro-nano new energy components.It has the advantages of low cost,fast and precise manufacturing process.In this paper,the application of piezoelectric inkjet printer in the preparation of SOFC cathode thin layer is studied,which provides a new method and idea for the preparation of porous structure of SOFC.The preparation of a stable cathode ceramic suspension ink suitable for ink jet printing is the material basis for a thin layer of inkjet printed cathode.This paper develops and characterizes a novel aqueous SOFC cathode suspension with extremely high dispersion.The perovskite ceramic material La_0.6Sr_0.4Co_0.2Fe_0.8O₃-δ（LSCF）was used as the cathode powder material,and the dispersion effects were compared using two dispersants,triethanolamine（TEA）and polyacrylic acid（PAA）.The suspension formulation is optimized by measurement of zeta potential,viscosity and surface tension as well as sedimentation,drying and sintering tests.The results show that the optimum dispersibility can be achieved in a suspension having a pH of 5.8（the zeta potential of 41.8 mV）using TEA as a dispersant.The ink jet printing test also demonstrated excellent printability of the suspension.It is capable of achieving long-term stability and uniformity of more than 120 days,while other suspensions are less dispersible.The SEM results further verified the excellent dispersibility and uniformity of INK-T1,which can be used to prepare a defect-free LSCF thin layer.The excellent droplet ejection effect and stable printing process play a decisive role in inkjet printing of the LSCF cathode thin layer on a dense electrolyte substrate.A thin layer of cathode is prepared using a novel aqueous SOFC cathode suspension loaded into an inkjet printer cartridge.The printing effect of the suspension is optimized by improving the printer voltage waveform and adjusting the voltage value,optimizing the suspension formulation,and reducing the particle size of the LSCF material by wet grinding.The results show that the suspension after grinding for 4 h with a 0.1 mm diameter zirconium ball at a ball ratio of 2:1using wet grinding has not only a suitable powder particle size but also a good printing effect.By changing the voltage value at the time of printing and filtering the printing suspension multiple times,it is possible to simultaneously work with six nozzles,and the phenomenon of satellite droplets is also eliminated.And the thin layer of cathode with different layer thickness was successfully fabricated on the substrate.After sintering,the fault and surface morphology were observed under electron microscope.The results show that the prepared cathode thin layer not only has certain mechanical properties,but also has small surface cracks after sintering,and the inside is a very good porous structure.