Provided is a nonaqueous electrolyte secondary battery separator having an excellent withstand voltage property after repeated charge-discharge cycles. The nonaqueous electrolyte secondary battery separator includes a polyolefin porous film, and a heat-resistant porous layer that contains a heat-resistant resin and that is formed on one surface or both surfaces of the polyolefin porous film, the nonaqueous electrolyte secondary battery separator having an absolute value of a ratio of change in thickness between before and after a heat-shock cycle test in a range of not more than 1.4%.

Provided is a nonaqueous electrolyte secondary battery separator having an excellent withstand voltage property after repeated charge-discharge cycles. The nonaqueous electrolyte secondary battery separator includes a polyolefin porous film, and a heat-resistant porous layer that contains a heat-resistant resin and that is formed on one surface or both surfaces of the polyolefin porous film, the nonaqueous electrolyte secondary battery separator having an absolute value of a ratio of change in thickness between before and after a heat-shock cycle test in a range of not more than 1.4%.

Provided is a nonaqueous electrolyte secondary battery porous layer which is capable of improving a capacity maintenance ratio shown when a nonaqueous electrolyte secondary battery is repeatedly subjected to a charge-discharge cycle. The nonaqueous electrolyte secondary battery porous layer contains at least one type of a resin having an amide bond, and an aspect ratio of a pore therein is not less than 1.0 and not more than 2.2.

As a nonaqueous electrolyte secondary battery porous layer which can improve battery performance such as initial charge-discharge efficiency of a nonaqueous electrolyte secondary battery, provided is a nonaqueous electrolyte secondary battery porous layer which contains a resin that has an amide bond and that contains a cyclic component, and in which a contained amount of the cyclic component is not less than 2.0% by weight and not more than 10.0% by weight relative to a total weight of the resin having the amide bond.

Provided are a micro-porous hybrid film and a method for preparing the same, and more particularly, a micro-porous hybrid film capable of improving reliability of a battery by simultaneously improving thermal stability at a high temperature and water properties, and a method for preparing the same. In addition, the present invention relates to a micro-porous hybrid film suitable for a separator of a high capacity/high output lithium secondary battery capable of increasing production stability, long term stability, and performance of the battery by improving adhesive force between a micro-porous film and a coating layer and permeability and minimizing a water content by the coating layer.

A battery according to the invention includes, as a separator, a first separator and a second separator having mutually different characteristics. The first separator and the second separator are disposed inside an electrode assembly in a state where the separators are not in contact with each other in a stacking direction of the electrode assembly. The first separator and the second separator have the following characteristic: when the battery is constructed including an electrode assembly formed by stacking the positive electrode, the first separator and the negative electrode, a resistance increase rate X=Delta X/Delta P satisfies X>0 (positive value), X being evaluated from a change amount Delta P of surface pressure applied in the stacking direction of the electrode assembly and a resistance increment Delta X of the battery upon application of the surface pressure change amount Delta P, and when the battery is constructed including an electrode assembly formed by stacking the positive electrode, the second separator and the negative electrode, a resistance increase rate Y=Delta Y/Delta P satisfies Y<0 (negative value), Y being evaluated from a change amount Delta P of surface pressure applied in the stacking direction of the electrode assembly and a resistance increment Delta Y of the battery upon application of the surface pressure change amount Delta P.

The present disclosure provides a heat-diffusible separator including a separator, and a porous heat transfer film formed on at least one surface of the separator.

An alkaline electrochemical cell includes a cathode, an anode which includes an anode active material, and a non-conductive separator disposed between the cathode and the anode, wherein from about 20% to about 50% by weight of the anode active material relative to a total amount of anode active material has a particle size of less than about 75 μm, and wherein the separator includes a unitary, cylindrical configuration having an open end, a side wall, and integrally formed closed end disposed distally to the open end.

Provided is an LDH-like compound separator that includes a porous substrate made of a polymer material and a layered double hydroxide (LDH)-like compound plugging pores in the porous substrate, and has a linear transmittance of 1% or more at a wavelength of 1000 nm.

Provided is a secondary battery capable of breaking an external electrical connection by way of a simpler configuration when an abnormality such as overcharge occurs. A secondary battery 1 comprises a battery element comprising a positive electrode 11, a negative electrode 12, a separator 13, and an electrolytic solution, and a casing sealing the battery element. The electrolytic solution comprises a gel component and an organic solvent having a boiling point of 125° C. or less. The separator 13 comprises a fiber assembly or a microporous structure composed of one or more resins selected from aramid, polyimide, and polyphenylenesulfide, and has an average void size of 0.1 μm or more.