The present disclosure refers to a ventilation device for a battery, particularly to a multifunctional breathing and venting device for a casing of one of a battery submodule, battery module or battery system, such as for an electric vehicle and an energy storage system (ESS). The ventilation device comprising a housing configured for being attached to a vent opening of a battery casing in a sealing manner and comprising at least one lateral wall, a breathable filter separating an interior of the battery casing from a breathing chamber within the housing, a venting membrane separating the breathing chamber from an exterior environment in a gas tight manner, and a breathing sprout fluidly connecting the breathing chamber and the environment and bypassing the venting membrane. The disclosure further relates to a battery comprising such a ventilation device attached to its casing.