Nanometer-scale electrochemical patterning of LiMn2O4 surfaces by an atomic force microscope operating in air

Kostecki, Robert ; Bonhomme, Frederic ; Servant, Laurent ; Argoul, Francoise ; McLarnon, Frank

Lawrence Berkeley National Laboratory

关键词: Manganese Oxides;    25 Energy Storage;    Reduction;    Air;    Oxidation;   

DOI  :  10.2172/834263
RP-ID  :  LBNL--48360
RP-ID  :  AC03-76SF00098
RP-ID  :  834263

美国|英语

来源: UNT Digital Library

【 摘 要 】

Electrochemical nanometer-scale patterning of the surface of a conducting lithium manganese oxide (LiMn{sub 2}O{sub 4}) by scanning probe microscopy (SPM) was studied. The ability to produce nanometer-size patterns of chemically modified oxide or nanometer-sized alterations of the oxide morphology is demonstrated and discussed with reference to possible mechanisms. It is demonstrated that unlike the SPM-based surface oxidation of metals and semiconductors, the LiMn{sub 2}O{sub 4} surface is altered via electrochemically generated species. We show that a localized surface chemical change can be confined to a depth which depends on the oxide-tip voltage difference and ambient humidity. In situ Raman microscopy measurements of localized electrochemical reaction products suggest complex mechanisms of processes induced at the LiMn{sub 2}O{sub 4} surface, such as delithiation through Li-proton exchange and disproportionation of LiMn{sub 2}O{sub 4} to MnO{sub 2} and soluble Mn{sup 2+} species.