High Performance Arsenic: Multiwall Carbon Nanotube Composite Anodes for Li-Ion Batteries

Li-alloying materials for Li-ion anodes have garnered much attention because of their abilities to react with large amounts of Li. As is another Li alloying element with a specific capacity of 10(73) mAh g(-1). Despite having a high specific capacity to alloy Li (10(73) mAh g(-1)), As has been largely ignored and little is known of its electrochemical behavior. The synthesis of nanoparticulate As is described herein and its excellent performance as the active material in Li-ion battery anodes demonstrated. Comparison of micron and nanoscale As mixed with multiwall carbon nanotubes (MWCNT) shows the later to have dramatically better performance, particularly when cycled in FEC: DEC rather than EC: DMC electrolyte. Further improvement is shown by synthesizing the nanoscale As directly on the MWCNT, with excellent performance with mass loadings up to 80% As, achieving a maximum capacity of 746 mAh g(-1) and fading only 17% over 200 cycles. The reversible capacity demonstrated here is more than twice that of the best previously reported, showing that As could be an inexpensive, high performance alternative active material for practical Li-ion battery anodes. (C) 2017 The Electrochemical Society. All rights reserved.