A battery module includes a plurality of unit batteries, a holder accommodating the unit batteries and including a pin extending from the holder, a protective circuit module electrically coupled to the plurality of unit batteries, and a coupling member coupled to the pin to fix the protective circuit module to the holder. The holder may include a boss supporting the protective circuit module. The protective circuit module may define a coupling opening configured to receive the pin.

Disclosed is a secondary battery capable of preventing damage to a current interrupt device caused by generation and transmission of vibration, and thereby achieving prevention of malfunction of the current interrupt device, and improvement of quality of the secondary battery. In addition, disclosed is a method of manufacturing the secondary battery. Specifically disclosed is a secondary battery, in which a positive electrode terminal is placed on the upper face of a sealing plate, a holder is placed on the lower face of the sealing plate, and the sealing plate is joined to the positive electrode terminal and the holder by a rivet. The secondary battery includes an adhered portion for adhering the holder to the sealing plate.

A positive electrode mixture layer (12) includes a first layer (12a) that has a main surface MS and a second layer (12b) formed closer to the positive electrode current collector (11) side than the first layer (12a). A ratio of the volume of the first layer (12a) to the volume of the positive electrode mixture layer (12) is 20 to 75 vol %. The first layer (12a) contains lithium iron phosphate (LFP) (1) and lithium nickel cobalt manganese composite oxide (NCM) (2). A ratio of the mass of the LFP (1) to the total mass of the LFP (1) and the NCM (2) in the first layer (12a) is more than 0 and 80 mass % or less. The second layer (12b) contains NCM (2). A ratio of the mass of the LFP (1) to the total mass of the positive electrode active material in the positive electrode mixture layer (12) is 7.5 to 20 mass %. A maximum pore size of the first layer (12a) is 0.50 to 0.70 μm.

A secondary battery includes an electrode assembly including first and second electrodes, an outer body having an opening and housing the electrode assembly, a conductive sealing plate sealing the opening, and a deformable member. The sealing plate has a first through-hole. The deformable member seals the first through-hole. When the opening of the outer body faces upward, a second electrode connecting member electrically connected to the second electrode is above the deformable member. A conductive conducting member is disposed between the second electrode connecting member and the deformable member. The diameter of the conducting member is larger than the diameter of the first through-hole. When the pressure inside the outer body becomes equal to or higher than a predetermined value, the deformable member is deformed and brings the conducting member into contact with the second electrode connecting member and electrically connects the sealing plate and the second electrode connecting member.

Embodiments are directed to contact plates configured to establish electrical bonds between battery cells in a battery module. In a first embodiment, the contact plate includes at least one primary conductive layer including a hole that is aligned with two or more terminals of two or more battery cells in a group of battery cells that are configured to be connected in parallel with each other, and a bonding connector configured to provide direct electrical bonds between the contact plate and the two or more terminals of the two or more battery cells. In a second embodiment, a contact plate includes at least one primary conductive layer and a set of bonding connectors made from at least one material that is selected to match at least one material used for the terminals of the at least one group of battery cells.

An embodiment is directed to a battery module, including a plurality of battery cell groups that are connected in series with each other, each of the plurality of battery cell groups including a plurality of battery cells that are connected to each other in parallel, a first terminal component at a first terminal of the battery module, the first terminal corresponding to either a positive terminal of the battery module or a negative terminal of the battery module, and a first heat pipe positioned in proximity to the first terminal component and configured to transfer heat away from the first terminal component.

An embodiment is directed to a multi-layer contact plate configured to establish electrical bonds to battery cells in a battery module. The multi-layer contact plate includes two or more primary conductive layers (e.g., Al, Cu, etc.), and a cell terminal connection layer (e.g., steel, Al, Cu, etc.) that is joined with, and sandwiched by, the two or more primary conductive layers. A portion of the cell terminal connection layer is configured to form a set of bonding connectors (e.g., bonding ribbons) to provide a direct electrical bond between the multi-layer contact plate and terminals (e.g., positive terminals, negative terminals, or a combination thereof) of at least one group of battery cells (e.g., a single group of battery cells, two groups of battery cells that are connected in series, etc.).

Embodiments are directed to establishing a direct electrical bond between a bonding connector of a contact plate and a battery cell in a battery module. In a first embodiment, an oscillating laser is used to weld the bonding connector to a battery cell terminal over a target area over which the bonding connector makes non-flush contact. In a second embodiment, the bonding connector is flattened to reduce a gap between the bonding connector and the target area on the battery cell terminal, and then laser-welded (e.g., using an oscillating or non-oscillating laser). In a third embodiment, at least one hold-down mechanism is applied over the bonding connector to secure the bonding connector to the battery cell terminal, after which the bonding connector is laser-welded to the battery cell terminal.

Embodiments are directed to establishing a direct electrical bond between a bonding connector of a contact plate and a battery cell in a battery module. In a first embodiment, an oscillating laser is used to weld the bonding connector to a battery cell terminal over a target area over which the bonding connector makes non-flush contact. In a second embodiment, the bonding connector is flattened to reduce a gap between the bonding connector and the target area on the battery cell terminal, and then laser-welded (e.g., using an oscillating or non-oscillating laser). In a third embodiment, at least one hold-down mechanism is applied over the bonding connector to secure the bonding connector to the battery cell terminal, after which the bonding connector is laser-welded to the battery cell terminal.

An embodiment is directed to a multi-layer contact plate configured to establish electrical bonds to battery cells in a battery module. The multi-layer contact plate includes two or more primary conductive layers (e.g., Al, Cu, etc.), and a cell terminal connection layer (e.g., steel, Al, Cu, etc.) that is joined with, and sandwiched by, the two or more primary conductive layers. A portion of the cell terminal connection layer is configured to form a set of bonding connectors (e.g., bonding ribbons) to provide a direct electrical bond between the multi-layer contact plate and terminals (e.g., positive terminals, negative terminals, or a combination thereof) of at least one group of battery cells (e.g., a single group of battery cells, two groups of battery cells that are connected in series, etc.).