i used galvanized carbon / graphite ..   good old carbon paper might work but is difficult to get ...   graphite works excellently .... and graphite powder can be obtained "cheaply" (can be used to make conductive ink ) ... [ try to get the middle of a pencil ( that's pure graphite) ] use a handkerchief , toilet paper or something else for the electrolyte   anyway used alu foil you can get easily from everywhere === for the volts you can use either "joule thief"  or one of those special ICs ...