• Separators

The separators were made of a glass fiber cloth having a thickness of 0.11 mm, an areal mass density of 99 g/m2, a weave lineal density of about 64 yarns per inch (ª24 yarns per centimeter), and an effective fiber volume fraction of about 35 percent.

• Structural Composite Batteries

Four structural composite batteries having the configuration shown in the figure were fabricated according to the procedure described in the last paragraph of immediately preceding article. In two of the batteries, designated for mechanical testing, the anodes were made of the woven carbon fabric. In all of the batteries, the perforated stainless steel was used as the cathode substrate material (the other cathode substrate materials were subjected to tensile tests but not incorporated into batteries).

Two of the batteries were designated for electrochemical tests. In one of these batteries, the anodes were made of the woven carbon fabric; in the other battery, the anodes were made of the non-woven carbon fabric.

One of the conclusions drawn from the results of the tensile tests was that the specific stiffness of a structural composite battery containing a perforated-foil cathode substrate can be expected to exceed that of an otherwise equivalent battery containing a wovenmesh or expanded-foil substrate. However, the tensile tests also drew attention to issues of design and fabrication that must be addressed in order to exploit synergies among the component materials to realize the full potential for strengthening and stiffening.

The electrochemical tests were limited to measurements of electrical resistances; further electrochemical tests could not be performed because these measurements revealed anode-to-cathode short-circuiting. An investigation to determine the cause of the short-circuiting was in progress at the time of reporting the information for this article.

This work was done by E. L. Wong, D. M. Baechle, K. Xu, R. H. Carter, J. F. Snyder, and E. D. Wetzel of the Army Research Laboratory.