Sulfur Batteries

Electrophoretic deposition (EPD) is anotlier metliod of casting slurries. EPD is accomplished tlirough tire controlled migration of charged particles under an applied electric field. During EPD, ceramic particles typically deposit on a mandrel to fonn coatings of limited tliickness, or tliin tubular shapes such as solid (3 " - AI2O2 electrolytes for sodium-sulfur batteries. 

Ionic conductivity is used in oxygen sensors and in batteries (qv). Stabilized zirconia, Zr Ca 02 has a very large number of oxygen vacancies and very high conductivity. P-Alurnina/72(9(9j5 -4< -(y, NaAl O y, is an excellent cation conductor because of the high mobiUty of Na" ions. Ceramics of P-alurnina are used as the electrolyte in sodium-sulfur batteries. 

Lithium Fluorobora.te, Lithium fluoroborate is used in a number of batteries (qv) as an electrolyte, for example in the hthium—sulfur battery... 

Includes hydrogen, sulfur, batteries, chemicals, and spent sulfite Hquor. 

Sodium, generally about 99.9% Na assay, is available in two grades regular, which contains 0.040 wt % Ca, and nuclear (low Ca), which has 0.001 wt % Ca. Both have 0.005 wt % Cl . The nuclear grade is packed in specially cleaned containers, and in some cases under special cover atmospheres. A special grade of sodium low in potassium and calcium (<10 ppm) is achievable to meet requirements for use in manufacture of the more newly developed sodium—sulfur batteries. 

Eig. 4. Constmction of a sodium—sulfur battery. A, Negative terminal B, springs plus graphite felt C, sulfur D, carbon E, sodium reservoir E, positive terminal G, iasulator H, aluminum sealing gaskets 1, steel case J, film of sodium K, P-alumiaa tube L, carbon felt M, wick N, aluminum can (67). 

Electrophoretic casting (38,59) is accompHshed by inducing controUed migration of charged particles under an appHed electric field to deposit on a mandrel. Thin tubular shapes and coatings of limited thickness are formed using this technique. Electrophoretic deposition (EPD) is also used to manufacture thin waU, soHd P -alumina [12005-16-2] NaAl Og, electrolytes for sodium—sulfur batteries. 

Sodium-Sulfur Batteries. The sodium-sulfur battery consists of molten sodium at the anode, molten sulfur at the cathode, and a solid electrolyte of a material that allows for the passage of sodium only. For the solid electrolyte to be sufficiently conductive and to keep the sodium and sulfur in a liquid state, sodium-sulfur cells must operate at 300°C to 350°C (570°F to 660°F). There has been great interest in this technology because sodium and sulfur are widely available and inexpensive, and each cell can deliver up to 2.3 volts. 

Though sodium-sulfur batteries have been under development for many years, major problems still exists with material stability. It is likely that the first commercial uses of this batteiy will not be for electric vehicles. Sodium-sulfur storage batteries may be more well-suited for hybrid electric vehicles or as part of a distributed energy resources system to provide power ill remote areas or to help meet municipal peak power requirements. 

Zinc-Bromide. Unlike sodium-sulfur batteries, zinc-bromide batteries operate at ordinary temperatures. Although they use low-cost, readily available... 

The disadvantage of the heat loss which is caused by the high operating temperature is compensated by the advantage that the sodium/sulfur battery can be operated independently of the ambient temperature, which can vary from -40 to +50 °C. 

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). 

J.L. Sudworth, A.R. Tilley (Eds.), The Sodium Sulfur Battery, Chapman and Hall, London, 1985. 

FIGURE 12.23 A sodium-sulfur battery used in an electric vehicle. 

Polysulfides are the key reactants in the high-density sodium-sulfur and Hthium-sulfur batteries [4] which are based on the following reversible redox reaction taking place in the polysulfide melt ... 

Kolosnitsyn VS, Karaseva EV (2008) Lithium-Sulfur batteries Problems and solutions. Russ J Electrochem 44 506-509... 

Park CW, Ahn JH, Ryu HS, Kim KW, Ahn HJ (2006) Room-temperature solid-state Sodium/Sulfur battery. Electrochem Solid State Lett 9 A123-A125... 

Other types Variable Variable Primary and secondary Nickel-metal hydride cells, sodium-sulfur batteries,... 

Hames, D. etal., Proc. Inst. Electr. Eng., 1979, 126, 1157-1161 Safety aspects of large arrays of sodium-sulfur batteries for rail traction are considered among technical aspects. 

The high ionic conductivity of sodium (3"-alumina suggested that it would form a suitable electrolyte for a battery using sodium as one component. Two such cells have been extensively studied, the sodium-sulfur cell and the sodium-nickel chloride (ZEBRA) cell. The principle of the sodium-sulfur battery is simple (Fig. 6.13a). The (3"-alumina electrolyte, made in the form of a large test tube, separates an anode of molten sodium from a cathode of molten sulfur, which is contained in a porous carbon felt. The operating temperature of the cell is about 300°C. 

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