PTC DEVICE AND SECONDARY BATTERY EQUIPPED WITH SAME

Disclosed are: a battery pack comprising a PTC device and a secondary battery; and a PTC device which enables the reduction in size of an electric device such as a dry-cell-type secondary battery. The PTC device comprises (1) a PTC element which comprises (A) a layered polymer PTC element comprising (a1) an electrically conductive filler and (a2) a polymeric material and (B) a PTC element comprising metal electrodes arranged on both surfaces of the polymer PTC element and (2) a lead of which at least a part is placed on each of the metal electrodes in the PTC element and which is connected to the metal electrodes through an electrically conductive material, wherein an exposed part of the electrically conductive material is covered with a protective member which comprises a material capable of absorbing or including an alkali.