An electrode body includes: a positive electrode that includes a positive electrode active material layer; a negative electrode that includes a negative electrode active material layer; and a separator that electrically separates the positive electrode and the negative electrode from each other, in which the positive electrode active material layer and the separator contain N-methylpyrrolidone (NMP). A N-methylpyrrolidone (NMP) content in the positive electrode active material layer is 54 ppm to 602 ppm with respect to a total solid content of the positive electrode active material layer, and a N-methylpyrrolidone content (NMP) in the separator is 10 ppm to 26 ppm with respect to the total solid content of the positive electrode active material layer.

A method for film production includes the steps of obtaining information on the position of a defect (D) in a separator (12a) and providing marks (LA, LB) at the respective positions in the vicinity of the defect (D), the marks indicating the position of the defect.

The following disclosure relates to a microporous polyolefin composite film having excellent heat resistance and thermal stability, and a method for manufacturing the same. More particularly, the present invention relates to a microporous polyolefin composite film capable of improving stability and reliability of a battery by heat sealing an edge of a microporous film provided with a coating layer that includes a polymer binder and inorganic particles, and a method for manufacturing the same.

A composition for forming a porous heat-resistant layer of a separator, a separator, and an electrochemical battery, the composition including a monomer including a cross-linkable functional group, an oligomer including a cross-linkable functional group, a polymer including a cross-linkable functional group, or a mixture thereof; a solvent; an initiator; first inorganic particles having an average particle diameter (D.sub.50) X of about 300 nm to about 700 nm; and second inorganics particle having an average particle diameter (D.sub.50) of 0.1X to 0.4X, wherein a weight ratio of the first inorganic particles to the second inorganic particles in the composition is about 7:3 to about 8.5:1.5.

A porous insulator is provided. The porous insulator comprises a porous structure comprising a polymer compound having communicating pores, and a solid having a melting point or glass transition temperature lower than that of the polymer compound.

A metal-ion battery is provided. The metal-ion battery includes a positive electrode, a negative electrode, a separating structure, and an electrolyte, wherein the positive electrode and the negative electrode are separated by the separating structure, and the electrolyte composition is disposed between the positive electrode and the negative electrode. The separating structure includes a first separator, a second separator, and a dielectric layer, wherein the dielectric layer is disposed between the first separator and the second separator. The dielectric layer consists of a dielectric material, and the dielectric material has a dielectric constant from 10 to 200.

The present invention provides a resin composition comprising the following resin (a) and filler particles. The use of this composition makes it possible to obtain a separator having excellent heat resistance. Resin (a): a copolymer comprising a structural unit represented by a formula (1) and a structural unit represented by a formula (2), ##STR00001##
wherein M.sup.n+ represents a metal ion, and n represents the valence thereof, ##STR00002##

An electrode assembly, comprises one or more first electrodes comprising a cathode; one or more second electrodes comprising an anode; and a separator sheet having a zigzag form interposed therebetween. The separator sheet comprises a first porous polymer substrate; a first coating layer formed on one surface of the first porous polymer substrate and comprising a polymer binder, the first coating layer being faced with the cathode; and a second coating layer formed on the other surface of the first porous polymer substrate and comprising a mixture a polymer binder and inorganic particles, the second coating layer being faced with the anode and having a composition, a thickness and a porosity different from those of the first porous coating layer. A separator has porous coating layers with a different composition, thickness or porosity formed on each surface thereof.

The invention is directed to a flexible and stretchable battery which is formed of an assembly having anode side and a cathode side separated by a separator and sealed in a packaging. The assembly is in a folded configuration and contains at least one cut therein, such that when the assembly is unfolded and subjected to subsequent deformation, a final folded state of the battery is able to stretch beyond a flat planar state of the battery in all dimensions.

Provided herein is a lithium battery including: a cathode including a cathode active material; an anode including an anode active material; an electrolyte between the cathode and the anode; and a separator impregnated with the electrolyte, wherein the separator includes cellulose nanofibers, and wherein a differential scanning calorimetry (DSC) thermogram of the separator evinces an exothermic reaction peak, represented by a differential value (dH/dT), at a temperature in a range of about 150° C. to about 200° C.