Zinc electrode type

Offshore, both Ag/AgCl and metallic zinc electrodes are used for potential measurements and are also employed for current density surveys undertaken on the offshore platforms and pipelines, as discussed below. It has been found beneficial for offshore applications to install together an electrode of each type on a structure, one acting as a function check on the other. ... 

It is so universally applied that it may be found in combination with metal oxide cathodes (e.g., HgO, AgO, NiOOH, Mn02), with catalytically active oxygen electrodes, and with inert cathodes using aqueous halide or ferricyanide solutions as active materials ("zinc-flow" or "redox" batteries). The cell (battery) sizes vary from small button cells for hearing aids or watches up to kilowatt-hour modules for electric vehicles (electrotraction). Primary and storage batteries exist in all categories except that of flow-batteries, where only storage types are found. Acidic, neutral, and alkaline electrolytes are used as well. The (simplified) half-cell reaction for the zinc electrode is the same in all electrolytes ... 

Vaughey J. T., O Hara J., Thackeray M. M., Intermetallic insertion electrodes with a zinc blende-type structure for Li Batteries A study of LixInSb (0 <= x <= 3), Electrochem. and Solid State Lett., (2000) 3 (1), 13-16. 

The electrolysis of alkyl or aryl halides in MeCN-benzene at a zinc electrode in the presence of bipy results in the formation of complexes of the type [RZnX(bipy)] (R = Me, CF3, Et, CH2==CHCH2, Ph, QFs or Bz X = halide). This provides a route to arylzinc complexes, since aryl halides do not normally react with metallic zinc. Oxidation of [RZnX] in the presence of RX and [R4N]X had resulted in the formation of [R4N]RZnX2 and these are the first examples of compounds containing the RZnX2 anion.581... 

Why do we use a salt bridge to connect the two solutions, instead of merely placing both electrodes into the same solution, containing both types of ions If the copper(ll) ions were in the solution with the zinc electrode, the two would simply react at the surface of that electrode there would be no need for electrons to travel through the wire to get the redox reaction to proceed. 

Another type of battery is the mercuiy batteiy often formerly used in pocket calculators. The mercuiy battery has a zinc electrode while mercuiy oxide HgO are oxidised in the basic environment consisting of typically KOH and Zn(OH)2. The figure below shows the set-up of the mercuiy diy cell batteiy. 

Figure 14.6-1 Two types of electrochemical cells, (a) A cell with two electrodes and shared electrolyte. One example of such a cell contains a copper electrode, a zinc electrode, and a zinc sulfate and copper sulfate electrolyte solution. The overall cell reaction is Cu" (aq) -)- Zn(s) —> Cu(s) -f Zn" (aq). (b) A cell with two separate compartments connected by a salt bridge. If the same electrodes as in the previous case were used, one compartment would contain a copper electrode and a CuSO solution, the other would have a zinc electrode and a ZnS04 solution as the electrolyte, and the two compartments would be connected by a bridge containing, for example, a sodium chloride solution.

Another novel type of polymer battery whose ionic carrier is a simple component was constructed with PE/PPy and zinc electrodes, respectively [20]. The characteristic of this battery is that the concentration of the electrolyte solution does not change with charge and discharge. 

For application directly to battery technology, the three modes of mass transport have meaningful significance. Convective and stirring processes can be employed to provide a flow of electroactive species to reaction sites. Examples of the utilization of stirring and flow processes in batteries are the circulating zinc/air system, the vibrating zinc electrode, and the zinc-chlorine hydrate battery. In some types of advanced lead-acid batteries, circulation of acid is provided to improve utilization of the active materials in the battery plates. 

The first recorded use of a silver battery was by Volta with his now historic silver-zinc pile battery, which he introduced to the world in 1800. This battery dominated the scene in the early nineteenth century, and during the next 100 years many experiments were made with cells containing silver and zinc electrodes. All these cells, however, were of the primary (nonrechargeable) type. 

Figure 38.16 shows the discharge characteristics of the 1200-Ah cell at several discharge loads. As a result of the use of a porous zinc electrode, and the direct formation of zinc oxide as the reaction product, the specific energy of this type of battery is higher than for the water-activated types. At low rates of discharge it is 285 Wh/kg. 

With the development of new types of separator and zinc electrodes, the nickel-zinc battery has now... 

The packaging approach utilized for tliis battery is similar to that for nickel—hydrogen single cylindrical cells as shown in Figure 23. The sdv er electrode is typically the sintered type used in rechargeable sdv er—zinc cells. The hydrogen electrode is a Teflon-bonded platinum black gas difhision electrode. 

---