Electric accumulator and storage cell

DETAILED DESCRIPTION I claim: 1.
A lead-acid accumulator or storage cell comprising: a first and a second stack of mutually spaced thin metal foils disposed in interleaved relationship and forming positive and negative plates respectively; respective separators between the foils of opposite polarity; a housing receiving the positive and negative plates and the separators between them and containing a sulfuric acid electrolyte, said housing having internal dimensions close to the external dimensions of said stacks and closely surrounding same; and electrically nonconductive and electrolyte-impermeable masks on only limited areas of juxtaposed faces of foils of opposite polarity surrounding active-mass regions thereof so that each foil has such masks coextensively on each of its faces, the masks of the juxtaposed faces being exactly in registry and of mutually coextensive areas, said masks being bonded to the respective foils and the faces of said foils not covered by said masks being continuously in contact with said electrolyte to sustain electrochemical reaction therewith.
2.
The accumulator defined in claim 1 wherein said electrolyte is dilute sulfuric acid, said foils are stacked and are composed of lead, and said masks form uninterrupted patterns upon the faces of the respective foils.
3.
The accumulator defined in claim 2 wherein said masks are printed on said lead foils.
4.
The accumulator defined in claim 2 wherein said masks are stamped from thin synthetic resin sheets and are bonded to said lead foils.
5.
The accumulator defined in claim 2 wherein said masks are composed of synthetic resin material reinforced with silicate glass fibers.
6.
The accumulator defined in claim 2 wherein said masks are reinforced with mutually orthogonal arrays of parallel glass fiber strands, the glass fiber strands overlying exposed regions of the lead foils surrounded by portions of the respective masks.
7.
The accumulator defined in claim 2 further comprising a layer of electrolyte-permeable glass fibers in a web coextensive with the surface of each of said foils and bonded to the respective mask