The present invention relates to an aqueous coating composition (A) comprising at least one cathodically depositable binder (A1) and optionally at least one crosslinking agent (A2), for at least partly coating an electrically conductive substrate with an electrocoat material, where the coating composition (A) has a pH in a range from 4.0 to 6.5 and comprises a total amount of at least 30 ppm of bismuth, based on the total weight of the coating composition (A), and where (A) is produced using at least 0.005% by weight of magnesium oxide particles (B), based on the total weight of the coating composition (A), to the use of (A) for at least partly coating an electrically conductive substrate with an electrocoat material, to a corresponding coating method, and to an at least partly coated substrate obtainable by this method.