A high-rate, high-capacity, nanostructured tin oxide electrode

Recently, Li-ion battery anodes derived from oxides of tin have been of con siderable interest because they can, in principle, store more than twice as much Li+ as graphite. However, large volume changes occur when Li+ is inse rted and removed from these Sn-based materials, and this causes internal da mage to the electrode resulting in loss of capacity and rechargeability. We describe here a nanostructured SnO2-based electrode that has extraordinary rate capabilities, can deliver very high capacities (e.g., >700 mAh g(-1) at the 8C rate), and still retain the ability to be discharged and recharge d for as many as 800 cycles. These electrodes, prepared via the template me thod, consist of monodisperse 110 nm diam SnO2 nanofibers protruding from a current-collector surface like the bristles of a brush. The dramatically i mproved rate and cycling performance are related to the small size of the n anofibers that make up the electrode and the small domain size of the Sn gr ains within the nanofibers. (C) 2000 The Electrochemical Society. S1099-006 2(00)03-041-8. All rights reserved.