Improvements relating to the production of electrodes

A composite porous sintered strip is formed by rolling a metal powder such as nickel, iron or stainless steel, sintering the strip to produce a rough surface and then applying nickel powder to both faces of the strip and resintering. The strip is preferably formed by rolling A type Ni powder in 2.5 cm. diameter rolls to form a strip 0.1 mm. thick and sintered at 1150 DEG C. to give a porosity of 20% to 30%. The Ni powder for coating the strip is B type powder with a low bulk density 0.6 to 1 gm./c.c. and a particle size of about 3 microns. The B type powder is spread on the strip to give a coating of 0.1 to 1 mm. thickness and sintered in hydrogen at 800 DEG to 1000 DEG C. to give a porosity of 70% to 85%. According to the Provisional Specification, methyl cellulose may be mixed with the nickel powder forming the base strip to produce a porosity of 20-50%. Specification 687,569 is referred to.