Si film electrodes prepared on discontinuous current collector

Abstract

Discontinuous Si film electrodes with 400, 800, and 1700 mu m discontinuous lines (break lines) were fabricated by a simple masking and etching process. The structural and electrochemical properties of continuous and discontinuous Si film electrodes were investigated by means of optical microscopy, field emission scanning electron microscopy, X-ray diffraction, and charge-discharge tests. Although all electrodes showed similar first-charge capacities in the range of 210-230 mu Ah/g, the discontinuous electrode exhibited improved coulombic efficiency and cyclability when compared to the continuous electrode. Up to 100 cycles, the discontinuous electrode with the shortest line distance of 400 mu m demonstrated the highest efficiency (95.2%) and capacity retention (89%). Observation of the cycled Si film electrodes revealed that discontinuity enhanced the structural stability of the electrode during the charge-discharge process. (C) 2013 Elsevier B.V. All rights reserved.