US 12,227,868 B2
Electrolytic copper foil capable of preventing tearing or wrinkle defects, electrode containing same, secondary battery containing same, and method for manufacturing same
Young Tae Kim, Jeongeup-si (KR); Sang Hyun Jun, Jeongeup-si (KR); Jeong Gil Lee, Jeongeup-si (KR); and Seung Min Kim, Jeongeup-si (KR)
Assigned to SK NEXILIS CO., LTD., Jeongeup-si (KR)
Appl. No. 17/432,593
Filed by SK NEXILIS CO., LTD., Jeongeup-si (KR)
PCT Filed Nov. 5, 2020, PCT No. PCT/KR2020/015390
§ 371(c)(1), (2) Date Aug. 20, 2021,
PCT Pub. No. WO2021/091250, PCT Pub. Date May 14, 2021.
Claims priority of application No. 10-2019-0142712 (KR), filed on Nov. 8, 2019.
Prior Publication US 2022/0119973 A1, Apr. 21, 2022
Int. Cl. H01M 4/66 (2006.01); C25D 3/38 (2006.01); C25D 5/48 (2006.01); H01M 4/02 (2006.01)
CPC C25D 3/38 (2013.01) [C25D 5/48 (2013.01); H01M 4/661 (2013.01); H01M 2004/027 (2013.01)] 8 Claims
 
1. An electrolytic copper foil that has a width direction weight deviation of 5% or less, a tensile strength of 25 kgf/mm2 to 62 kgf/mm2, a valley depth-to-thickness (VDT) of 3.5 to 66.9, the electrolytic copper foil comprising a copper layer, and a deviation of valley depth-to-thickness in a width direction (DVDT) of 2.6 μm2 or less,
wherein the width direction weight deviation is calculated according to Equation 1 below, the VDT is calculated according to Equation 2 below, and the DVDT is calculated according to Equation 3 below:

OG Complex Work Unit Math
wherein the VDT is measured at least three points of the electrolytic copper foil, and an average value of values of the measured VDT is denoted as VDTaverage, a highest value thereof is denoted as VDTmax, and a lowest value thereof is denoted as VDTmin.