At one edge of a positive electrode plate in a winding axis direction of an electrode body, two positive electrode tabs per turn are provided to protrude from the edge. At the other edge of a negative electrode plate in the winding axis direction of the electrode body, two negative electrode tabs per turn are provided to protrude from the edge. The multiple positive electrode tabs provided to protrude from the positive electrode plate include multiple types of positive electrode tabs having different protrusion lengths and proximal end widths, and the multiple negative electrode tabs provided to protrude from the negative electrode plate include multiple types of negative electrode tabs having different protrusion lengths and base end widths.

An electronic device includes an electrode assembly. The electrode assembly is configured to be a wound structure and is provided with a first bending section. The electrode assembly comprises a first electrode plate, a second electrode plate, and a conductive member. The first electrode plate includes a first current collector and a first active material layer, and along a winding direction, the first current collector includes a first part and a second part that are connected in sequence. Both surfaces of the first part are arranged with the first active material layer, an inner surface of the second part is provided with the first active material layer, and the second part includes a bending part located at an outermost layer of the first bending section. The conductive member connects the outer surfaces of the first part and the second part, and/or covers on the outer surface of the bending part.

An electrochemical device including an electrode assembly including a first section, a first bend section, a second section, and a second bend section connected in sequence along a winding direction. A first bonding piece includes a first body portion disposed on the first bend section and a first extension portion disposed on the first section. The first body portion is configured to bond the first bend section to the housing. A second bonding piece includes a second body portion disposed on the second bend section and a second extension portion disposed on the first section. The second body portion is configured to bond the second bend section to the housing. A third bonding piece is disposed between the electrode assembly and the housing. The third bonding piece is bonded to the housing, the first extension portion, and the second extension portion.

There is provided a method for producing a separator for an electricity storage device that includes a step of contacting a porous body formed from a silane-modified polyolefin-containing molded sheet with a base solution or acid solution, and a separator for an electricity storage device comprising a microporous film with a melted film rupture temperature of 180° C. to 220° C. as measured by thermomechanical analysis (TMA).

An embodiment of the present invention relates to a cylindrical secondary battery comprising: a cylindrical can having one open end; an electrode assembly received in the can, and wherein a first electrode plate having a first electrode uncoated part, a separator, a second electrode plate having a second electrode uncoated part disposed in a direction opposite to the first electrode uncoated part are stacked and wound into a cylindrical shape; and a cap assembly for closing the open end of the can while the electrode assembly is received in the can, wherein an end of at least one of the first electrode uncoated part and the second electrode uncoated part is bent to form a bending part. An embodiment of the present invention is advantageous for a welding process in that, when a current collection plate is welded, the thickness and number of weldable substrates are increased and the gaps between the substrates are reduced, thereby increasing the heat capacity of a welding part. Furthermore, there are fewer empty spaces between the substrates after the substrates are compacted for welding than a structure having no bending part, and thus the electrode plates or the separator can be prevented from being damaged due to the penetration of welding heat, thereby improving a stability risk.

An electrode assembly, a battery cell, a battery, and a method and device for manufacturing an electrode assembly are provided. In some embodiments, the electrode assembly includes a positive electrode plate and a negative electrode plate. The positive electrode plate and the negative electrode plate are wound or folded to form a bend region. The positive electrode plate includes a plurality of bend portions located in the bend region. Each bend portion includes a positive current collecting layer and a positive active material layer. The positive current collecting layer is coated with the positive active material layer on at least one surface in a thickness direction of the positive electrode plate. A barrier layer is disposed between the positive current collecting layer and the positive active material 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.

A secondary battery includes a jelly roll-type electrode assembly impregnated with an electrolyte solution; a battery case for housing the electrode assembly and the electrolyte solution; a cap assembly coupled with an upper portion of the battery case; and a reference electrode in which one end is immersed with the electrolyte solution and the other end is exposed to the outside through the battery case and the cap assembly.

A lithium-ion battery, including a battery cell, an electrolytic solution, and a packaging film. The battery cell is formed by winding a positive electrode plate and a negative electrode plate that are separated by a separator. The lithium-ion battery is half-charged to obtain a half-charged full battery. The half-charged full battery is stripped of the packaging film to obtain a half-charged cell. When a width of the half-charged full battery is w.sub.1, a width of the half-charged cell is w.sub.2, and g=w.sub.2/w.sub.1, the following conditional expression (1) is satisfied: 0.4<g<0.997. A negative active material of the negative electrode plate includes a silicon-based material. When a capacity per unit volume of the negative electrode plate is a, a and g satisfy the following conditional expression (2): 420 mAh/cm.sup.3<g×a<2300 mAh/cm.sup.3, where 619 mAh/cm.sup.3<a<3620 mAh/cm.sup.3. The present invention further provides an electronic device.

Electrodes are formed with a porous layer of particulate electrode material bonded to each of the two major sides of a compatible metal current collector. In one embodiment, opposing electrodes are formed with like lithium-ion battery anode materials or like cathode materials or capacitor materials on both sides of the current collector. In another embodiment, a battery electrode material is applied to one side of a current collector and capacitor material is applied to the other side. In general, the electrodes are formed by combining a suitable grouping of capacitor layers with un-equal numbers of anode and cathode battery layers. One or more pairs of opposing electrodes are assembled to provide a combination of battery and capacitor energy and power properties in a hybrid electrochemical cell. The cells may be formed by stacking or winding rolls of the opposing electrodes with interposed separators.