Unraveling the Voltage Decay Phenomenon in Li‐Rich Layered Oxide Cathode of No Oxygen Activity

Unraveling the Voltage Decay Phenomenon in Li‐Rich Layered Oxide Cathode of No Oxygen Activity

TitleUnraveling the Voltage Decay Phenomenon in Li‐Rich Layered Oxide Cathode of No Oxygen Activity
Publication TypeJournal Article
Year of Publication2019
AuthorsNing Li, Sooyeon Hwang, Meiling Sun, Yanbao Fu, Vincent S Battaglia, Dong Su, Wei Tong
JournalAdvanced Energy Materials
Volume9
Issue47
Pagination1902258
Date Published11/2019
ISSN1614-6832
Abstract

Extensive efforts have been devoted to unraveling the true cause of voltage decay in Li, Mn‐rich layered oxides. An initial consensus was reached on structural rearrangement, then leaned toward the newly discovered lattice oxygen activity. It is challenging to differentiate their explicit roles because these events typically coexist during the electrochemical reaction of most Li‐rich layered oxides. Here, the voltage decay behavior is probed in Li1.2Ni0.2Ru0.6O2, a structurally and electrochemically relevant compound to Li, Mn‐rich layered oxide, but of no oxygen activity. Such intriguing characteristics allow the explicit decoupling of the contribution of transition metal migration and lattice oxygen activity to voltage decay in Li‐rich layered oxides. The results demonstrate that the microstructural evolution, mainly originating from transition metal migration, is a direct cause of voltage decay, and lattice oxygen activity likely accelerates the decay.

DOI10.1002/aenm.201902258
Short TitleAdv. Energy Mater.
Refereed DesignationRefereed