Publications

Abstract : Abstract High aspect ratio, electrospun CuO nanofibers have been fabricated and tested for its electrochemical performance as lithium ion battery anode. These nanofibers are composed of CuO nanoparticles about 35–40nbsp;nm in size forming good inter-connected network. Fabricated half cells maintained specific capacity of 310nbsp;mAhnbsp;g−1 at 1C rate for 100 cycles and stabilized capacity of about 120nbsp;mAhnbsp;g−1 at 5C rate for 1000 cycles. Ex situ x-ray photoelectron spectroscopy (XPS) was performed to understand the electrodes surface chemical changes at the end of first discharge, first charge and after tenth charge. The solid electrolyte interface (SEI) layer comprised of LiF, Li2CO3 and Li2O while their quantity varied depending on the stage of lithiation/delithiation. Initially, no copper signal is observed on the surface of the {SEI} layer. However, in situ sputtering of the electrodes in the {XPS} chamber revealed that at the end of first discharge, formation Cu0 with detectable fraction of LixCuO2 and hydroxide in the {SEI} layer. At the end of first charge, a large fraction of Cu2O phase with a small fraction of hydroxide is observed. At the end of 10th charge no change in {SEI} layer content but increase in thickness was observed.