Lg Chem, Ltd

Lg Energy Solution, Ltd.

Han-Gab Song

Pil-Kyu Park

Min-Gyu Kim

Young-Tae Kim

An-Soo Jeong

Nam-Won Kim

Joo-Hwan Sung

Jong-Hoon Park

Sung-Min Park

A lithium secondary battery is provided which includes a cylindrical jelly roll in which an electrode assembly having a stacked structure including a positive electrode is wound cylindrically, wherein a semi-cylindrical first winding core and second winding core are spaced apart from each other by a predetermined interval, the positive electrode includes a non-coated portion sheet having a positive electrode tab fused thereto and a coated portion sheet, and the non-coated portion sheet and the coated portion sheet are attached by a tape to provide the positive electrode, one end of the positive electrode is positioned at the core portion of the cylindrical jelly roll, and a portion of the positive electrode having the tape is positioned around a circumference of the winding core member such that it avoids a portion where the first winding core is spaced apart from the second winding core by the predetermined interval.

Lithium secondary battery including cylindrical jelly roll

Apparatus and methods of evaluating brittleness by measuring force applied to an electrode specimen by simulating a wound state of a jelly-roll type electrode assembly are disclosed herein. In an embodiment, a brittleness evaluation apparatus includes a jig unit, a driving unit, and a measurement analyzing unit. The jig unit includes two jigs, a groove formed between the jigs, a pressing plate, and guides. The jigs facing each other and have top surfaces formed in a horizontal plane and configured to receive a specimen arranged on the top surfaces along a length direction extending between and along the top surfaces. The pressing plate is arranged perpendicular to the length direction and configured to cause the specimen to bend by descending into the groove. The guides are located on each of the top surfaces of the jigs and configured to prevent distortion of the specimen during descent of the pressing plate.

Apparatus and method for evaluating electrode embrittlement

A jig assembly for measuring the tensile strength of an electrode at a bend having a similar radius to a core, an apparatus for measuring bending tensile strength including the jig assembly, and a method for measuring bending tensile strength that measures the tensile strength of an electrode at a bend having a similar radius to a core using the apparatus for measuring bending tensile strength are provided. The jig assembly of the present disclosure includes a fixing unit configured to fix a first end part of a sample, and a plate shaped bending jig configured to provide a one point bend to a lengthwise direction cross section of the sample and to guide a second end part of the sample toward a tensile testing load unit. According to the present disclosure, it is possible to measure the tensile strength of the electrode under a similar condition to a winding process before the electrode is used in real winding applications.

Jig assembly comprising bending jig and apparatus and method for measuring bending tensile strength using the same

Growing community of inventors

Daejeon, South Korea

Han-Gab Song