Nanomaterial-based Li-ion battery electrodes

We have been exploring the use of the template method to prepare rranostruc tured Li-ion battery electrodes. These nanostructured electrodes show impro ved rate capabilities relative to thin-film control electrodes prepared fro m the same material. In this paper we discuss nanostructured Sn-based anode s. Li-ion battery anodes derived from oxides of tin have been of considerab le recent interest because they can, in principle, store over twice as much Li+ as graphite. However, large volume changes occur when Li+ is inserted and removed from these Sn-based materials, and this causes internal damage to the electrode resulting in loss of capacity and rechargability. We descr ibe here a new nanostructured SnO2-based electrode that has extraordinary l ate capabilities, can deliver very high capacities (e.g.,700 mAh g(-1) at 8 degreesC), and still retain the ability to be discharged and recharged thr ough as many as 800 cycles. These electrodes, prepared via the template met hod, consist of monodisperse 110 nm-diameter SnO2 nanofibers protruding fro m a current-collector surface like the bristles of a brush, The dramaticall y-improved rate and cycling performance is related to the small size of the nanofibers that make up the electrode and the small domain size of the Sn grains within the nanofibers. (C) 2001 Elsevier Science B.V. All rights res erved.