An exhaust gas treatment system (A) and an apparatus (D), for use in treating exhaust gas of a battery pack (M). The exhaust gas treatment system (A) comprises: a mixing means (1) configured to mix oxygen with the exhaust gas of the battery pack (M) to form a gas mixture; a reacting means (2), a catalyst (26) in the reacting means (2) being used for catalyzing the gas mixture; and a discharging means (3) configured to discharge a catalyzed substance. The apparatus (D) comprises the battery pack (M) and the exhaust gas treatment system (A).