Separator

The separator is a thin, porous membrane placed between the anode and cathode of a battery that prevents direct electrical contact — which would cause a short circuit — while allowing ions to pass through the electrolyte. Separator integrity is a key safety factor, since failure can trigger internal shorts and thermal runaway. It is part of the cell architecture that determines a battery’s safety performance assessed during conformity assessment under Regulation (EU) 2023/1542.