An electrochemical device includes a positive electrode plate, a negative electrode plate, a separator, and an electrolytic solution. The positive electrode plate includes a positive active material having lithium transition metal oxide particles represented by a chemical formula Li.sub.aCo.sub.xM1.sub.yM2.sub.zO.sub.2, where 0.95≤a≤1.05, 0.05<x<1, 0≤y≤0.9, 0<z≤0.2, x+y+z=1, an M1 is one or two selected from the group consisting of Ni and Mn, and an M2 is at least one selected from the group consisting of Mg, Al, Ti, La, Y, and Zr. The separator includes a porous substrate and a polymer adhesive layer. The polymer adhesive layer is disposed between the porous substrate and the positive electrode plate. An adhesive force of the polymer adhesive layer between the positive electrode plate is 3 N/m to 100 N/m.

A battery cell including an electrode assembly present in a battery casing. The electrode assembly includes a positive electrode, a negative electrode and a separator interposed between the positive electrode and the negative electrode. The separator includes a porous polymer substrate, a first organic/inorganic porous coating layer on at least one surface of the porous polymer substrate, and a second organic/inorganic porous coating layer on a surface of the first organic/inorganic porous coating layer. The first organic/inorganic porous coating layer includes first inorganic particles and a first binder polymer, the second organic/inorganic porous coating layer includes second inorganic particles and a second binder polymer, the second organic/inorganic porous coating layer faces the positive electrode, and the second binder polymer has a weight average molecular weight higher than the weight average molecular weight of the first binder polymer.

A composite separator for an electrochemical device. The composite separator has an electrode adhesive layer, and two types of solvents are used when coating the electrode adhesive layer. The ratio of polarity of the solvents is used to induce a beta crystal phase of the second binder resin, and thus a uniform porous structure is formed to provide an improved lithium-ion conduction path. In this manner, even when the electrode adhesive layer is formed on the composite separator, the composite separator does not cause an increase in resistance.

The present invention refers to a method of preparing a separator, a separator prepared therefrom and an electrochemical device having the separator. The method of preparing a separator according to the present invention comprises providing a planar and porous substrate having multiple pores; and coating a first slurry on at least one surface of the porous substrate through a slot section to form a porous coating layer, while continuously coating a second slurry on the porous coating layer through a slide section adjacent to the slot section to form a layer for adhesion with an electrode, the first slurry comprising inorganic particles, a first binder polymer and a first solvent, and the second slurry comprising a second binder polymer and a second solvent.

Disclosed are a separator membrane, a separator membrane roll, a battery cell, and a power lithium battery. The separator membrane includes a porous base film and a bonding layer; in a preset direction of the porous base film, the surface of the porous substrate includes a middle blank area, and a coated area at the two ends; the bonding layer is applied on the two coated areas. By means of applying the bonding layer to both ends of the porous base film surface, it is possible, during the process of assembling and forming the lithium battery cell, to cause the bonding layer to contact and bond with the two ends of the negative electrode inside the lithium battery cell, effectively ensuring that the lithium battery bears sufficient tension, pressure, and vibration during assembly, vibration testing, and long-term cycling.

A power storage device is provided with a movement restricting member including: an electrode-body bonding portion bonded to a fixing surface of a thickness-direction outside surface of outer surfaces of an electrode body; and an extended portion extending from the electrode-body bonding portion and protruding more than the electrode body in a movement restricting direction. When the electrode body moves in the movement restricting direction, the extended portion contacts an inner peripheral surface of a can, thereby restricting the electrode body from moving in the movement restricting direction.

The separator disclosed herein includes a substrate and an adhesive layer. The adhesive layer is partially provided on one side of, or both of two sides of, the substrate. Where an initial thickness of the separator is T0, a thickness of the separator when the separator is impregnated with an electrolyte solution and supplied with a pressure of 1 MPa is T1, a thickness of the separator when, after this, the separator is supplied with a pressure of 2 MPa for 1 hour, and the pressure is decreased to 0.5 MPa, is T2, and a thickness of the separator when, after this, the separator is supplied with a pressure of 4 MPa for 48 hours, is T4, the separator satisfies inequalities (1) through (3): (1) 1≤T1/T0≤1.1; (2) 0.92≤T2/T1≤1; and (3) 0.6≤T4/T1≤0.8.

An adhesive resin composition for a secondary battery for bonding a separator for a secondary battery and an electrode for a secondary battery, wherein the composition comprises an adhesive resin having a unit derived from an aromatic vinyl monomer and having a glass transition temperature of 25° C. or lower.

A lithium-ion secondary battery including a plurality of layered units (U), wherein: the layered unit (U) is a unit including a positive electrode layer, a separator layer and a negative electrode layer, and an adhesive layer (NS) interposed between the negative electrode layer and the separator layer to bond them together, the unit having a plurality of edge portions; and the adhesive layer (NS) has a protruding portion protruding to an outer peripheral side of the negative electrode layer at one or more of the edge portions; and a method for producing the lithium-ion secondary battery.

A composite battery cell includes a plurality of electricity supply elements connected to each other in series/parallel to form the electricity supply element groups. The electricity supply element groups are connected to each other in parallel/series and packed to form the battery cell with high capacity and high voltage. Each electricity supply element is an in-dependent module and the electrolyte system does not circulate therebetween. There only have charges transferred rather than electrochemical reactions between the adjacent electricity supply elements. Therefore, the electrolyte decomposition would not occur result from the high voltage caused by connecting in series. Both series and parallel connection are made within the package of the battery cell to achieve high capacity and high voltage.