16 - Imides and amides as hydrogen storage materials

Abstract

Not only the Li–N–H system was groundbreaking in terms of creating a reversible storage system that readily met the gravimetric and volumetric criteria of the US Department of Energy (DoE), but also there was a revolutionary new system of “chemical hydrides” that was neither based solely around metals and alloys nor depended on high surface area non-metals for the physisorption of hydrogen. In fact, the system was composed of both metallic and non-metallic elements in chemically distinct phases that were interconvertible by the making and breaking of non-metal (N)–hydrogen bonds. The ramifications of this discovery were immediate, but it soon became apparent that many of the challenges that had confronted the previous generations of complex hydrides—reversibility, kinetics, operating (desorption) temperatures—would be similarly challenging for the new nitrides, imides and amides. This chapter describes how swiftly the field has moved and ultimately where it may move to if these materials are to be viable in terms of automotive and mobile applications. It also considers the underpinning chemistry of the nitrides, imides, and amides and a history of hydrogen interaction and inclusion.