Battery pack

An apparatus comprising:

• a plurality of battery cells, wherein one or more of said plurality of battery cells is provided with a gas discharge valve;
• a battery pack which is mounted in an electronic device upon being used, comprising:
• an inside battery compartment which accommodates therein a part of the plurality of battery cells and is located inside an outline of a body of the electronic device when the battery pack is mounted on the electronic device;
• and
• an outside battery compartment which mounts therein a remainder of the plurality of battery cells and is located outside the outline of the body of the electronic device;
• and
• a partition wall structure which is arranged between the inside battery compartment and the outside battery compartment, wherein the partition wall structure comprises:
• a fireproof wall layer which does not melt at a temperature of gas discharged from a gas discharge valve;
• and
• a heat insulating layer comprising a holding wall forming a cantilever disposed between said fireproof wall layer and said outside battery compartment, and further comprising a plurality of holding walls disposed between said fireproof wall layer and said inside battery compartment to define an air layer arranged between said holding wall and said plurality of holding walls.

An apparatus comprising:

• a plurality of battery cells, wherein one or more of said plurality of battery cells is provided with a gas discharge valve;
• a battery pack which is mounted in an electronic device upon being used, comprising:
• an inside battery compartment which accommodates therein a part of the plurality of battery cells and is located inside an outline of a body of the electronic device when the battery pack is mounted on the electronic device;
• and
• an outside battery compartment which mounts therein a remainder of the plurality of battery cells and is located outside the outline of the body of the electronic device;
• and
• a partition wall structure which is arranged between the inside battery compartment and the outside battery compartment, wherein the partition wall structure comprises:
• a heat insulating layer;
• and
• a fireproof wall layer which does not melt at a temperature of gas discharged from a gas discharge valve;
• the heat insulating layer comprises a plurality of holding walls defining an air layer and a space for holding said fireproof wall layer;
• the fireproof wall layer is disposed in said space;
• and
• said fireproof wall layer and one of said plurality of walls are configured to displace toward the inside battery compartment responsive to an impact upon said outside battery compartment.

An apparatus comprising:

• a plurality of battery cells, wherein one or more of said plurality of battery cells is provided with a gas discharge valve;
• a housing containing the plurality of battery cells, wherein the housing constitutes a part of an outline of a body of an electronic device when the battery pack is mounted in the electronic device;
• and
• a partition wall structure which is arranged among the battery cells and comprises:
• a heat insulating layer comprising a plurality of partition walls;
• and
• a fireproof wall disposed between said plurality of partition walls, the fireproof wall layer comprising a material that does not melt at a temperature of gas discharged from a gas discharge valve.