Method of electrode fabrication and an electrode for metal chloride battery

DETAILED DESCRIPTION OF THE INVENTION Sodium/metal-chloride cells and batteries are viable alternatives to Carnot systems for energy storage and transportation applications.
It has been learned that electrode constituent particle sizes have the greatest effect on utilization and on lessening voltage losses, i.
e.
, the ASI, in Na/MCl.
sub.
2 cell cathodes.
In accordance with a feature of the present invention, the reduction/oxidation reaction between an alkali-metal halide and a metal is used to create a cathode with extremely high surface area characteristics.
Selected particle sizes of cathode constituents incorporated into the electrode fabrication process greatly increases electrode surface area.
Increased cathode surface area corresponds to higher utilization of metal which is proportional to higher specific performance values of the cell.
Generally, in fabricating high specific energy cathodes, metal particles of a predetermined size are first combined with unsized alkali-metal halides.
Conversely, alkali-metal particles of a predetermined size are mixed with unsized metal particles.
This initial mixing causes the metal particles to channel between the sodium chloride particles.
A myriad of metal particle morphologies can be used, including, but not limited to, spheres, chains, spikes, filaments and combinations thereof.
Aside from forming continuous metal channels, mixing also allows the metal to surround the sodium chloride particles.
In a second fabrication step the mixture is sintered or compressed into an electrode configuration so as to create a somewhat rigid, thin electrode.
The mixture is rigidified after the metal particles coalesce together during sintering and then cool into a hard network of metal.
It is noted that as radial thickness of the positive electrode is decreased, there is a marked decrease in resistance.
The specific power of the cells also improves by increasing the ratio of solid electrolyte area to cell capacity which results in thinner positive electrodes.
The above two fabrication steps are performed with the electrodes in an uncharged state