Starts 8 Mar 2013 11:30
Ends 8 Mar 2013 20:00
Central European Time
Leonardo da Vinci Building Luigi Stasi Seminar Room
Strada Costiera, 11 I - 34151 Trieste (Italy)
Lithium ion transport attracts much interest because it is fundamental process at lithium ion battery electrodes, particularly at nanowire electrodes. To study irreversible transport process at charging–discharging process directly at atomic scale, we developed an aberration corrected electron microscope which allows us to form an electron probe having a diameter of sub-50pm. The spherical electron wave emitting from the electron probe scans the specimen surface was found for the first time to give structure image of individual lithium ions. In electrodes of spinel structure, i.e., LiMn2O4, dislocation of lithium ions from the tetrahedral sites induces local structure change at octahedral sites, which makes charging-discharging cycle of ion transport irreversible#). Structure change is discussed in relation to the current-voltage relation of a mode LIB. At excess or deficient concentration of lithium ions, spinel electrodes exhibited local disorder. To characterize local disorder, we devised a new method which can allow us to find not only pair correlation but also higher order correlation of the local disorder. #)This work is supported by CREST project, “nanocycle at nano-in-macro interface”
  • M. Poropat