The present invention relates to a system and a method of detecting swelling of a battery cell, which, when abnormal swelling is generated in a battery cell embedded in a battery pack, rapidly detect the abnormal swelling and control a supply of a power source to the battery pack to be blocked, thereby preventing a structural deformation of the battery cell and the battery pack and life shortening of the battery, and preventing an accident, such as ignition and explosion.

An object is to reduce the overall height and outside dimensions of a secondary battery. Another object is to prevent the secondary battery from being damaged by nut tightening torque. A secondary battery includes an electrode body (15), an outer can (11), a sealing plate (12), a pair of electrode terminals (13), and a short-circuit mechanism (20). The pair of electrode terminals (13) includes a first electrode terminal (13A) and a second electrode terminal (13B). The short-circuit mechanism (20) includes a conductive reversible plate (22) secured to the sealing plate (12), and a reversible plate receiver (25) disposed opposite the reversible plate (22). The reversible plate receiver (25) includes a first output terminal (31), and the first output terminal (31) is electrically insulated from the sealing plate (12). The first output terminal is electrically connected to the first electrode terminal, and is spaced from the first electrode terminal.

A battery module includes a battery unit, a circuit board, and an expansion portion. The expansion portion is disposed between a first body and a second body and/or between a first tab and a second tab of the battery unit, and the expansion portion is configured to disconnect the first tab and/or the second tab from the circuit board.

A battery module includes a battery unit, a circuit board, and an expansion portion. The expansion portion is disposed between a first body and a second body and/or between a first tab and a second tab of the battery unit, and the expansion portion is configured to disconnect the first tab and/or the second tab from the circuit board.

A circuit connection apparatus includes a first member and a second member sequentially stacked along a first direction. The first member is conductive. The first member includes a first section, a second section, and a third section. The first section and the second section are spaced apart in the first member. The third section is connected to the first section and the second section separately. The second member includes a boss extending toward the first member. Viewed along the first direction, the boss at least partly overlaps the third section. Along the first direction, the boss and the third section are interspaced with a clearance. The first member and the second member are able to approach each other. The boss is configured to be able to press against and be pressed by the third section to fracture the third section.

Provided are a secondary battery and a battery pack including the secondary battery. A sealing plate has a positive electrode terminal attachment hole. A positive electrode terminal penetrates the positive electrode terminal attachment hole. An external conductive member is connected to a portion of the positive electrode terminal located on the battery outer side with respect to the sealing plate. The conduction path between a positive electrode plate and the positive electrode terminal is provided with a current interrupting mechanism. A first insulating member made of resin is disposed between the sealing plate and the positive electrode terminal. A second insulating member having higher thermal resistance than the first insulating member is disposed between the external conductive member and the sealing plate.

Provided are a secondary battery and a battery pack including the secondary battery. A sealing plate has a positive electrode terminal attachment hole. A positive electrode terminal penetrates the positive electrode terminal attachment hole. An external conductive member is connected to a portion of the positive electrode terminal located on the battery outer side with respect to the sealing plate. The conduction path between a positive electrode plate and the positive electrode terminal is provided with a current interrupting mechanism. A first insulating member made of resin is disposed between the sealing plate and the positive electrode terminal. A second insulating member having higher thermal resistance than the first insulating member is disposed between the external conductive member and the sealing plate.

A cylindrical secondary battery may have an insulation layer formed in a region in which the top cap and the first gasket are coupled to each other. The insulation layer may include a ceramic material and a binder. The secondary battery is designed so that, when an external electrical conductive object is electrically connected directly to a positive electrode and a negative electrode of the secondary battery, an electrode tab of the secondary battery is broken as quickly as possible.

The use of a blend of a lithium nickel oxide and a lithium manganese iron phosphate as an active material composition in the cathode of a lithium secondary electrochemical cell for automotive applications, such as hybrid and electric vehicles. This blend allows decreasing the porosity of a lithium manganese iron phosphate-based cathode. It also allows improving the detectability of a gas release in the cell in case of an abnormal operation of the cell. It allows lowering the cell impedance at a low state of charge, typically less than 30%, and reducing the impedance increase of the cell during the cell lifespan.

The use of a blend of a lithium nickel oxide and a lithium manganese iron phosphate as an active material composition in the cathode of a lithium secondary electrochemical cell for automotive applications, such as hybrid and electric vehicles. This blend allows decreasing the porosity of a lithium manganese iron phosphate-based cathode. It also allows improving the detectability of a gas release in the cell in case of an abnormal operation of the cell. It allows lowering the cell impedance at a low state of charge, typically less than 30%, and reducing the impedance increase of the cell during the cell lifespan.