The present invention relates to a separator arrangement (20) for an electrochemical battery cell (10) comprising an ionically conductive and electrically insulating separator layer (22), characterized in that the separator arrangement (20) further comprises a reduction layer (24) comprising a reductant, wherein the reduction layer (24) has a specific surface area which is in a range of not less than 10 m2/g, preferably of not less than 100 m2/g, for example of not less than 1000 m2/g, and wherein the reduction layer (24) is porous and has an open porosity in a range from not less than 10% to not more than 90%, preferably from not less than 30% to not more than 70%.