title: An in-situ gas chromatography investigation into the suppression of oxygen gas evolution by coated amorphous cobalt-phosphate nanoparticles on oxide electrode.
abstract: The real time detection of quantitative oxygen release from the cathode is performed by in-situ Gas Chromatography as a tool to not only determine the amount of oxygen release from a lithium-ion cell but also to address the safety concerns. This in-situ gas chromatography technique monitoring the gas evolution during electrochemical reaction presents opportunities to clearly understand the effect of surface modification and predict on the cathode stability. The oxide cathode, 0.5Li2MnO3∙0.5LiNi0.4Co0.2Mn0.4O2, surface modified by amorphous cobalt-phosphate nanoparticles (a-CoPO4) is prepared by a simple co-precipitation reaction followed by a mild heat treatment. The presence of a 40 nm thick a-CoPO4 coating layer wrapping the oxide powders is confirmed by electron microscopy. The electrochemical measurements reveal that the a-CoPO4 coated overlithiated layered oxide cathode shows better performances than the pristine counterpart. The enhanced performance of the surface modified oxide is attributed to the uniformly coated Co-P-O layer facilitating the suppression of O2 evolution and offering potential lithium host sites. Further, the formation of a stable SEI layer protecting electrolyte decomposition also contributes to enhanced stabilities with lesser voltage decay. The in-situ gas chromatography technique to study electrode safety offers opportunities to investigate the safety issues of a variety of nanostructured electrodes.
authors.affiliation: Department of Materials Science and Engineering, Chonnam National University, Gwangju 500-757, South Korea.
authors.forename: Jihyeon
authors.initials: J
authors.lastname: Gim
authors.affiliation: Department of Materials Science and Engineering, Chonnam National University, Gwangju 500-757, South Korea.
authors.forename: Jinju
authors.initials: J
authors.lastname: Song
authors.affiliation: Department of Materials Science and Engineering, Chonnam National University, Gwangju 500-757, South Korea.
authors.forename: Sungjin
authors.initials: S
authors.lastname: Kim
authors.affiliation: Department of Materials Science and Engineering, Chonnam National University, Gwangju 500-757, South Korea.
authors.forename: Jeonggeun
authors.initials: J
authors.lastname: Jo
authors.affiliation: Department of Materials Science and Engineering, Chonnam National University, Gwangju 500-757, South Korea.
authors.forename: Seokhun
authors.initials: S
authors.lastname: Kim
authors.affiliation: Energy Lab, Samsung Advanced Institute of Technology (SAIT), Samsung Electronics, Suwon 443-803, South Korea.
authors.forename: Jaegu
authors.initials: J
authors.lastname: Yoon
authors.affiliation: Energy Lab, Samsung Advanced Institute of Technology (SAIT), Samsung Electronics, Suwon 443-803, South Korea.
authors.forename: Donghan
authors.initials: D
authors.lastname: Kim
authors.affiliation: Energy Lab, Samsung Advanced Institute of Technology (SAIT), Samsung Electronics, Suwon 443-803, South Korea.
authors.forename: Suk-Gi
authors.initials: SG
authors.lastname: Hong
authors.affiliation: Energy Lab, Samsung Advanced Institute of Technology (SAIT), Samsung Electronics, Suwon 443-803, South Korea.
authors.forename: Jin-Hwan
authors.initials: JH
authors.lastname: Park
authors.affiliation: Department of Materials Science and Engineering, Chonnam National University, Gwangju 500-757, South Korea.
authors.forename: Vinod
authors.initials: V
authors.lastname: Mathew
authors.affiliation: Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 305-701, South Korea.
authors.forename: Junhee
authors.initials: J
authors.lastname: Han
authors.affiliation: Department of Materials Science and Engineering, Chonnam National University, Gwangju 500-757, South Korea.
authors.forename: Sun-Ju
authors.initials: SJ
authors.lastname: Song
authors.affiliation: Department of Materials Science and Engineering, Chonnam National University, Gwangju 500-757, South Korea.
authors.forename: Jaekook
authors.initials: J
authors.lastname: Kim