An electrochemical device includes a housing including a body portion and a first portion, an electrode assembly, and a tab. In a second direction, the body portion includes a first wall and a second wall disposed opposite to each other. In a third direction, the body portion includes a first sidewall and a second sidewall disposed opposite to each other. The first portion includes a first seal edge and a second seal edge. The first seal edge is connected to the first sidewall and the second wall. The second seal edge is connected to the first seal edge. The second seal edge is disposed between the first seal edge and the first sidewall. The housing includes a first housing part and a second housing part disposed opposite to each other. The first housing part includes a first polymer layer. The second housing part includes a second polymer layer.

An electrochemical device includes a housing including a body portion and a first portion, an electrode assembly, and a tab. In a second direction, the body portion includes a first wall and a second wall disposed opposite to each other. In a third direction, the body portion includes a first sidewall and a second sidewall disposed opposite to each other. The first portion includes a first seal edge and a second seal edge. The first seal edge is connected to the first sidewall and the second wall. The second seal edge is connected to the first seal edge. The second seal edge is disposed between the first seal edge and the first sidewall. The housing includes a first housing part and a second housing part disposed opposite to each other. The first housing part includes a first polymer layer. The second housing part includes a second polymer layer.

A cylindrical secondary battery includes: an electrode assembly including a positive electrode plate having a positive electrode multi-tab, a separator, and a negative electrode plate having a negative electrode multi-tab, the positive electrode plate, the separator, and the negative electrode plate being laminated and wound; a cylindrical can accommodating the electrode assembly; a cap plate coupled at an upper end of the cylindrical can and being electrically connected to the negative electrode multi-tab; and a positive electrode terminal protruding upwardly through the cap plate and being electrically connected to the positive electrode multi-tab.

In one embodiment, a connecting lead connecting between a current collecting tab of an electrode group and an electrode terminal in a battery is provided. The connecting lead includes a top plate portion and a leg portion, a leg portion is bent relative to the top plate portion to one side in a thickness direction of the top plate portion, and a bend line at a bend position to the top plate portion is along a width direction of the top plate portion. The leg portion includes an extension portion located apart from the bend position to the top plate portion. The extension portion includes, on an outer surface, a side face relaying between a pair of main faces and facing one side in the width direction of the top plate portion. The side face is joined to the current collecting tab.

W1/T1 is equal to or greater than 5, assuming that the width of an electrode body in a direction perpendicular to a winding axis direction and a thickness direction of the electrode body is W1 (mm) and the thickness of the electrode body 3 is T1 (mm).

An electrochemical device includes a negative electrode plate, a positive electrode plate and a separator provided between the negative electrode plate and the positive electrode plate. There are m negative tabs electrically connected to the negative electrode plate, wherein m is a positive integer greater than or equal to 1. There are n positive tabs electrically connected to the positive electrode plate, wherein n is a positive integer greater than 1, and n>m. The electrochemical device is charged with a multi-stage constant current charging method.

A method includes, by a folding station: receiving an anode assembly including anode collectors connected by anode interconnects and coated with a separator; receiving a cathode assembly including cathode collectors connected by cathode interconnects; locating a first anode collector over a folding stage; locating a first cathode collector over the first anode collector to form a first battery cell between the first anode collector and the first cathode collector; folding a first anode interconnect to locate a second anode collector over the first cathode collector to form a second battery cell between the first cathode collector and the second anode collector; folding a first cathode interconnect to locate a second cathode collector over the second anode collector to form a third battery cell between the second anode collector and the second cathode collector; wetting the separator with solvated ions; and loading the anode and cathode assemblies into a battery housing.

Provided are a secondary battery and a battery pack including the secondary battery. A sealing plate has a positive electrode terminal attachment hole. A positive electrode terminal penetrates the positive electrode terminal attachment hole. An external conductive member is connected to a portion of the positive electrode terminal located on the battery outer side with respect to the sealing plate. The conduction path between a positive electrode plate and the positive electrode terminal is provided with a current interrupting mechanism. A first insulating member made of resin is disposed between the sealing plate and the positive electrode terminal. A second insulating member having higher thermal resistance than the first insulating member is disposed between the external conductive member and the sealing plate.

A secondary battery is provided including an electrode wound body housed in a battery can, with the electrode wound body having a structure including a band-shaped positive electrode and a band-shaped negative electrode laminated and wound with a separator interposed therebetween, where the positive electrode includes a positive electrode active material layer on both sides of a band-shaped positive electrode foil, the negative electrode includes a negative electrode active material layer on both sides of a band-shaped negative electrode foil, the electrode wound body includes a positive electrode tab at a central part of the positive electrode, includes a negative electrode tab on a winding end side of the negative electrode, and includes a foil tab in a flat plate shape on a winding start side of either one or both of the positive electrode and the negative electrode.

A secondary battery is provided including an electrode wound body housed in a battery can, with the electrode wound body having a structure including a band-shaped positive electrode and a band-shaped negative electrode laminated and wound with a separator interposed therebetween, where the positive electrode includes a positive electrode active material layer on both sides of a band-shaped positive electrode foil, the negative electrode includes a negative electrode active material layer on both sides of a band-shaped negative electrode foil, the electrode wound body includes a positive electrode tab at a central part of the positive electrode, includes a negative electrode tab on a winding end side of the negative electrode, and includes a foil tab in a flat plate shape on a winding start side of either one or both of the positive electrode and the negative electrode.