A sealing film which seals between a metal first base and a second base, the sealing film including: a first adhesive layer that mainly contains an acid-modified polyolefin and adheres to the first base; a second adhesive layer that mainly contains a polyolefin and adheres to the second base; and a base material layer provided between the first adhesive layer and the second adhesive layer, in which the base material layer contains (A), (B), and (C), a ratio [(A)/(B)+(C)] is 90/10 to 20/80, a content percentage of (B) with respect to a total amount of (A), (B), and (C) is 5% by mass or more and 70% by mass or less, and a content percentage of (C) with respect to the total amount of (A), (B), and (C) is 5% by mass or more and 70% by mass or less.

A cell includes an electrode assembly and a tab electrically connected to the electrode assembly, the packaging housing includes a housing body, a cover, and a polymer layer. The housing body is provided with an accommodating portion, where the accommodating portion is configured to accommodate the electrode assembly, the tab extends from the accommodating portion to the outside of the housing body, and the housing body is further provided with a first sealing portion extending from an edge of an opening of the accommodating portion to the outside of the housing body along a first direction. The cover is provided with a second sealing portion extending along the first direction. The cover covers the opening of the accommodating portion, and the first sealing portion and the second sealing portion are disposed opposite to each other. The polymer layer is disposed between the first sealing portion and the second sealing portion.

The present invention relates to a secondary battery having improved output and safety. In one embodiment, disclosed is a secondary battery comprising: an electrode assembly comprising a first electrode, a second electrode and a separator; a case for accommodating the electrode assembly; and a cap assembly coupled to the upper part of the case, wherein the first electrode comprises a first current collector, a first active material layer in which the first active material layer is applied onto the first current collector, a first uncoated area on which a first active material is not applied, and a first electrode tab electrically connected to the first current collector, and the first electrode tab comprises a current collection tab, which is a part of the first current collector, and a lead tab attached to the first current collector.

A secondary battery includes: an electrode assembly including a negative electrode tab at a first end and a positive electrode tab at a second end; a case including a pair of first side portions facing each of a pair of long side portions of the electrode assembly, and a pair of second side portions facing each of a pair of short side portions of the electrode assembly, the case being open in directions of the negative electrode tab and the positive electrode tab; and a retainer between at least one of the second side portions and the electrode assembly and including a concave-convex structure.

A secondary battery includes: an electrode assembly including a negative electrode tab at a first end and a positive electrode tab at a second end; a case including a pair of first side portions facing each of a pair of long side portions of the electrode assembly, and a pair of second side portions facing each of a pair of short side portions of the electrode assembly, the case being open in directions of the negative electrode tab and the positive electrode tab; and a retainer between at least one of the second side portions and the electrode assembly and including a concave-convex structure.

A method of manufacturing a secondary battery including an electrode body element fabricating step in which a first electrode body element including a positive electrode plate and a negative electrode plate, and a second electrode body element including a positive electrode plate and a negative electrode plate are fabricated, a tab-connecting step in which a first positive electrode tab group of the first electrode body element and a second positive electrode tab group of the second electrode body element are connected to a second positive electrode collector, and a first negative electrode tab group of the first electrode body element and a second negative electrode tab group of the second electrode body element are connected to a second negative electrode collector, and an electrode body fabricating step in which, after the tab-connecting step, the first electrode body element and the second electrode body element are unified.

An electrochemical apparatus includes an electrode assembly. The electrode assembly includes a first electrode plate and a first tab group electrically connected to the first electrode plate, and an end of the electrode assembly includes a reusable region. The first electrode plate includes a first region located at an end of the first electrode plate and a second region connected to the first region, a thickness of the first region is less than a thickness of the second region, and the first region is disposed within the reusable region. The first tab group includes a first connecting portion located at an end of a first tab and a first bending portion connected to the first connecting portion and located on a side face of the electrode assembly, the first bending portion is disposed within the reusable region.

An electrode assembly includes an electrode plate and an embedded tab provided on the electrode plate. A spinning layer is provided on a surface of the electrode plate, the spinning layer covers the surface of the electrode plate and is in contact with the surface of the electrode plate, and the surface of the electrode plate includes a surface of the tab. The spinning layer replaces a conventional separator, and the spinning layer and the electrode plate are integrated as a whole. Especially in a battery structure with the embedded tabs, because the spinning layer is able to isolate metal burrs. The spinning layer replaces the green glue originally affixed on the tab region, thereby eliminating the glue affixed on the tab region.

A secondary battery includes a positive electrode, a negative electrode, an electrolytic solution, and an insulating member. The positive electrode includes a positive electrode current collector and a positive electrode active material layer. The negative electrode is opposed to the positive electrode. The electrolytic solution includes a chain carboxylic acid ester. The insulating member includes an adhesive layer including a rubber-based polymer compound. The positive electrode includes an exposed part in which the positive electrode current collector is exposed. The insulating member is adhered to the exposed part via the adhesive layer on a side opposed to the negative electrode.

Embodiments described herein relate to electrodes and electrochemical cells with positive temperature coefficient coatings and methods of producing the same. In some embodiments, an electrode can include a layer of a film material, a positive temperature coefficient (PTC) coating disposed in the layer of film material. The PTC material resists a flow of current through at least a portion of the PTC material when a temperature of the at least a portion of the PTC material exceeds a threshold value. The electrode further includes an electrode material disposed on the PTC material. In some embodiments, the electrode can further include an electrode tab coupled to the PTC material and the electrode film. In some embodiments, the PTC material can include a conductive polymer. In some embodiments, the electrode material can include a semi-solid and/or a binderless electrode material.