| Abstrakt: |
The aim of the work is the first stage in the development of a new ampoule backup chemical current source based on the lead dioxide reduction reaction, namely the selection of the cathode base material. The main objects of the study were cathodes made of titanium, steel, and lead with a galvanic coating of lead dioxide formed from a nitrate electrolyte using current density 1...2 A/dm2. To obtain a titanium cathode, the problem of surface passivation was solved using an initial symmetric cathode polarization for 30 seconds. To establish the dependence of the specific characteristics of the system on the material of the base, discharge curves were obtained and the dynamics of the discharge of different cathodes were established. The discharge curves were taken at a constant resistance of 7.3 Ω using a system with zinc anodes and perchloric acid as an electrolyte. The maximum stable discharge potential of the current source was found in titanium cathodes (1.8 V for 23 seconds). Moreover, when obtaining the polarization curves, the tendency of the steel cathode to peel off the coating and corrosion in the electrolyte was revealed, while the titanium cathode demonstrated stable current rates from cycle to cycle. Researching of the lead cathode showed low adhesion and/or conductivity between the formed powder coating and the base material. The study revealed that the optimal material for the base of the lead dioxide cathode for the backup current source, both from the point of view of chemical stability and discharge characteristics, was titanium. Therefore, it will be used in further studies of other components of the electrochemical system. [ABSTRACT FROM AUTHOR] |
