Composite Silicon Nanowire Anodes for Secondary Lithium-Ion Cells

A composite anode with active materials including 15% (w/w) silicon nanowires and graphite is demonstrated for use in secondary lithium-ion cells. The electrochemical behavior of the composite anode including voltammetry and charge/discharge capacities over the first 15 cycles is shown and compared with an equivalent graphite anode. Electrolessly etched nanowires swell in diameter upon lithiation and undergo reversible cycling without pulverization or agglomeration. Experimental results reveal high initial capacities (approximately 811 mA hg(-1)) near theoretical predictions and a reversible capacity of 512 mA hg(-1) after 10 cycles with a capacity fade of approximately 1.4%/cycle. Capacity loss mechanisms are considered in comparison with other silicon-containing anodes. (C) 2009 The Electrochemical Society. [DOI: 10.1149/1.3251341] All rights reserved.