| 摘要 |
<p>1475491 Coated cathodes CANADA DEFENCE MINISTER OF and T VALAND 2 Oct 1973 [2 Oct 1972] 45358/72 Heading B2E [Also in Divisions C7 and H1] A cathode, useful in a LeclanchÚ cell, comprises a lead base, e.g. of perforated or expanded Pb foil, bearing an anodized layer onto which is adhered a compressed conductive layer of MnO 2 and C. The anodized layer must be no thicker than that produced by anodising in 8N H 2 SO 4 with the passages of 18 coulombs of electricity/in<SP>2</SP> of Pb surface. Anodising may be effected in 1-12N H 2 SO 4 using 3.6 to 14.4 coulombs/in<SP>2</SP>, the MnO 2 -C coating being applied as an aqueous paste containing carboxymethyl cellulose as binder and being subsequently pressed e.g. at 7000 psi. The coating may contain 10-20% by wt C, e.g. as graphite, relative to MnO 2 . The LeclanchÚ cell has an amalgamated Zn anode, e.g. prepared by dipping Zn sheet in aqueous HgCl 2 -H 2 SO 4 , may contain an expanded polypropylene mesh separator, and is activated with H 2 SO 4 . Comparative cells may have cathodes of Pt, unanodized Pb, Ni, Ag or stainless steel.</p> |
