A battery module has a plurality of battery cells each including a cell case and a battery element contained in the cell case. The battery module includes a lead to electrically connect a terminal of each of the battery cells to a current collector and a heat shutoff mechanism to break electrical connection between the terminal and the current collector by heat from the cell case when the cell case reaches a predetermined temperature or higher.

The invention relates to a method for operating a battery cell (10), in particular a lithium-ion battery cell, having at least one wound or stacked electrode assembly (28) arranged in a housing, said electrode assembly comprising a first electrode layer (12), at least one separator layer (16) and a second electrode layer (14), and a non-aqueous electrolyte containing one or more solvents and one or more conductive salts. When the battery cell (10) reaches a critical state, a chemical substance or a chemical substance mixture (46) is released, which forms complexes with the lithium ions (22) in the electrolyte (26).

An electrical breaker responsive to a fault condition is disclosed. A thermally-activated switch can be disposed between a first terminal and second and third terminals of the breaker. The switch can have a normal operating condition in which the first terminal is electrically connected to the second terminal. The switch can have a fault condition in which the first terminal is electrically connected to both the second terminal and the third terminal, causing a majority of the current to flow between the first terminal and the third terminal and a minority of the current to flow between the first terminal and the second terminal. The breaker can include a positive temperature coefficient (PTC) resistor between the first terminal and one of the second and third terminals. The thermally-activated switch can be integrated into a variety of structures, for example, a battery pack which can house one or more cells.

A battery connection structure includes a plurality of battery units connected in series. At least one battery unit is connected in series to other battery units through a temperature switch; the temperature switch includes a first connection member connected to a first electrode terminal of the battery unit and a second connection member connected to a second electrode terminal of the battery unit; at normal operating temperature, the first connection member and the second connection member are disconnected, and the first connection member and the second connection member are respectively connected to the two electrode terminals of the battery unit; when the temperature is higher than the normal operating temperature, the first connection member and/or the second connection member are/is deformed and disconnected from the corresponding electrode terminal(s) of the battery unit, and the first connection member and the second connection member are connected.

A cylindrical battery cell, a battery and a method for forming cylindrical battery cell are provided.

In the cylindrical cell, an opening is created on a bottom side of the cell housing and a copper plate is forged with the cell housing to form a bi-metal plate on the bottom side of the cell housing, and the copper plate is welded with the jellyroll structure. Therefore, joining/welding the cell housing with the jellyroll structure is achieved by using a laser from outside of the cell housing, while risk of corrosion of cell housing is not introduced.

An electrical bypass device has two electrical conductors electrically insulated from one another and arranged such that two surface regions of the conductors are spaced apart from one another by a gap. Above the surface regions is a bypass element having at least one electrically conductive layer in the form of or connected to a mechanical energy store. The mechanical energy store is transferable by thermal triggering from a first mechanical state to a stable second mechanical state in which the electrically conductive layer of the bypass element makes electrical contact with the surface regions and shorts the two electrical conductors. Above the surface regions is a reactive element where an exothermic reaction can be triggered, resulting in the mechanical energy store transferring to the stable second mechanical state.

The present invention describes a component for a secondary battery and a manufacturing method thereof, and a secondary battery manufactured by using the component. The component for a secondary battery according to the present invention comprises a lead-free soldering bridge having a melting point of 150 to 300 C. and containing tin (Sn) and copper (Cu) as a main ingredient; the first and second metal plates spaced therebetween through a gap and coupling with the lead-free soldering bridge. According to the present invention, when an over-current flows through the component for a secondary battery, the temperature of the lead-free soldering bridge is locally increased rapidly to melt the lead-free soldering bridge, thereby efficiently interrupting the flow of an over-current.

A secondary battery is disclosed. In one aspect, the secondary battery includes a case accommodating an electrode assembly, a cap plate sealing an opening of the case, an electrode terminal electrically connected to the electrode assembly and disposed over the cap, and an insulating member provided between the cap plate and the electrode terminal and configured to insulate the electrode terminal from the cap plate. The battery also includes a connection tab disposed over the electrode terminal, and a safety device having a portion positioned under the connection tab and electrically connected to the electrode terminal via the connection tab. The safety device has at least one of electric conductivity and thermal conductivity greater than that of the connection tab, and at least a part of the safety device is seated on the insulating member.

A secondary battery, includes a bare cell including an upper surface having an electrode terminal and side surfaces perpendicular to the upper surface; and a first coverlay and a second coverlay electrically connected to the bare cell, the side surfaces including a pair of first side surfaces that are in parallel with each other, and a pair of second side surfaces connecting the pair of first side surfaces to each other and having a smaller area than that of the pair of first side surfaces, the first coverlay including a first region on the upper surface, and a second region bent perpendicularly from the first region and on one of the pair of the second side surfaces, the second coverlay including a third region on the first region, and a fourth region bent perpendicularly from the third region and on the second region.

A method of protecting a battery pack in which first and second battery cells, each having a positive electrode, a negative electrode, and an edge are aligned so that the positive electrodes of the first and second battery cells are adjacent. An electrically conductive busbar configured to be positioned on an edge of the first and second battery cells electrically connects the positive electrode of the first battery cell to a first protection device, the positive electrode of the second battery cell to a second protection device, the first protection device to the second protection device, and the negative electrode of the first battery cell to the negative electrode of the second battery cell. Also provided is a battery pack protection assembly.