Layered Li‐Mn‐Oxide with the O2 Structure: A Cathode Material for Li‐Ion Cells Which Does Not Convert to Spinel

Layered sodium manganese bronzes having the P2 structure , were used to prepare layered lithium manganese oxides by ion exchange of Na by Li using LiBr in hexanol. X‐ray diffraction and chemical analysis show that layered has an O2 type structure. The arrangement of manganese and oxygen atoms in this phase differs fundamentally from that found in layered (O3 structure), in orthorhombic , and in spinel so that conversion to spinel during electrochemical cycling is not expected. as well as the related and have a reversible charge capacity of about 150 mAh/g. During cycling the new cathode materials do not convert to spinel, in contrast to the behavior of layered and orthorhombic . © 1999 The Electrochemical Society. All rights reserved.