US 12,438,140 B2
Method of manufacturing negative electrode
Oh Byong Chae, Daejeon (KR); Ye Ri Kim, Daejeon (KR); Su Yeon Lee, Daejeon (KR); Seo Young Jeon, Daejeon (KR); and Seung Hae Hwang, Daejeon (KR)
Assigned to LG ENERGY SOLUTION, LTD., Seoul (KR)
Appl. No. 17/797,232
Filed by LG ENERGY SOLUTION, LTD., Seoul (KR)
PCT Filed May 18, 2021, PCT No. PCT/KR2021/006191
§ 371(c)(1), (2) Date Aug. 3, 2022,
PCT Pub. No. WO2021/235816, PCT Pub. Date Nov. 25, 2021.
Claims priority of application No. 10-2020-0059135 (KR), filed on May 18, 2020.
Prior Publication US 2023/0072109 A1, Mar. 9, 2023
Int. Cl. H01M 4/04 (2006.01); H01M 4/139 (2010.01); H01M 4/02 (2006.01)
CPC H01M 4/0452 (2013.01) [H01M 4/0404 (2013.01); H01M 4/0416 (2013.01); H01M 4/139 (2013.01); H01M 2004/027 (2013.01)] 14 Claims
OG exemplary drawing
 
1. A method of manufacturing a negative electrode, comprising:
preparing a negative electrode roll on which a negative electrode structure is wound, the negative electrode structure comprising a negative electrode current collector and a negative electrode active material layer on at least one surface of the negative electrode current collector, wherein the negative electrode active material layer comprises side parts partitioned at both sides of the negative electrode active material layer and a central part partitioned by excluding the side parts;
preparing a pre-lithiation bath comprising a pre-lithiation solution, wherein the pre-lithiation bath is sequentially divided into an impregnation section and a pre-lithiation section;
impregnating the negative electrode structure with the pre-lithiation solution while unwinding the negative electrode structure from the negative electrode roll and moving the negative electrode structure through the impregnation section; and
pre-lithiating the negative electrode structure through electrochemical charging while moving the negative electrode structure through the pre-lithiation section,
wherein during the pre-lithiating step, the pre-lithiation section comprises a first section and a second section, the central part is electrochemically charged in the first section, the side is parts are electrochemically charged in the second section, the central part and the side part parts are alternately electrochemically charged in one or more cycles, and a charge current applied to the central part is higher than a charge current applied to the side parts,
wherein a first lithium metal counter electrode faces and is spaced apart from the central part of the negative electrode active material layer in the first section,
a second lithium metal counter electrode faces and is spaced apart from the side parts of the negative electrode active material layer in the second section,
the first lithium metal counter electrode and the negative electrode structure are connected to each other through a first electrochemical charger/discharger, the second lithium metal counter electrode and the negative electrode structure are connected to each other through a second electrochemical charger/discharger, and
the pre-lithiation is performed by setting a charge current applied from the first electrochemical charger/discharger to be higher than a charge current applied from the second electrochemical charger/discharger and alternately electrochemically charging the central part and the side parts of the negative electrode structure in one or more cycles while alternately operating the first electrochemical charger/discharger and the second electrochemical charger/discharger.