Properties of fused polysulphides—III. EMF measurements on the sodium-sulphur cell, and sulphur activities and constitution in fused sodium polysulphides

Electrochemical Behavior of Graphite and Ni‐Cr Electrodes in Sodium Polysulfide in the Absence and Presence of Hydrogen Sulfide

“…This reference electrode compartment was partially filled with pure sulfur before being introduced into the cell, which resulted in the entry of some melt from the main cell through the fritted glass. A stable potential of the reference electrode was achieved, since the electrode potential of the Na2SJS couple (x > 5) is independent of composition (8,9), and the composition at the interface between the sodium polysulfide (lower part) and the sulfur (top part) is constant. All potentials given are relative to this reference electrode.…”

The electrical conductivity of sodium polysulfide melts

“…Xe dlnlle+Xodlnao =0, and equation (2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18)(19)(20), the term of In lle in equation can be expressed in terms of dVI· On the other hand, let us apply the definition of the electrolyte molality, and the chain rule to the term of din m on the right side of equation . Consequently, equation can be rewritten as…”

“…If the electrolyte is a dilute solution with an excess supporting electrolyte and only one depleting component is present in the overall electrode reaction, the diffusion impedance (also called the Warburg impedance) can be obtained using equation (3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18)(19)(20)(21)(22). Zw = 1JJi =cr(l-j)/Yro , where As shown in this equation, the higher the frequency is, the smaller the Warburg impedance is.…”

“…With an excess supporting electrolyte, conductivity variations are negligible. Therefore, for dilute solutions with an excess supporting electrolyte, the above equation becomes (3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16) The last term can be neglected since it is on the order of the reactant concentration divided by the at a-y2 (3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18) Y is the distance from the surface. In this case, the movement of the species due to migration and convection is neglected, and the diffusion coefficient is assumed to be independent of concentration.…”

“…Let us apply this concentration equation in equation (3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17) to obtain the concentration overpotential for dilute solutions with an excess electrolyte.…”