Electrodeposited porous-microspheres Li-Si films as negative electrodes in lithium-ion batteries

A porous-microspheres Li-Si film (PMLSF) is prepared by multi-step constant current (MSCC) electrodeposition on Cu foil. Its structure and morphology are characterized using X-ray diffraction (XRD) and scanning electron microscope (SEM). As negative electrodes of lithium-ion batteries, the PMLSF electrode delivers the first gravimetric and geometric charge capacities of 2805.7 mA h g(-1) and 621.9 mu A h cm(-2) at the current density of 25.5 mu A cm(-2), and its initial coulombic efficiency is as high as 98.2%. When the PMLSF electrode is cycled in VC-containing electrolyte, the superior cycling performance can be obtained. After 50 cycles, 96.0% of its initial capacity is retained at the current density of 50.0 mu A cm(-2). Electrochemical impedance spectra (EIS) research confirms the positive effect of VC additive on the behavior of the PMLSF electrode. (c) 2011 Elsevier B.V. All rights reserved.