麦立强，学者凯发k8国际首页主页-凯发网

we report the single nanowire electrode devices designed as a unique platform for in situ probing the intrinsicreason for electrode capacity fading in li ion based energy storage devices in this device, a single vanadium oxide nanowireor single si/a-si core/shell nanowire was used as wo rking electrode, and electrical transport of the single nanowire was reco rdedin situ to detect the evolution of the nanowire during charging and discharging along with lithium ion intercalation by shallowdischarge, the vanadium oxide nanowire conductance was decreased over 2 orders the conductance change can be restoredto previous scale upon lithium ion deintercalation with shallow charge however, when the nanowire was deeply discharged, the conductance dropped over 5 orders, indicating that permanent structure change happens when too many lithium ions wereintercalated into the vanadium oxide layered structures different from vanadium oxide, the conductance of a single si/a-sicore/shell nanowire monotonously decreased along with the electrochemical test, which agrees with raman mapping of singlesi/a-si nanowire at different charge/discharge states, indicating permanent structure change after lithium ion insertion andextraction our present work provides the direct relationship between electrical transport, structure, and electrochemicalproperties of a single nanowire electrode, which will be a promising and straightforward way for nanoscale battery diagnosis.

we report langmuir-blodgett (lb) based assembly of vanadium dioxide (vo2) nanowires. vo2 nanowires were functionalized with stearic acid(sa) and cetyltrimethyl ammonium bromide (ctab) and then spread on the surface an aqueous phase in a lb trough. surface pressure-area (π-a) isotherms were recorded on the lb trough and show hysteretic behavior. scanning electron microscopy (sem) investigations of morphology and alignment of the vo2 nanowire films transferred at different points on the π-a curve demonstrate with increasing surface pressure there is a transition from well-separated domains of nanowires to compact and locally-ordered nanowire monolayers, while aggregates raft-like nanowire structures remain after expansion. interestingly, x-ray diffraction (xrd) studies show that vo2 nanowire lb films exhibits (00l) crystal plane orientation, which was attributed to preferential coordination of sa and ctab-sa complex to (001) surface of vo2 nanowires thereby driving this orientation.