LiCu x Mn2 − x O 4 Spinels ( 0.1 ⩽ x ⩽ 0.5 ) : A New Class of Cathode Materials for Li Batteries: II. In Situ Measurements

Abstract

Electrochemical data obtained from lithium cycling in , spinels show a remarkable, highly reversible, electrochemical cycling behavior at 4.9 V. In situ X‐ray absorption near edge structure spectroscopy revealed that this ultrahigh voltage is due to the existence of the redox couple. The origin of the high stability at the 5 V region was studied with the in situ X‐ray diffraction technique. It was found that the unit cell dimension undergoes minimal change during charge‐discharge cycles at the 5 V plateau.