I-coke ye-petroleum ene-calcined ingahlulwa ibe yi-coke ene-sulfur ephezulu, enomthamo we-sulfur ongaphezulu kwe-3%, kunye ne-coke ene-sulfur ephantsi, enomthamo we-sulfur ongaphantsi kwe-3%. I-coke ye-petroleum ene-calcined ephantsi isetyenziselwa ukunyibilikisa i-silicon yemizi-mveliso kunye nokuvelisa iiplastiki ze-anode. I-coke ene-sulfur ephezulu isetyenziswa njengepetroli kwizityalo zesamente nakwizityalo zombane.