Bulk and surface structure investigation for the positive electrodes of degraded lithium-ion cell after storage test using X-ray absorption near-edge structure measurement

• Published in: Journal of power sources Vol. 189; no. 1; pp. 676 - 680
• Main Authors: Mori, Daisuke, Kobayashi, Hironori, Shikano, Masahiro, Nitani, Hiroaki, Kageyama, Hiroyuki, Koike, Shinji, Sakaebe, Hikari, Tatsumi, Kuniaki
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Amsterdam Elsevier B.V 01.04.2009; Elsevier
• Subjects: Applied sciences; Carbon; Degradation; Direct energy conversion and energy accumulation; Electric cells; Electrical engineering. Electrical power engineering; Electrical power engineering; Electrochemical conversion: primary and secondary batteries, fuel cells; Electrodes; Exact sciences and technology; Lithium batteries; Lithium–nickel-based oxide; Neutron diffraction; Nickel; Positive electrode; Power fade of lithium-ion cell; Surface chemistry; Synchrotron radiation; X-rays; XANES measurement; Lithium–nickel-based oxide; Positive electrode; Power fade of lithium-ion cell; Neutron diffraction; XANES measurement; Synchrotron radiation; Measurement; Aluminium oxide; Cobalt oxide; XANES spectrometry; Anode; Cathode; Secondary cell; Surface structure; Lithium-nickel-based oxide; Lithium oxide; X ray diffractometry; State of charge; Lithium ion; Nickel oxide
• ISSN: 0378-7753; 1873-2755
• DOI: 10.1016/j.jpowsour.2008.08.073

Cylindrical lithium-ion cells with a lithium–nickel–cobalt–aluminum oxide (LiNi 0.8Co 0.15Al 0.05O 2) and a non-graphitizable carbon (hard carbon) as the positive and negative electrodes, respectively, were degraded by the storage tests with 50% state-of-charge (SOC). The degraded cells were disassembled and positive electrodes obtained were examined. The cation distribution of lithium and nickel in the positive electrode was clarified using neutron and synchrotron X-ray diffraction measurements. The degree of lithium and nickel disordering varied with the storage condition. X-ray absorption near-edge structure (XANES) analysis demonstrated that the structural change was mainly located near the surface of the positive electrode and the valence state of Ni and Co ions did not change with the storage test. The disordering of the cations near the surface was closely related to the power fade of the cell. The storage condition is an important factor in the power fade of lithium-ion cells.