The mathematical-physical equation concerning the process of calorimetry of electrode reactions was deduced, and the corresponding
solutions were obtained respectively for the period of the electrochemical polarization and that of the natural cooling. The
calorimetry of the anodic oxidation of ferrocyanide to ferricyanide under linear sweep-current polarization was carried out,
the obtained apparent enthalpy change of the electrode reaction agreed well with that obtained by the calorimetry with constant
currents. The developed calorimetry with linear sweep-current and the data processing method are applicable for quick determination
of apparent enthalpy changes of electrode reactions.
The reversible heat of electrodereaction, called as the electrochemical Peltier heat (EPH), is also a very important quantity in the thermoelectrochemistry, is often used to research on thermodynamics and kinetics of reversible [ 12 – 16
We report voltammetric and chronoamperometric investigations on the reduction of Np/III/ in the /Li–K/Cl melt. The electrode reaction is nearly reversible and a nucleation phenomenon appears in the early deposition of neptunium metal. The Tafel equation corresponding to that deposition indicates that the charge transfer is the rate-determining step of the overall electrode process.
The electrochemical reductions of hexavalent and tetravalent uranium are reported in -butyrolactone, -valerolactone, -octanoiclactone and in the mixed solvent -butyrolactone/tetrahydrofuran. The transient techniques foresee either the formation of uranium dioxide or uranium metal according to a two-step reduction but the presence of these cathodic products is difficult to ascertain in controlled potential electrolysis. While mixing a lactone with tetrahydrofuran, the reversibility of the electrode reactions increases. The conducting salt noticeably determines the current yield of uranium deposition. As additional kinetic phenomena are made clear, we found that sampled polarography is the best method to gain a full understanding of the electrode mechanisms.
An apparatus to study the battery system has been set up. The thermal effects of charge and discharge of Ni-MH batteries have been studied. The calorimetric measurements indicate that the net heat dissipation during charging is larger than that during discharging. It is observed that the ratio of heat dissipation to charging energy varies with charging capacity, and almost 90 percent of charging energy is lost as heat dissipation near the end of the charging process at 97.7 mA. A jump of thermal curve near the end of discharge due to a secondary electrode reaction has been observed.
generation during charging. Usually heat generated during charging consists of reaction heat, polarization heat, Ohm heat, and recombination heat [ 6 ]. When the battery is charged in high rate, the reaction heat increases as the electrodereaction
enhanced electrodereactions, simplified water management and cooling system, increased CO tolerance, and so on [ 3 – 5 ]. Sometimes, PEMFCs must be started at sub-zero temperature. Accordingly, thermal properties of PFSIs should be understood fundamentally
(ϕ 0.5 mm × 37 mm)) and reference electrode (Ag/AgCl, saturated potassium chloride). The current density and electrode material can affect the reversibility of the electrodereaction. Generally speaking, overpotentials are small and can be ignored
by the overpotential at the cathode.
The state of the art of the SOFC uses lanthanum manganites (La 1− x Sr x MnO 3 ) as cathode materials. In this case, the electrodereaction takes place at the triple phase boundary (TPB), gas phase
transition metals whereas the ionic conductivity is due to the presence of mobile oxygen vacancies at high temperatures.
It seems evident that the electrodereaction in oxygen electrodes and the oxygen transport in ceramic membranes should be related