A battery pack may include a pack housing including an accommodation space and a venting passage connecting the accommodation space to outside, a partition wall member partitioning the accommodation space, a plurality of pack units including battery cells, the plurality of pack units disposed in the accommodation space, and a blocking unit provided between the accommodation space and the venting passage, the blocking unit blocking a substance generated in the pack unit from entering the venting passage.

A wound-type battery includes a wound electrode group having a first electrode and a second electrode with polarity opposite to the first electrode, an electrolyte, a battery case, a sealing plate that seals an opening of the battery case, an insulating plate that is disposed between the electrode group and the sealing plate and that has a hole, and a first tab that passes through the hole to electrically connect the first electrode and the sealing plate to each other. At least a part of a region of the first tab that extends through the hole to a sealing plate side is covered with a tab tape on a side facing the insulating plate. The tab tape includes at least a first adhesive layer and a second adhesive layer on a side opposite the first adhesive layer and is in contact with the first tab through the first adhesive layer.

A wound-type battery includes a wound electrode group having a first electrode and a second electrode with polarity opposite to the first electrode, an electrolyte, a battery case, a sealing plate that seals an opening of the battery case, an insulating plate that is disposed between the electrode group and the sealing plate and that has a hole, and a first tab that passes through the hole to electrically connect the first electrode and the sealing plate to each other. At least a part of a region of the first tab that extends through the hole to a sealing plate side is covered with a tab tape on a side facing the insulating plate. The tab tape includes at least a first adhesive layer and a second adhesive layer on a side opposite the first adhesive layer and is in contact with the first tab through the first adhesive layer.

Provided are a composition for a lithium ion secondary battery separator containing: a liquid medium; and 40 mass % or less of a first compound including a function-displaying functional group and having a molecular weight of 50,000 or less, and having a surface tension of 15 mN/m to 30 mN/m, and a two-part composition for a lithium ion secondary battery separator including: a first liquid containing a first compound and first liquid medium; and a second liquid containing a second compound and second liquid medium, wherein the first compound includes a function-displaying functional group and has a molecular weight of 50,000 or less, the second compound is reactive with the first compound and has a molecular weight of 50,000 or less, and the first and second liquids each contain the corresponding compound in a proportion of 40 mass % or less and have a surface tension of 15 mN/m to 30 mN/m.

The safety of an assembled battery is improved. An insulating sheet 10 is to be interposed between battery cells 20 having planar surfaces 34 facing each other and is formed of a resin composition containing an inorganic filler. An assembled battery 50 includes a plurality of battery cells 20 having planar surfaces 34 and the insulating sheet 10. The insulating sheet 10 is interposed in at least one facing section 36 of the plurality of battery cells 20 whose planar surfaces 34 are arranged to face each other.

The safety of an assembled battery is improved. An insulating sheet 10 is to be interposed between battery cells 20 having planar surfaces 34 facing each other and is formed of a resin composition containing an inorganic filler. An assembled battery 50 includes a plurality of battery cells 20 having planar surfaces 34 and the insulating sheet 10. The insulating sheet 10 is interposed in at least one facing section 36 of the plurality of battery cells 20 whose planar surfaces 34 are arranged to face each other.

The present disclosure relates to a battery cell to alleviate the problem of impurities falling into an electrode assembly. Wherein, the battery cell includes: an electrode assembly including a tab and a cell body, wherein the tab is connected to the cell body; a cover plate assembly including an electrode terminal and a cover plate, wherein the electrode terminal is disposed on the cover plate; a connecting sheet connected between the tab and the electrode terminal, the connecting sheet includes a first connecting portion and a second connecting portion, wherein the first connecting portion is connected to the tab, and the second connecting portion is connected to the electrode terminal; an insulating pallet disposed between the cell body and the connecting sheet; and an insulation member disposed between the insulating pallet and the second connecting portion.

Provided is a technique capable of suppressing the occurrence of uneven drying inside an electrode body. A secondary battery disclosed herein includes an electrode body and a battery case. The battery case has a pair of rectangular wide surfaces and four rectangular side surfaces between the pair of wide surfaces. The electrode body is accommodated in the battery case, wherein rectangular surfaces of the electrode body face the wide surfaces of the battery case. The battery case is provided with protrusions inside, and the protrusions are in contact with at least a part of a central region including a center line in the long side direction of the rectangular surfaces of the electrode body accommodated in the battery case.

A bipolar lithium secondary battery having a bipolar unit that includes a current collector with positive and negative electrodes formed on opposite sides thereof. The bipolar lithium secondary battery may prevent self-discharging and the generation of bypass currents by separating the electrolyte solutions adjacent to the electrodes having different polarities by a polymer film attached to the edge of the current collector, and by preventing the movement of the separated electrolyte solutions.

A rectangular secondary battery is provided with: a rectangular exterior body having an opening, a bottom part, a first lateral wall, a second lateral wall, a third lateral wall, and a fourth lateral wall; a sealing plate for sealing the opening; and a flat wound electrode body obtained by winding a positive electrode plate and a negative electrode plate with a separator therebetween, wherein a plurality of the flat wound electrode bodies are arranged in the rectangular exterior body. The flat wound electrode bodies each have: a flat region formed at the center, a first bent region having a bent outer surface and being formed on one end side of the flat region; and a second bent region having a bent outer surface and being formed on the other end side of the flat region.