TITLE: Preparation of ink for electrode deposition via paint brushing using oxide powder    
AUTHORS: Giulio Cordaro

[DESCRIPTION]
<div class = "text-blocks"><div class = "text-block">A simple and efficient procedure to produce a viscous ink for brush painting of porous electrodes on top of electrolyte pellets for Solid Oxide Fuel Cells (SOFCs). </div><div class = "text-block">The layers have a variable porosity between 20 and 40%, depending on the choice of the calcination parameters, which is strongly influenced on the electrode and electrolyte materials, the particle size distribution and the morphology of the electrode powder. </div><div class = "text-block">The thickness of the layers is variable in the 10-100 μm range, depending upon the amount of ink deposited.</div><div class = "text-block">All the calcination parameters, the electrode and electrolyte materials, the particle size distribution and the morphology influence the adhesion of the electrode layer on the electrolyte substrate. </div></div>

[STEPS]
?. [1.	Preparation of organic viscous paste ]
Weigh terpineol directly inside the bottle CompoundsCAS NumberPercentage [wt./wt.]Amount [g]Ethyl-cellulose9004-57-3 4%0.0800Terpineol95-55-5 76%1.5200Iso-propanol67-63-0 20%0.4000
[or rescale all ingredients if need different amount ]
CompoundsCAS NumberPercentage [wt./wt.]Amount [g]Ethyl-cellulose9004-57-3 4%0.0800Terpineol95-55-5 76%1.5200Iso-propanol67-63-0 20%0.4000
?. [1.	Preparation of organic viscous paste ]
Add iso-propanol
0.4 g
?. [1.	Preparation of organic viscous paste ]
Close the lid and stir few minutes on a magnetic plate
?. [1.	Preparation of organic viscous paste ]
Weigh ethyl-cellulose separately on tin foil
0.08 g
?. [1.	Preparation of organic viscous paste ]
Add the ethyl-cellulose little by little to avoid big agglomerationsBe careful to limit the solid on the walls and on the top of the stirrer
?. [1.	Preparation of organic viscous paste ]
Close the lid and stir until complete dissolution and homogenizationBe careful that there are no clumps on the walls
?. [2.	Treatment of the electrode powder for ink preparation]
The electrode powder ideally will be treated previously to ink preparation to avoid the presence of big agglomerates
?. [2.	Treatment of the electrode powder for ink preparation]
Ball milling at 300 rpm for 4 hours with balls/powder mass ratio of 10 to 20 with ethanol as media (covering powder), with zirconia or WC jar/ballsBe careful that milling hard materials can pollute the powder with worn particles from balls or jar
?. [2.	Treatment of the electrode powder for ink preparation]
Rinse with ethanol and recover the powder in a beaker, then dry on a hotplate or in a muffle at 80°C
?. [3.	Mixing of organic vehicle with powder (powder:paste = 60:40 wt.) and painting]
Clean and weigh a plastic bottle with cone-shaped bottom
?. [3.	Mixing of organic vehicle with powder (powder:paste = 60:40 wt.) and painting]
Weigh about 0.2 g of viscous paste with a thin metal tip (Figure Step 1)
?. [3.	Mixing of organic vehicle with powder (powder:paste = 60:40 wt.) and painting]
Calculate the amount of electrode powder to add (ratio 3:2 in weight)
?. [3.	Mixing of organic vehicle with powder (powder:paste = 60:40 wt.) and painting]
Weigh, add the electrode powder and mix with the metal tip to perfectly homogenize the inkBe careful to completely incorporate all the powder
?. [3.	Mixing of organic vehicle with powder (powder:paste = 60:40 wt.) and painting]
Rest for sedimentation at least 15 minutes
?. [3.	Mixing of organic vehicle with powder (powder:paste = 60:40 wt.) and painting]
Dip the brush only in the top part of the ink and paint the electrolyte surface as more homogeneous as possible
?. [3.	Mixing of organic vehicle with powder (powder:paste = 60:40 wt.) and painting]
Dry at 150 °C for 3 hours and paint the other side
?. [3.	Mixing of organic vehicle with powder (powder:paste = 60:40 wt.) and painting]
Calcine at 1000 °C for 2 hours (±1 °C/min) and check the adhesion! Be careful that these values are indicative. The optimal parameters need to be evaluated for each sample, depending on the choice of electrode and electrolyte materials, and on the particle size distribution and the morphology of the electrode powder.