Method of preparing a negative electrode including lithium alloy for use within a secondary electrochemical cell

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT In the FIGURE, an experimental electrochemical cell is shown contained within a ceramic crucible 11.
The cell includes a negative electrode 13, a positive electrode 15, both submerged within a molten electrolytic salt 17.
Electrical conductors 19 and 21 extend from the positive and negative electrodes, respectively, for connection to electrical instrumentation (not shown) for evaluating the cell.
In practice, various cell designs may be used with electrodes produced by the improved method of the present invention.
The cell of the figure merely represents an example of the type cell used experimentally to test and prove operability.
Other cell designs which may be more suitable for use in making up electrochemical batteries are illustrated and described in U.
S.
Pat.
No.
3,887,396 and U.
S.
patent application Ser.
No.
565,021, both cited above.
The positive electrode 15 is illustrated as a covered structure with a central chamber fore containing the cathode reactant composition 25.
The structure is illustrated as a graphite cup 26 covered with a wetted porous carbon cloth 27 that permits permeation of the molten electrolyte.
The electrolyte 17 that surrounds the two electrodes can be a eutectic salt composition that is molten at the cell operating temperatures of, for instance, 375.
degree.
to 500.
degree.
C.
Electrolytes such as compositions of LiCl--KCl or LiCl--LiF--KBr salt have been found to be suitable in this application.
Various other suitable electrolytes can be selected from those listed in U.
S.
Pat.
No.
3,488,221.
Negative electrode 13 is illustrated surrounded by a cylinder of electrically insulative material 23 such as alumina or beryllia.
Sleeve 23 prevents shorting of the cell through any loose electrode materials that may have escaped during operation.
The negative electrode is shown mechanically fastened to conductor 21.
Of course, various other suitable techniques such as soldering or unitary fabrication can be employed in attaching the cell electrical conductor to the electrode