Nuclear reaction analysis profiling as direct evidence for lithium ion mass transport in thin film ‘‘rocking-chair’’ structures

Abstract

A nuclear reaction analysis technique using the p,γ reaction, 7Li(p,γ)8Be, occurring at approximately 440 keV, (half-width≊12 keV), has been utilized to determine the lithium concentration profiles in multilayer electrochromic window (‘‘smart window’’)/rechargeable battery cells when in their ‘‘colored’’/charged and ‘‘bleached’’/discharged states. The lithium profiles have been observed to shift according to the cells’ states, thereby providing direct experimental evidence for the so-called rocking-chair model for such structures.