Abstract: A pouch type battery case configured to accommodate an electrode assembly, in which electrodes and separators are stacked, according to an embodiment of the present invention for achieving the above object includes: a first cup part and a second cup part, which are arranged parallel to a pouch film and formed to be recessed; and a bridge formed between the first cup part and the second cup part and having a constant width and height, wherein the first cup part includes: a first outer wall formed toward an opposite to the bridge; a second outer wall formed toward the bridge; and a first bottom portion configured to connect the first outer wall to the second outer wall, and the second cup part includes: a third outer wall formed toward the bridge; a fourth outer wall formed toward the opposite to the bridge; and a second bottom portion configured to connect the third outer wall to the fourth outer wall, wherein the fourth outer wall has a height greater than that of the first outer wall.

Abstract: A lithium secondary battery includes a positive electrode including a lithium manganese-based first positive electrode active material having a spinel structure doped and coated and a lithium nickel-manganese-cobalt-based second positive active material, a negative electrode including artificial graphite having a specific surface area (BET) of 0.1-1.2 m2/g and at least one selected from the group consisting of soft carbon and natural graphite which have a greater specific surface area than the artificial graphite, a separator interposed between the positive electrode and the negative electrode, and an electrolyte.

Abstract: Provided are a secondary battery, a battery module, and a battery pack, which have improved safety. Particularly, since a bulletproof material is disposed on the inside and/or the outside of an exterior part, even when a conductive needle-shaped member penetrates a secondary battery, heating, burning, discharge of evaporated electrolyte, and electrical contact between the needle-shaped member and an electrode can be prevented, thereby improving safety of the secondary battery, the battery module, and the battery pack.

Abstract: The soldering connector according to the present invention, which electrically connects a plurality of unit cells to each other, comprises a lead-free alloy including tin (Sn) and copper (Cu). According to the present invention, when a secondary battery overheats due to the malfunction thereof, electrical connection between unit cells comprised in a battery module rapidly disconnects under a relatively low temperature and current range, thereby ensuring the safety of the secondary battery.

Abstract: Provided is a secondary battery, comprising an electrode assembly including a first electrode plate, a second electrode plate and a separator; and a case having a receiving portion for receiving the electrode assembly and an electrolyte therein, the secondary battery comprising: a blowing agent applied onto at least one of a first tab and a second tab in a width direction of the tab, the first and second tabs being, respectively, connected to the first and second electrode plates and connected to leads which extend through the case.

Abstract: Provided is a positive electrode active material. The positive electrode active material includes: a small-diameter active material having an average particle diameter of about 0.5 ?m and a maximum particle diameter of less than about 1 ?m; and a large-diameter active material having an average particle diameter of about 5 ?m to about 20 ?m and a maximum particle diameter of less than about 100 ?m.

Abstract: Provided is a positive electrode active material. The positive electrode active material includes: a small-diameter active material having an average particle diameter of about 0.5 ?m and a maximum particle diameter of less than about 1 ?m; and a large-diameter active material having an average particle diameter of about 5 ?m to about 20 ?m and a maximum particle diameter of less than about 100 ?m.

Abstract: Provided are a secondary battery, a battery module, and a battery pack, which have improved safety. Particularly, since a bulletproof material is disposed on the inside and/or the outside of an exterior part, even when a conductive needle-shaped member penetrates a secondary battery, heating, burning, discharge of evaporated electrolyte, and electrical contact between the needle-shaped member and an electrode can be prevented, thereby improving safety of the secondary battery, the battery module, and the battery pack.

Abstract: Provided is a secondary battery, comprising an electrode assembly including a first electrode plate, a second electrode plate and a separator; and a case having a receiving portion for receiving the electrode assembly and an electrolyte therein, the secondary battery comprising: a blowing agent applied onto at least one of a first tab and a second tab in a width direction of the tab, the first and second tabs being, respectively, connected to the first and second electrode plates and connected to leads which extend through the case.