title: Understanding the electrochemical mechanism of K-αMnO2 for magnesium battery cathodes.
abstract: Batteries based on magnesium are an interesting alternative to current state-of-the-art lithium-ion systems; however, high-energy-density cathodes are needed for further development. Here we utilize TEM, EDS, and EELS in addition to soft-XAS to determine electrochemical magnesiation mechanism of a high-energy density cathode, K-αMnO2. Rather than following the typical insertion mechanism similar to Li(+), we propose the gradual reduction of K-αMnO2 to form Mn2O3 then MnO at the interface of the cathode and electrolyte, finally resulting in the formation of K-αMnO2@(Mg,Mn)O core-shell product after discharge of the battery. Understanding the mechanism is a vital guide for future magnesium battery cathodes.
authors.affiliation: Toyota Research Institute of North America , 1555 Woodridge Avenue, Ann Arbor, Michigan 48105, United States.
authors.forename: Timothy S
authors.initials: TS
authors.lastname: Arthur
authors.forename: Ruigang
authors.initials: R
authors.lastname: Zhang
authors.forename: Chen
authors.initials: C
authors.lastname: Ling
authors.forename: Per-Anders
authors.initials: PA
authors.lastname: Glans
authors.forename: Xudong
authors.initials: X
authors.lastname: Fan
authors.forename: Jinghua
authors.initials: J
authors.lastname: Guo
authors.forename: Fuminori
authors.initials: F
authors.lastname: Mizuno