Project Title:

Sodium Modulated AMTEC Electrode Deposition

Advanced Modular Power System, Inc.
4667 Freedom Drive
Ann Arbor, MI 48108

93-1		10.04	4260			Amount Requested $69,926

Sodium Modulated AMTEC Electrode Deposition

Abstract:

A key component in the Alkali Metal Thermal to Electric Converter 
(AMTEC) is the electrode that is generally sputter deposited on the 
beta"-alumina solid electrolyte (BASE).  Electrode deposition, as 
it is now practiced however, is a random process that covers active 
sites on the BASE and places many electrode pore openings at 
inactive sites.  This proposal describes a novel fabrication 
process for improving electrode components of AMTEC cells.  
Exchange current densities will be increased by 500% at the 
BASE/electrode interface by selectively exposing all of the active 
sodium sites to the 3-phase electrode-BASE-sodium vapor boundary.  
The new process will selectively deposit the electrode only on the 
inactive sites of the BASE using the charge sensitive properties of 
the BASE to control where the electrode is deposited.  This leaves 
the active sites of the BASE conduction plane at the electrode 
edges.  This process will use the common electrode materials, Mo, 
W(Rh,Pt) and/or TiN.  If successful, this process can increase the 
power output of an AMTEC cell by 50% without increasing the size or 
weight

While space power systems are of intrinsic interest, terrestrial 
applications will offer large scale commercial opportunities for 
AMTEC systems.  At the 25+% efficiency now projected for the AMTEC 
systems and projected costs of $350/kWe, AMTEC is expected to prove 
useful for a very wide variety of distributed generation 
applications including self-powered fans for high efficiency 
furnaces and water heaters and recreational vehicle power supplies.  
Cathodic protection of pipelines, remote telemetry from oil well 
sites and general residential and commercial cogeneration will also 
be attractive.

AMTEC, electrode, sputtering, beta"-alumina