Batterijen : twee elektroden in een potje

A review with 2 refs. The topics discussed include: a spontaneous process (Ag/Zn cell), types and sizes, primary batteries, secondary batteries, high-energy (Na/alumina/S, and metal hydride batteries. [on SciFinder (R)

Ellipsometry of metal deposition

The initial stages during galvanic deposition were monitored by ellipsometry in combination with cyclic voltammetry for the growth of Bi, Cu and Ge films on polycryst. Au, Pd and Pt substrates. The underpotential deposition (upd) of Bi on Au, of Ge on Pt and of Cu on Au could be detected ellipsometrically but not for Bi on Pd or Pt. The refractive index of the upd film of Bi on Au changes with increasing coverage. The bulk deposit film of Bi on Au and of Cu on Au grows at const. refractive index. [on SciFinder (R)

Hydrogen production during zinc deposition from alkaline zincate solutions

The determination of the amount of hydrogen produced during the electrodeposition f zinc from alkaline zincate solutions was carried out using the rotating ring-disc electrode (RRDE) technique. The experimental conditions for which the RRDE technique offers reliable results are discussed. Hydrogen production during zinc deposition was studied for a range of cathodic (disc) current densities (20-500 A m-2) and electrolyte compositions (1-7 M KOH, 0.01-0.2 M zincate). It was found that an increasing amount of hydrogen was formed with increasing (disc) current density and decreasing KOH and zincate concentration. The impact of hydrogen formation during the charging process on nickel oxide/zinc secondary battery performance is expected to be small. It is concluded that in battery electrolytes (8 M KOH, 1 M zincate) hydrogen is formed chiefly by corrosion of the zinc electrode rather than by electrochemical formation durirtg the electrochemical reduction of zinc. 1

Computer controlled testing of batteries

A computerized testing device for batteries consists of a power supply, a multiplexer circuit connected to the batteries, a protection circuit, and an IBM Data Aquisition and Control Adapter card, connected to a personal computer. The software is written in Turbo-Pascal and can be easily adapted to user specifications; a simplified flow chart of the program is given. The system is capable of monitoring several batteries simultaneously; charging and discharging is controlled by pre-set cut off voltages and max. charge times. [on SciFinder (R)

The effect of Sn on Pt/C catalysts for the methanol electro-oxidation

The effect of Sn for the methanol oxidn. in sulfuric acid is investigated using electrodeposited Pt and carbon supported Pt. The prepn. has a considerable influence, as the Sn effects range from a small increase to a decrease in methanol oxidn. activity. Sn is believed to act through the activation of H2O. The optimum Sn surface coverage is found to be low; of the order 10%. [on SciFinder (R)