Lg Chem, Ltd

Sungjong Kim

Jaehan Jung

Ji Hyun Lee

Hong-Jeong Kim

BongTae Kim

Chahun Ku

Hokyung Byun

Geun Ho Seo

Dongsub Lee

Ji Young Kim

Sooryoung Kim

In Sung Lee

Kwan Soo Lee

Byung Kyu Jung

Byung Kwon Jung

Heeseok Kim

SangMinh Lee

SangHun Jeung

Nakjin Kim

Munsung Kim

Dukhyun Ryu

SooRyoung Kim

Jungjin Kim

Sm Lee

A cylindrical battery has a crimp region is formed at the upper end of the container. The upper end of the crimp region is gently bent to surround a gasket located at the inside of the crimp region. A bent front end is continuously bent twice to press the gasket, while the bent front end extends inward, such that a radius of curvature (R1) of the first bent area is less than a radius of curvature (R2) of the second bent area. The upper end of the crimp region of the cylindrical container is continuously bent twice in a predetermined condition. Consequently, when external physical impacts are applied to the battery, and when the internal pressure of the battery increases, the sealed portions are restrained from being separated from each other, thereby preventing the leakage of an electrolyte and thus greatly improving the safety of the battery.

Lithium ion battery of crimping shape of increased safety

Provided is a cylindrical battery in which an electrode assembly fabricated by rolling a cathode/separator/anode and an electrolyte are provided in a cylindrical can, wherein a cap assembly mounted on the opening top of the cylindrical can comprises: a safety vent provided with a predetermined notch, to allow breakage due to high-pressure gas of the battery, a current interruptive device to interrupt current, welded to the bottom of the safety vent, and a gasket for the current interruptive device to surround the periphery of the current interruptive device, wherein the current interruptive device comprises two or more through holes to allow exhaustion of gas, wherein the through holes have a size of 20 to 50% with respect to the total area of the current interruptive device.

Cylindrical secondary battery of improved safety

A cylindrical battery constructed in a structure in which a crimp region is gently bent, such that the crimp region surrounds a gasket located at the inside of the crimp region, a bent front end is continuously bent twice to press the gasket, to be in the form of a compound curve. Under external physical impacts, such as vibration or dropping, applied to the battery, and when the internal pressure of the battery increases, the sealed portions are restrained from being separated from each other, thereby preventing the leakage of an electrolyte and thus greatly improving the safety of the battery. Furthermore, it is possible to minimize the deformation of the container, such as wrinkles, which may be formed due to failure to form the bent area gently when bending the front end of the crimp region with a small radius of curvature.

Disclosed herein is a cap assembly loaded on an open upper end of a cylindrical container of a battery in which an electrode assembly is mounted in the cylindrical container, the cap assembly including a safety vent having a predetermined notch configured to rupture by high-pressure gas generated in the battery, a current interruptive device coupled to a bottom of the safety vent by welding for interrupting current when internal pressure of the battery increases, and a current interruptive device gasket for surrounding an outer circumference of the current interruptive device, wherein the current interruptive device includes two or more through holes for gas discharge, the through holes being formed such that the sum of areas of the through holes is equal to 20% to 50% of an entire area of the current interruptive device. When high-pressure gas is generated in the battery, the cap assembly effectively interrupts current and rapidly discharges the gas, thereby greatly improving safety of the battery.

Cap assembly of improved safety and cylindrical secondary battery employed with the same

Disclosed herein is a cylindrical secondary battery including a cap assembly constructed in a structure in which a vent, which intercepts electric current and discharges pressurized gas when the interior pressure of the battery is increased due to abnormal operation of the battery, is in contact with a top cap having a protruding central part, wherein the end of the vent is bent to surround the outer circumferential surface of the top cap, and a groove for preventing the leakage of an electrolyte and preventing the occurrence of defectiveness of the battery during the assembly of the battery is formed at interfaces between the vent and the top cap such that the groove is arranged in parallel with the outer circumferential surface of the top cap. The secondary battery according to the present invention has the effect of accomplishing high charging and discharging rate, providing uniform output even when external physical impacts, such as vibration or dropping, are applied to the secondary battery, and preventing the occurrence of defectiveness during the assembly of the secondary battery. Furthermore, the leakage of the electrolyte out of the battery is restrained under these conditions. Consequently, the secondary battery according to the present invention can be preferably used as a high-output power source.

High rate charging and discharging cylindrical secondary battery

Disclosed herein is a cylindrical secondary battery constructed in a structure in which a crimping region, at which a cap assembly is mounted to the open upper end of a cylindrical container having an electrode assembly mounted therein, is formed at the upper end of the container, wherein the crimping region is constructed in a structure in which the upper end of the crimping region is gently bent at a predetermined radius of curvature (R), such that the crimping region surrounds a gasket located at the inside of the crimping region, the bent front end extends inward, such that the bent end presses the gasket, and an inclination of a predetermined angle is formed at the sidewall of the crimping region, such that the upper part of the crimping region is directed inward. According to the secondary battery of the present invention, the sealability of the gasket is improved, and external impacts are partially absorbed by the inclination formed at the crimping region. Consequently, the deformation of the crimping region is minimized, whereby the leakage of the electrolyte is prevented, and the safety of the battery is greatly improved.

Disclosed herein are an electrode assembly having separators the upper ends of which are sealed and a secondary battery including the same. The electrode assembly has a cathode/separator/anode structure that can be charged and discharged. The separators, which protrude beyond the upper ends of the electrodes, are bent in one direction, the separators are heat-treated such that the bent state of the separators is fixed, and an insulative coating layer is formed at the bent surfaces of the separators. Consequently, foreign matter is prevented from being introduced into the electrode assembly, and therefore, the safety of electrode assembly is improved.

Battery assembly employed with separator of sealed top portion and secondary battery comprising the same

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Daejeon, South Korea

Sungjong Kim