I've got some bare copper bus bars I made when the cells I have didn't come with enough factory ones.
My prep method is to sand the contact surfaces with a fine grit sandpaper enough to get a bright shine. then, rub a VERY THIN layer of a conductive antioxidant compound like noalox onto the contact surfaces and assemble. So far, no issues. (36000 ev miles and 4 years)
Assuming your cell modules are reasonably protected from weather you should not have too much trouble with oxidization or galvanic corrosion. Oxidized gunky bus bars were much more trouble with old liquid electrolyte batteries like flooded lead and flooded nicads.
My prep method is to sand the contact surfaces with a fine grit sandpaper enough to get a bright shine. then, rub a VERY THIN layer of a conductive antioxidant compound like noalox onto the contact surfaces and assemble. So far, no issues. (36000 ev miles and 4 years)
Assuming your cell modules are reasonably protected from weather you should not have too much trouble with oxidization or galvanic corrosion. Oxidized gunky bus bars were much more trouble with old liquid electrolyte batteries like flooded lead and flooded nicads.