The present invention relates to a button-type secondary battery comprising: a can assembly configured to accommodate an electrode assembly and an electrolyte, wherein the can assembly comprises: a lower can configured to accommodate the electrode assembly and the electrolyte and serve as a first electrode terminal; an upper can coupled to surround the lower can and configured to serve as a second electrode terminal; and a gasket provided between the lower can and the upper can to seal a gap between the lower can and the upper can, wherein a first leakage detection member configured to detect whether the electrolyte leaks is provided on an outer surface of the lower can that is in close contact with the gasket, and the first leakage detection member is provided with a recessed lower coupling groove formed in the outer surface of the lower can.

The present invention relates to a button-type secondary battery comprising: a can assembly configured to accommodate an electrode assembly and an electrolyte, wherein the can assembly comprises: a lower can configured to accommodate the electrode assembly and the electrolyte and serve as a first electrode terminal; an upper can coupled to surround the lower can and configured to serve as a second electrode terminal; and a gasket provided between the lower can and the upper can to seal a gap between the lower can and the upper can, wherein a first leakage detection member configured to detect whether the electrolyte leaks is provided on an outer surface of the lower can that is in close contact with the gasket, and the first leakage detection member is provided with a recessed lower coupling groove formed in the outer surface of the lower can.

A battery cell assembly, including a rolled cell formed from a first electrode and a second electrode rolled together about a longitudinal axis. The rolled cell includes a primary section in which the first electrode and the second electrode overlap in a radial direction from the longitudinal axis, and a first extension end extending from a first longitudinal end of the primary section and formed from a first edge section of the first electrode. The first edge section includes a first folded portion folded to contact an adjacent portion of the first edge section. The battery cell assembly further includes a first end cap coupled to the rolled cell and contacting the first folded portion.

A battery cell assembly, including a rolled cell formed from a first electrode and a second electrode rolled together about a longitudinal axis. The rolled cell includes a primary section in which the first electrode and the second electrode overlap in a radial direction from the longitudinal axis, and a first extension end extending from a first longitudinal end of the primary section and formed from a first edge section of the first electrode. The first edge section includes a first folded portion folded to contact an adjacent portion of the first edge section. The battery cell assembly further includes a first end cap coupled to the rolled cell and contacting the first folded portion.

A battery cell includes a casing provided with openings at two ends of the casing in a first direction, a first end cap and a second end cap connected to the casing and configured to close the openings at the two ends of the casing, respectively, and a connecting piece disposed in the casing and configured to be connected to the first end cap or be connected to the first end cap and the second end cap. The battery cell is provided with a weak structure at one of the two ends. A connecting force between the connecting piece and the first end cap is greater than a connecting force between the connecting piece and the second end cap. A connecting position where the connecting piece is connected to the first end cap is located in an area surrounded by the weak structure.

A battery cell includes a casing provided with openings at two ends of the casing in a first direction, a first end cap and a second end cap connected to the casing and configured to close the openings at the two ends of the casing, respectively, and a connecting piece disposed in the casing and configured to be connected to the first end cap or be connected to the first end cap and the second end cap. The battery cell is provided with a weak structure at one of the two ends. A connecting force between the connecting piece and the first end cap is greater than a connecting force between the connecting piece and the second end cap. A connecting position where the connecting piece is connected to the first end cap is located in an area surrounded by the weak structure.

An end cap assembly, a battery cell, a battery, and an electrical device are provided. The end cap assembly is applicable to a battery cell. The end cap assembly includes: an end cap body; a pressure relief component, connected to the end cap body, where a first through-hole configured to inject an electrolytic solution is made on the pressure relief component, and the pressure relief component is configured to be actuated when an internal pressure of the battery cell reaches a threshold, so as to release the internal pressure of the battery cell; and a closing component, detachably disposed on the pressure relief component, where the closing component is configured to close the first through-hole.

An end cap assembly, a battery cell, a battery, and an electrical device are provided. The end cap assembly is applicable to a battery cell. The end cap assembly includes: an end cap body; a pressure relief component, connected to the end cap body, where a first through-hole configured to inject an electrolytic solution is made on the pressure relief component, and the pressure relief component is configured to be actuated when an internal pressure of the battery cell reaches a threshold, so as to release the internal pressure of the battery cell; and a closing component, detachably disposed on the pressure relief component, where the closing component is configured to close the first through-hole.

The present disclosure provides a secondary battery configured such that an electrode assembly including a positive electrode, a separator, and a negative electrode is housed in a battery case together with an electrolyte solution, wherein the battery case is made of metal, and a conductive layer made of one selected from the group consisting of a conductive carbon layer, a conductive polymer layer, and a conductive epoxy layer is formed on a part or the whole of the inner surface of the battery case coming into contact with the electrolyte solution.

Energy storage devices, battery cells, and batteries of the present technology may include a housing characterized by a first end and a second end opposite the first end. The housing may include a circumferential indentation proximate the first end. The housing may define a first interior region between the first end and the circumferential indentation, and the housing may define a second interior region between the circumferential indentation and the second end. The batteries may include a set of electrodes located within the housing. The set of electrodes may be positioned within the second interior region of the housing. The batteries may include a cap at least partially contained within the first interior region of the housing. The batteries may also include a first insulator positioned within the housing. The first insulator may extend across the circumferential indentation from the cap to the set of electrodes.