Corrosion of sintered plate as a life limiting factor in battery

Production of rechargeable nickel-cadmium cells with sintered plates in Poland started in the early 70's. It utilizes two types of nickel powder; one, is the well known Mond nickel powder 255, the other is carbonyl nickel powder PNK. Their bulk density values are the same. The PNK powder has grain size of 1.5 u (determined by Fisher method) and specific area of approx. 0.9 m2/g (powder type 255 - 0.55 m2/g). due to differences in powder characteristics it was necessary to modify paste composition and conditions of sintering. However, the plates manufactured with both types of nickel powder revealed similar properties (porosity 72 - 75 %, specific area 0.20 - 0.24 m2/g). In spite of slight differences in physical properties the sinter made of PNK powder is being desolved after 10 - 15 minutes of the first impregnation cycle, while the other made of 255 powder, after about 20 minutes. The author discusses factors which influence corrosion of these sintered plates