Design of amorphous alloy electrodes for Li-ion batteries - A big challenge

To make quantum improvements in the energy density of lithium-ion batteries, we are faced with learning to make electrodes from materials that undergo volume changes as large as 250% during charge-discharge cycling or settling for small incremental improvements. It is our opinion that electrodes of amorphous alloy particles that expand and contract by up to 250% can probably be successfully designed, provided sufficient attention is paid to the importance of the binder system that holds the electrode particles to each other and to the current collector. Using a combinatorial study of amorphous Si0.64Sn0.36 electrodes in an elastomeric binder, we illustrate the magnitude of the problem. (C) 2004 The Electrochemical Society.