Lithium transport within the solid electrolyte interphase

A LiClO4 SEI film grown on copper was examined with time-of-flight secondary ion mass spectrometry. The SEI porosity profile and Li+ transport processes within the SEI were studied with isotopically labeled (LiBF4)-Li-6 electrolyte. An similar to 5 nm porous region, into which electrolytes can easily diffuse, was observed at the electrolyte/SEI interface. Below the porous region, a densely packed layer of Li2O and/or Li2CO3 prevents electrolyte diffusion, but Li+ transports through this region via ion exchange. (C) 2011 Elsevier B.V. All rights reserved.