Frank M. Delnick

Passive Iron A Semiconductor Model for the Oxide Film

Through a study of the kinetics of the hexacyanoferrate redox reaction on passive iron, a semiconductor model is proposed for the electronic structure of the oxide film. An electron acceptor level located approximately 0.6 eV above the valence band is introduced into the oxide film by the formation and migration of interstitial iron ions. The high electronic conductivity of the film, the unusual Tafel behavior, and the non-integral reaction orders of the hexacyanoferrate redox couple on passive iron are directly attributable to the presence of this acceptor level. The differential capacitance of the passive iron electrode further substantiates the proposed semiconductor electronic structure. The approximate concentration of acceptor ions, and the flat band potential of the oxide are both determined from a linear Mott-Schottky relationship. The pH of the solution strongly influences the ectrocatalytic activity of passive iron electrodes by controlling the distribution of electronic energy levels in the oxide film. The overvoltage is linearly partitioned between the oxide film and the Helmholtz layer.

The kinetics of charge-transfer reactions on passive lithium electrodes

Abstract Lithium anodes are covered by LiCl passive films in SOCl 2 solutions. At open-circuit, film growth is controlled by electronic processes within the film. Under discharge, solid-state ionic processes control the kinetic behavior of the electrode. These processes are not independent of each other. In this report, the interaction of electronic and ionic processes in LiCl passive films is reviewed. Special attention is directed to the role of lattice imperfections in establishing and controlling the mechanisms of electronic and ionic charge transport.

Active primary lithium thionyl chloride battery for artillery application

Sandia National Laboratories and Eagle-Picher Industries have successfully developed an active lithium thionyl chloride (ALTC) power battery for unique artillery applications. The program goal was to provide a direct replacement power battery for the no-longer-produced reserve ammonia battery, capable of extended dynamic environments. This goal was met using the active lithium thionyl chloride flat-plate design. Flight worthiness has been demonstrated through actual artillery projectile usage. The authors provide a summary of maximum dynamic environments in which the ALTC battery has successfully survived and operated in a normal manner. The ALTC battery has successfully provided uninterrupted 24 to 32 VDC at up to 450 milliamperes at -35 degrees C, 25 and 55 degrees C in actual artillery tests at maximum dynamic environments.<<ETX>>