Composite cover and method of manufacturing the cover

A composite battery cover, comprising:

• a generally rectangular main portion having four main portion edges about a perimeter of the main portion and having opposing top and bottom surfaces defining respective upward and downward directions;
• and
• four generally rectangular side portions each contiguous with and extending downward from a respective one of the main portion edges;
• wherein the main portion and the four side portions generally enclose an interior space and are made of a sandwich structure comprising an interior layer of continuous fiber reinforcements and resin and an exterior layer of metallic foil bonded to the interior layer;
• wherein the continuous fiber reinforcements include at least one of carbon fiber, fiberglass, aramid and polyamide and have an average nominal fiber length of at least 500 mm and a stiffness of at least 40 GPa, the resin includes an epoxy resin with additives mixed therein or a phenolic resin wherein the additives include at least one of aluminum trihydrate, aluminum trihydroxide, ammonium polyphosphate and expandable graphite, and the metallic foil is made of at least one of steel, aluminum and titanium and has a thickness of 0.1 to 1.0 mm;
• and
• wherein the composite cover, as viewed from above, has four generally right-angled top corners, each of which is either generally pointed or generally rounded wherein the composite cover has four corner junctures, with each corner juncture having a respective corner juncture volume thereabout, and with each corner juncture volume comprising a respective first segment of the main portion, a respective second segment of an adjacent one of the side portions, and a respective third segment of another adjacent one of the side portions;
• and
• wherein the interior layer defines elongated voids and is made of a plurality of individual layers of the continuous fiber reinforcements and resin, wherein each individual layer includes two or more sheets of the continuous fiber reinforcements disposed in-plane with each other, each of the two or more sheets of each individual layer has an edge separated from a neighboring edge of a neighboring one of the two or more sheets such that the edge and the neighboring edge define a respective one of the elongated voids, wherein a respective group of the elongated voids is located within each corner juncture volume such that the elongated voids of each respective group run generally parallel to each other and are staggered and non-overlapping with respect to each other.