Anodization sealing

A prerequisite of long-life sodium/sulfur batteries is that the cells contain suitable corrosion-resistant materials which withstand the aggressively corrosive environment of this high—temperature system. Stackpool and Maclachlan have reported on investigations in this field [17], The components in an Na/S cell are required to be corrosion-resistant towards sodium, sulfur and especially sodium polysulphides. Four cell components suffer particularly in the Na/S environment the glass seal, the anode seal, the cathode seal, and the current collector (in central sodium arrangements, the cell case). 

The anode seal which closes the sodium compartment is a nickel—chromium alloy (Inconel 600). The application of Inconel 600 minimizes the growth of thick inter-metallics and it was shown that seals of this material have been operated for over three years. Contrarily to Inconel, the application of mild steel as the anode seal material gave a life of only 6000 h due to gross intermetallic growth which caused sodium attack of this intermetallic layer in the mild steel. 

But perhaps the most satisfactory chemical process for the preparation of ozone is the electrolysis of dilute sulphuric acid. A 15 per cent, solution of acid is recommended, coupled with a high current density, namely, 80 amperes per sq. cm., at the (platinum) anode. Wflth a platinum-foil anode sealed into glass so that only athm edge is obtained projecting to an extent of about one-tenth of a millimetre, it is possible to produce oxygen containing over 20 per cent, of ozone by volume.5... 

I. Richards developed the electrolytic method of separation of thallium from TlgSO. It is advisable to treat the solution with HgSO to avoid cathodic separation of Zn and anodic deposition of TI3O3. Further, the solution should be sufficiently diluted to depress inclusion of the sulfate in the depositing metal and a low current density should be employed so that the separating metal is as crystalline and compact as possible. Short Pt wires serve as the electrodes. These are immersed in the solution only for a length of 1 cm. The anode, sealed in a glass tube, is inserted into... 

It can be seen from Eq. (3.7) that the analyte line intensity excited by the continuum is proportional to the atomic number of the anode. Thus, higher atomic number anodes would be expected to yield higher sensitivities. Unfortunately this is not always the case. In high-power, grounded-anode, sealed x-ray tubes, the higher the atomic number of the anode, the greater is the fraction of incident electrons that are scattered in the direction of the x-ray tube window. This in turn requires a relatively thick window (perhaps 500- to 1000-jim beryllium) to dissipate the... 

Anode spacer Anode seal Separator plate... 

A second type of photoelectric device is the vacuum phototube, which consists of a semicylindrical cathode and a wire anode sealed inside an evacuated transparent envelope (see Figure 7-29). The concave surface of the electrode supports a layer of photoemissive material (Section 6C-1) that tends to emit electrons when it is irradiated. When a voltage is applied across the electrodes, the emitted electrons flow to the wire anode generating a photocurrent that is generally about one tenth as great as that a.ssociated with a photovoltaic cell for a given radiant intensity. In contrast. 

Four cell components suffer particularly in the Na/S environment the glass seal, the anode seal, the cathode seal, the current collector, and, in central sodium arrangements, the cell case. 

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