Faure Pasted-Plate Accumulator

Plante's cell worked and nobody could sell it. His plates had to be GROWN: charge and discharge lead foil over and over until the surface had converted deep enough to hold a useful charge, a process that ran for weeks or months per plate. Twenty-two years passed between a working lead-acid cell and a lead-acid industry, and that gap is entirely the formation time. Camille Alphonse Faure closed it by refusing to grow anything. Patent the active material on instead: coat a lead support with a layer of lead oxide worked into a paste, hold it there while it sets, and the plate begins life with its capacity rather than earning it. French patent 20. October 1880; US 252,002 "Polarization or Secondary Electric Batteries", filed 30. April 1881 and granted 3. January 1882. The patent is broader than the paste. Its first claim is an electrode "coated on one or more faces with an active layer of absorptive substance... so as to be or instantly become spongy"; the second adds "inert material - such as crushed coke - mixed or incorporated therewith" to keep it porous. The third is the one that made it work in practice: an "open-work, perforate, or porous medium" over the layer, "which, while allowing free percolation of the electrolytic liquid, prevents the active material from separating". Faure lists felt, cloth, asbestos board, cane netting, gutta-percha, lead wire-cloth and porous earthenware, fastened with rivets, cement, or wound woollen yarn. That third claim names the real problem. Pasted material is not attached to anything the way grown material is - it sits on the plate, and it falls off. Every lead-acid battery since has been an argument about how to hold it on: the grid, the separator, the compression of the stack. Faure did not solve shedding. He made it the price of admission, and the price was worth paying. You are building the plate, not the cell - the cell is the previous blueprint in this chain, and it still applies. Lead compounds are toxic and sulfuric acid burns: this one is gated for a reason.