An explosion-proof over-current protection element includes a fuse body, a ceramic shell, an explosion-proof layer, an arc-extinguishing layer, and a protection layer. The fuse body includes two electrodes and a fuse wire between the electrodes. The fuse body is integrally formed. The fuse wire is arranged within a cavity of the ceramic shell. The electrodes protrude from inside of the cavity toward outside of the cavity to contact an outer wall of the ceramic shell. The explosion-proof layer is arranged within the cavity and contacts a bottom surface of the cavity. The arc-extinguishing layer is arranged within the cavity and covers the fuse wire. The explosion-proof layer and the arc-extinguishing layer are made of different materials. The protection layer is arranged within the cavity. The arc-extinguishing layer is located between the explosion-proof layer and the protection layer.

A protection device and a battery pack are provided, the protection device includes multiple terminal electrodes including a first terminal electrode and a second terminal electrode; a fusible conductor, where a lower surface of the fusible conductor is disposed on the first and second terminal electrodes, and the fusible conductor is supported by the first and second terminal electrodes, and two ends of the fusible conductor are electrically connected to the first and second terminal electrodes, respectively; and a first heat generating element, where one end of the first heat generating element is coupled to another surface of the fusible conductor different to the lower surface, or one end of the first heat generating element is coupled to a surface of any one of the first and second terminal electrodes.

A fuse including a first housing part and a second housing part that are joined together to define a cavity, a fuse element disposed within the cavity, a first terminal extending from a first end of the fuse element and out of the housing, and a second terminal extending from a second end of the fuse element and out of the housing, the housing having a vent channel extending from an outer surface of the housing to the cavity for allowing vapor to escape from the cavity.

A fuse includes a fuse body, two terminals, and a termination reinforcement. The fuse body surrounds a fusible element. The first terminal is located at one end of the fuse body and the second terminal is located at the other end of the fuse body. The fusible element is mechanically connected to the first and second terminals. The termination reinforcement is located at one end of the fuse body.

A protective element includes: a fuse element configured to be energized in a first direction, which is a direction from a first end portion of the fuse element to a second end portion of the fuse element; a first terminal electrically connected to the first end portion; a second terminal electrically connected to the second end portion; a case made of an insulating material, having therein a housing portion storing the fuse element, and exposing a portion of the first terminal and a portion of the second terminal to an outside of the case; and a cover made of an insulating material having a tube shape, covering a lateral face along the first direction of the case, and exposing a portion of the first terminal from a first end of the cover, and exposes a portion of the second terminal from a second end of the cover.